[top]
000
FXUS63 KMQT 240528 AAB
AFDMQT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MARQUETTE MI
1228 AM EST MON NOV 23 2009
UPDATED FOR 06Z AVIATION DISCUSSION
.SYNOPSIS... /ISSUED AT 400 PM EST/
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW ACROSS THE
CONUS/SRN CANADA. IN THE SRN BRANCH...A TROF WAS SHIFTING E OF THE
ROCKIES AND A DOWNSTREAM RIDGE WAS ALONG THE E COAST. IN THE SW FLOW
INTO THE GREAT LAKES...A TROF WITH A COUPLE OF EMBEDDED SHORTWAVES
WAS LIFTING THRU THE UPPER MISSISSIPPI VALLEY AND WRN GREAT LAKES.
SHRA ASSOCIATED WITH ONE OF THE SHORTWAVES HAS BEEN OCCURRING ACROSS
NRN AND ERN MN INTO NW WI AND WRN LAKE SUPERIOR. SHRA OCCASIONALLY
AFFECTED THE FAR WRN FCST AREA IN THE KIWD VCNTY EARLIER IN THE DAY.
THE OTHER SHORTWAVE IN THE LOWER OHIO VALLEY IS ALSO GENERATING SOME
-SHRA...BUT WITH MUCH LESS COVERAGE. OTHER THAN THE EARLY SHRA
AROUND KIWD...THE REMAINDER OF THE FCST AREA HAS BEEN DRY TODAY...
BUT FOG WAS SLOW TO DISSIPATE.
&&
.SHORT TERM (TONIGHT AND TUE)... /ISSUED AT 400 PM EST/
WEAKENING MIDLEVEL TROF WILL LIFT NE OF THE AREA TONIGHT. EVEN PRIOR
TO ITS EXIT...PCPN IS NOT MUCH OF A CONCERN AS DRIER AIR NOTED ON
12Z KGRB SOUNDING IS MOVING NNW OVER THE FCST AREA. ONLY POSSIBLE
EXCEPTION IS OVER THE FAR W AS TAIL END OF SHORTWAVE OVER THE ERN
DAKOTAS/WRN MN HAS RECENTLY BEGAN TO GENERATE A NARROW BAND OF
-SHRA/SPRINKLES SWD INTO SE MN. WILL NEED TO MONITOR -SHRA PROGRESS
OVER THE NEXT FEW HRS...BUT FOR NOW WILL MAINTAIN A DRY FCST TONIGHT
OVER WRN UPPER MI AS PCPN SHOULD ENCOUNTER DRIER AIR. THIS INFLUX OF
DRIER AIR HAS BEEN NOTED NICELY BY SHARP SE EDGE TO PCPN LIFTING N
OVER MN/NW WI/WRN LAKE SUPERIOR TODAY. OTHERWISE...STAGE WILL AGAIN
BE SET FOR FOG ACROSS MOST OF THE FCST AREA TONIGHT AS BOUNDARY
LAYER MOISTURE REMAINS VERY HIGH. FOG WILL BE LEAST LIKELY/LEAST
DENSE IN LOCATIONS THAT SEE DOWNSLOPING UNDER LIGHT S TO SE WINDS
WHICH INCLUDES MAINLY THE AREAS NEAR LAKE SUPERIOR. FOG SHOULD BE
MOST DENSE ACROSS CNTRL UPPER MI WHERE LIGHT WINDS WILL BE
UPSLOPING. IT WILL BE ANOTHER NIGHT OF WELL ABOVE NORMAL TEMPS WITH
MINS AOA NORMAL HIGH TEMPS FOR THIS TIME OF YEAR.
AS WAS THE CASE TODAY...EXPECT FOG TO BE SLOW TO DISSIPATE TUE
MORNING. THEN ATTENTION TURNS TO SHORTWAVE CURRENTLY MOVING ACROSS
WRN KS. DEEP LAYER FORCING ASSOCIATED WITH THIS FEATURE WILL STAY S
OF UPPER MI THRU TUE AFTN. SFC TROF EXTENDING N FROM DEVELOPING SFC
LOW OVER MO/IA WILL REMAIN NEARLY STATIONARY TUE OVER MN...AND THIS
SHOULD KEEP ANY SHRA IN THE VCNTY OF TROF TO THE W OF UPPER MI.
HOWEVER...WITH THE PRESENCE OF WEAK ISENTROPIC ASCENT...WILL KEEP A
MENTION OF SLIGHT CHC POPS OVER THE FAR W TUE AFTN.
.LONG TERM (TUESDAY NIGHT THROUGH NEXT MONDAY)...
UPPER PATTERN STARTS OUT STILL LOOKING MILD...WITH A WESTERLY SPLIT
FLOW ACROSS SOUTHERN CANADA INTO THE CONUS. INITIAL SHORTWAVE TROUGH
OVR THE CNTRL MISSISSIPPI RIVER VALLEY LIFTS NORTHEAST TOWARD THE
UPR GREAT LAKES ON TUE NIGHT AS ANOTHER SHORTWAVE DIGS INTO THE
NORTHERN PLAINS. LIKELY POPS LATE TUE NIGHT INTO WED WITH LEAD WAVE
AND ENHANCEMENT PROVIDED BY UPPER DIVERGENCE IN LFQ OF JET STREAK
MOVING INTO THE CNTRL GREAT LAKES. 1000-500MB/1000-850MB CRITICAL
THICKNESSES IN THE VCNTY OF THE LEAD SHORTWAVE ARE HIGH ENOUGH TO
ONLY JUSTIFY RAIN AS PTYPE THROUGH WED. ADVECTION OF DWPNTS IN THE
UPR 30S/AROUND 40F WELL ABOVE CURRENT 2 INCH GROUND TEMPS IN THE LWR
30S ALONG WITH PERSISTENT SE LOW-LEVEL WINDS...AS WELL AS JUST A
PERSISTENCE FCST...RESULTS IN MORE FOG TUE NIGHT INTO WED...
ESPECIALLY IN THE UPSLOPE AREAS OF CNTRL CWA.
SECOND SHORTWAVE DIGGING IN FM THE NORTHERN PLAINS DEEPENING OVR THE
UPR GREAT LAKES WED NIGHT INTO THU HELPS DRAW SLIGHTLY COLDER AIR IN
FM CNTRL CANADA. CYCLONIC FLOW THROUGH H85 AND DEEP MOISTURE LEADS
TO CONTINUING LIKELY POPS WED NIGHT INTO THU. CRITICAL THICKNESSES
AND H85 TEMPS MARGINAL FOR MUCH IN THE WAY OF SNOW WED NIGHT BUT DO
CONTINUE TO LOWER ON THANKSGIVING. SOUNDINGS OFF GFS IN THE FAR WRN
CWA INDICATE ABOVE FREEZING LAYER IS ONLY IN THE LOWEST 50 MB WITH
DEEP MOISTURE INTERSECTING THE -10C TO -15C ISOTHERMS...SO MAJORITY
OF PCPN IN THOSE AREAS SHOULD BE IN THE FORM OF SNOW. SOUNDINGS AND
THICKNESSES INDICATE WARMER AIR PERSISTS THROUGH ALL OF THU OVR THE
CNTRL AND EAST...SO PTYPE THROUGH THU SHOULD STAY IN THE FORM OF
RAIN AWAY FM THE WESTERN CWA. POTENTIAL FOR RAIN AMOUNTS TO EXCEED
ONE-HALF INCH OVR THE SOUTH AND EAST CWA LATE WED INTO WED NIGHT DUE
TO DEVELOPING DEFORMATION AREA ON NORTH SIDE OF THE DEVELOPING UPPER
LOW. GFS/ECMWF/NAM/UKMET/CANADIAN IN GOOD AGREEMENT WITH THIS
POSSIBILITY.
NE FLOW AND DWPNTS WELL INTO THE 30S ON WED EVENING SHOULD INITIALLY
RESULT IN FOG IN THE UPSLOPE AREAS OF NW CWA LATER WED INTO WED
NIGHT AND PERHAPS INTO THU MORNING. SETUP MAY FAVOR DENSE FOG.
OVERALL...THE FOG AND MIX OF LGT RAIN AND SNOW MAY LEAD TO TRICKY
TRAVEL LATE ON WED INTO THU MORNING. ON THE FLIP SIDE...TEMPS
REMAINING WARM IN THE BLYR ALSO CUTS DOWN ON SNOW AMOUNTS OVR THE
WESTERN CWA. WILL CONTINUE TO MENTION THE SYSTEM IN THE HAZARDOUS
WEATHER OUTLOOK DUE TO THE SLOPPY MIX OF RAIN/SNOW AND POTENTIALLY
DENSE FOG.
DIFFERENCES ARISE IN HOW DEEP TROUGH BECOMES OVR THE GREAT LAKES
INTO FRIDAY. ESSENTIALLY...OPERATIONAL GFS IS STRONGEST AND HAS
MUCH COLDER AIR INTO FRIDAY WITH H85 TEMPS BLO -8C. ABOUT HALF OF
THE GEFS ENSEMBLES INDICATE STRONGER TROUGH...WHILE THE OTHER HALF
OF THE MEMBERS ARE MORE IN LINE WITH ECMWF/ECMWF ENSEMBLES AND
CANADIAN/CANADIAN ENSEMBLES WHICH INDICATE TROUGH DEPARTING EARLY
AND MUCH WARMER H85 TEMPS ONLY AROUND -2C ON FRI. LATEST ECMWF HAS
TRENDED COLDER THOUGH. IF USING THE UKMET TO BREAK THE TIE...IT TOO
IS SIMILAR TO ECMWF AND CANADIAN BY BUILDING A RIDGE FM THE NORTHERN
PLAINS TO THE UPR LAKES ON FRIDAY. IN GENERAL...KEPT THEME OF PREV
FCST WITH LOW CHANCE POPS IN NW FLOW AREAS NEAR LK SUPERIOR OVR THE
ERN CWA.
HPC PREFERRED ECMWF/CANADIAN AND ENSEMBLES POINT TO RIDGING AND
ABOVE NORMAL TEMPS FOR EARLY WEEKEND...BUT QUICK FLOW ALLOWS TROUGH
TO ALREADY PUSH INTO THE UPR LAKES BY LATE NEXT WEEKEND. 00Z ECMWF
WAS QUICKER WITH ARRIVAL OF TROUGH...BUT LATEST GFS/CANADIAN HAVE
ALSO TRENDED TOWARD PCPN ON SUN. COMPARED TO THE ENSEMBLES...00Z
ECMWF LOOKS A BIT QUICK AND DEEP WITH ITS SFC LOW PUSHING ACROSS AS
EARLY AS SUN. INTERESTING THAT 12Z ECMWF IS NOT AS STRONG/WIDESPREAD
WITH QPF. USED SLIGHT CHANCE POPS FOR SUN UNTIL TRENDS BECOME MORE
CLEAR. ALSO USED SMALL CHANCE POPS FOR EARLY NEXT WEEK AS UPPER
TROUGH/UNSETTLED WEATHER AFFECTS UPR LAKES. TEMPS SHOULD ALSO TRY
TO TREND BACK TOWARD NORMAL FOR LATE NOVEMBER EARLY NEXT WEEK.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
LOOK FOR MORE FOG AND LOW STRATUS TO REDEVELOP OVERNIGHT AT
KCMX/KSAW UNDER LIGHT WINDS/NOCTURNAL COOLING. EXPECT LIFR
CONDITIONS AT KSAW BY 10Z UNDER LIGHT UPSLOPING SSE WINDS. SSE WINDS
AT KCMX WILL BE LESS FAVORABLE FOR THICK FOG SO ONLY HAVE CONDITIONS
LOWERING TO IFR THERE LATE TONIGHT. SIMILAR TO TODAY...CIG/VIS
IMPROVEMENT TUE MORNING WILL BE VERY SLOW AT BOTH TAF SITES.
EVENTUALLY EXPECT FOG TO DISSIPATE AND CIGS TO RAISE TO MVFR BY
EARLY TUE AFTERNOON. VSBYS SHOULD LOWER TO MVFR AGAIN BY LATE TUE
EVENING.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
LIGHT WINDS UNDER 20KT SHOULD BE THE RULE THRU TUE NIGHT UNDER A
WEAK PRES GRADIENT BTWN HIGH PRES OVER SE CANADA AND ORGANIZING LOW
PRES OVER THE CNTRL PLAINS. AS THE LOW MOVES ACROSS THE UPPER GREAT
LAKES THRU THU AND THEN REDEVELOPS OVER THE MID ATLANTIC STATES AND
NEW ENGLAND FRI...N WINDS WILL INCREASE LATE WED AND THU. A PERIOD
OF 20-30KT N WINDS APPEARS LIKELY ACROSS MUCH OF LAKE SUPERIOR WED
NIGHT INTO FRI ALTHOUGH WINDS WILL BEGIN TO DIMINISH OVER THE W THU
NIGHT. A HIGH PRES RIDGE WILL ARRIVE FRI NIGHT AND SAT...BRINGING
LIGHTER WINDS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS/SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...JV
MARINE...ROLFSON
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000
FXUS63 KDTX 240459
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1159 PM EST MON NOV 23 2009
.AVIATION...
ABUNDANT LOW LEVEL MOISTURE WILL REMAIN FIRMLY ENTRENCHED ACROSS
SOUTHEAST LOWER MI AGAIN TONIGHT. THIS IS TRANSLATING PRIMARILY
INTO A STRATUS DECK AND LOOKS TO BE THE DOMINANT CONDITION FOR AT
LEAST THE EARLY PART OF THE NIGHT /IFR TO BRIEF LIFR PTK SOUTH...
MVFR-IFR TO THE NORTH/. POCKETS OF CLEARING AND THE PERSISTENT
MOIST SOUTHEAST FLOW OFF LAKES HURON/ERIE MAY YET ALLOW FOR BETTER
FOG FORMATION...ALBEIT LESS WIDESPREAD/DENSE. THE POTENTIAL
REMAINS FOR A PERIOD OF LIFR VISIBILITY BETWEEN 10-14Z WITH THE
BEST OPPORTUNITY AT MBS. OTHERWISE MAINLY IFR CONDITIONS AT ALL
TERMINALS INTO THE MID MORNING HOURS. GRADUAL IMPROVEMENT THROUGH
LATE MORNING/EARLY AFTERNOON...ALTHOUGH MVFR CLOUD COVER WILL
PERSIST INTO THE EVENING.
&&
.PREV DISCUSSION...ISSUED 353 PM EST MON NOV 23 2009
SHORT TERM...TONIGHT
HIGH PRESSURE CONTINUES TO PULL AWAY FROM THE REGION AS A BROAD AREA
OF LOW PRESSURE ADVANCES FROM THE PLAINS. A SHORTWAVE LIFTING ACROSS
THE MIDWEST IS HELPING TO LIFT AN AREA OF DEEPER MOISTURE NORTH FROM
OHIO INTO ONTARIO...CLIPPING EXTREME SOUTHEAST MICHIGAN ON THE WAY.
LIGHT RADAR ECHOS HAVE BEEN MOVING NORTH ACROSS OHIO WITH SEVERAL
ASOS SITES REPORTING TRACE AMOUNTS ACROSS NORTH CENTRAL OHIO.
REPORTS ARE HARDER TO FIND UPSTREAM ACROSS NORTHWESTERN OHIO BUT
HAVE ADDED A SLIGHT CHANCE OF LIGHT SHOWERS/SPRINKLES INTO THE
FORECAST THROUGH THIS EVENING WITH QPF OF .01 OR LESS.
THE FOG FORECAST IS CHALLENGING FOR TONIGHT AS THE DECK OF CLOUD
SPREADING NORTH WILL LIMIT COOLING DURING THE EVENING HOURS. HOWEVER
NAM/GFS SHOW THESE CLOUDS STARTING TO CLEAR OUT AFTER MIDNIGHT...
WHICH WOULD STILL LEAVE PLENTY OF TIME FOR LOW LEVEL MOISTURE TO
COME IN OFF LAKE ERIE/HURON UNDER SOUTHEASTERLY FLOW. WILL STILL
EXPECT AREAS OF FOG TO DEVELOP LATE WITH PATCHY DENSE FOG POSSIBLE.
HAVE RAISED TEMPS A DEGREE OR SO FOR TONIGHT WITH LOWS IN THE UPPER
30S TO NEAR 40 EXPECTED.
LONG TERM...
INTERACTING/MERGING-CONSOLIDATING UPPER WAVES WILL LEAD TO LARGE
PV ANOMALY/UPPER LEVEL LOW DEVELOPING AND TRACKING THROUGH THE
SOUTHERN GREAT LAKES/OHIO VALLEY...SENDING TEMPERATURES BACK TO
NORMAL (IF NOT BELOW)...WITH SNOW POSSIBLE AS WE HEAD INTO
THANKSGIVING AND INTO FRIDAY.
THE FIRST SHORTWAVE/UPPER WAVE IS CURRENTLY MOVING INTO THE CENTRAL
PLAINS...AND WILL PROVIDE SOME GOOD LARGE SCALE/ISENTROPIC ASCENT
TUESDAY NIGHT WITH SURFACE LOW/REFLECTION MOVING OVER LAKE MICHIGAN.
THE CENTER OF THIS WAVE...AS SEEN ON GFS TROPOPAUSE MAP AND
INDICATED BY 12 HR 500 MB HEIGHT FALL CENTER...WILL MOVE THROUGH
SOUTHEAST MICHIGAN ON WEDNESDAY....AS THIS SYSTEM CONTINUES TO HEAD
OFF TO THE NORTHEAST...OUTPACING THE NEXT UPSTREAM SYSTEM. THE
850-700 MB THETA-E RIDGE AXIS IS NARROW...BUT SHOULD PROVE
SUFFICIENT TO GENERATE RAIN TUESDAY NIGHT WITH THE WARM
FRONT/MOISTURE ADVECTION...AND HAVE RAMPED POPS TO HIGH LIKELY WITH
12Z UKMET/NAM/GFS ALL ON BOARD. COLD FRONT/FAIRLY STEEP MID LEVEL
LAPSE RATES ON WEDNESDAY WILL PROBABLY BE ENOUGH FOR A FEW SHOWERS.
THE MORE IMPRESSIVE UPPER WAVE/TROUGH IS CRASHING ASHORE BRITISH
COLUMBIA AND LOOKS TO BE DIGGING THROUGH THE PLAINS-MIDWEST AND INTO
THE OHIO VALLEY/SOUTHERN GREAT LAKES ON THURSDAY. THE CENTER OF THE
COLD CORE (-32 C AT 500 MB/-8 C AT 850 MB) LOOKS TO RESIDE OVER THE
NORTHERN OHIO VALLEY...WITH MATURE MID LEVEL DRY SLOT PUNCHING INTO
THE CWA...LIKELY LIMITING OUR PRECIPITATION CHANCES DURING THE
DAYTIME HOURS (PER 12Z GFS/EUROPEAN) OF THURSDAY. HOWEVER...IT
SHOULD BE NOTED...THE TIMING OF THE MERGING UPPER WAVES AND
SUBSEQUENT POSITION OF 500 MB LOW REMAIN IN PLAY...AS SECOND UPPER
WAVE DROPS SOUTH FROM ONTARIO PROVIDING AN ADDITIONAL COLD INFUSION
AS WE HEAD INTO FRIDAY. REGARDLESS...WITH THE 12Z UKMET/NAM BOTH
FASTER AND FARTHER NORTH WITH THE 500 MB LOW ON THANKSGIVING AND
COLDER (850 MB TEMPS OF -6 TO -7 C NEAR THE OHIO BORDER) IN THE LOW
LEVELS...FELT A LOW CHANCE OF BOTH SNOW AND RAIN SHOWERS WERE
JUSTIFIED OVER SOUTH TWO THIRDS OF THE CWA DURING THE DAYTIME HOURS.
MUCH BETTER CHANCE OF PRECIPITATION (LIKELY IN THE FORM OF SNOW)
THURSDAY NIGHT INTO FRIDAY AS WRAP AROUND/DEFORMATION AXIS WORKS
THROUGH (WITH LAKE ENHANCEMENT). CLOUDS AND FURTHER LOW LEVEL COLD
ADVECTION DURING THE DAY ON FRIDAY WILL MAKE 40 DEGREE MAXES
DIFFICULT TO ACHIEVE. WITH RIDGE AXIS SETTLING OVER LOWER MICHIGAN
FRIDAY NIGHT...AND ASSUMING SKIES AT LEAST PARTIALLY CLEAR
OUT...LOWS IN THE 20S APPEAR TO BE A GOOD BET.
A MODEST WARMUP APPEARS ON TAP FOR THE WEEKEND AS RATHER FLAT UPPER
LEVEL RIDGE BUILDS INTO THE GREAT LAKES DURING THE FIRST HALF OF THE
WEEKEND. POTENTIAL NEXT STORM SYSTEM MAY IMPACT THE AREA SUNDAY OR
EARLY NEXT WEEK. SIGNIFICANT DIFFERENCES WITH MEDIUM RANGE
MODELS...AS EUROPEAN STILL ADVERTISING MORE OF A SPLIT FLOW
PATTERN. NONE-THE-LESS...WITH 12Z UKMET/EUROPEAN AND GFS ALL SHOWING
SOME SEMBLANCE OF LOW PRESSURE SYSTEM/SHORTWAVE TRAVERSING THROUGH
THE AREA ON SUNDAY...WILL INTRODUCE CHANCE POPS.
MARINE...
SOUTHEASTERLY WINDS WILL CONTINUE AS HIGH PRESSURE EXITS TO THE EAST
COAST AND A LOW PRESSURE SYSTEM SLOWLY APPROACHES FROM THE PLAINS.
SOUTHEASTERLY WINDS WILL INCREASE TO 15 TO 20 KNOTS ON THE OPEN
WATERS ON WEDNESDAY AS THIS AREA OF LOW PRESSURE APPROACHES...WITH
THE POSSIBILITY FOR SMALL CRAFT ADVISORIES ON WEDNESDAY NIGHT AS
WINDS VEER AROUND TO THE WEST. WAVES SHOULD INCREASE TO 3 TO 5 FEET
ON THE SAGINAW BAY ON WEDNESDAY NIGHT BUT WILL HOPEFULLY BE ABLE TO
HOLD OFF ON ANY SMALL CRAFT ADVISORIES ELSEWHERE UNTIL THE PASSAGE
OF A STRONGER COLD FRONT ON FRIDAY. THIS SYSTEM WILL BRING COOLER
TEMPERATURES WITH THE POSSIBILITY FOR A MIX OF RAIN AND SNOW SHOWERS
BY THURSDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MR
SHORT TERM...KEC
LONG TERM....SF
MARINE.......KEC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
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000
FXUS63 KGRR 240451
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1150 PM EST MON NOV 23 2009
LATEST UPDATE...AVIATION...
.SYNOPSIS...(415 PM EST MON NOV 23 2009)
AN AREA OF LOW PRESSURE WILL SWING THROUGH THE GREAT LAKES REGION
THIS WEEK...SPREADING RAIN INTO SOUTHWEST LOWER MICHIGAN TUESDAY
EVENING. CHANCES FOR RAIN WILL CONTINUE INTO WEDNESDAY AND WEDNESDAY
NIGHT. COLDER AIR WILL FILTER INTO THE GREAT LAKES BEHIND THE SYSTEM
FROM WEDNESDAY NIGHT INTO FRIDAY. THE AIR WILL BE COLD ENOUGH WHERE
SOME SNOW MAY MIX IN ON THANKSGIVING AND INTO FRIDAY. HEAVY SNOW IS
NOT EXPECTED...AND FOR THE MOST PART ANY ACCUMULATION WILL BE
MINIMAL. BY THE END OF THE WEEK...TEMPERATURES WILL BE MUCH CLOSER
TO NORMAL WITH HIGHS AROUND 40 AND LOWS DROPPING TO AROUND 30.
&&
.SHORT TERM...(415 PM EST MON NOV 23 2009)
(TONIGHT THROUGH WEDNESDAY NIGHT)
MAIN ISSUES TO DEAL WITH IN THE SHORT TERM PERTAIN TO FOG FORMATION
TONIGHT...PRECIPITATION CHANCES TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT AND THE CHANCE FOR SNOW MIXING IN INTO THANKSGIVING MORNING.
WE ARE EXPECTING FOG ONCE AGAIN TONIGHT WITH A WEAK PRESSURE
GRADIENT IN PLACE AND CLEARING SKIES. BEST CHANCES OF DENSE FOG WILL
BE IN AREAS THAT HAVE CLEARED OUT THIS EVENING...NAMELY ALONG AND
SOUTH OF INTERSTATE 96. NOT CONFIDENT ENOUGH AT THIS POINT TO ISSUE
AN ADVISORY...BUT WE WILL BE CLOSELY WATCHING VSBY/S AS WE HEAD INTO
THE OVERNIGHT HOURS.
THE FOG WILL LIFT OUT TOWARD MIDDAY ON TUESDAY...WITH A LULL IN THE
ACTIVE WEATHER THROUGH THE AFTERNOON. RAIN WILL BE PRESS INTO THE
AREA AFTER DARK ON TUESDAY EVENING IN ADVANCE OF THE DEEPENING LOW.
IT APPEARS THE HEAVIEST PRECIPITATION SHOULD OCCUR TUESDAY NIGHT
WITH THE SYSTEM AS STRONG LIFT PROGRESSES THROUGH THE FORECAST AREA.
PRECIPITATION WILL CONTINUE INTO WEDNESDAY IN DEEP CYCLONIC FLOW.
SOME LAKE ENHANCED RAIN SHOWERS WILL BE POSSIBLE BY THE END OF THE
DAY AS DELTA T/S INCREASE TO AROUND 8 DEGREES C.
DELTA T/S WILL INCREASE FURTHER TO AROUND 12 DEGREES C BY
THANKSGIVING MORNING. RAIN SHOWERS WILL TRY TO MIX WITH SNOW SHOWERS
WEDNESDAY NIGHT WITH THE LOW TO THE NORTH OF THE AREA AND COLD AIR
WRAPPING INTO SOUTHWEST LOWER MICHIGAN. 850MB TEMPS WILL BE IN THE
-2 TO -6 DEGREE C RANGE...SO SNOW IS A POSSIBILITY BY 12Z THURS.
&&
.LONG TERM...(400 PM EST MON NOV 23 2009)
(THURSDAY THROUGH MONDAY)
MAIN CHALLENGES IN THE LONG TERM CONTINUE TO BE THE THREAT OF PCPN
IN AN INCREASINGLY ACTIVE WEATHER PATTERN...AND P-TYPE THROUGH MOST
OF THE PERIOD AS COLDER AIR FILTERS INTO THE STATE.
COLDER AIR WILL BE ALREADY MAKING ITS WAY INTO THE AREA AT THE
BEGINNING OF THE LONG TERM THU MORNING AS A SECONDARY AND MORE
POTENT SHORT WAVE DIVES SE TOWARD THE GREAT LAKES. THE EXACT TRACK
OF THE COLDEST AIR IS A BIT IN QUESTION DUE TO THE INTERACTION WITH
THE FIRST TROUGH. EITHER WAY...THE AIR COMING IN WILL BE APPROACHING
RAIN/SNOW THRESHOLDS. THE NIGHT TIME HOURS WILL SEE THE BEST THREAT
OF SNOW AS THE BOUNDARY LAYER COOLS AND FREEZING LEVELS DROP TO 1K
FEET OR LESS. ACCUMULATING SNOW DOES NOT LOOK LIKELY...ESPECIALLY
WITH A WARM GROUND. IT IS NOT TOTALLY OUT OF THE QUESTION HOWEVER IF
WE CAN COOL THE LOW LEVELS OFF ENOUGH.
MODELS HAVE BEEN VARYING ON THE TIMING OF THE EXIT OF THE UPPER
TROUGH FROM ANYWHERE BETWEEN FRI AFTERNOON TO SAT NIGHT/SUN. THE 12Z
MODELS HAVE TIGHTENED THIS RANGE UP A BIT TO FRI NIGHT/SAT MORNING.
ANY INSTABILITY SHOWERS AND/OR LAKE EFFECT WILL THEN SHUT OFF AS
TEMPS AT 850 WARM. RIDGING WILL THEN MOVE IN FOR ABOUT 24-36
HOURS...AND SLIGHTLY WARM TEMPS A BIT.
THE NEXT SHORT WAVE IN THE SERIES COMING IN FROM THE NW WILL MOVE IN
DURING THE DAY ON SUN. TEMPS WILL BE WARM ENOUGH AHEAD OF THE
SYSTEM THAT P-TYPE WILL BE ALL RAIN. THIS WILL TRANSITION TO AT
LEAST A MIX IF NOT ALL SNOW BY NEXT MON AS A SHOT OF COLD AIR
FOLLOWS IN THE WAKE OF THIS FRONT.
&&
.AVIATION...(1150 PM EST MON NOV 23 2009)
THE PRIMARY ISSUE REMAINS THE EXPECTED REDEVELOPMENT OF STRATUS AND
FOG OVERNIGHT.
THE LOW CLOUD DECK OVERSPREAD THE SOUTHERN CWA BY 8 PM. HOWEVER
THERE IS AN AREA OF DRIER AIR OVER NORTHERN OH AND NRN IN HEADING
INTO SOUTHWEST LOWER MICHIGAN. THAT CAN BE SEEN ON THE NAM12 925 MB
RH/DEW POINT FORECAST AS WELL AS LOOKING AT LOOPS OF THE IR FOG
IMAGES (SHOWING CLEARING PROGRESSING NORTHWARD TOWARD I-94). THAT
BEING SO... DENSE FOG WILL QUICKLY FOLLOW AS CAN ALSO BE SEEN ON
RECENT SURFACE OBS IN THE CLEAR AREAS OVER NRN IN AND OH.
AT THE WESTERN TAF SITES I BROUGHT THE FOG IN AFTER BRIEFLY CLEARING
THE LOW CLOUDS. IN THE EASTERN TAF SITES THE LOW CLOUDS EXTEND
FATHER SOUTH... I WAS NOT SURE THE CLEARING WOULD REALLY MOVE IN
THERE. SO I DID NOT BRING THE VIS DOWN AS MUCH TOWARD MORNING.
SKIES WILL CLEAR BY MID AFTERNOON AS THE STORM APPROACHES FROM THE
SOUTHWEST AND BRINGS IN BETTER DEEP MIXING. RAIN WILL FOLLOW IN THE
01Z TO 04Z TIME FRAME.
&&
.MARINE...(415 PM EST MON NOV 23 2009)
LIGHT EASTERLY FLOW WILL KEEP WAVE HEIGHTS IN CHECK TONIGHT AND
TUESDAY. WINDS AND WAVES WILL BE ON THE INCREASE TUESDAY NIGHT INTO
WEDNESDAY THOUGH AS A DEEPENING LOW MOVES INTO THE NORTHERN GREAT
LAKES. WINDS WILL BECOME SOUTHERLY AS THE LOW MOVES NORTH OF THE
AREA WHICH WILL BUILD WAVES TO 3 TO 5 FEET INTO WEDNESDAY MORNING.
WESTERLY FLOW ON WEDNESDAY SHOULD BUILD WAVES HEIGHTS FURTHER ON
WEDNESDAY INTO THE 3 TO 6 FOOT RANGE TOWARD THE END OF THE DAY.
&&
.HYDROLOGY...(415 PM EST MON NOV 23 2009)
STILL NOT EXPECTING ANY HYDRO PROBLEMS WITH THE SYSTEM MOVING
THROUGH THIS WEEK. IT APPEARS MOST LOCATIONS WILL SEE RAINFALL OF A
HALF INCH OR BELOW. THERE MAY BE A FEW SPOTS THAT PICK UP .50 TO .75
IN THE NORTHWEST PORTION OF THE FORECAST AREA THOUGH.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: DUKE
SHORT TERM: DUKE
LONG TERM: NJJ
AVIATION: WDM
MARINE: DUKE
HYDROLOGY: DUKE
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000
FXUS63 KAPX 240450
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1150 PM EST MON NOV 23 2009
.SYNOPSIS.../ISSUED AT 357 PM/
RAIN CHANCES WILL INCREASE HEADING INTO TUESDAY NIGHT AND
WEDNESDAY AS A PAIR OF UPPER LEVEL DISTURBANCES ROTATE TOWARD THE
UPPER GREAT LAKES REGION THROUGH THANKSGIVING DAY. DOES APPEAR
THAT THE PRE-HOLIDAY TRAVEL PERIOD WILL ONLY BE WET...WITH WINTRY
PRECIPITATION NOT EXPECTED TO INTERFERE WITH TRAVEL PLANS THROUGH
THANKSGIVING DAY.
JPB
&&
.SHORT TERM.../ISSUED AT 1034 PM/...OVERNIGHT
SURFACE RIDGE AXIS IS HOLDING JUST NORTH OF MICHIGAN LATE THIS
EVENING...WITH WEAK LOW LEVEL WAA UNDERWAY. ANY BRIEF BREAKS IN THE
CLOUD COVER EARLIER THIS EVENING HAVE QUICKLY FILLED BACK IN AS LOW
STRATUS HAS REDEVELOPED WITHIN THESE BREAKS. AREAS OF FOG LINGER
ACROSS ERN AND SRN SECTIONS OF OUR CWA AHEAD OF AN APPROACHING WEAK
WAVE CURRENTLY OVER SRN LOWER MICHIGAN. OBS ACROSS THE REST OF THE
CWA SHOW LITTLE IN THE WAY OF FOG...BUT CERTAINLY QUITE A BIT OF
STRATUS STILL IN PLACE. AS WEAK WAVE TO THE SOUTH LIFTS NORTHWARD
OVERNIGHT...EXPECT AREAS OF FOG WILL SPREAD BACK INTO THE REST OF
OUR CWA. HAVE REDUCED FOG WORDING FROM AREAS OF DENSE FOG TO AREAS
OF FOG...AND HAVE SLIGHTLY INCREASED CLOUD COVER OVERNIGHT.
REMAINDER OF THE FORECAST WILL BE UNCHANGED.
&&
.LONG TERM.../ISSUED AT 357 PM/...TUESDAY AND BEYOND
LARGE SCALE PATTERN FEATURES A NUMBER OF SHORT WAVE TROUGH ACROSS
NORTH AMERICA EXTENDING BACK OUT INTO THE PACIFIC...A PROGRESSIVE 5
WAVE PATTERN WITH MEAN TROUGHING ROUGHLY ACROSS CENTRAL NORTH
AMERICA. INITIAL FOCUS WILL BE ON A TROUGH DIGGING SOUTHEAST
THROUGH THE CENTRAL ROCKIES THIS AFTERNOON...AND A FOLLOW UP TROUGH
CURRENTLY CROSSING THE BRITISH COLUMBIA COAST. LEAD WAVE FORECAST
TO BOTTOM OUT OVER THE CENTRAL PLAINS TUESDAY...THEN GET KICKED
NORTHEAST AS TRAILING FEATURE DIGS INTO THE MIDWEST BEHIND IT BY
THANKSGIVING. SO POTENTIAL IMPACTS ON HOLIDAY TRAVEL WITH THESE
SYSTEMS WILL BE THE PRIMARY FORECAST ISSUE IN THE NEAR TERM. BEYOND
THAT...SOME SMALL HINTS OF THE PATTERN TRYING TO SHIFT TO SOMETHING
A LITTLE COLDER...BUT NOTHING REAL DEFINITIVE AT THIS POINT. AND
WITH THE COLDEST AIR STILL PINNED NORTH OF THE ARCTIC CIRCLE (AND
ACROSS MUCH OF ASIA...FOR THAT MATTER)...WILL NEED A STRONG BUCKLING
OF THE FLOW TO TAP INTO THAT.
TUESDAY...SHORT WAVE DIGGING ACROSS THE CENTRAL ROCKIES FORECAST TO
BOTTOM OUT OVER KANSAS TONIGHT AND HEAD INTO THE MID MISSISSIPPI
VALLEY DURING THE DAY TUESDAY. MAIN PROBLEM FOR TUESDAY WILL DEAL
WITH CLOUD COVER...AFTERNOON VISIBLE IMAGERY SHOWS ANOTHER PUSH OF
LOW CLOUDS LIFTING NORTHWARD ACROSS OHIO WITHIN A ZONE OF ISENTROPIC
ASCENT AND SOME FRONTOGENETIC FORCING. LOOKS LIKE SOME OF THIS
MOISTURE WILL GRAZE PARTS OF NORTHEAST LOWER AND EASTERN UPPER...
POSSIBLY CONTRIBUTING ENOUGH MOISTURE/LIFT TO SQUEEZE OUT SOME
DRIZZLE. OTHERWISE EXPECTING TO START THE DAY WITH MORE WIDESPREAD
LOW CLOUDS/FOG...THOUGH MAY SEE CLOUDS THIN OUT AND ALLOW FOR SOME
SUN LATER IN THE AFTERNOON ACROSS PARTS OF NORTHERN LOWER.
MEASURABLE RAIN CHANCES WILL INCREASE TUESDAY NIGHT AS LEAD SHORT
WAVE CROSSES THE MISSISSIPPI RIVER AND INTO NORTHERN ILLINOIS BY
WEDNESDAY MORNING. NARROW AXIS OF LOW LEVEL MOISTURE INFLOW
INTERACTS WITH INCREASING DIVERGENCE IN LEFT EXIT REGION OF A 100KT
JET STREAK OVER THE OHIO VALLEY. RAIN EXPECTED TO SPREAD INTO THE
REGION FROM SOUTHWEST TO NORTHEAST...NOT REACHING THE ST. MARY`S
RIVER UNTIL NEAR DAYBREAK WEDNESDAY.
WEDNESDAY...SHORT WAVE OVER ILLINOIS EXPECTED TO LIFT NORTHEAST
ACROSS LOWER MICHIGAN DURING THE DAY...AS NEXT PIECE OF ENERGY DIGS
IN BEHIND IT OVER IOWA. SOME HINTS OF MID LEVEL DRYING WITH ARRIVAL
OF UPPER WAVE...THOUGH AT WORST WILL INCREASE CONVECTIVE INSTABILITY
AND ALLOW PRECIPITATION TO BECOME MORE SHOWERY WITH FORECAST CROSS
SECTIONS SHOWING A FAIRLY DEEP LAYER BELOW 600MB WITH WEAKER
STABILITY. HIGH END POPS STILL JUSTIFIED FOR WEDNESDAY...PERHAPS
EVEN AN EMBEDDED THUNDERSTORM WITHIN MID LEVEL COLD POOL. AS UPPER
LOW OVER IOWA PIVOTS TOWARD THE UPPER GREAT LAKES WEDNESDAY
NIGHT...EXPECT PRECIPITATION FOCUS TO MOVE AWAY FROM NORTHERN
MICHIGAN AND TOWARD WISCONSIN/WESTERN UPPER BENEATH DEVELOPING
DEFORMATION AXIS...WITH ANOTHER PUSH OF MID LEVEL DRYING POSSIBLE
LATER WEDNESDAY NIGHT. WILL KEEP HIGHER POPS ACROSS EASTERN
UPPER/FAR NORTHWEST LOWER CLOSER TO DEFORMATION AXIS. ASSOCIATED
SURFACE LOW SHOULD TRACK ACROSS CENTRAL LAKE MICHIGAN UP TOWARD THE
STRAITS/ EASTERN UPPER BY THURSDAY MORNING. UPSTREAM WAVE NOT
EXPECTED TO HAVE MUCH OF A SURFACE RESPONSE WITH IT...BUT ASSOCIATED
COLDER AIR WILL FILTER DOWN ACROSS THE CENTRAL U.S./OHIO VALLEY AND
REINFORCE COLD FRONT ASSOCIATED WITH THE LOW MOVING THROUGH NORTHERN
MICHIGAN WEDNESDAY NIGHT. WITH MAIN COLD AIR PUSH SOUTH OF THE
STATE...LOOKS LIKE NORTHERN MICHIGAN WILL REMAIN ON THE WARMER SIDE
OF THIS SYSTEM THROUGH WEDNESDAY NIGHT...AND THUS PRECIP TYPE
EXPECTED TO REMAIN ALL RAIN AT THIS POINT. SO A WET PRE-
THANKSGIVING TRAVEL DAY EXPECTED...BUT WINTRY PRECIPITATION NOT
EXPECTED TO HAMPER THINGS.
EXTENDED FORECAST (THURSDAY THROUGH MONDAY)...THANKSGIVING DAY LOOKS
TO START WITH LOW PRESSURE IN THE VICINITY OF THE STRAITS/EASTERN
UPPER MICHIGAN...WITH A DEFORMATION DRIVEN PRECIPITATION BAND ACROSS
WISCONSIN/UPPER MICHIGAN (MAYBE SOME SNOW ON THE BACK EDGE).
NORTHERN MICHIGAN WILL STILL BE ON THE WARM SIDE OF THE SYSTEM...
WITH DRY SLOTTING POTENTIALLY COMPLICATING THE PRECIP/SKY FORECAST
FOR THANKSGIVING DAY. IN GENERAL THE AFTERNOON MAY NOT TURN OUT
THAT TERRIBLE (AT LEAST ACROSS LOWER MICHIGAN)...BUT WON`T WORRY
ABOUT THE SMALLER SCALE DETAILS AT THIS POINT. RAIN CHANCES WILL
CONTINUE FOR THURSDAY...THEN WITH WHAT REMAINS OF DEFORMATION ZONE
PRECIP THURSDAY NIGHT INTO FRIDAY AS UPPER LOW OPENS UP AND SWINGS
ACROSS THE LOWER GREAT LAKES. WILL MENTION MIXED RAIN/SNOW FOR
THURSDAY NIGHT AS OPPOSED TO ALL SNOW. WILL EVENTUALLY NEED TO
EVALUATE POTENTIAL FOR SOME LAKE INDUCED CONVECTION FRIDAY NIGHT
GOING INTO SATURDAY... A LITTLE IFFY WHETHER ENOUGH COLD AIR WILL
COME DOWN AND/OR WHETHER LOW LEVEL MOISTURE/CYCLONIC FLOW WILL HANG
ON. FOR NOW WILL MAINTAIN CURRENT FORECAST CONTINUITY AND KEEP
FRIDAY NIGHT/SATURDAY DRY. BIGGER ISSUES CREEP INTO THE FORECAST
FOR THE START OF NEXT WEEK...WITH A MYRIAD OF POSSIBILITIES WITH
NEXT ROUND OF PACIFIC ENERGY MOVING INTO THE WESTERN U.S. REGARDING
TIMING/NORTHERN VERSUS SOUTHERN BRANCH EMPHASIS/DOWNSTREAM
WAVELENGTH ISSUES. THOUGH SOME CONSENSUS LEANING TOWARD THE
FASTER/MORE SOUTHERN BRANCH GGEM SOLUTION...NOT CONFIDENT ENOUGH IN
BITING OFF ANYTHING AT THIS POINT. WILL INTRODUCE PRECIP CHANCES
INTO THE SUNDAY NIGHT/MONDAY TIME FRAME...AND HOLD ONTO A DRY SUNDAY
FOR NOW.
TEMPERATURES LOOK TO CONTINUE TO AVERAGE NEAR TO A LITTLE ABOVE
NORMAL THROUGH THE EXTENDED PERIOD...WITHOUT A SIGNIFICANT PUSH OF
COLD AIR IN THE OFFING.
JPB
&&
.MARINE.../ISSUED AT 357 PM/
GENERALLY LIGHT SOUTH TO SOUTHEAST FLOW EXPECTED TUESDAY WITH THE
UPPER LAKES BETWEEN HIGH PRESSURE TO THE EAST AND APPROACHING LOW
PRESSURE FROM THE SOUTHWEST. WINDS WILL BACK AROUND TOWARD MORE OF
AN EASTERLY DIRECTION TUESDAY NIGHT AS THE SURFACE LOW LIFTS
NORTHEAST INTO LAKE MICHIGAN WEDNESDAY MORNING. LOW THEN EXPECTED
TO CROSS THE AREA IN THE VICINITY OF THE STRAITS/EASTERN UPPER
MICHIGAN WEDNESDAY NIGHT INTO THURSDAY. SO WIND DIRECTIONS WILL
VARY ACROSS THE NEARSHORE ZONES RELATIVE TO LOCATION VERSUS SURFACE
LOW POSITION. BUT HEADLINE CRITERIA CONDITIONS NOT ANTICIPATED
THROUGH THANKSGIVING DAY MORNING.
JPB
&&
.AVIATION.../ISSUED AT 1150 PM/...VALID FOR 06Z TAFS
MAINLY MVFR VSBYS AND MVFR/IFR CIGS ARE EXPECTED OVERNIGHT AND THRU
TUESDAY AS LOW STRATUS AND AREAS OF FOG CONTINUE TO HANG OVER THE
AREA. WINDS WILL REMAIN AOB 10 KTS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KAPX 240334
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1034 PM EST MON NOV 23 2009
.SYNOPSIS.../ISSUED AT 357 PM/
RAIN CHANCES WILL INCREASE HEADING INTO TUESDAY NIGHT AND
WEDNESDAY AS A PAIR OF UPPER LEVEL DISTURBANCES ROTATE TOWARD THE
UPPER GREAT LAKES REGION THROUGH THANKSGIVING DAY. DOES APPEAR
THAT THE PRE-HOLIDAY TRAVEL PERIOD WILL ONLY BE WET...WITH WINTRY
PRECIPITATION NOT EXPECTED TO INTERFERE WITH TRAVEL PLANS THROUGH
THANKSGIVING DAY.
JPB
&&
.SHORT TERM.../ISSUED AT 1034 PM/...OVERNIGHT
SURFACE RIDGE AXIS IS HOLDING JUST NORTH OF MICHIGAN LATE THIS
EVENING...WITH WEAK LOW LEVEL WAA UNDERWAY. ANY BRIEF BREAKS IN THE
CLOUD COVER EARLIER THIS EVENING HAVE QUICKLY FILLED BACK IN AS LOW
STRATUS HAS REDEVELOPED WITHIN THESE BREAKS. AREAS OF FOG LINGER
ACROSS ERN AND SRN SECTIONS OF OUR CWA AHEAD OF AN APPROACHING WEAK
WAVE CURRENTLY OVER SRN LOWER MICHIGAN. OBS ACROSS THE REST OF THE
CWA SHOW LITTLE IN THE WAY OF FOG...BUT CERTAINLY QUITE A BIT OF
STRATUS STILL IN PLACE. AS WEAK WAVE TO THE SOUTH LIFTS NORTHWARD
OVERNIGHT...EXPECT AREAS OF FOG WILL SPREAD BACK INTO THE REST OF
OUR CWA. HAVE REDUCED FOG WORDING FROM AREAS OF DENSE FOG TO AREAS
OF FOG...AND HAVE SLIGHTLY INCREASED CLOUD COVER OVERNIGHT.
REMAINDER OF THE FORECAST WILL BE UNCHANGED.
&&
.LONG TERM.../ISSUED AT 357 PM/...TUESDAY AND BEYOND
LARGE SCALE PATTERN FEATURES A NUMBER OF SHORT WAVE TROUGH ACROSS
NORTH AMERICA EXTENDING BACK OUT INTO THE PACIFIC...A PROGRESSIVE 5
WAVE PATTERN WITH MEAN TROUGHING ROUGHLY ACROSS CENTRAL NORTH
AMERICA. INITIAL FOCUS WILL BE ON A TROUGH DIGGING SOUTHEAST
THROUGH THE CENTRAL ROCKIES THIS AFTERNOON...AND A FOLLOW UP TROUGH
CURRENTLY CROSSING THE BRITISH COLUMBIA COAST. LEAD WAVE FORECAST
TO BOTTOM OUT OVER THE CENTRAL PLAINS TUESDAY...THEN GET KICKED
NORTHEAST AS TRAILING FEATURE DIGS INTO THE MIDWEST BEHIND IT BY
THANKSGIVING. SO POTENTIAL IMPACTS ON HOLIDAY TRAVEL WITH THESE
SYSTEMS WILL BE THE PRIMARY FORECAST ISSUE IN THE NEAR TERM. BEYOND
THAT...SOME SMALL HINTS OF THE PATTERN TRYING TO SHIFT TO SOMETHING
A LITTLE COLDER...BUT NOTHING REAL DEFINITIVE AT THIS POINT. AND
WITH THE COLDEST AIR STILL PINNED NORTH OF THE ARCTIC CIRCLE (AND
ACROSS MUCH OF ASIA...FOR THAT MATTER)...WILL NEED A STRONG BUCKLING
OF THE FLOW TO TAP INTO THAT.
TUESDAY...SHORT WAVE DIGGING ACROSS THE CENTRAL ROCKIES FORECAST TO
BOTTOM OUT OVER KANSAS TONIGHT AND HEAD INTO THE MID MISSISSIPPI
VALLEY DURING THE DAY TUESDAY. MAIN PROBLEM FOR TUESDAY WILL DEAL
WITH CLOUD COVER...AFTERNOON VISIBLE IMAGERY SHOWS ANOTHER PUSH OF
LOW CLOUDS LIFTING NORTHWARD ACROSS OHIO WITHIN A ZONE OF ISENTROPIC
ASCENT AND SOME FRONTOGENETIC FORCING. LOOKS LIKE SOME OF THIS
MOISTURE WILL GRAZE PARTS OF NORTHEAST LOWER AND EASTERN UPPER...
POSSIBLY CONTRIBUTING ENOUGH MOISTURE/LIFT TO SQUEEZE OUT SOME
DRIZZLE. OTHERWISE EXPECTING TO START THE DAY WITH MORE WIDESPREAD
LOW CLOUDS/FOG...THOUGH MAY SEE CLOUDS THIN OUT AND ALLOW FOR SOME
SUN LATER IN THE AFTERNOON ACROSS PARTS OF NORTHERN LOWER.
MEASURABLE RAIN CHANCES WILL INCREASE TUESDAY NIGHT AS LEAD SHORT
WAVE CROSSES THE MISSISSIPPI RIVER AND INTO NORTHERN ILLINOIS BY
WEDNESDAY MORNING. NARROW AXIS OF LOW LEVEL MOISTURE INFLOW
INTERACTS WITH INCREASING DIVERGENCE IN LEFT EXIT REGION OF A 100KT
JET STREAK OVER THE OHIO VALLEY. RAIN EXPECTED TO SPREAD INTO THE
REGION FROM SOUTHWEST TO NORTHEAST...NOT REACHING THE ST. MARY`S
RIVER UNTIL NEAR DAYBREAK WEDNESDAY.
WEDNESDAY...SHORT WAVE OVER ILLINOIS EXPECTED TO LIFT NORTHEAST
ACROSS LOWER MICHIGAN DURING THE DAY...AS NEXT PIECE OF ENERGY DIGS
IN BEHIND IT OVER IOWA. SOME HINTS OF MID LEVEL DRYING WITH ARRIVAL
OF UPPER WAVE...THOUGH AT WORST WILL INCREASE CONVECTIVE INSTABILITY
AND ALLOW PRECIPITATION TO BECOME MORE SHOWERY WITH FORECAST CROSS
SECTIONS SHOWING A FAIRLY DEEP LAYER BELOW 600MB WITH WEAKER
STABILITY. HIGH END POPS STILL JUSTIFIED FOR WEDNESDAY...PERHAPS
EVEN AN EMBEDDED THUNDERSTORM WITHIN MID LEVEL COLD POOL. AS UPPER
LOW OVER IOWA PIVOTS TOWARD THE UPPER GREAT LAKES WEDNESDAY
NIGHT...EXPECT PRECIPITATION FOCUS TO MOVE AWAY FROM NORTHERN
MICHIGAN AND TOWARD WISCONSIN/WESTERN UPPER BENEATH DEVELOPING
DEFORMATION AXIS...WITH ANOTHER PUSH OF MID LEVEL DRYING POSSIBLE
LATER WEDNESDAY NIGHT. WILL KEEP HIGHER POPS ACROSS EASTERN
UPPER/FAR NORTHWEST LOWER CLOSER TO DEFORMATION AXIS. ASSOCIATED
SURFACE LOW SHOULD TRACK ACROSS CENTRAL LAKE MICHIGAN UP TOWARD THE
STRAITS/ EASTERN UPPER BY THURSDAY MORNING. UPSTREAM WAVE NOT
EXPECTED TO HAVE MUCH OF A SURFACE RESPONSE WITH IT...BUT ASSOCIATED
COLDER AIR WILL FILTER DOWN ACROSS THE CENTRAL U.S./OHIO VALLEY AND
REINFORCE COLD FRONT ASSOCIATED WITH THE LOW MOVING THROUGH NORTHERN
MICHIGAN WEDNESDAY NIGHT. WITH MAIN COLD AIR PUSH SOUTH OF THE
STATE...LOOKS LIKE NORTHERN MICHIGAN WILL REMAIN ON THE WARMER SIDE
OF THIS SYSTEM THROUGH WEDNESDAY NIGHT...AND THUS PRECIP TYPE
EXPECTED TO REMAIN ALL RAIN AT THIS POINT. SO A WET PRE-
THANKSGIVING TRAVEL DAY EXPECTED...BUT WINTRY PRECIPITATION NOT
EXPECTED TO HAMPER THINGS.
EXTENDED FORECAST (THURSDAY THROUGH MONDAY)...THANKSGIVING DAY LOOKS
TO START WITH LOW PRESSURE IN THE VICINITY OF THE STRAITS/EASTERN
UPPER MICHIGAN...WITH A DEFORMATION DRIVEN PRECIPITATION BAND ACROSS
WISCONSIN/UPPER MICHIGAN (MAYBE SOME SNOW ON THE BACK EDGE).
NORTHERN MICHIGAN WILL STILL BE ON THE WARM SIDE OF THE SYSTEM...
WITH DRY SLOTTING POTENTIALLY COMPLICATING THE PRECIP/SKY FORECAST
FOR THANKSGIVING DAY. IN GENERAL THE AFTERNOON MAY NOT TURN OUT
THAT TERRIBLE (AT LEAST ACROSS LOWER MICHIGAN)...BUT WON`T WORRY
ABOUT THE SMALLER SCALE DETAILS AT THIS POINT. RAIN CHANCES WILL
CONTINUE FOR THURSDAY...THEN WITH WHAT REMAINS OF DEFORMATION ZONE
PRECIP THURSDAY NIGHT INTO FRIDAY AS UPPER LOW OPENS UP AND SWINGS
ACROSS THE LOWER GREAT LAKES. WILL MENTION MIXED RAIN/SNOW FOR
THURSDAY NIGHT AS OPPOSED TO ALL SNOW. WILL EVENTUALLY NEED TO
EVALUATE POTENTIAL FOR SOME LAKE INDUCED CONVECTION FRIDAY NIGHT
GOING INTO SATURDAY... A LITTLE IFFY WHETHER ENOUGH COLD AIR WILL
COME DOWN AND/OR WHETHER LOW LEVEL MOISTURE/CYCLONIC FLOW WILL HANG
ON. FOR NOW WILL MAINTAIN CURRENT FORECAST CONTINUITY AND KEEP
FRIDAY NIGHT/SATURDAY DRY. BIGGER ISSUES CREEP INTO THE FORECAST
FOR THE START OF NEXT WEEK...WITH A MYRIAD OF POSSIBILITIES WITH
NEXT ROUND OF PACIFIC ENERGY MOVING INTO THE WESTERN U.S. REGARDING
TIMING/NORTHERN VERSUS SOUTHERN BRANCH EMPHASIS/DOWNSTREAM
WAVELENGTH ISSUES. THOUGH SOME CONSENSUS LEANING TOWARD THE
FASTER/MORE SOUTHERN BRANCH GGEM SOLUTION...NOT CONFIDENT ENOUGH IN
BITING OFF ANYTHING AT THIS POINT. WILL INTRODUCE PRECIP CHANCES
INTO THE SUNDAY NIGHT/MONDAY TIME FRAME...AND HOLD ONTO A DRY SUNDAY
FOR NOW.
TEMPERATURES LOOK TO CONTINUE TO AVERAGE NEAR TO A LITTLE ABOVE
NORMAL THROUGH THE EXTENDED PERIOD...WITHOUT A SIGNIFICANT PUSH OF
COLD AIR IN THE OFFING.
JPB
&&
.MARINE.../ISSUED AT 357 PM/
GENERALLY LIGHT SOUTH TO SOUTHEAST FLOW EXPECTED TUESDAY WITH THE
UPPER LAKES BETWEEN HIGH PRESSURE TO THE EAST AND APPROACHING LOW
PRESSURE FROM THE SOUTHWEST. WINDS WILL BACK AROUND TOWARD MORE OF
AN EASTERLY DIRECTION TUESDAY NIGHT AS THE SURFACE LOW LIFTS
NORTHEAST INTO LAKE MICHIGAN WEDNESDAY MORNING. LOW THEN EXPECTED
TO CROSS THE AREA IN THE VICINITY OF THE STRAITS/EASTERN UPPER
MICHIGAN WEDNESDAY NIGHT INTO THURSDAY. SO WIND DIRECTIONS WILL
VARY ACROSS THE NEARSHORE ZONES RELATIVE TO LOCATION VERSUS SURFACE
LOW POSITION. BUT HEADLINE CRITERIA CONDITIONS NOT ANTICIPATED
THROUGH THANKSGIVING DAY MORNING.
JPB
&&
.AVIATION.../ISSUED AT 600 AM/...VALID FOR 00Z TAFS
MVFR CONDITIONS WILL DETERIORATE TO IFR OVERNIGHT AND INTO TUESDAY
MORNING AS LOW STRATUS AND FOG CONTINUE TO HANG OVER THE AREA.
CONDITIONS WILL AGAIN IMPROVE TO MVFR BY MIDDAY TUESDAY. WINDS WILL
REMAIN AOB 10 KTS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KMQT 240026 AAA
AFDMQT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MARQUETTE MI
726 PM EST MON NOV 23 2009
UPDATED FOR 00Z AVIATION DISCUSSION
.SYNOPSIS... /ISSUED AT 400 PM EST/
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW ACROSS THE
CONUS/SRN CANADA. IN THE SRN BRANCH...A TROF WAS SHIFTING E OF THE
ROCKIES AND A DOWNSTREAM RIDGE WAS ALONG THE E COAST. IN THE SW FLOW
INTO THE GREAT LAKES...A TROF WITH A COUPLE OF EMBEDDED SHORTWAVES
WAS LIFTING THRU THE UPPER MISSISSIPPI VALLEY AND WRN GREAT LAKES.
SHRA ASSOCIATED WITH ONE OF THE SHORTWAVES HAS BEEN OCCURRING ACROSS
NRN AND ERN MN INTO NW WI AND WRN LAKE SUPERIOR. SHRA OCCASIONALLY
AFFECTED THE FAR WRN FCST AREA IN THE KIWD VCNTY EARLIER IN THE DAY.
THE OTHER SHORTWAVE IN THE LOWER OHIO VALLEY IS ALSO GENERATING SOME
-SHRA...BUT WITH MUCH LESS COVERAGE. OTHER THAN THE EARLY SHRA
AROUND KIWD...THE REMAINDER OF THE FCST AREA HAS BEEN DRY TODAY...
BUT FOG WAS SLOW TO DISSIPATE.
&&
.SHORT TERM (TONIGHT AND TUE)... /ISSUED AT 400 PM EST/
WEAKENING MIDLEVEL TROF WILL LIFT NE OF THE AREA TONIGHT. EVEN PRIOR
TO ITS EXIT...PCPN IS NOT MUCH OF A CONCERN AS DRIER AIR NOTED ON
12Z KGRB SOUNDING IS MOVING NNW OVER THE FCST AREA. ONLY POSSIBLE
EXCEPTION IS OVER THE FAR W AS TAIL END OF SHORTWAVE OVER THE ERN
DAKOTAS/WRN MN HAS RECENTLY BEGAN TO GENERATE A NARROW BAND OF
-SHRA/SPRINKLES SWD INTO SE MN. WILL NEED TO MONITOR -SHRA PROGRESS
OVER THE NEXT FEW HRS...BUT FOR NOW WILL MAINTAIN A DRY FCST TONIGHT
OVER WRN UPPER MI AS PCPN SHOULD ENCOUNTER DRIER AIR. THIS INFLUX OF
DRIER AIR HAS BEEN NOTED NICELY BY SHARP SE EDGE TO PCPN LIFTING N
OVER MN/NW WI/WRN LAKE SUPERIOR TODAY. OTHERWISE...STAGE WILL AGAIN
BE SET FOR FOG ACROSS MOST OF THE FCST AREA TONIGHT AS BOUNDARY
LAYER MOISTURE REMAINS VERY HIGH. FOG WILL BE LEAST LIKELY/LEAST
DENSE IN LOCATIONS THAT SEE DOWNSLOPING UNDER LIGHT S TO SE WINDS
WHICH INCLUDES MAINLY THE AREAS NEAR LAKE SUPERIOR. FOG SHOULD BE
MOST DENSE ACROSS CNTRL UPPER MI WHERE LIGHT WINDS WILL BE
UPSLOPING. IT WILL BE ANOTHER NIGHT OF WELL ABOVE NORMAL TEMPS WITH
MINS AOA NORMAL HIGH TEMPS FOR THIS TIME OF YEAR.
AS WAS THE CASE TODAY...EXPECT FOG TO BE SLOW TO DISSIPATE TUE
MORNING. THEN ATTENTION TURNS TO SHORTWAVE CURRENTLY MOVING ACROSS
WRN KS. DEEP LAYER FORCING ASSOCIATED WITH THIS FEATURE WILL STAY S
OF UPPER MI THRU TUE AFTN. SFC TROF EXTENDING N FROM DEVELOPING SFC
LOW OVER MO/IA WILL REMAIN NEARLY STATIONARY TUE OVER MN...AND THIS
SHOULD KEEP ANY SHRA IN THE VCNTY OF TROF TO THE W OF UPPER MI.
HOWEVER...WITH THE PRESENCE OF WEAK ISENTROPIC ASCENT...WILL KEEP A
MENTION OF SLIGHT CHC POPS OVER THE FAR W TUE AFTN.
.LONG TERM (TUESDAY NIGHT THROUGH NEXT MONDAY)...
UPPER PATTERN STARTS OUT STILL LOOKING MILD...WITH A WESTERLY SPLIT
FLOW ACROSS SOUTHERN CANADA INTO THE CONUS. INITIAL SHORTWAVE TROUGH
OVR THE CNTRL MISSISSIPPI RIVER VALLEY LIFTS NORTHEAST TOWARD THE
UPR GREAT LAKES ON TUE NIGHT AS ANOTHER SHORTWAVE DIGS INTO THE
NORTHERN PLAINS. LIKELY POPS LATE TUE NIGHT INTO WED WITH LEAD WAVE
AND ENHANCEMENT PROVIDED BY UPPER DIVERGENCE IN LFQ OF JET STREAK
MOVING INTO THE CNTRL GREAT LAKES. 1000-500MB/1000-850MB CRITICAL
THICKNESSES IN THE VCNTY OF THE LEAD SHORTWAVE ARE HIGH ENOUGH TO
ONLY JUSTIFY RAIN AS PTYPE THROUGH WED. ADVECTION OF DWPNTS IN THE
UPR 30S/AROUND 40F WELL ABOVE CURRENT 2 INCH GROUND TEMPS IN THE LWR
30S ALONG WITH PERSISTENT SE LOW-LEVEL WINDS...AS WELL AS JUST A
PERSISTENCE FCST...RESULTS IN MORE FOG TUE NIGHT INTO WED...
ESPECIALLY IN THE UPSLOPE AREAS OF CNTRL CWA.
SECOND SHORTWAVE DIGGING IN FM THE NORTHERN PLAINS DEEPENING OVR THE
UPR GREAT LAKES WED NIGHT INTO THU HELPS DRAW SLIGHTLY COLDER AIR IN
FM CNTRL CANADA. CYCLONIC FLOW THROUGH H85 AND DEEP MOISTURE LEADS
TO CONTINUING LIKELY POPS WED NIGHT INTO THU. CRITICAL THICKNESSES
AND H85 TEMPS MARGINAL FOR MUCH IN THE WAY OF SNOW WED NIGHT BUT DO
CONTINUE TO LOWER ON THANKSGIVING. SOUNDINGS OFF GFS IN THE FAR WRN
CWA INDICATE ABOVE FREEZING LAYER IS ONLY IN THE LOWEST 50 MB WITH
DEEP MOISTURE INTERSECTING THE -10C TO -15C ISOTHERMS...SO MAJORITY
OF PCPN IN THOSE AREAS SHOULD BE IN THE FORM OF SNOW. SOUNDINGS AND
THICKNESSES INDICATE WARMER AIR PERSISTS THROUGH ALL OF THU OVR THE
CNTRL AND EAST...SO PTYPE THROUGH THU SHOULD STAY IN THE FORM OF
RAIN AWAY FM THE WESTERN CWA. POTENTIAL FOR RAIN AMOUNTS TO EXCEED
ONE-HALF INCH OVR THE SOUTH AND EAST CWA LATE WED INTO WED NIGHT DUE
TO DEVELOPING DEFORMATION AREA ON NORTH SIDE OF THE DEVELOPING UPPER
LOW. GFS/ECMWF/NAM/UKMET/CANADIAN IN GOOD AGREEMENT WITH THIS
POSSIBILITY.
NE FLOW AND DWPNTS WELL INTO THE 30S ON WED EVENING SHOULD INITIALLY
RESULT IN FOG IN THE UPSLOPE AREAS OF NW CWA LATER WED INTO WED
NIGHT AND PERHAPS INTO THU MORNING. SETUP MAY FAVOR DENSE FOG.
OVERALL...THE FOG AND MIX OF LGT RAIN AND SNOW MAY LEAD TO TRICKY
TRAVEL LATE ON WED INTO THU MORNING. ON THE FLIP SIDE...TEMPS
REMAINING WARM IN THE BLYR ALSO CUTS DOWN ON SNOW AMOUNTS OVR THE
WESTERN CWA. WILL CONTINUE TO MENTION THE SYSTEM IN THE HAZARDOUS
WEATHER OUTLOOK DUE TO THE SLOPPY MIX OF RAIN/SNOW AND POTENTIALLY
DENSE FOG.
DIFFERENCES ARISE IN HOW DEEP TROUGH BECOMES OVR THE GREAT LAKES
INTO FRIDAY. ESSENTIALLY...OPERATIONAL GFS IS STRONGEST AND HAS
MUCH COLDER AIR INTO FRIDAY WITH H85 TEMPS BLO -8C. ABOUT HALF OF
THE GEFS ENSEMBLES INDICATE STRONGER TROUGH...WHILE THE OTHER HALF
OF THE MEMBERS ARE MORE IN LINE WITH ECMWF/ECMWF ENSEMBLES AND
CANADIAN/CANADIAN ENSEMBLES WHICH INDICATE TROUGH DEPARTING EARLY
AND MUCH WARMER H85 TEMPS ONLY AROUND -2C ON FRI. LATEST ECMWF HAS
TRENDED COLDER THOUGH. IF USING THE UKMET TO BREAK THE TIE...IT TOO
IS SIMILAR TO ECMWF AND CANADIAN BY BUILDING A RIDGE FM THE NORTHERN
PLAINS TO THE UPR LAKES ON FRIDAY. IN GENERAL...KEPT THEME OF PREV
FCST WITH LOW CHANCE POPS IN NW FLOW AREAS NEAR LK SUPERIOR OVR THE
ERN CWA.
HPC PREFERRED ECMWF/CANADIAN AND ENSEMBLES POINT TO RIDGING AND
ABOVE NORMAL TEMPS FOR EARLY WEEKEND...BUT QUICK FLOW ALLOWS TROUGH
TO ALREADY PUSH INTO THE UPR LAKES BY LATE NEXT WEEKEND. 00Z ECMWF
WAS QUICKER WITH ARRIVAL OF TROUGH...BUT LATEST GFS/CANADIAN HAVE
ALSO TRENDED TOWARD PCPN ON SUN. COMPARED TO THE ENSEMBLES...00Z
ECMWF LOOKS A BIT QUICK AND DEEP WITH ITS SFC LOW PUSHING ACROSS AS
EARLY AS SUN. INTERESTING THAT 12Z ECMWF IS NOT AS STRONG/WIDESPREAD
WITH QPF. USED SLIGHT CHANCE POPS FOR SUN UNTIL TRENDS BECOME MORE
CLEAR. ALSO USED SMALL CHANCE POPS FOR EARLY NEXT WEEK AS UPPER
TROUGH/UNSETTLED WEATHER AFFECTS UPR LAKES. TEMPS SHOULD ALSO TRY
TO TREND BACK TOWARD NORMAL FOR LATE NOVEMBER EARLY NEXT WEEK.
&&
.AVIATION /FOR THE 00Z TAF ISSUANCE/...
LOOK FOR MORE FOG AND LOW STRATUS TO REDEVELOP THIS EVENING AT
KCMX/KSAW UNDER LIGHT WINDS/NOCTURNAL COOLING. EXPECT THE LOWEST
LIFR CONDITIONS AT KSAW UNDER LIGHT UPSLOPING SSE WINDS. SIMILAR TO
TODAY...CIG/VIS IMPROVEMENT TUE MORNING WILL BE VERY SLOW.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
LIGHT WINDS UNDER 20KT SHOULD BE THE RULE THRU TUE NIGHT UNDER A
WEAK PRES GRADIENT BTWN HIGH PRES OVER SE CANADA AND ORGANIZING LOW
PRES OVER THE CNTRL PLAINS. AS THE LOW MOVES ACROSS THE UPPER GREAT
LAKES THRU THU AND THEN REDEVELOPS OVER THE MID ATLANTIC STATES AND
NEW ENGLAND FRI...N WINDS WILL INCREASE LATE WED AND THU. A PERIOD
OF 20-30KT N WINDS APPEARS LIKELY ACROSS MUCH OF LAKE SUPERIOR WED
NIGHT INTO FRI ALTHOUGH WINDS WILL BEGIN TO DIMINISH OVER THE W THU
NIGHT. A HIGH PRES RIDGE WILL ARRIVE FRI NIGHT AND SAT...BRINGING
LIGHTER WINDS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS/SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...JV
MARINE...ROLFSON
000
FXUS63 KDTX 232353
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
653 PM EST MON NOV 23 2009
.AVIATION...
ABUNDANT LOW LEVEL MOISTURE WILL REMAIN FIRMLY ENTRENCHED ACROSS
SOUTHEAST LOWER MI AGAIN FOR THIS TAF PERIOD. THIS WILL CONTINUE
TO TRANSLATE INTO DETERIORATING CONDITIONS IN BOTH FOG AND STRATUS
OVERNIGHT...AIDED BY POCKETS OF CLEARING AND THE PERSISTENT MOIST
SOUTHEAST FLOW OFF LAKES HURON/ERIE. LATEST OBSERVATIONS AND
SATELLITE IMAGERY SUGGEST MAINLY MVFR STRATUS FOR THE EVENING
HOURS. THIS STRATUS DECK MAY TEND TO SCATTER SOME OVERNIGHT...
ALLOWING FOR BETTER NEAR SURFACE SATURATION AS COOLING INCREASES.
THEREFORE WILL CONTINUE TO HIGHLIGHT PREVAILING IFR CONDITIONS AFTER
09Z. THE POTENTIAL CERTAINLY EXISTS FOR A PERIOD OF LIFR IN
FOG/STRATUS BETWEEN 10-14Z. GRADUAL IMPROVEMENT THROUGH LATE
MORNING/EARLY AFTERNOON...ALTHOUGH MVFR CLOUD COVER WILL PERSIST
INTO THE EVENING.
&&
.PREV DISCUSSION...ISSUED 353 PM EST MON NOV 23 2009
SHORT TERM...TONIGHT
HIGH PRESSURE CONTINUES TO PULL AWAY FROM THE REGION AS A BROAD AREA
OF LOW PRESSURE ADVANCES FROM THE PLAINS. A SHORTWAVE LIFTING ACROSS
THE MIDWEST IS HELPING TO LIFT AN AREA OF DEEPER MOISTURE NORTH FROM
OHIO INTO ONTARIO...CLIPPING EXTREME SOUTHEAST MICHIGAN ON THE WAY.
LIGHT RADAR ECHOS HAVE BEEN MOVING NORTH ACROSS OHIO WITH SEVERAL
ASOS SITES REPORTING TRACE AMOUNTS ACROSS NORTH CENTRAL OHIO.
REPORTS ARE HARDER TO FIND UPSTREAM ACROSS NORTHWESTERN OHIO BUT
HAVE ADDED A SLIGHT CHANCE OF LIGHT SHOWERS/SPRINKLES INTO THE
FORECAST THROUGH THIS EVENING WITH QPF OF .01 OR LESS.
THE FOG FORECAST IS CHALLENGING FOR TONIGHT AS THE DECK OF CLOUD
SPREADING NORTH WILL LIMIT COOLING DURING THE EVENING HOURS. HOWEVER
NAM/GFS SHOW THESE CLOUDS STARTING TO CLEAR OUT AFTER MIDNIGHT...
WHICH WOULD STILL LEAVE PLENTY OF TIME FOR LOW LEVEL MOISTURE TO
COME IN OFF LAKE ERIE/HURON UNDER SOUTHEASTERLY FLOW. WILL STILL
EXPECT AREAS OF FOG TO DEVELOP LATE WITH PATCHY DENSE FOG POSSIBLE.
HAVE RAISED TEMPS A DEGREE OR SO FOR TONIGHT WITH LOWS IN THE UPPER
30S TO NEAR 40 EXPECTED.
LONG TERM...
INTERACTING/MERGING-CONSOLIDATING UPPER WAVES WILL LEAD TO LARGE
PV ANOMALY/UPPER LEVEL LOW DEVELOPING AND TRACKING THROUGH THE
SOUTHERN GREAT LAKES/OHIO VALLEY...SENDING TEMPERATURES BACK TO
NORMAL (IF NOT BELOW)...WITH SNOW POSSIBLE AS WE HEAD INTO
THANKSGIVING AND INTO FRIDAY.
THE FIRST SHORTWAVE/UPPER WAVE IS CURRENTLY MOVING INTO THE CENTRAL
PLAINS...AND WILL PROVIDE SOME GOOD LARGE SCALE/ISENTROPIC ASCENT
TUESDAY NIGHT WITH SURFACE LOW/REFLECTION MOVING OVER LAKE MICHIGAN.
THE CENTER OF THIS WAVE...AS SEEN ON GFS TROPOPAUSE MAP AND
INDICATED BY 12 HR 500 MB HEIGHT FALL CENTER...WILL MOVE THROUGH
SOUTHEAST MICHIGAN ON WEDNESDAY....AS THIS SYSTEM CONTINUES TO HEAD
OFF TO THE NORTHEAST...OUTPACING THE NEXT UPSTREAM SYSTEM. THE
850-700 MB THETA-E RIDGE AXIS IS NARROW...BUT SHOULD PROVE
SUFFICIENT TO GENERATE RAIN TUESDAY NIGHT WITH THE WARM
FRONT/MOISTURE ADVECTION...AND HAVE RAMPED POPS TO HIGH LIKELY WITH
12Z UKMET/NAM/GFS ALL ON BOARD. COLD FRONT/FAIRLY STEEP MID LEVEL
LAPSE RATES ON WEDNESDAY WILL PROBABLY BE ENOUGH FOR A FEW SHOWERS.
THE MORE IMPRESSIVE UPPER WAVE/TROUGH IS CRASHING ASHORE BRITISH
COLUMBIA AND LOOKS TO BE DIGGING THROUGH THE PLAINS-MIDWEST AND INTO
THE OHIO VALLEY/SOUTHERN GREAT LAKES ON THURSDAY. THE CENTER OF THE
COLD CORE (-32 C AT 500 MB/-8 C AT 850 MB) LOOKS TO RESIDE OVER THE
NORTHERN OHIO VALLEY...WITH MATURE MID LEVEL DRY SLOT PUNCHING INTO
THE CWA...LIKELY LIMITING OUR PRECIPITATION CHANCES DURING THE
DAYTIME HOURS (PER 12Z GFS/EUROPEAN) OF THURSDAY. HOWEVER...IT
SHOULD BE NOTED...THE TIMING OF THE MERGING UPPER WAVES AND
SUBSEQUENT POSITION OF 500 MB LOW REMAIN IN PLAY...AS SECOND UPPER
WAVE DROPS SOUTH FROM ONTARIO PROVIDING AN ADDITIONAL COLD INFUSION
AS WE HEAD INTO FRIDAY. REGARDLESS...WITH THE 12Z UKMET/NAM BOTH
FASTER AND FARTHER NORTH WITH THE 500 MB LOW ON THANKSGIVING AND
COLDER (850 MB TEMPS OF -6 TO -7 C NEAR THE OHIO BORDER) IN THE LOW
LEVELS...FELT A LOW CHANCE OF BOTH SNOW AND RAIN SHOWERS WERE
JUSTIFIED OVER SOUTH TWO THIRDS OF THE CWA DURING THE DAYTIME HOURS.
MUCH BETTER CHANCE OF PRECIPITATION (LIKELY IN THE FORM OF SNOW)
THURSDAY NIGHT INTO FRIDAY AS WRAP AROUND/DEFORMATION AXIS WORKS
THROUGH (WITH LAKE ENHANCEMENT). CLOUDS AND FURTHER LOW LEVEL COLD
ADVECTION DURING THE DAY ON FRIDAY WILL MAKE 40 DEGREE MAXES
DIFFICULT TO ACHIEVE. WITH RIDGE AXIS SETTLING OVER LOWER MICHIGAN
FRIDAY NIGHT...AND ASSUMING SKIES AT LEAST PARTIALLY CLEAR
OUT...LOWS IN THE 20S APPEAR TO BE A GOOD BET.
A MODEST WARMUP APPEARS ON TAP FOR THE WEEKEND AS RATHER FLAT UPPER
LEVEL RIDGE BUILDS INTO THE GREAT LAKES DURING THE FIRST HALF OF THE
WEEKEND. POTENTIAL NEXT STORM SYSTEM MAY IMPACT THE AREA SUNDAY OR
EARLY NEXT WEEK. SIGNIFICANT DIFFERENCES WITH MEDIUM RANGE
MODELS...AS EUROPEAN STILL ADVERTISING MORE OF A SPLIT FLOW
PATTERN. NONE-THE-LESS...WITH 12Z UKMET/EUROPEAN AND GFS ALL SHOWING
SOME SEMBLANCE OF LOW PRESSURE SYSTEM/SHORTWAVE TRAVERSING THROUGH
THE AREA ON SUNDAY...WILL INTRODUCE CHANCE POPS.
MARINE...
SOUTHEASTERLY WINDS WILL CONTINUE AS HIGH PRESSURE EXITS TO THE EAST
COAST AND A LOW PRESSURE SYSTEM SLOWLY APPROACHES FROM THE PLAINS.
SOUTHEASTERLY WINDS WILL INCREASE TO 15 TO 20 KNOTS ON THE OPEN
WATERS ON WEDNESDAY AS THIS AREA OF LOW PRESSURE APPROACHES...WITH
THE POSSIBILITY FOR SMALL CRAFT ADVISORIES ON WEDNESDAY NIGHT AS
WINDS VEER AROUND TO THE WEST. WAVES SHOULD INCREASE TO 3 TO 5 FEET
ON THE SAGINAW BAY ON WEDNESDAY NIGHT BUT WILL HOPEFULLY BE ABLE TO
HOLD OFF ON ANY SMALL CRAFT ADVISORIES ELSEWHERE UNTIL THE PASSAGE
OF A STRONGER COLD FRONT ON FRIDAY. THIS SYSTEM WILL BRING COOLER
TEMPERATURES WITH THE POSSIBILITY FOR A MIX OF RAIN AND SNOW SHOWERS
BY THURSDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MR
SHORT TERM...KEC
LONG TERM....SF
MARINE.......KEC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KGRR 232301
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
602 PM EST MON NOV 23 2009
LATEST UPDATE...AVIATION...
.SYNOPSIS...(415 PM EST MON NOV 23 2009)
AN AREA OF LOW PRESSURE WILL SWING THROUGH THE GREAT LAKES REGION
THIS WEEK...SPREADING RAIN INTO SOUTHWEST LOWER MICHIGAN TUESDAY
EVENING. CHANCES FOR RAIN WILL CONTINUE INTO WEDNESDAY AND WEDNESDAY
NIGHT. COLDER AIR WILL FILTER INTO THE GREAT LAKES BEHIND THE SYSTEM
FROM WEDNESDAY NIGHT INTO FRIDAY. THE AIR WILL BE COLD ENOUGH WHERE
SOME SNOW MAY MIX IN ON THANKSGIVING AND INTO FRIDAY. HEAVY SNOW IS
NOT EXPECTED...AND FOR THE MOST PART ANY ACCUMULATION WILL BE
MINIMAL. BY THE END OF THE WEEK...TEMPERATURES WILL BE MUCH CLOSER
TO NORMAL WITH HIGHS AROUND 40 AND LOWS DROPPING TO AROUND 30.
&&
.SHORT TERM...(415 PM EST MON NOV 23 2009)
(TONIGHT THROUGH WEDNESDAY NIGHT)
MAIN ISSUES TO DEAL WITH IN THE SHORT TERM PERTAIN TO FOG FORMATION
TONIGHT...PRECIPITATION CHANCES TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT AND THE CHANCE FOR SNOW MIXING IN INTO THANKSGIVING MORNING.
WE ARE EXPECTING FOG ONCE AGAIN TONIGHT WITH A WEAK PRESSURE
GRADIENT IN PLACE AND CLEARING SKIES. BEST CHANCES OF DENSE FOG WILL
BE IN AREAS THAT HAVE CLEARED OUT THIS EVENING...NAMELY ALONG AND
SOUTH OF INTERSTATE 96. NOT CONFIDENT ENOUGH AT THIS POINT TO ISSUE
AN ADVISORY...BUT WE WILL BE CLOSELY WATCHING VSBY/S AS WE HEAD INTO
THE OVERNIGHT HOURS.
THE FOG WILL LIFT OUT TOWARD MIDDAY ON TUESDAY...WITH A LULL IN THE
ACTIVE WEATHER THROUGH THE AFTERNOON. RAIN WILL BE PRESS INTO THE
AREA AFTER DARK ON TUESDAY EVENING IN ADVANCE OF THE DEEPENING LOW.
IT APPEARS THE HEAVIEST PRECIPITATION SHOULD OCCUR TUESDAY NIGHT
WITH THE SYSTEM AS STRONG LIFT PROGRESSES THROUGH THE FORECAST AREA.
PRECIPITATION WILL CONTINUE INTO WEDNESDAY IN DEEP CYCLONIC FLOW.
SOME LAKE ENHANCED RAIN SHOWERS WILL BE POSSIBLE BY THE END OF THE
DAY AS DELTA T/S INCREASE TO AROUND 8 DEGREES C.
DELTA T/S WILL INCREASE FURTHER TO AROUND 12 DEGREES C BY
THANKSGIVING MORNING. RAIN SHOWERS WILL TRY TO MIX WITH SNOW SHOWERS
WEDNESDAY NIGHT WITH THE LOW TO THE NORTH OF THE AREA AND COLD AIR
WRAPPING INTO SOUTHWEST LOWER MICHIGAN. 850MB TEMPS WILL BE IN THE
-2 TO -6 DEGREE C RANGE...SO SNOW IS A POSSIBILITY BY 12Z THURS.
&&
.LONG TERM...(400 PM EST MON NOV 23 2009)
(THURSDAY THROUGH MONDAY)
MAIN CHALLENGES IN THE LONG TERM CONTINUE TO BE THE THREAT OF PCPN
IN AN INCREASINGLY ACTIVE WEATHER PATTERN...AND P-TYPE THROUGH MOST
OF THE PERIOD AS COLDER AIR FILTERS INTO THE STATE.
COLDER AIR WILL BE ALREADY MAKING ITS WAY INTO THE AREA AT THE
BEGINNING OF THE LONG TERM THU MORNING AS A SECONDARY AND MORE
POTENT SHORT WAVE DIVES SE TOWARD THE GREAT LAKES. THE EXACT TRACK
OF THE COLDEST AIR IS A BIT IN QUESTION DUE TO THE INTERACTION WITH
THE FIRST TROUGH. EITHER WAY...THE AIR COMING IN WILL BE APPROACHING
RAIN/SNOW THRESHOLDS. THE NIGHT TIME HOURS WILL SEE THE BEST THREAT
OF SNOW AS THE BOUNDARY LAYER COOLS AND FREEZING LEVELS DROP TO 1K
FEET OR LESS. ACCUMULATING SNOW DOES NOT LOOK LIKELY...ESPECIALLY
WITH A WARM GROUND. IT IS NOT TOTALLY OUT OF THE QUESTION HOWEVER IF
WE CAN COOL THE LOW LEVELS OFF ENOUGH.
MODELS HAVE BEEN VARYING ON THE TIMING OF THE EXIT OF THE UPPER
TROUGH FROM ANYWHERE BETWEEN FRI AFTERNOON TO SAT NIGHT/SUN. THE 12Z
MODELS HAVE TIGHTENED THIS RANGE UP A BIT TO FRI NIGHT/SAT MORNING.
ANY INSTABILITY SHOWERS AND/OR LAKE EFFECT WILL THEN SHUT OFF AS
TEMPS AT 850 WARM. RIDGING WILL THEN MOVE IN FOR ABOUT 24-36
HOURS...AND SLIGHTLY WARM TEMPS A BIT.
THE NEXT SHORT WAVE IN THE SERIES COMING IN FROM THE NW WILL MOVE IN
DURING THE DAY ON SUN. TEMPS WILL BE WARM ENOUGH AHEAD OF THE
SYSTEM THAT P-TYPE WILL BE ALL RAIN. THIS WILL TRANSITION TO AT
LEAST A MIX IF NOT ALL SNOW BY NEXT MON AS A SHOT OF COLD AIR
FOLLOWS IN THE WAKE OF THIS FRONT.
&&
.AVIATION...(602 PM EST MON NOV 23 2009)
THE PRIMARY ISSUE REMAINS THE EXPECTED REDEVELOPMENT OF STRATUS AND
FOG OVERNIGHT.
THE LOW CLOUDS CONTINUE TO CLEAR FROM SOUTH TO NORTH ACROSS THE
SOUTHERN SECTIONS OF THE CWA. THE CLEARING OF LOW CLOUDS HAS
REACHED INTESTATE 96 BY 5 PM. MUSKEGON REMAINS ON THE EDGE AND
SHOULD SEE THEIR CEILING LIFT WITHIN THE NEXT HOUR. THERE IS A PATCH
OF STRATUS WITH CEILING AROUND 500 FT AGL HEADING NORTH NORTHEAST
TOWARD AZO...BTL AND GRR AND IT SHOULD REACH THOSE SITES BTW 00Z
AND 01Z. THE QUESTION THERE IS WILL THE LOW CLOUDS QUICKLY FILL BACK
IN OR WILL THE CLEAR SKIES (BELOW 3000 FT) SOUTH OF THE STATE OF
MICHIGAN PREVAIL OVERNIGHT.
THE HRRR RUC SHOWS THE CLOUDS FILLING BACK IN AFTER 1 AM. IT ALSO
DOES NOT SHOW MUCH IN THE WAY OF LESS THAN 1 MILE VISIBILITIES OVER
ANY OF THE TAF SITES OVERNIGHT. IF THE STRATUS FILLS IN AS
FORECAST...THAN THAT WOULD MAKE SENSE. UNLIKE LAST NIGHT WINDS BELOW
5000 FT SHOULD FOR THE MOST PART BE UNDER 10 KNOTS SO IF WE DO GET
FOG IT WILL NOT MIX OUT QUICKLY IN THE MORNING. I KEEP THE LOW
CLOUDS IN ALL DAY TUESDAY.
&&
.MARINE...(415 PM EST MON NOV 23 2009)
LIGHT EASTERLY FLOW WILL KEEP WAVE HEIGHTS IN CHECK TONIGHT AND
TUESDAY. WINDS AND WAVES WILL BE ON THE INCREASE TUESDAY NIGHT INTO
WEDNESDAY THOUGH AS A DEEPENING LOW MOVES INTO THE NORTHERN GREAT
LAKES. WINDS WILL BECOME SOUTHERLY AS THE LOW MOVES NORTH OF THE
AREA WHICH WILL BUILD WAVES TO 3 TO 5 FEET INTO WEDNESDAY MORNING.
WESTERLY FLOW ON WEDNESDAY SHOULD BUILD WAVES HEIGHTS FURTHER ON
WEDNESDAY INTO THE 3 TO 6 FOOT RANGE TOWARD THE END OF THE DAY.
&&
.HYDROLOGY...(415 PM EST MON NOV 23 2009)
STILL NOT EXPECTING ANY HYDRO PROBLEMS WITH THE SYSTEM MOVING
THROUGH THIS WEEK. IT APPEARS MOST LOCATIONS WILL SEE RAINFALL OF A
HALF INCH OR BELOW. THERE MAY BE A FEW SPOTS THAT PICK UP .50 TO .75
IN THE NORTHWEST PORTION OF THE FORECAST AREA THOUGH.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: DUKE
SHORT TERM: DUKE
LONG TERM: NJJ
AVIATION: WDM
MARINE: DUKE
HYDROLOGY: DUKE
000
FXUS63 KAPX 232300
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
600 PM EST MON NOV 23 2009
.SYNOPSIS.../ISSUED AT 357 PM/
RAIN CHANCES WILL INCREASE HEADING INTO TUESDAY NIGHT AND
WEDNESDAY AS A PAIR OF UPPER LEVEL DISTURBANCES ROTATE TOWARD THE
UPPER GREAT LAKES REGION THROUGH THANKSGIVING DAY. DOES APPEAR
THAT THE PRE-HOLIDAY TRAVEL PERIOD WILL ONLY BE WET...WITH WINTRY
PRECIPITATION NOT EXPECTED TO INTERFERE WITH TRAVEL PLANS THROUGH
THANKSGIVING DAY.
JPB
&&
.SHORT TERM.../ISSUED AT 357 PM/...TONIGHT
WEAKISH WARM ADVECTION FLOW UNDERWAY ACROSS THE WESTERN GREAT LAKES
WITH SOME SEMBLANCE OF A LOW-MID LEVEL SHORT WAVE AXIS LIFTING UP
THROUGH THE REGION. MORE DEFINABLE SHORT WAVE CIRCULATION NOTED
MOVING ACROSS OHIO INTO PENNSYLVANIA AND PRODUCING SPOTTY SHOWERS
LIFTING NORTHWARD INTO SE LOWER MICHIGAN/ONTARIO. ACROSS NRN
MICHIGAN...LOW STRATUS REMAINS BLANKETED ACROSS MUCH OF THE REGION.
HOWEVER...SHARP CLEARING LINE HAS BEEN MAKING NORTHWARD PROGRESS
INTO CENTRAL LOWER MICHIGAN OVER THE LAST FEW HOURS...AND SOME
ADDITIONAL HOLES HAVE OPENED ACROSS THE FORECAST AREA.
A COUPLE PROBLEMS TO ADDRESS FOR TONIGHT. FIRST OFF...PER SATELLITE
TRENDS AND SUGGESTED BY MODEL RH FORECASTS...STILL SOME POTENTIAL
FOR THINNING/CLEARING OF THE LOW CLOUDS FOR AT LEAST PORTIONS OF THE
FORECAST AREA HEADING INTO THE EVENING HOURS. TOUGH FORECAST AS IT
CERTAINLY WON/T BE A LINEAR PROCESS AND ANY CLEARING WILL PROBABLY
BE FLEETING...ONLY AIDING FOG REDEVELOPMENT. NONETHELESS...HAVE
TAKEN A STAB AT THINNING OUT THE CLOUDS FOR A SOME AREAS (MAINLY THE
SRN COUNTIES AND DOWNSLOPE AREAS OF EASTERN UPPER AND NRN LOWER) ONLY
TO BEEF UP CLOUDS AGAIN LATER ON AS FOG REDEVELOPS. CERTAINLY EXPECT
ONGOING SKY GRID UPDATES AS THE NIGHT PROCEEDS.
SECOND PROBLEM...SHORT WAVE TROUGH AXIS LIFTING NORTHWARD AND SPOTTY
SHOWER ACTIVITY THAT HAS BEEN ADVANCING INTO SE LOWER MICHIGAN. AS
THIS MID LEVEL TROUGH AXIS CONTINUES TO WORK NORTHWARD...NOT OUT OF
THE QUESTION FOR AT LEAST SOME SPOTTY SHOWER ACTIVITY TO SKIRT THE
FORECAST AREA...PARTICULARLY NE LOWER MICHIGAN. DON/T THINK THE
CHANCES AREA VERY HIGH...AND WON/T INCLUDE EXPLICIT SHOWER WORDING
IN THE FORECAST. BUT WILL INDICATE A SUBTLE INCREASE IN POPS
OVERNIGHT ALONG WITH PATCHY DRIZZLE WORDING NOSING INTO NE LOWER
MICHIGAN WHERE THE DEEPER MOISTURE WILL SKIRT THROUGH.
ADAM
&&
.LONG TERM.../ISSUED AT 357 PM/...TUESDAY AND BEYOND
LARGE SCALE PATTERN FEATURES A NUMBER OF SHORT WAVE TROUGH ACROSS
NORTH AMERICA EXTENDING BACK OUT INTO THE PACIFIC...A PROGRESSIVE 5
WAVE PATTERN WITH MEAN TROUGHING ROUGHLY ACROSS CENTRAL NORTH
AMERICA. INITIAL FOCUS WILL BE ON A TROUGH DIGGING SOUTHEAST
THROUGH THE CENTRAL ROCKIES THIS AFTERNOON...AND A FOLLOW UP TROUGH
CURRENTLY CROSSING THE BRITISH COLUMBIA COAST. LEAD WAVE FORECAST
TO BOTTOM OUT OVER THE CENTRAL PLAINS TUESDAY...THEN GET KICKED
NORTHEAST AS TRAILING FEATURE DIGS INTO THE MIDWEST BEHIND IT BY
THANKSGIVING. SO POTENTIAL IMPACTS ON HOLIDAY TRAVEL WITH THESE
SYSTEMS WILL BE THE PRIMARY FORECAST ISSUE IN THE NEAR TERM. BEYOND
THAT...SOME SMALL HINTS OF THE PATTERN TRYING TO SHIFT TO SOMETHING
A LITTLE COLDER...BUT NOTHING REAL DEFINITIVE AT THIS POINT. AND
WITH THE COLDEST AIR STILL PINNED NORTH OF THE ARCTIC CIRCLE (AND
ACROSS MUCH OF ASIA...FOR THAT MATTER)...WILL NEED A STRONG BUCKLING
OF THE FLOW TO TAP INTO THAT.
TUESDAY...SHORT WAVE DIGGING ACROSS THE CENTRAL ROCKIES FORECAST TO
BOTTOM OUT OVER KANSAS TONIGHT AND HEAD INTO THE MID MISSISSIPPI
VALLEY DURING THE DAY TUESDAY. MAIN PROBLEM FOR TUESDAY WILL DEAL
WITH CLOUD COVER...AFTERNOON VISIBLE IMAGERY SHOWS ANOTHER PUSH OF
LOW CLOUDS LIFTING NORTHWARD ACROSS OHIO WITHIN A ZONE OF ISENTROPIC
ASCENT AND SOME FRONTOGENETIC FORCING. LOOKS LIKE SOME OF THIS
MOISTURE WILL GRAZE PARTS OF NORTHEAST LOWER AND EASTERN UPPER...
POSSIBLY CONTRIBUTING ENOUGH MOISTURE/LIFT TO SQUEEZE OUT SOME
DRIZZLE. OTHERWISE EXPECTING TO START THE DAY WITH MORE WIDESPREAD
LOW CLOUDS/FOG...THOUGH MAY SEE CLOUDS THIN OUT AND ALLOW FOR SOME
SUN LATER IN THE AFTERNOON ACROSS PARTS OF NORTHERN LOWER.
MEASURABLE RAIN CHANCES WILL INCREASE TUESDAY NIGHT AS LEAD SHORT
WAVE CROSSES THE MISSISSIPPI RIVER AND INTO NORTHERN ILLINOIS BY
WEDNESDAY MORNING. NARROW AXIS OF LOW LEVEL MOISTURE INFLOW
INTERACTS WITH INCREASING DIVERGENCE IN LEFT EXIT REGION OF A 100KT
JET STREAK OVER THE OHIO VALLEY. RAIN EXPECTED TO SPREAD INTO THE
REGION FROM SOUTHWEST TO NORTHEAST...NOT REACHING THE ST. MARY`S
RIVER UNTIL NEAR DAYBREAK WEDNESDAY.
WEDNESDAY...SHORT WAVE OVER ILLINOIS EXPECTED TO LIFT NORTHEAST
ACROSS LOWER MICHIGAN DURING THE DAY...AS NEXT PIECE OF ENERGY DIGS
IN BEHIND IT OVER IOWA. SOME HINTS OF MID LEVEL DRYING WITH ARRIVAL
OF UPPER WAVE...THOUGH AT WORST WILL INCREASE CONVECTIVE INSTABILITY
AND ALLOW PRECIPITATION TO BECOME MORE SHOWERY WITH FORECAST CROSS
SECTIONS SHOWING A FAIRLY DEEP LAYER BELOW 600MB WITH WEAKER
STABILITY. HIGH END POPS STILL JUSTIFIED FOR WEDNESDAY...PERHAPS
EVEN AN EMBEDDED THUNDERSTORM WITHIN MID LEVEL COLD POOL. AS UPPER
LOW OVER IOWA PIVOTS TOWARD THE UPPER GREAT LAKES WEDNESDAY
NIGHT...EXPECT PRECIPITATION FOCUS TO MOVE AWAY FROM NORTHERN
MICHIGAN AND TOWARD WISCONSIN/WESTERN UPPER BENEATH DEVELOPING
DEFORMATION AXIS...WITH ANOTHER PUSH OF MID LEVEL DRYING POSSIBLE
LATER WEDNESDAY NIGHT. WILL KEEP HIGHER POPS ACROSS EASTERN
UPPER/FAR NORTHWEST LOWER CLOSER TO DEFORMATION AXIS. ASSOCIATED
SURFACE LOW SHOULD TRACK ACROSS CENTRAL LAKE MICHIGAN UP TOWARD THE
STRAITS/ EASTERN UPPER BY THURSDAY MORNING. UPSTREAM WAVE NOT
EXPECTED TO HAVE MUCH OF A SURFACE RESPONSE WITH IT...BUT ASSOCIATED
COLDER AIR WILL FILTER DOWN ACROSS THE CENTRAL U.S./OHIO VALLEY AND
REINFORCE COLD FRONT ASSOCIATED WITH THE LOW MOVING THROUGH NORTHERN
MICHIGAN WEDNESDAY NIGHT. WITH MAIN COLD AIR PUSH SOUTH OF THE
STATE...LOOKS LIKE NORTHERN MICHIGAN WILL REMAIN ON THE WARMER SIDE
OF THIS SYSTEM THROUGH WEDNESDAY NIGHT...AND THUS PRECIP TYPE
EXPECTED TO REMAIN ALL RAIN AT THIS POINT. SO A WET PRE-
THANKSGIVING TRAVEL DAY EXPECTED...BUT WINTRY PRECIPITATION NOT
EXPECTED TO HAMPER THINGS.
EXTENDED FORECAST (THURSDAY THROUGH MONDAY)...THANKSGIVING DAY LOOKS
TO START WITH LOW PRESSURE IN THE VICINITY OF THE STRAITS/EASTERN
UPPER MICHIGAN...WITH A DEFORMATION DRIVEN PRECIPITATION BAND ACROSS
WISCONSIN/UPPER MICHIGAN (MAYBE SOME SNOW ON THE BACK EDGE).
NORTHERN MICHIGAN WILL STILL BE ON THE WARM SIDE OF THE SYSTEM...
WITH DRY SLOTTING POTENTIALLY COMPLICATING THE PRECIP/SKY FORECAST
FOR THANKSGIVING DAY. IN GENERAL THE AFTERNOON MAY NOT TURN OUT
THAT TERRIBLE (AT LEAST ACROSS LOWER MICHIGAN)...BUT WON`T WORRY
ABOUT THE SMALLER SCALE DETAILS AT THIS POINT. RAIN CHANCES WILL
CONTINUE FOR THURSDAY...THEN WITH WHAT REMAINS OF DEFORMATION ZONE
PRECIP THURSDAY NIGHT INTO FRIDAY AS UPPER LOW OPENS UP AND SWINGS
ACROSS THE LOWER GREAT LAKES. WILL MENTION MIXED RAIN/SNOW FOR
THURSDAY NIGHT AS OPPOSED TO ALL SNOW. WILL EVENTUALLY NEED TO
EVALUATE POTENTIAL FOR SOME LAKE INDUCED CONVECTION FRIDAY NIGHT
GOING INTO SATURDAY... A LITTLE IFFY WHETHER ENOUGH COLD AIR WILL
COME DOWN AND/OR WHETHER LOW LEVEL MOISTURE/CYCLONIC FLOW WILL HANG
ON. FOR NOW WILL MAINTAIN CURRENT FORECAST CONTINUITY AND KEEP
FRIDAY NIGHT/SATURDAY DRY. BIGGER ISSUES CREEP INTO THE FORECAST
FOR THE START OF NEXT WEEK...WITH A MYRIAD OF POSSIBILITIES WITH
NEXT ROUND OF PACIFIC ENERGY MOVING INTO THE WESTERN U.S. REGARDING
TIMING/NORTHERN VERSUS SOUTHERN BRANCH EMPHASIS/DOWNSTREAM
WAVELENGTH ISSUES. THOUGH SOME CONSENSUS LEANING TOWARD THE
FASTER/MORE SOUTHERN BRANCH GGEM SOLUTION...NOT CONFIDENT ENOUGH IN
BITING OFF ANYTHING AT THIS POINT. WILL INTRODUCE PRECIP CHANCES
INTO THE SUNDAY NIGHT/MONDAY TIME FRAME...AND HOLD ONTO A DRY SUNDAY
FOR NOW.
TEMPERATURES LOOK TO CONTINUE TO AVERAGE NEAR TO A LITTLE ABOVE
NORMAL THROUGH THE EXTENDED PERIOD...WITHOUT A SIGNIFICANT PUSH OF
COLD AIR IN THE OFFING.
JPB
&&
.MARINE.../ISSUED AT 357 PM/
GENERALLY LIGHT SOUTH TO SOUTHEAST FLOW EXPECTED TUESDAY WITH THE
UPPER LAKES BETWEEN HIGH PRESSURE TO THE EAST AND APPROACHING LOW
PRESSURE FROM THE SOUTHWEST. WINDS WILL BACK AROUND TOWARD MORE OF
AN EASTERLY DIRECTION TUESDAY NIGHT AS THE SURFACE LOW LIFTS
NORTHEAST INTO LAKE MICHIGAN WEDNESDAY MORNING. LOW THEN EXPECTED
TO CROSS THE AREA IN THE VICINITY OF THE STRAITS/EASTERN UPPER
MICHIGAN WEDNESDAY NIGHT INTO THURSDAY. SO WIND DIRECTIONS WILL
VARY ACROSS THE NEARSHORE ZONES RELATIVE TO LOCATION VERSUS SURFACE
LOW POSITION. BUT HEADLINE CRITERIA CONDITIONS NOT ANTICIPATED
THROUGH THANKSGIVING DAY MORNING.
JPB
&&
.AVIATION.../ISSUED AT 600 AM/...VALID FOR 00Z TAFS
MVFR CONDITIONS WILL DETERIORATE TO IFR OVERNIGHT AND INTO TUESDAY
MORNING AS LOW STRATUS AND FOG CONTINUE TO HANG OVER THE AREA.
CONDITIONS WILL AGAIN IMPROVE TO MVFR BY MIDDAY TUESDAY. WINDS WILL
REMAIN AOB 10 KTS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KGRR 232116
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
415 PM EST MON NOV 23 2009
LATEST UPDATE...ALL SECTIONS EXCEPT AVIATION...
.SYNOPSIS...(415 PM EST MON NOV 23 2009)
AN AREA OF LOW PRESSURE WILL SWING THROUGH THE GREAT LAKES REGION
THIS WEEK...SPREADING RAIN INTO SOUTHWEST LOWER MICHIGAN TUESDAY
EVENING. CHANCES FOR RAIN WILL CONTINUE INTO WEDNESDAY AND WEDNESDAY
NIGHT. COLDER AIR WILL FILTER INTO THE GREAT LAKES BEHIND THE SYSTEM
FROM WEDNESDAY NIGHT INTO FRIDAY. THE AIR WILL BE COLD ENOUGH WHERE
SOME SNOW MAY MIX IN ON THANKSGIVING AND INTO FRIDAY. HEAVY SNOW IS
NOT EXPECTED...AND FOR THE MOST PART ANY ACCUMULATION WILL BE
MINIMAL. BY THE END OF THE WEEK...TEMPERATURES WILL BE MUCH CLOSER
TO NORMAL WITH HIGHS AROUND 40 AND LOWS DROPPING TO AROUND 30.
&&
.SHORT TERM...(415 PM EST MON NOV 23 2009)
(TONIGHT THROUGH WEDNESDAY NIGHT)
MAIN ISSUES TO DEAL WITH IN THE SHORT TERM PERTAIN TO FOG FORMATION
TONIGHT...PRECIPITATION CHANCES TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT AND THE CHANCE FOR SNOW MIXING IN INTO THANKSGIVING MORNING.
WE ARE EXPECTING FOG ONCE AGAIN TONIGHT WITH A WEAK PRESSURE
GRADIENT IN PLACE AND CLEARING SKIES. BEST CHANCES OF DENSE FOG WILL
BE IN AREAS THAT HAVE CLEARED OUT THIS EVENING...NAMELY ALONG AND
SOUTH OF INTERSTATE 96. NOT CONFIDENT ENOUGH AT THIS POINT TO ISSUE
AN ADVISORY...BUT WE WILL BE CLOSELY WATCHING VSBY/S AS WE HEAD INTO
THE OVERNIGHT HOURS.
THE FOG WILL LIFT OUT TOWARD MIDDAY ON TUESDAY...WITH A LULL IN THE
ACTIVE WEATHER THROUGH THE AFTERNOON. RAIN WILL BE PRESS INTO THE
AREA AFTER DARK ON TUESDAY EVENING IN ADVANCE OF THE DEEPENING LOW.
IT APPEARS THE HEAVIEST PRECIPITATION SHOULD OCCUR TUESDAY NIGHT
WITH THE SYSTEM AS STRONG LIFT PROGRESSES THROUGH THE FORECAST AREA.
PRECIPITATION WILL CONTINUE INTO WEDNESDAY IN DEEP CYCLONIC FLOW.
SOME LAKE ENHANCED RAIN SHOWERS WILL BE POSSIBLE BY THE END OF THE
DAY AS DELTA T/S INCREASE TO AROUND 8 DEGREES C.
DELTA T/S WILL INCREASE FURTHER TO AROUND 12 DEGREES C BY
THANKSGIVING MORNING. RAIN SHOWERS WILL TRY TO MIX WITH SNOW SHOWERS
WEDNESDAY NIGHT WITH THE LOW TO THE NORTH OF THE AREA AND COLD AIR
WRAPPING INTO SOUTHWEST LOWER MICHIGAN. 850MB TEMPS WILL BE IN THE
-2 TO -6 DEGREE C RANGE...SO SNOW IS A POSSIBILITY BY 12Z THURS.
&&
.LONG TERM...(400 PM EST MON NOV 23 2009)
(THURSDAY THROUGH MONDAY)
MAIN CHALLENGES IN THE LONG TERM CONTINUE TO BE THE THREAT OF PCPN
IN AN INCREASINGLY ACTIVE WEATHER PATTERN...AND P-TYPE THROUGH MOST
OF THE PERIOD AS COLDER AIR FILTERS INTO THE STATE.
COLDER AIR WILL BE ALREADY MAKING ITS WAY INTO THE AREA AT THE
BEGINNING OF THE LONG TERM THU MORNING AS A SECONDARY AND MORE
POTENT SHORT WAVE DIVES SE TOWARD THE GREAT LAKES. THE EXACT TRACK
OF THE COLDEST AIR IS A BIT IN QUESTION DUE TO THE INTERACTION WITH
THE FIRST TROUGH. EITHER WAY...THE AIR COMING IN WILL BE APPROACHING
RAIN/SNOW THRESHOLDS. THE NIGHT TIME HOURS WILL SEE THE BEST THREAT
OF SNOW AS THE BOUNDARY LAYER COOLS AND FREEZING LEVELS DROP TO 1K
FEET OR LESS. ACCUMULATING SNOW DOES NOT LOOK LIKELY...ESPECIALLY
WITH A WARM GROUND. IT IS NOT TOTALLY OUT OF THE QUESTION HOWEVER IF
WE CAN COOL THE LOW LEVELS OFF ENOUGH.
MODELS HAVE BEEN VARYING ON THE TIMING OF THE EXIT OF THE UPPER
TROUGH FROM ANYWHERE BETWEEN FRI AFTERNOON TO SAT NIGHT/SUN. THE 12Z
MODELS HAVE TIGHTENED THIS RANGE UP A BIT TO FRI NIGHT/SAT MORNING.
ANY INSTABILITY SHOWERS AND/OR LAKE EFFECT WILL THEN SHUT OFF AS
TEMPS AT 850 WARM. RIDGING WILL THEN MOVE IN FOR ABOUT 24-36
HOURS...AND SLIGHTLY WARM TEMPS A BIT.
THE NEXT SHORT WAVE IN THE SERIES COMING IN FROM THE NW WILL MOVE IN
DURING THE DAY ON SUN. TEMPS WILL BE WARM ENOUGH AHEAD OF THE
SYSTEM THAT P-TYPE WILL BE ALL RAIN. THIS WILL TRANSITION TO AT
LEAST A MIX IF NOT ALL SNOW BY NEXT MON AS A SHOT OF COLD AIR
FOLLOWS IN THE WAKE OF THIS FRONT.
&&
.AVIATION...(1233 PM EST MON NOV 23 2009)
BIGGEST CONCERN IN AVIATION WITH THIS SET OF TERMINALS IS THE
FOG/STRATUS POTENTIAL FOR TONIGHT.
FOG AND STRATUS FROM THIS MORNING IS SLOWLY LIFTING AND DIMINISHING
AT THIS HOUR. ALL TERMINALS HAVE LIFTED TO ABOVE IFR CONDITIONS AND
CLEARING IS TAKING PLACE FROM THE SE TO NW. WE EXPECT ALL TERMINALS
TO CLEAR OUT BY 20-21Z WITH KMKG BEING THE LAST TO CLEAR.
WE DO EXPECT FOG/STRATUS TO BE PROBLEMATIC ONCE AGAIN TONIGHT...AND
IFR AND/OR LIFR IS EXPECTED. BOUNDARY LAYER WILL BE PRIMED WITH
RESIDUAL MOISTURE REMAINING IN PLACE. WE EXPECT VSBYS TO BEGIN GOING
DOWN SHORTLY AFTER SUNSET. THE WORST CONDITIONS ARE EXPECTED AFTER
06Z AS WINDS ALOFT ARE SHOWN TO DIMINISH SOME WHICH WILL ALLOW FOR
LESS MIXING. SOME STRATUS IS EXPECTED ONCE AGAIN WITH SOME WIND
ALOFT. THE STRATUS SHOULD KEEP VSBYS FROM DROPPING TOO FAR.
CONDITIONS WILL BE SLOW ONCE AGAIN ON TUE MORNING WITH A WEAK
NOVEMBER SUNSHINE WORKING ON THE CLOUDS.
&&
.MARINE...(415 PM EST MON NOV 23 2009)
LIGHT EASTERLY FLOW WILL KEEP WAVE HEIGHTS IN CHECK TONIGHT AND
TUESDAY. WINDS AND WAVES WILL BE ON THE INCREASE TUESDAY NIGHT INTO
WEDNESDAY THOUGH AS A DEEPENING LOW MOVES INTO THE NORTHERN GREAT
LAKES. WINDS WILL BECOME SOUTHERLY AS THE LOW MOVES NORTH OF THE
AREA WHICH WILL BUILD WAVES TO 3 TO 5 FEET INTO WEDNESDAY MORNING.
WESTERLY FLOW ON WEDNESDAY SHOULD BUILD WAVES HEIGHTS FURTHER ON
WEDNESDAY INTO THE 3 TO 6 FOOT RANGE TOWARD THE END OF THE DAY.
&&
.HYDROLOGY...(415 PM EST MON NOV 23 2009)
STILL NOT EXPECTING ANY HYDRO PROBLEMS WITH THE SYSTEM MOVING
THROUGH THIS WEEK. IT APPEARS MOST LOCATIONS WILL SEE RAINFALL OF A
HALF INCH OR BELOW. THERE MAY BE A FEW SPOTS THAT PICK UP .50 TO .75
IN THE NORTHWEST PORTION OF THE FORECAST AREA THOUGH.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: DUKE
SHORT TERM: DUKE
LONG TERM: NJJ
AVIATION: NJJ
MARINE: DUKE
HYDROLOGY: DUKE
000
FXUS63 KMQT 232100
AFDMQT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
400 PM EST MON NOV 23 2009
.SYNOPSIS... /ISSUED AT 400 PM EST/
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A SPLIT FLOW ACROSS THE
CONUS/SRN CANADA. IN THE SRN BRANCH...A TROF WAS SHIFTING E OF THE
ROCKIES AND A DOWNSTREAM RIDGE WAS ALONG THE E COAST. IN THE SW FLOW
INTO THE GREAT LAKES...A TROF WITH A COUPLE OF EMBEDDED SHORTWAVES
WAS LIFTING THRU THE UPPER MISSISSIPPI VALLEY AND WRN GREAT LAKES.
SHRA ASSOCIATED WITH ONE OF THE SHORTWAVES HAS BEEN OCCURRING ACROSS
NRN AND ERN MN INTO NW WI AND WRN LAKE SUPERIOR. SHRA OCCASIONALLY
AFFECTED THE FAR WRN FCST AREA IN THE KIWD VCNTY EARLIER IN THE DAY.
THE OTHER SHORTWAVE IN THE LOWER OHIO VALLEY IS ALSO GENERATING SOME
-SHRA...BUT WITH MUCH LESS COVERAGE. OTHER THAN THE EARLY SHRA
AROUND KIWD...THE REMAINDER OF THE FCST AREA HAS BEEN DRY TODAY...
BUT FOG WAS SLOW TO DISSIPATE.
&&
.SHORT TERM (TONIGHT AND TUE)... /ISSUED AT 400 PM EST/
WEAKENING MIDLEVEL TROF WILL LIFT NE OF THE AREA TONIGHT. EVEN PRIOR
TO ITS EXIT...PCPN IS NOT MUCH OF A CONCERN AS DRIER AIR NOTED ON
12Z KGRB SOUNDING IS MOVING NNW OVER THE FCST AREA. ONLY POSSIBLE
EXCEPTION IS OVER THE FAR W AS TAIL END OF SHORTWAVE OVER THE ERN
DAKOTAS/WRN MN HAS RECENTLY BEGAN TO GENERATE A NARROW BAND OF
-SHRA/SPRINKLES SWD INTO SE MN. WILL NEED TO MONITOR -SHRA PROGRESS
OVER THE NEXT FEW HRS...BUT FOR NOW WILL MAINTAIN A DRY FCST TONIGHT
OVER WRN UPPER MI AS PCPN SHOULD ENCOUNTER DRIER AIR. THIS INFLUX OF
DRIER AIR HAS BEEN NOTED NICELY BY SHARP SE EDGE TO PCPN LIFTING N
OVER MN/NW WI/WRN LAKE SUPERIOR TODAY. OTHERWISE...STAGE WILL AGAIN
BE SET FOR FOG ACROSS MOST OF THE FCST AREA TONIGHT AS BOUNDARY
LAYER MOISTURE REMAINS VERY HIGH. FOG WILL BE LEAST LIKELY/LEAST
DENSE IN LOCATIONS THAT SEE DOWNSLOPING UNDER LIGHT S TO SE WINDS
WHICH INCLUDES MAINLY THE AREAS NEAR LAKE SUPERIOR. FOG SHOULD BE
MOST DENSE ACROSS CNTRL UPPER MI WHERE LIGHT WINDS WILL BE
UPSLOPING. IT WILL BE ANOTHER NIGHT OF WELL ABOVE NORMAL TEMPS WITH
MINS AOA NORMAL HIGH TEMPS FOR THIS TIME OF YEAR.
AS WAS THE CASE TODAY...EXPECT FOG TO BE SLOW TO DISSIPATE TUE
MORNING. THEN ATTENTION TURNS TO SHORTWAVE CURRENTLY MOVING ACROSS
WRN KS. DEEP LAYER FORCING ASSOCIATED WITH THIS FEATURE WILL STAY S
OF UPPER MI THRU TUE AFTN. SFC TROF EXTENDING N FROM DEVELOPING SFC
LOW OVER MO/IA WILL REMAIN NEARLY STATIONARY TUE OVER MN...AND THIS
SHOULD KEEP ANY SHRA IN THE VCNTY OF TROF TO THE W OF UPPER MI.
HOWEVER...WITH THE PRESENCE OF WEAK ISENTROPIC ASCENT...WILL KEEP A
MENTION OF SLIGHT CHC POPS OVER THE FAR W TUE AFTN.
.LONG TERM (TUESDAY NIGHT THROUGH NEXT MONDAY)...
UPPER PATTERN STARTS OUT STILL LOOKING MILD...WITH A WESTERLY SPLIT
FLOW ACROSS SOUTHERN CANADA INTO THE CONUS. INITIAL SHORTWAVE TROUGH
OVR THE CNTRL MISSISSIPPI RIVER VALLEY LIFTS NORTHEAST TOWARD THE
UPR GREAT LAKES ON TUE NIGHT AS ANOTHER SHORTWAVE DIGS INTO THE
NORTHERN PLAINS. LIKELY POPS LATE TUE NIGHT INTO WED WITH LEAD WAVE
AND ENHANCEMENT PROVIDED BY UPPER DIVERGENCE IN LFQ OF JET STREAK
MOVING INTO THE CNTRL GREAT LAKES. 1000-500MB/1000-850MB CRITICAL
THICKNESSES IN THE VCNTY OF THE LEAD SHORTWAVE ARE HIGH ENOUGH TO
ONLY JUSTIFY RAIN AS PTYPE THROUGH WED. ADVECTION OF DWPNTS IN THE
UPR 30S/AROUND 40F WELL ABOVE CURRENT 2 INCH GROUND TEMPS IN THE LWR
30S ALONG WITH PERSISTENT SE LOW-LEVEL WINDS...AS WELL AS JUST A
PERSISTENCE FCST...RESULTS IN MORE FOG TUE NIGHT INTO WED...
ESPECIALLY IN THE UPSLOPE AREAS OF CNTRL CWA.
SECOND SHORTWAVE DIGGING IN FM THE NORTHERN PLAINS DEEPENING OVR THE
UPR GREAT LAKES WED NIGHT INTO THU HELPS DRAW SLIGHTLY COLDER AIR IN
FM CNTRL CANADA. CYCLONIC FLOW THROUGH H85 AND DEEP MOISTURE LEADS
TO CONTINUING LIKELY POPS WED NIGHT INTO THU. CRITICAL THICKNESSES
AND H85 TEMPS MARGINAL FOR MUCH IN THE WAY OF SNOW WED NIGHT BUT DO
CONTINUE TO LOWER ON THANKSGIVING. SOUNDINGS OFF GFS IN THE FAR WRN
CWA INDICATE ABOVE FREEZING LAYER IS ONLY IN THE LOWEST 50 MB WITH
DEEP MOISTURE INTERSECTING THE -10C TO -15C ISOTHERMS...SO MAJORITY OF
PCPN IN THOSE AREAS SHOULD BE IN THE FORM OF SNOW. SOUNDINGS AND
THICKNESSES INDICATE WARMER AIR PERSISTS THROUGH ALL OF THU OVR THE
CNTRL AND EAST...SO PTYPE THROUGH THU SHOULD STAY IN THE FORM OF
RAIN AWAY FM THE WESTERN CWA. POTENTIAL FOR RAIN AMOUNTS TO EXCEED
ONE-HALF INCH OVR THE SOUTH AND EAST CWA LATE WED INTO WED NIGHT DUE
TO DEVELOPING DEFORMATION AREA ON NORTH SIDE OF THE DEVELOPING UPPER
LOW. GFS/ECMWF/NAM/UKMET/CANADIAN IN GOOD AGREEMENT WITH THIS
POSSIBILITY.
NE FLOW AND DWPNTS WELL INTO THE 30S ON WED EVENING SHOULD INITIALLY
RESULT IN FOG IN THE UPSLOPE AREAS OF NW CWA LATER WED INTO WED
NIGHT AND PERHAPS INTO THU MORNING. SETUP MAY FAVOR DENSE FOG.
OVERALL...THE FOG AND MIX OF LGT RAIN AND SNOW MAY LEAD TO TRICKY
TRAVEL LATE ON WED INTO THU MORNING. ON THE FLIP SIDE...TEMPS
REMAINING WARM IN THE BLYR ALSO CUTS DOWN ON SNOW AMOUNTS OVR THE
WESTERN CWA. WILL CONTINUE TO MENTION THE SYSTEM IN THE HAZARDOUS
WEATHER OUTLOOK DUE TO THE SLOPPY MIX OF RAIN/SNOW AND POTENTIALLY
DENSE FOG.
DIFFERENCES ARISE IN HOW DEEP TROUGH BECOMES OVR THE GREAT LAKES
INTO FRIDAY. ESSENTIALLY...OPERATIONAL GFS IS STRONGEST AND HAS
MUCH COLDER AIR INTO FRIDAY WITH H85 TEMPS BLO -8C. ABOUT HALF OF
THE GEFS ENSEMBLES INDICATE STRONGER TROUGH...WHILE THE OTHER HALF
OF THE MEMBERS ARE MORE IN LINE WITH ECMWF/ECMWF ENSEMBLES AND
CANADIAN/CANADIAN ENSEMBLES WHICH INDICATE TROUGH DEPARTING EARLY
AND MUCH WARMER H85 TEMPS ONLY AROUND -2C ON FRI. LATEST ECMWF HAS
TRENDED COLDER THOUGH. IF USING THE UKMET TO BREAK THE TIE...IT TOO
IS SIMILAR TO ECMWF AND CANADIAN BY BUILDING A RIDGE FM THE NORTHERN
PLAINS TO THE UPR LAKES ON FRIDAY. IN GENERAL...KEPT THEME OF PREV
FCST WITH LOW CHANCE POPS IN NW FLOW AREAS NEAR LK SUPERIOR OVR THE
ERN CWA.
HPC PREFERRED ECMWF/CANADIAN AND ENSEMBLES POINT TO RIDGING AND
ABOVE NORMAL TEMPS FOR EARLY WEEKEND...BUT QUICK FLOW ALLOWS TROUGH
TO ALREADY PUSH INTO THE UPR LAKES BY LATE NEXT WEEKEND. 00Z ECMWF
WAS QUICKER WITH ARRIVAL OF TROUGH...BUT LATEST GFS/CANADIAN HAVE
ALSO TRENDED TOWARD PCPN ON SUN. COMPARED TO THE ENSEMBLES...00Z
ECMWF LOOKS A BIT QUICK AND DEEP WITH ITS SFC LOW PUSHING ACROSS AS
EARLY AS SUN. INTERESTING THAT 12Z ECMWF IS NOT AS STRONG/WIDESPREAD
WITH QPF. USED SLIGHT CHANCE POPS FOR SUN UNTIL TRENDS BECOME MORE
CLEAR. ALSO USED SMALL CHANCE POPS FOR EARLY NEXT WEEK AS UPPER
TROUGH/UNSETTLED WEATHER AFFECTS UPR LAKES. TEMPS SHOULD ALSO TRY
TO TREND BACK TOWARD NORMAL FOR LATE NOVEMBER EARLY NEXT WEEK.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
MVFR VIS AT KCMX SHOULD IMPROVE TO VFR EARLY THIS AFTN. VFR
CONDITIONS SHOULD THEN PREVAIL THRU THE AFTN. AT KSAW...FOG/STRATUS
HAS BEEN SLOW TO DISSIPATE THIS MORNING. STILL EXPECT SLOW
IMPROVEMENT TO VFR VIS/MVFR CIG THIS AFTN UNDER WEAK DAYTIME
HEATING. MORE FOG AND STRATUS WILL REDEVELOP THIS EVENING AT
KCMX/KSAW UNDER LIGHT WINDS/NOCTURNAL COOLING. EXPECT LOWEST LIFR
CONDITIONS AT KSAW UNDER LIGHT UPSLOPING SSE WINDS. SIMILAR TO
TODAY...CIG/VIS IMPROVEMENT TUE MORNING WILL BE VERY SLOW.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
LIGHT WINDS UNDER 20KT SHOULD BE THE RULE THRU TUE NIGHT UNDER A
WEAK PRES GRADIENT BTWN HIGH PRES OVER SE CANADA AND ORGANIZING LOW
PRES OVER THE CNTRL PLAINS. AS THE LOW MOVES ACROSS THE UPPER GREAT
LAKES THRU THU AND THEN REDEVELOPS OVER THE MID ATLANTIC STATES AND
NEW ENGLAND FRI...N WINDS WILL INCREASE LATE WED AND THU. A PERIOD
OF 20-30KT N WINDS APPEARS LIKELY ACROSS MUCH OF LAKE SUPERIOR WED
NIGHT INTO FRI ALTHOUGH WINDS WILL BEGIN TO DIMINISH OVER THE W THU
NIGHT. A HIGH PRES RIDGE WILL ARRIVE FRI NIGHT AND SAT...BRINGING
LIGHTER WINDS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS/SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...ROLFSON
000
FXUS63 KAPX 232057
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
357 PM EST MON NOV 23 2009
.SYNOPSIS.../ISSUED AT 357 PM/
RAIN CHANCES WILL INCREASE HEADING INTO TUESDAY NIGHT AND
WEDNESDAY AS A PAIR OF UPPER LEVEL DISTURBANCES ROTATE TOWARD THE
UPPER GREAT LAKES REGION THROUGH THANKSGIVING DAY. DOES APPEAR
THAT THE PRE-HOLIDAY TRAVEL PERIOD WILL ONLY BE WET...WITH WINTRY
PRECIPITATION NOT EXPECTED TO INTERFERE WITH TRAVEL PLANS THROUGH
THANKSGIVING DAY.
JPB
&&
.SHORT TERM.../ISSUED AT 357 PM/...TONIGHT
WEAKISH WARM ADVECTION FLOW UNDERWAY ACROSS THE WESTERN GREAT LAKES
WITH SOME SEMBLANCE OF A LOW-MID LEVEL SHORT WAVE AXIS LIFTING UP
THROUGH THE REGION. MORE DEFINABLE SHORT WAVE CIRCULATION NOTED
MOVING ACROSS OHIO INTO PENNSYLVANIA AND PRODUCING SPOTTY SHOWERS
LIFTING NORTHWARD INTO SE LOWER MICHIGAN/ONTARIO. ACROSS NRN
MICHIGAN...LOW STRATUS REMAINS BLANKETED ACROSS MUCH OF THE REGION.
HOWEVER...SHARP CLEARING LINE HAS BEEN MAKING NORTHWARD PROGRESS
INTO CENTRAL LOWER MICHIGAN OVER THE LAST FEW HOURS...AND SOME
ADDITIONAL HOLES HAVE OPENED ACROSS THE FORECAST AREA.
A COUPLE PROBLEMS TO ADDRESS FOR TONIGHT. FIRST OFF...PER SATELLITE
TRENDS AND SUGGESTED BY MODEL RH FORECASTS...STILL SOME POTENTIAL
FOR THINNING/CLEARING OF THE LOW CLOUDS FOR AT LEAST PORTIONS OF THE
FORECAST AREA HEADING INTO THE EVENING HOURS. TOUGH FORECAST AS IT
CERTAINLY WON/T BE A LINEAR PROCESS AND ANY CLEARING WILL PROBABLY
BE FLEETING...ONLY AIDING FOG REDEVELOPMENT. NONETHELESS...HAVE
TAKEN A STAB AT THINNING OUT THE CLOUDS FOR A SOME AREAS (MAINLY THE
SRN COUNTIES AND DOWNSLOPE AREAS OF EASTERN UPPER AND NRN LOWER) ONLY
TO BEEF UP CLOUDS AGAIN LATER ON AS FOG REDEVELOPS. CERTAINLY EXPECT
ONGOING SKY GRID UPDATES AS THE NIGHT PROCEEDS.
SECOND PROBLEM...SHORT WAVE TROUGH AXIS LIFTING NORTHWARD AND SPOTTY
SHOWER ACTIVITY THAT HAS BEEN ADVANCING INTO SE LOWER MICHIGAN. AS
THIS MID LEVEL TROUGH AXIS CONTINUES TO WORK NORTHWARD...NOT OUT OF
THE QUESTION FOR AT LEAST SOME SPOTTY SHOWER ACTIVITY TO SKIRT THE
FORECAST AREA...PARTICULARLY NE LOWER MICHIGAN. DON/T THINK THE
CHANCES AREA VERY HIGH...AND WON/T INCLUDE EXPLICIT SHOWER WORDING
IN THE FORECAST. BUT WILL INDICATE A SUBTLE INCREASE IN POPS
OVERNIGHT ALONG WITH PATCHY DRIZZLE WORDING NOSING INTO NE LOWER
MICHIGAN WHERE THE DEEPER MOISTURE WILL SKIRT THROUGH.
ADAM
&&
.LONG TERM.../ISSUED AT 357 PM/...TUESDAY AND BEYOND
LARGE SCALE PATTERN FEATURES A NUMBER OF SHORT WAVE TROUGH ACROSS
NORTH AMERICA EXTENDING BACK OUT INTO THE PACIFIC...A PROGRESSIVE 5
WAVE PATTERN WITH MEAN TROUGHING ROUGHLY ACROSS CENTRAL NORTH
AMERICA. INITIAL FOCUS WILL BE ON A TROUGH DIGGING SOUTHEAST
THROUGH THE CENTRAL ROCKIES THIS AFTERNOON...AND A FOLLOW UP TROUGH
CURRENTLY CROSSING THE BRITISH COLUMBIA COAST. LEAD WAVE FORECAST
TO BOTTOM OUT OVER THE CENTRAL PLAINS TUESDAY...THEN GET KICKED
NORTHEAST AS TRAILING FEATURE DIGS INTO THE MIDWEST BEHIND IT BY
THANKSGIVING. SO POTENTIAL IMPACTS ON HOLIDAY TRAVEL WITH THESE
SYSTEMS WILL BE THE PRIMARY FORECAST ISSUE IN THE NEAR TERM. BEYOND
THAT...SOME SMALL HINTS OF THE PATTERN TRYING TO SHIFT TO SOMETHING
A LITTLE COLDER...BUT NOTHING REAL DEFINITIVE AT THIS POINT. AND
WITH THE COLDEST AIR STILL PINNED NORTH OF THE ARCTIC CIRCLE (AND
ACROSS MUCH OF ASIA...FOR THAT MATTER)...WILL NEED A STRONG BUCKLING
OF THE FLOW TO TAP INTO THAT.
TUESDAY...SHORT WAVE DIGGING ACROSS THE CENTRAL ROCKIES FORECAST TO
BOTTOM OUT OVER KANSAS TONIGHT AND HEAD INTO THE MID MISSISSIPPI
VALLEY DURING THE DAY TUESDAY. MAIN PROBLEM FOR TUESDAY WILL DEAL
WITH CLOUD COVER...AFTERNOON VISIBLE IMAGERY SHOWS ANOTHER PUSH OF
LOW CLOUDS LIFTING NORTHWARD ACROSS OHIO WITHIN A ZONE OF ISENTROPIC
ASCENT AND SOME FRONTOGENETIC FORCING. LOOKS LIKE SOME OF THIS
MOISTURE WILL GRAZE PARTS OF NORTHEAST LOWER AND EASTERN UPPER...
POSSIBLY CONTRIBUTING ENOUGH MOISTURE/LIFT TO SQUEEZE OUT SOME
DRIZZLE. OTHERWISE EXPECTING TO START THE DAY WITH MORE WIDESPREAD
LOW CLOUDS/FOG...THOUGH MAY SEE CLOUDS THIN OUT AND ALLOW FOR SOME
SUN LATER IN THE AFTERNOON ACROSS PARTS OF NORTHERN LOWER.
MEASURABLE RAIN CHANCES WILL INCREASE TUESDAY NIGHT AS LEAD SHORT
WAVE CROSSES THE MISSISSIPPI RIVER AND INTO NORTHERN ILLINOIS BY
WEDNESDAY MORNING. NARROW AXIS OF LOW LEVEL MOISTURE INFLOW
INTERACTS WITH INCREASING DIVERGENCE IN LEFT EXIT REGION OF A 100KT
JET STREAK OVER THE OHIO VALLEY. RAIN EXPECTED TO SPREAD INTO THE
REGION FROM SOUTHWEST TO NORTHEAST...NOT REACHING THE ST. MARY`S
RIVER UNTIL NEAR DAYBREAK WEDNESDAY.
WEDNESDAY...SHORT WAVE OVER ILLINOIS EXPECTED TO LIFT NORTHEAST
ACROSS LOWER MICHIGAN DURING THE DAY...AS NEXT PIECE OF ENERGY DIGS
IN BEHIND IT OVER IOWA. SOME HINTS OF MID LEVEL DRYING WITH ARRIVAL
OF UPPER WAVE...THOUGH AT WORST WILL INCREASE CONVECTIVE INSTABILITY
AND ALLOW PRECIPITATION TO BECOME MORE SHOWERY WITH FORECAST CROSS
SECTIONS SHOWING A FAIRLY DEEP LAYER BELOW 600MB WITH WEAKER
STABILITY. HIGH END POPS STILL JUSTIFIED FOR WEDNESDAY...PERHAPS
EVEN AN EMBEDDED THUNDERSTORM WITHIN MID LEVEL COLD POOL. AS UPPER
LOW OVER IOWA PIVOTS TOWARD THE UPPER GREAT LAKES WEDNESDAY
NIGHT...EXPECT PRECIPITATION FOCUS TO MOVE AWAY FROM NORTHERN
MICHIGAN AND TOWARD WISCONSIN/WESTERN UPPER BENEATH DEVELOPING
DEFORMATION AXIS...WITH ANOTHER PUSH OF MID LEVEL DRYING POSSIBLE
LATER WEDNESDAY NIGHT. WILL KEEP HIGHER POPS ACROSS EASTERN
UPPER/FAR NORTHWEST LOWER CLOSER TO DEFORMATION AXIS. ASSOCIATED
SURFACE LOW SHOULD TRACK ACROSS CENTRAL LAKE MICHIGAN UP TOWARD THE
STRAITS/ EASTERN UPPER BY THURSDAY MORNING. UPSTREAM WAVE NOT
EXPECTED TO HAVE MUCH OF A SURFACE RESPONSE WITH IT...BUT ASSOCIATED
COLDER AIR WILL FILTER DOWN ACROSS THE CENTRAL U.S./OHIO VALLEY AND
REINFORCE COLD FRONT ASSOCIATED WITH THE LOW MOVING THROUGH NORTHERN
MICHIGAN WEDNESDAY NIGHT. WITH MAIN COLD AIR PUSH SOUTH OF THE
STATE...LOOKS LIKE NORTHERN MICHIGAN WILL REMAIN ON THE WARMER SIDE
OF THIS SYSTEM THROUGH WEDNESDAY NIGHT...AND THUS PRECIP TYPE
EXPECTED TO REMAIN ALL RAIN AT THIS POINT. SO A WET PRE-
THANKSGIVING TRAVEL DAY EXPECTED...BUT WINTRY PRECIPITATION NOT
EXPECTED TO HAMPER THINGS.
EXTENDED FORECAST (THURSDAY THROUGH MONDAY)...THANKSGIVING DAY LOOKS
TO START WITH LOW PRESSURE IN THE VICINITY OF THE STRAITS/EASTERN
UPPER MICHIGAN...WITH A DEFORMATION DRIVEN PRECIPITATION BAND ACROSS
WISCONSIN/UPPER MICHIGAN (MAYBE SOME SNOW ON THE BACK EDGE).
NORTHERN MICHIGAN WILL STILL BE ON THE WARM SIDE OF THE SYSTEM...
WITH DRY SLOTTING POTENTIALLY COMPLICATING THE PRECIP/SKY FORECAST
FOR THANKSGIVING DAY. IN GENERAL THE AFTERNOON MAY NOT TURN OUT
THAT TERRIBLE (AT LEAST ACROSS LOWER MICHIGAN)...BUT WON`T WORRY
ABOUT THE SMALLER SCALE DETAILS AT THIS POINT. RAIN CHANCES WILL
CONTINUE FOR THURSDAY...THEN WITH WHAT REMAINS OF DEFORMATION ZONE
PRECIP THURSDAY NIGHT INTO FRIDAY AS UPPER LOW OPENS UP AND SWINGS
ACROSS THE LOWER GREAT LAKES. WILL MENTION MIXED RAIN/SNOW FOR
THURSDAY NIGHT AS OPPOSED TO ALL SNOW. WILL EVENTUALLY NEED TO
EVALUATE POTENTIAL FOR SOME LAKE INDUCED CONVECTION FRIDAY NIGHT
GOING INTO SATURDAY... A LITTLE IFFY WHETHER ENOUGH COLD AIR WILL
COME DOWN AND/OR WHETHER LOW LEVEL MOISTURE/CYCLONIC FLOW WILL HANG
ON. FOR NOW WILL MAINTAIN CURRENT FORECAST CONTINUITY AND KEEP
FRIDAY NIGHT/SATURDAY DRY. BIGGER ISSUES CREEP INTO THE FORECAST
FOR THE START OF NEXT WEEK...WITH A MYRIAD OF POSSIBILITIES WITH
NEXT ROUND OF PACIFIC ENERGY MOVING INTO THE WESTERN U.S. REGARDING
TIMING/NORTHERN VERSUS SOUTHERN BRANCH EMPHASIS/DOWNSTREAM
WAVELENGTH ISSUES. THOUGH SOME CONSENSUS LEANING TOWARD THE
FASTER/MORE SOUTHERN BRANCH GGEM SOLUTION...NOT CONFIDENT ENOUGH IN
BITING OFF ANYTHING AT THIS POINT. WILL INTRODUCE PRECIP CHANCES
INTO THE SUNDAY NIGHT/MONDAY TIME FRAME...AND HOLD ONTO A DRY SUNDAY
FOR NOW.
TEMPERATURES LOOK TO CONTINUE TO AVERAGE NEAR TO A LITTLE ABOVE
NORMAL THROUGH THE EXTENDED PERIOD...WITHOUT A SIGNIFICANT PUSH OF
COLD AIR IN THE OFFING.
JPB
&&
.MARINE.../ISSUED AT 357 PM/
GENERALLY LIGHT SOUTH TO SOUTHEAST FLOW EXPECTED TUESDAY WITH THE
UPPER LAKES BETWEEN HIGH PRESSURE TO THE EAST AND APPROACHING LOW
PRESSURE FROM THE SOUTHWEST. WINDS WILL BACK AROUND TOWARD MORE OF
AN EASTERLY DIRECTION TUESDAY NIGHT AS THE SURFACE LOW LIFTS
NORTHEAST INTO LAKE MICHIGAN WEDNESDAY MORNING. LOW THEN EXPECTED
TO CROSS THE AREA IN THE VICINITY OF THE STRAITS/EASTERN UPPER
MICHIGAN WEDNESDAY NIGHT INTO THURSDAY. SO WIND DIRECTIONS WILL
VARY ACROSS THE NEARSHORE ZONES RELATIVE TO LOCATION VERSUS SURFACE
LOW POSITION. BUT HEADLINE CRITERIA CONDITIONS NOT ANTICIPATED
THROUGH THANKSGIVING DAY MORNING.
JPB
&&
.AVIATION.../ISSUED AT 1142 AM/...VALID FOR 18Z TAFS
WILL TREND CONSIDERABLY MORE PESSIMISTIC WITH THE FORECASTS...
PARTICULARLY IN REGARD TO CLOUD COVER. LOW STRATUS (IFR) ONCE
AGAIN DEVELOPED OVERNIGHT AND PERSISTS THIS MORNING. BUT UNLIKE
PREVIOUS DAYS...INCREASING WARM ADVECTION/STRENGTHENING INVERSION
AND INCREASING HIGH CLOUD COVER LIMITING HEATING...WILL CONSPIRE
TO KEEP STRATUS LAYER INTACT THROUGH TODAY AND POSSIBLY THROUGH
TONIGHT. THINNING/LIFTING OF THE LOW CLOUDS NOT COMPLETELY OUT OF
THE QUESTION...BUT NOT BANKING ON IT. THUS HIGH IFR/LOW MVFR
ANTICIPATED THROUGH THE PERIOD.
ADAM
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KDTX 232053
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
353 PM EST MON NOV 23 2009
.SHORT TERM...TONIGHT
HIGH PRESSURE CONTINUES TO PULL AWAY FROM THE REGION AS A BROAD AREA
OF LOW PRESSURE ADVANCES FROM THE PLAINS. A SHORTWAVE LIFTING ACROSS
THE MIDWEST IS HELPING TO LIFT AN AREA OF DEEPER MOISTURE NORTH FROM
OHIO INTO ONTARIO...CLIPPING EXTREME SOUTHEAST MICHIGAN ON THE WAY.
LIGHT RADAR ECHOS HAVE BEEN MOVING NORTH ACROSS OHIO WITH SEVERAL
ASOS SITES REPORTING TRACE AMOUNTS ACROSS NORTH CENTRAL OHIO.
REPORTS ARE HARDER TO FIND UPSTREAM ACROSS NORTHWESTERN OHIO BUT
HAVE ADDED A SLIGHT CHANCE OF LIGHT SHOWERS/SPRINKLES INTO THE
FORECAST THROUGH THIS EVENING WITH QPF OF .01 OR LESS.
THE FOG FORECAST IS CHALLENGING FOR TONIGHT AS THE DECK OF CLOUD
SPREADING NORTH WILL LIMIT COOLING DURING THE EVENING HOURS. HOWEVER
NAM/GFS SHOW THESE CLOUDS STARTING TO CLEAR OUT AFTER MIDNIGHT...
WHICH WOULD STILL LEAVE PLENTY OF TIME FOR LOW LEVEL MOISTURE TO
COME IN OFF LAKE ERIE/HURON UNDER SOUTHEASTERLY FLOW. WILL STILL
EXPECT AREAS OF FOG TO DEVELOP LATE WITH PATCHY DENSE FOG POSSIBLE.
HAVE RAISED TEMPS A DEGREE OR SO FOR TONIGHT WITH LOWS IN THE UPPER
30S TO NEAR 40 EXPECTED.
&&
.LONG TERM...
INTERACTING/MERGING-CONSOLIDATING UPPER WAVES WILL LEAD TO LARGE
PV ANOMALY/UPPER LEVEL LOW DEVELOPING AND TRACKING THROUGH THE
SOUTHERN GREAT LAKES/OHIO VALLEY...SENDING TEMPERATURES BACK TO
NORMAL (IF NOT BELOW)...WITH SNOW POSSIBLE AS WE HEAD INTO
THANKSGIVING AND INTO FRIDAY.
THE FIRST SHORTWAVE/UPPER WAVE IS CURRENTLY MOVING INTO THE CENTRAL
PLAINS...AND WILL PROVIDE SOME GOOD LARGE SCALE/ISENTROPIC ASCENT
TUESDAY NIGHT WITH SURFACE LOW/REFLECTION MOVING OVER LAKE MICHIGAN.
THE CENTER OF THIS WAVE...AS SEEN ON GFS TROPOPAUSE MAP AND
INDICATED BY 12 HR 500 MB HEIGHT FALL CENTER...WILL MOVE THROUGH
SOUTHEAST MICHIGAN ON WEDNESDAY....AS THIS SYSTEM CONTINUES TO HEAD
OFF TO THE NORTHEAST...OUTPACING THE NEXT UPSTREAM SYSTEM. THE
850-700 MB THETA-E RIDGE AXIS IS NARROW...BUT SHOULD PROVE
SUFFICIENT TO GENERATE RAIN TUESDAY NIGHT WITH THE WARM
FRONT/MOISTURE ADVECTION...AND HAVE RAMPED POPS TO HIGH LIKELY WITH
12Z UKMET/NAM/GFS ALL ON BOARD. COLD FRONT/FAIRLY STEEP MID LEVEL
LAPSE RATES ON WEDNESDAY WILL PROBABLY BE ENOUGH FOR A FEW SHOWERS.
THE MORE IMPRESSIVE UPPER WAVE/TROUGH IS CRASHING ASHORE BRITISH
COLUMBIA AND LOOKS TO BE DIGGING THROUGH THE PLAINS-MIDWEST AND INTO
THE OHIO VALLEY/SOUTHERN GREAT LAKES ON THURSDAY. THE CENTER OF THE
COLD CORE (-32 C AT 500 MB/-8 C AT 850 MB) LOOKS TO RESIDE OVER THE
NORTHERN OHIO VALLEY...WITH MATURE MID LEVEL DRY SLOT PUNCHING INTO
THE CWA...LIKELY LIMITING OUR PRECIPITATION CHANCES DURING THE
DAYTIME HOURS (PER 12Z GFS/EUROPEAN) OF THURSDAY. HOWEVER...IT
SHOULD BE NOTED...THE TIMING OF THE MERGING UPPER WAVES AND
SUBSEQUENT POSITION OF 500 MB LOW REMAIN IN PLAY...AS SECOND UPPER
WAVE DROPS SOUTH FROM ONTARIO PROVIDING AN ADDITIONAL COLD INFUSION
AS WE HEAD INTO FRIDAY. REGARDLESS...WITH THE 12Z UKMET/NAM BOTH
FASTER AND FARTHER NORTH WITH THE 500 MB LOW ON THANKSGIVING AND
COLDER (850 MB TEMPS OF -6 TO -7 C NEAR THE OHIO BORDER) IN THE LOW
LEVELS...FELT A LOW CHANCE OF BOTH SNOW AND RAIN SHOWERS WERE
JUSTIFIED OVER SOUTH TWO THIRDS OF THE CWA DURING THE DAYTIME HOURS.
MUCH BETTER CHANCE OF PRECIPITATION (LIKELY IN THE FORM OF SNOW)
THURSDAY NIGHT INTO FRIDAY AS WRAP AROUND/DEFORMATION AXIS WORKS
THROUGH (WITH LAKE ENHANCEMENT). CLOUDS AND FURTHER LOW LEVEL COLD
ADVECTION DURING THE DAY ON FRIDAY WILL MAKE 40 DEGREE MAXES
DIFFICULT TO ACHIEVE. WITH RIDGE AXIS SETTLING OVER LOWER MICHIGAN
FRIDAY NIGHT...AND ASSUMING SKIES AT LEAST PARTIALLY CLEAR
OUT...LOWS IN THE 20S APPEAR TO BE A GOOD BET.
A MODEST WARMUP APPEARS ON TAP FOR THE WEEKEND AS RATHER FLAT UPPER
LEVEL RIDGE BUILDS INTO THE GREAT LAKES DURING THE FIRST HALF OF THE
WEEKEND. POTENTIAL NEXT STORM SYSTEM MAY IMPACT THE AREA SUNDAY OR
EARLY NEXT WEEK. SIGNIFICANT DIFFERENCES WITH MEDIUM RANGE
MODELS...AS EUROPEAN STILL ADVERTISING MORE OF A SPLIT FLOW
PATTERN. NONE-THE-LESS...WITH 12Z UKMET/EUROPEAN AND GFS ALL SHOWING
SOME SEMBLANCE OF LOW PRESSURE SYSTEM/SHORTWAVE TRAVERSING THROUGH
THE AREA ON SUNDAY...WILL INTRODUCE CHANCE POPS.
&&
.MARINE...
SOUTHEASTERLY WINDS WILL CONTINUE AS HIGH PRESSURE EXITS TO THE EAST
COAST AND A LOW PRESSURE SYSTEM SLOWLY APPROACHES FROM THE PLAINS.
SOUTHEASTERLY WINDS WILL INCREASE TO 15 TO 20 KNOTS ON THE OPEN
WATERS ON WEDNESDAY AS THIS AREA OF LOW PRESSURE APPROACHES...WITH
THE POSSIBILITY FOR SMALL CRAFT ADVISORIES ON WEDNESDAY NIGHT AS
WINDS VEER AROUND TO THE WEST. WAVES SHOULD INCREASE TO 3 TO 5 FEET
ON THE SAGINAW BAY ON WEDNESDAY NIGHT BUT WILL HOPEFULLY BE ABLE TO
HOLD OFF ON ANY SMALL CRAFT ADVISORIES ELSEWHERE UNTIL THE PASSAGE
OF A STRONGER COLD FRONT ON FRIDAY. THIS SYSTEM WILL BRING COOLER
TEMPERATURES WITH THE POSSIBILITY FOR A MIX OF RAIN AND SNOW SHOWERS
BY THURSDAY.
&&
.PREV DISCUSSION...ISSUED 1251 PM EST MON NOV 23 2009
AVIATION...
MVFR STRATUS REMAINS ACROSS THE SAGINAW VALLEY WITH REDUCED
VISIBILITIES HOLDING ON IN THIS AREA. THE VISIBILITIES SHOULD
CONTINUE TO IMPROVE THIS AFTERNOON AS STRATUS BECOMES BROKEN
DURING THE AFTERNOON. ANOTHER AREA OF WIDESPREAD LOW AND MID
CLOUDS COVERING OHIO CONTINUES TO STEADILY ADVANCE NORTH TOWARDS
SOUTHEAST MICHIGAN. THIS WILL OVERSPREAD THE AREA WITH CEILINGS
REMAINING AOB 2000 FEET INTO THIS EVENING.
WINDS WILL REMAIN OUT OF THE SOUTHEAST AGAIN TONIGHT WHICH WILL
ALLOW LOW LEVEL MOISTURE TO COME INLAND OFF LAKE ERIE AGAIN. THE
OVERCAST SKIES MAY HELP TO KEEP AN ACTUAL FOG FROM DEVELOPING UNTIL
VERY LATE WHEN MODELS SHOW THE 2000 FOOT DECK EXCITING THE AREA.
THIS COULD ALLOW CEILINGS AND VISIBILITIES TO QUICKLY CRATER AND
REMAIN LOW INTO TUESDAY MORNING. THE TAFS SHOW A LOW STRATUS
DEVELOPING AROUND 8-9Z AND WILL MONITOR FOR DENSE FOG POTENTIAL
OVERNIGHT. A FEW SPRINKLES MAY ALSO BE POSSIBLE BUT CONFIDENCE WAS
NOT HIGH ENOUGH TO INCLUDE IN THE TAFS AT THIS TIME. SOME
IMPROVEMENT CAN BE EXPECTED BY LATE MORNING ON TUESDAY BUT MVFR
CLOUDS WILL LIKELY PERSIST THROUGH THE AFTERNOON.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...KEC
LONG TERM....SF
MARINE.......KEC
AVIATION.....KEC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KDTX 231751
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1251 PM EST MON NOV 23 2009
.AVIATION...
MVFR STRATUS REMAINS ACROSS THE SAGINAW VALLEY WITH REDUCED
VISIBILITIES HOLDING ON IN THIS AREA. THE VISIBILITIES SHOULD
CONTINUE TO IMPROVE THIS AFTERNOON AS STRATUS BECOMES BROKEN
DURING THE AFTERNOON. ANOTHER AREA OF WIDESPREAD LOW AND MID
CLOUDS COVERING OHIO CONTINUES TO STEADILY ADVANCE NORTH TOWARDS
SOUTHEAST MICHIGAN. THIS WILL OVERSPREAD THE AREA WITH CEILINGS
REMAINING AOB 2000 FEET INTO THIS EVENING.
WINDS WILL REMAIN OUT OF THE SOUTHEAST AGAIN TONIGHT WHICH WILL
ALLOW LOW LEVEL MOISTURE TO COME INLAND OFF LAKE ERIE AGAIN. THE
OVERCAST SKIES MAY HELP TO KEEP AN ACTUAL FOG FROM DEVELOPING UNTIL
VERY LATE WHEN MODELS SHOW THE 2000 FOOT DECK EXCITING THE AREA.
THIS COULD ALLOW CEILINGS AND VISIBILITIES TO QUICKLY CRATER AND
REMAIN LOW INTO TUESDAY MORNING. THE TAFS SHOW A LOW STRATUS
DEVELOPING AROUND 8-9Z AND WILL MONITOR FOR DENSE FOG POTENTIAL
OVERNIGHT. A FEW SPRINKLES MAY ALSO BE POSSIBLE BUT CONFIDENCE WAS
NOT HIGH ENOUGH TO INCLUDE IN THE TAFS AT THIS TIME. SOME
IMPROVEMENT CAN BE EXPECTED BY LATE MORNING ON TUESDAY BUT MVFR
CLOUDS WILL LIKELY PERSIST THROUGH THE AFTERNOON.
&&
.PREV DISCUSSION...ISSUED 341 AM EST MON NOV 23 2009
SHORT TERM...TODAY
LOW STRATUS/AREAS OF FOG WILL BE PREVALENT AGAIN THIS MORNING...AND
EXPECT IT TO TAKE MUCH OF THE MORNING TO BURN THIS OFF. EVEN BY THE
AFTERNOON...SKIES WILL BE PARTLY/MOSTLY CLOUDY AS CLOUDS LIFT NORTH
INTO THE REGION AS LOW PRESSURE BEGINS EDGING TOWARDS THE AREA. THE
HIGHS WILL CLIMB TO BETWEEN 50 AND 55 DEGREES AGAIN...SO NO MAJOR
CHANGES WILL BE NEEDED TO THE GOING FORECAST.
LONG TERM...TONIGHT THROUGH NEXT SUNDAY
ONE MORE MORNING OF FOG TO AFFECT LOWER MICHIGAN BEFORE THE NEXT
STORM SYSTEM MOVES IN...BRINGING RAIN AND SNOW WITH IT. HIGH
PRESSURE STRETCHING FROM THE GREAT LAKES TO THE NEW ENGLAND STATES
WILL CONTINUE ITS TRACK EASTWARD THROUGH TUESDAY WHEN IT WILL
FINALLY LOSE ITS INFLUENCE ON THE WEATHER IN SE MICHIGAN. THE
HIGH PRESSURE WILL AGAIN GIVE US A WEAK EASTERLY WIND FIELD OFF THE
LAKES REINFORCING THE ALREADY HIGH MOISTURE VALUES IN THE LOW
LEVELS. SURFACE DEWPOINTS WILL REMAIN NEAR 40F UNDER A STRONG
INVERSION LOCATED AROUND 975MB. MODEL SOUNDINGS SHOW HIGHER
POTENTIAL TO THE NORTH AROUND FNT/MBS BUT DUE TO THE PERSISTENCE OF
THIS PATTERN WITH MOISTURE AMOUNTS AND FOG DEVELOPMENT...WILL LEAVE
MENTION FOR ALL AREAS.
MODELS COMING INTO BETTER AGREEMENT WITH EACH NEW RUN RECENTLY IN
REGARDS TO THE MID WEEK STORM SYSTEM HEADING FOR THE GREAT LAKES
REGION. THE GFS IS TRENDING A BIT SLOWER EACH RUN BECOMING MORE IN
PHASE WITH THE ECMWF...WHICH HAS BEEN THE MOST CONSISTENT MODEL IN
HANDLING THIS SYSTEM. THE NAM DIGS THE TROUGH/LOW DEEPER INTO THE
PLAINS THEN BOTH THE GFS AND ECMWF WHICH ALSO ACTS TO SLOW IT DOWN.
THIS SURFACE LOW SHOULD TRACK NORTH ALONG LAKE MICHIGAN ON WEDNESDAY
LEADING TO PRECIP CHANCES BEGINNING OVERNIGHT TUESDAY. THIS INITIAL
UPPER WAVE LOOKS TO WEAKEN A BIT AS IT MOVES OVER MI BUT WILL BE
QUICKLY REINFORCED BY A SECOND STRONGER WAVE DIGGING INTO THE
CENTRAL PLAINS FROM THE NORTHERN BRANCH OF THE JET STREAM ON
WEDNESDAY. MODELS ARE ONCE AGAIN SHOWING A FAIRLY COLD AIRMASS BEING
BROUGHT IN WITH THIS SECOND IMPULSE. 850MB TEMPS AROUND -5C ARE
BEING ADVERTISED FOR THURSDAY INTO FRIDAY WITH MOST MODELS
NOW...GFS/DGEX/ECMWF. TEMPS HAVE ALREADY BEEN HEDGED LOWER TO TAKE
THIS INTO ACCOUNT SO WILL WAIT TO SEE IF THIS BECOMES A MORE
CONSISTENT SOLUTION BEFORE ACTING FURTHER ON IT. AS THE MODELS SEEM
SLOWER WITH EACH SUCCESSIVE RUN...STILL BELIEVE THANKSGIVING DAY
WILL BE A RAIN EVENT CHANGING OVER TO RAIN/SNOW OVERNIGHT INTO
FRIDAY THOUGH AMOUNTS SHOULD STAY ON THE LOW SIDE.
UPPER LEVEL RIDGING WILL MOVE IN BEHIND THIS SYSTEM ON SATURDAY
PUTTING AN END TO PRECIP CHANCES ALTHOUGH IT LOOKS LIKE THE COLDER
TEMPS...HIGHS IN THE LOWER 40S...WILL REMAIN WITH US.
MARINE...
LIGHT SOUTHEAST WINDS WILL INCREASE SLIGHTLY INTO TUESDAY AS HIGH
PRESSURE RETREATS EAST...AWAY FROM THE AREA. THE PATTERN BECOMES
MORE ACTIVE MID/LATE NEXT WEEK AS AN UPPER LEVEL STORM SYSTEM LIFTS
INTO THE REGION LATE TUESDAY INTO WEDNESDAY AND BRINGS THE CHANCE OF
RAIN AS WELL AS INCREASED WINDS. ANOTHER MORE AGGRESSIVE DISTURBANCE
WILL THEN DIVE SOUTHEAST INTO THE SOUTHERN GREAT LAKES AND OHIO
VALLEY BRINGING COLDER TEMPERATURES AND A MIX OF RAIN/SNOW SHOWERS
LATE IN THE WEEK. WINDS/WAVES WILL BE MUCH MORE TURBULENT AS THIS
SYSTEM WAFFLES THROUGH THE AREA.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....KEC
SHORT TERM...DG
LONG TERM....DRK
MARINE.......DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KMQT 231749 AAB
AFDMQT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MARQUETTE MI
1248 PM EST MON NOV 23 2009
UPDATED FOR AVIATION DISCUSSION FOR 18Z TAF ISSUANCE
.DISCUSSION... /ISSUED AT 342 AM EST/
.TODAY THROUGH TUESDAY...SURFACE RIDGING EXTENDING WESTWARD FROM
NOVA SCOTIA CONTINUES TO INFLUENCE THE GREAT LAKES. LATEST WV
IMAGERY SHOWS MOISTURE STREAMING NORTHEASTWARD AROUND THE
PERIPHERY OF THIS RIDGE AS A COLD FRONT TRACKS EAST ACROSS THE
SOUTHERN CANADIAN PRAIRIES...REMAINING NORTHWEST OF UPPER
MICHIGAN. BROAD AREA OF SHOWERS HAVE DEVELOPED WITHIN THIS
MOISTURE PLUME AIDED BY WEAK ISENTROPIC LIFT NOTED ON 305
THETA-E/PRESSURE ANALYSIS. SHORT TERM GUIDANCE AGREES THESE
SHOWERS WILL REMAIN WEST OF LINE FROM L`ANSE TO WATERSMEET...WITH
THE HEAVIER SHOWERS REMAINING OFFSHORE. EXPECT CLOUDS TO REMAIN
OVER THE FAR WEST MOST OF THE DAY WITH PARTIAL CLEARING AND
PERIODS OF SUNSHINE EXPECTED OVER THE REMAINDER OF UPPER MICHIGAN.
EXPECT AREAS OF DENSE FOG EARLY THIS MORNING UNDER THIS CLEARING.
THIS SHOULD ALSO ALLOW FOR ANOTHER MILD DAY WITH HIGH TEMPERATURES
IN THE LOW 50S...SOME 15 TO 20 DEGREES ABOVE NORMAL. A WEAK S/W
TROUGH NOTED IN THE 500MB FLOW WILL PASS THROUGH THE CWA
TONIGHT...HOWEVER WITH LIMITED MOISTURE DON/T EXPECT MEASURABLE
RAINFALL. IN FACT EXPECT A DRY FORECAST THROUGH TUESDAY.
.TUESDAY NIGHT INTO FRIDAY...BY TUESDAY NIGHT ATTENTION TURNS TO
S/W TROUGH CURRENTLY SITUATED OVER EASTERN COLORADO. THIS FEATURE
IS PROGGED TO SHIFT NORTHEAST OUT THE CENTRAL PLAINS ON
TUESDAY...CROSSING NORTHERN LAKE MICHIGAN ON WEDNESDAY NIGHT WHILE
STRENGTHENING SLIGHTLY. GOING FORECAST APPEARS TO HANDLE
INCREASING POPS WELL...WITH LIKELY POPS BY WEDNESDAY AS DEEPER
MOISTURE/BEST 500MB HEIGHT FALLS ARRIVE OVER UPPER MICHIGAN. MAIN
CHANGES WERE RELATED TO RAIN/SNOW COVERAGE. ATTM IT APPEARS THE
EASTERN ZONES WILL STAY MOSTLY RAIN PER BUFKIT SOUNDINGS/CRITICAL
THICKNESS VALUES. COLD AIR IS LACKING AND IN FACT THE NECESSARY
COLD AIR IS SITUATED WELL TO OUR NORTH ON WEDNESDAY OVER HUDSON
BAY AND NORTHERN MANITOBA. EXPECT SOME SNOW FLAKES THOUGH BY
WEDNESDAY NIGHT OVER SOME OF THE HIGHER TERRAIN AIDED BY DIABATIC
COOLING PROCESSES WITH A RAIN/SNOW MIX ELSEWHERE EXCEPT THE EAST
WHERE ALL RAIN IS EXPECTED THROUGH THURSDAY. ADJUSTED WORDING IN
HWO TO REFLECT LESSER POTENTIAL FOR SIGNIFICANT ACCUMULATING
SNOWFALL.
STILL DISAGREEMENT AMONG LONG TERM GUIDANCE MODELS AS TO WHETHER
ENOUGH COLD AIR IS AVAILABLE FOR LAKE EFFECT SNOW BEHIND THIS
SYSTEM. 23/00Z GFS GUIDANCE BRINGS 850MB TEMPERATURES AS COLD AS
-9C...WHICH GIVEN THE CURRENT LAKE SUPERIOR WATER TEMPERATURE OF
5C WOULD BE JUST ENOUGH FOR LAKE PROCESSES TO BEGIN. THE PREFERRED
ECMWF SOLUTION OFFERS A MUCH WARMER AIRMASS WITH 850MB
TEMPERATURES NEVER FALLING BELOW -4C. A QUICK GLANCE AT 850MB
TEMPERATURES ACROSS THE NORTHERN HEMISPHERE SHOWS COLD AIR IS
NOWHERE TO BE FOUND OVER THE WESTERN HEMISPHERE WITH VIRTUALLY ALL
THE COLD AIR...-20 OR COLDER...LOCKED UP OVER SIBERIA.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
MVFR VIS AT KCMX SHOULD IMPROVE TO VFR EARLY THIS AFTN. VFR
CONDITIONS SHOULD THEN PREVAIL THRU THE AFTN. AT KSAW...FOG/STRATUS
HAS BEEN SLOW TO DISSIPATE THIS MORNING. STILL EXPECT SLOW
IMPROVEMENT TO VFR VIS/MVFR CIG THIS AFTN UNDER WEAK DAYTIME
HEATING. MORE FOG AND STRATUS WILL REDEVELOP THIS EVENING AT
KCMX/KSAW UNDER LIGHT WINDS/NOCTURNAL COOLING. EXPECT LOWEST LIFR
CONDITIONS AT KSAW UNDER LIGHT UPSLOPING SSE WINDS. SIMILAR TO
TODAY...CIG/VIS IMPROVEMENT TUE MORNING WILL BE VERY SLOW.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
EXPECT HI PRES TO REMAIN NEARLY STATIONARY OVER SE CANADA AND THE
NE STATES INTO WED WHILE LO PRES DEVELOPING IN THE PLAINS MOVES
SLOWLY NE TO WISCONSIN. WINDS WILL BE UNDER 25 KTS THRU THIS TIME.
AS THE HI FINALLY RETREATS...THE LO CENTER WILL MOVE GRADUALLY E TO
OVER SE ONTARIO ON FRI. PLAN ON A PERIOD OF STRONGER N WINDS TO 30
KTS ON WED NIGHT INTO FRI ON THE NW FLANK OF THIS LO. SINCE THIS LO
NOW APPEARS WILL DEVELOP MORE SLOWLY THAN EXPECTED BEFORE...THE N
GALES PREVIOUSLY FORECAST APPEAR LESS LIKELY. LOOK FOR A HI PRES
RIDGE TO BUILD TOWARD THE WESTERN GREAT LAKES ON FRI AND BRING
DIMINISHING WINDS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
DISCUSSION...PEARSON
AVIATION...ROLFSON
MARINE...KC
000
FXUS63 KGRR 231734
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1233 PM EST MON NOV 23 2009
LATEST UPDATE...AVIATION...
.SYNOPSIS...(438 AM EST MON NOV 23 2009)
THE WARMER THAN NORMAL TEMPERATURES WILL CONTINUE INTO MID WEEK AS
SOUTHERLY WINDS PREVAIL. THE CHANCE OF RAIN RETURNS BY TUESDAY
NIGHT INTO WEDNESDAY AS LOW PRESSURE ENTERS THE WESTERN GREAT
LAKES. IT WILL BECOME COOLER BEHIND THIS SYSTEM AND SOME SNOW COULD
MIX IN WITH THE RAIN BY LATE WEDNESDAY NIGHT INTO THANKSGIVING DAY.
AT THIS POINT LITTLE TO NO SNOW ACCUMULATION IS EXPECTED.
&&
.SHORT TERM...(1220 PM EST MON NOV 23 2009)
(THIS AFTERNOON)
UPDATED LAST HOUR TO NUDGE TEMPS UP IN THE SOUTH ALONG WITH LESS IN
THE WAY OF CLOUDS THERE AS WELL. MODEL GUIDANCE VIA THE RUC
CONTINUES TO SHOW CLOUDS CLEARING FROM SOUTH TO NORTH THIS AFTERNOON
AND THE TREND GOES ALONG WITH THIS GUIDANCE. RUC GUIDANCE SUGGESTS
THE CLEARING LINE WILL MAKE IT TO A ALMA TO MUSKEGON LINE BY SUNSET
AND THAT LOOKS VERY REASONABLE.
A FEW SHOWERS MAY TRY TO CLIP THE FAR SOUTHEAST CWA NEAR JACKSON.
HAVE NOT SEEN MUCH IN THE WAY OF PRECIPITATION IN THE OBS THOUGH.
THE SHOWERS ARE ASSOCIATED WITH A SHORTWAVE MOVING NORTHEAST OUT OF
THE OHIO VALLEY.
&&
.LONG TERM...(438 AM EST MON NOV 23 2009)
(WEDNESDAY NIGHT THROUGH SUNDAY)
100-130 KT UPPER LEVEL JET DIVING SOUTH FROM CENTRAL CANADA THROUGH
THE NRN PLAINS WILL HELP CARVE OUT A LONG WAVE TROUGH OVER THE GREAT
LAKES REGION FOR THANKSGIVING. THE RESULT WILL BE COLDER AIR AND
SHOWERY PCPN IN THE FORM OF MIXED RAIN AND SNOW SHOWERS.
WHILE THE AIR PROGGED AT H8 AROUND -5C SUPPORTS SNOW ON
THANKSGIVING...THE SFC TEMPS ARE STILL PROGGED TO BE NEAR 40F WHICH
SUPPORTS MOSTLY RAIN. THE BEST OPPORTUNITY TO EXPERIENCE ANY WET
SNOW WOULD BE THURSDAY NIGHT AND EARLY FRIDAY WHEN SFC TEMPS WILL BE
A LITTLE COOLER AND THE CLOSED UPPER LOW WILL STILL BE NEARBY.
NOTHING SIGNIFICANT IN TERMS OF ACCUMULATION IS EXPECTED AT THIS
POINT.
THE LONGWAVE TROUGH/COLD AIR IS PROGGED TO MOVE EAST OF THE AREA
FRIDAY AND FRIDAY NIGHT AS THE NEXT UPSTREAM SYSTEM DIGS INTO THE
NRN ROCKIES. UPPER RIDGING IN BETWEEN THESE TWO TROUGHS WILL RESIDE
OVER THE GREAT LAKES REGION SATURDAY AND SUNDAY...WHICH SHOULD
PROMOTE DRY CONDITIONS WITH SLIGHTLY ABOVE NORMAL TEMPS.
&&
.AVIATION...(1233 PM EST MON NOV 23 2009)
BIGGEST CONCERN IN AVIATION WITH THIS SET OF TERMINALS IS THE
FOG/STRATUS POTENTIAL FOR TONIGHT.
FOG AND STRATUS FROM THIS MORNING IS SLOWLY LIFTING AND DIMINISHING
AT THIS HOUR. ALL TERMINALS HAVE LIFTED TO ABOVE IFR CONDITIONS AND
CLEARING IS TAKING PLACE FROM THE SE TO NW. WE EXPECT ALL TERMINALS
TO CLEAR OUT BY 20-21Z WITH KMKG BEING THE LAST TO CLEAR.
WE DO EXPECT FOG/STRATUS TO BE PROBLEMATIC ONCE AGAIN TONIGHT...AND
IFR AND/OR LIFR IS EXPECTED. BOUNDARY LAYER WILL BE PRIMED WITH
RESIDUAL MOISTURE REMAINING IN PLACE. WE EXPECT VSBYS TO BEGIN GOING
DOWN SHORTLY AFTER SUNSET. THE WORST CONDITIONS ARE EXPECTED AFTER
06Z AS WINDS ALOFT ARE SHOWN TO DIMINISH SOME WHICH WILL ALLOW FOR
LESS MIXING. SOME STRATUS IS EXPECTED ONCE AGAIN WITH SOME WIND
ALOFT. THE STRATUS SHOULD KEEP VSBYS FROM DROPPING TOO FAR.
CONDITIONS WILL BE SLOW ONCE AGAIN ON TUE MORNING WITH A WEAK
NOVEMBER SUNSHINE WORKING ON THE CLOUDS.
&&
.MARINE...(438 AM EST MON NOV 23 2009)
AREAS OF FOG WILL BE AN ISSUE EARLY THIS MORNING AND AGAIN LATE
TONIGHT. WINDS AND WAVES HOWEVER WILL REMAIN FAIRLY LOW...
ESPECIALLY FOR NOV.
&&
.HYDROLOGY...(438 AM EST MON NOV 23 2009)
RAINFALL FROM TUESDAY NIGHT AND WEDNESDAY WILL BE RATHER LIGHT WITH
MOST AREAS RECEIVING BETWEEN A QUARTER AND A HALF INCH OF RAIN.
THIS SHOULD HAVE LITTLE IMPACT ON HYDRO.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: JK
SHORT TERM: DUKE
LONG TERM: MEADE
AVIATION: NJJ
MARINE: JK
HYDROLOGY: JK
000
FXUS63 KGRR 231722
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1220 PM EST MON NOV 23 2009
LATEST UPDATE...SHORT TERM...
.SYNOPSIS...(438 AM EST MON NOV 23 2009)
THE WARMER THAN NORMAL TEMPERATURES WILL CONTINUE INTO MID WEEK AS
SOUTHERLY WINDS PREVAIL. THE CHANCE OF RAIN RETURNS BY TUESDAY
NIGHT INTO WEDNESDAY AS LOW PRESSURE ENTERS THE WESTERN GREAT
LAKES. IT WILL BECOME COOLER BEHIND THIS SYSTEM AND SOME SNOW COULD
MIX IN WITH THE RAIN BY LATE WEDNESDAY NIGHT INTO THANKSGIVING DAY.
AT THIS POINT LITTLE TO NO SNOW ACCUMULATION IS EXPECTED.
&&
.SHORT TERM...(1220 PM EST MON NOV 23 2009)
(THIS AFTERNOON)
UPDATED LAST HOUR TO NUDGE TEMPS UP IN THE SOUTH ALONG WITH LESS IN
THE WAY OF CLOUDS THERE AS WELL. MODEL GUIDANCE VIA THE RUC
CONTINUES TO SHOW CLOUDS CLEARING FROM SOUTH TO NORTH THIS AFTERNOON
AND THE TREND GOES ALONG WITH THIS GUIDANCE. RUC GUIDANCE SUGGESTS
THE CLEARING LINE WILL MAKE IT TO A ALMA TO MUSKEGON LINE BY SUNSET
AND THAT LOOKS VERY REASONABLE.
A FEW SHOWERS MAY TRY TO CLIP THE FAR SOUTHEAST CWA NEAR JACKSON.
HAVE NOT SEEN MUCH IN THE WAY OF PRECIPITATION IN THE OBS THOUGH.
THE SHOWERS ARE ASSOCIATED WITH A SHORTWAVE MOVING NORTHEAST OUT OF
THE OHIO VALLEY.
&&
.LONG TERM...(438 AM EST MON NOV 23 2009)
(WEDNESDAY NIGHT THROUGH SUNDAY)
100-130 KT UPPER LEVEL JET DIVING SOUTH FROM CENTRAL CANADA THROUGH
THE NRN PLAINS WILL HELP CARVE OUT A LONG WAVE TROUGH OVER THE GREAT
LAKES REGION FOR THANKSGIVING. THE RESULT WILL BE COLDER AIR AND
SHOWERY PCPN IN THE FORM OF MIXED RAIN AND SNOW SHOWERS.
WHILE THE AIR PROGGED AT H8 AROUND -5C SUPPORTS SNOW ON
THANKSGIVING...THE SFC TEMPS ARE STILL PROGGED TO BE NEAR 40F WHICH
SUPPORTS MOSTLY RAIN. THE BEST OPPORTUNITY TO EXPERIENCE ANY WET
SNOW WOULD BE THURSDAY NIGHT AND EARLY FRIDAY WHEN SFC TEMPS WILL BE
A LITTLE COOLER AND THE CLOSED UPPER LOW WILL STILL BE NEARBY.
NOTHING SIGNIFICANT IN TERMS OF ACCUMULATION IS EXPECTED AT THIS
POINT.
THE LONGWAVE TROUGH/COLD AIR IS PROGGED TO MOVE EAST OF THE AREA
FRIDAY AND FRIDAY NIGHT AS THE NEXT UPSTREAM SYSTEM DIGS INTO THE
NRN ROCKIES. UPPER RIDGING IN BETWEEN THESE TWO TROUGHS WILL RESIDE
OVER THE GREAT LAKES REGION SATURDAY AND SUNDAY...WHICH SHOULD
PROMOTE DRY CONDITIONS WITH SLIGHTLY ABOVE NORMAL TEMPS.
&&
.AVIATION...(650 AM EST MON NOV 23 2009)
WIDESPREAD IFR/LIFR STRATUS WITH BASES BELOW 1K FEET FORMED
OVERNIGHT AND WILL LIKELY LINGER THROUGH 14-16Z. IT/S UNCERTAIN
HOWEVER WHETHER THE STRATUS WILL TOTALLY SCATTER OUT AND GO VFR BY
18Z OR JUST GRADUALLY LIFT TO AN MVFR DECK WITH A FEW BREAKS IN IT.
HAVE OPTED TO FCST THE LATTER IN THE TAFS SINCE IT IS LATE NOVEMBER
AND THE SUN ANGLE DOES LITTLE TO HELP WITH MIXING OUT STRATUS.
IT IS WORTH NOTING THE IDEA SHOWN BY THE HRRR RUC MODEL AND THAT IS
THAT THE STRATUS WILL CLEAR FROM SOUTHEAST TO NORTHWEST THIS
MORNING. THIS SOLUTION IS CERTAINLY GAINING SOME CREDENCE SINCE
CURRENT SATELLITE FOG IMAGERY SHOWS THAT MOST OF OHIO IS FOG/STRATUS
FREE AND LOW LEVEL TRAJECTORIES ARE FROM THE SOUTHEAST. IF THIS
STARTS TO HAPPEN... WILL AMEND THE TAFS AND TIME THE CLEARING LINE
INTO THE AREA.
MORE FOG/STRATUS ISSUES ARE LIKELY AGAIN TONIGHT... WITH IFR
CATEGORY OR LOWER A POSSIBILITY AGAIN.
&&
.MARINE...(438 AM EST MON NOV 23 2009)
AREAS OF FOG WILL BE AN ISSUE EARLY THIS MORNING AND AGAIN LATE
TONIGHT. WINDS AND WAVES HOWEVER WILL REMAIN FAIRLY LOW...
ESPECIALLY FOR NOV.
&&
.HYDROLOGY...(438 AM EST MON NOV 23 2009)
RAINFALL FROM TUESDAY NIGHT AND WEDNESDAY WILL BE RATHER LIGHT WITH
MOST AREAS RECEIVING BETWEEN A QUARTER AND A HALF INCH OF RAIN.
THIS SHOULD HAVE LITTLE IMPACT ON HYDRO.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: JK
SHORT TERM: DUKE
LONG TERM: MEADE
AVIATION: MEADE
MARINE: JK
HYDROLOGY: JK
000
FXUS63 KAPX 231642
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1142 AM EST MON NOV 23 2009
.SYNOPSIS.../ISSUED AT 429 AM/
HIGH PRESSURE TO OUR EAST WILL MAINTAIN MILD AND QUIET WEATHER
THROUGH TUESDAY. LOW PRESSURE WILL START TO ORGANIZE IN THE CENTRAL
PLAINS TONIGHT...AND THEN SLOWLY MOVE TOWARD NORTHERN MICHIGAN THRU
THANKSGIVING DAY. THIS SYSTEM WILL BRING COOLER AND WETTER WEATHER
BY WEDNESDAY AND THURSDAY...THOUGH LITTLE IN THE WAY OF SNOW IS
EXPECTED.
JZ
&&
.SHORT TERM.../ISSUED AT 1035 AM/...TODAY
DEPARTING HIGH PRESSURE WILL REMAIN IN CONTROL OF NRN MICHIGAN/S
WEATHER THROUGH TODAY BEFORE GIVING WAY TO MORE UNSETTLE WEATHER
OVER THE NEXT FEW DAYS. PERSISTENT WITH THE LAST FEW MORNINGS...LOW
STRATUS/PATCHY FOG ONCE AGAIN WIDESPREAD ACROSS NRN MICHIGAN.
SHALLOW TO BE SURE...LESS THAN 1000 FEET IN DEPTH PER 12Z APX
SOUNDING. DIFFERENCE TODAY VERSUS THE LAST FEW DAYS RESTS IN WARM
ADVECTION HIGH CLOUD COVER WHICH HAS INCHED INTO THE STATE ON THE
BACKSIDE OF THE SLOWLY DEPARTING HIGH PRESSURE SYSTEM...AS WELL AS A
SLIGHTLY STRONGER INVERSION SITTING AT 900 MB. COMBINED...WILL BE A
BIT MORE DIFFICULT TO THIN/ERODE THE LOW STRATUS LAYER TODAY VERSUS
THE PREVIOUS FEW DAYS. HEATING/MIXING MAY ULTIMATELY THIN OUT THE
LOW LAYER TO SOME EXTENT. BUT HAVING SERIOUS DOUBTS ABOUT THAT AND
PLAN FOR NOW IS TO NUDGE THE FORECAST TOWARD THE CLOUDIER SIDE OF
THINGS...TODAY AS WELL AS THROUGH TONIGHT. THIS WILL OF COURSE HAVE
OBVIOUS IMPLICATIONS ON TODAY/S MAX TEMPS AND WILL TWEAK EXPECTED
HIGHS DOWNWARD ACCORDINGLY.
ADAM
&&
.LONG TERM.../ISSUED AT 429 AM/...TONIGHT AND BEYOND
HIGH PRESSURE AND DRY AIR OVER THE ERN LAKES TO REMAIN IN CONTROL
MONDAY NIGHT THROUGH TUESDAY AFTERNOON...WHILE A SRN PLAINS STORM
SYSTEM LIFTS INTO THE CENTRAL PLAINS AND AN UPPER TROUGH DIGS INTO
THE CENTRAL PLAINS. MODEL SOUNDINGS AND MSTR PROGS SHOW 850/500MB
RH LINGERING AROUND 40 PCT THRU 00Z WED. WILL CONTINUE A DRY FCST
OVER THE NRN LAKES MONDAY NIGHT AND TUESDAY. LOW TEMPS TUESDAY IN
THE MID 30S AS AIRMASS REMAINS UNCHANGED...AFTN TEMPS IN THE 45 TO
50 DEGREE RANGE AS SOME UPPER CLOUDS INCREASE OVER THE STATE IN
ADVANCE OF APPROACHING SFC AND UPPER LEVELS FEATURES.
TUESDAY NIGHT AND WEDNESDAY...CENTRAL PLAINS STORM SYSTEM LIFTS
NORTH INTO THE UPPER MIDWEST TUESDAY NIGHT BEFORE LIFTING NORTH INTO
THE STRAITS AND ERN UPPER MICHIGAN WEDNESDAY. MODEL SOUNDINGS AND
MSTR PROGS SHOWING MSTR INCREASE OVER THE NRN LAKES THROUGH THE PD
AS THE STORM SYSTEM LIFTS INTO NRN MI. 850/500MB RH WILL INCREASE TO
AROUND 80 PCT WHILE 850MB DEW PTS INCREASE FROM -8C TUESDAY TO 0C BY
12Z WEDNESDAY. MODEL SOUNDINGS SHOWING ABV FREEZING LAYER FROM THE
SFC TO ARND 4000 FT TUESDAY NIGHT...EXTENDING TO 5500 FEET
WEDNESDAY. THEREFORE PCPN ALL IN THE FORM OF RAIN THROUGH THIS
PERIOD. LOW TEMPS IN THE 30S TUESDAY NIGHT WITH HIGHS IN THE MID 40S
WEDNESDAY.
WEDNESDAY NIGHT AND THURSDAY...STORM SYSTEM OVER THE NRN LAKES
LINGERS BUT BECOMES STRETCHED OUT ACROSS THE STATE...AS THE LOW
TRIES TO LIFT NORTH TWD HUDSON BAY. THE DIGGING 500MB TROUGH DROPS
SOUTH OF THE STATE AND MOVES EAST OVER THE OHIO VALLEY. MODEL
SOUNDINGS SHOWING COLDEST 850MB AIR TO LINGER WEST OF THE REGION AND
SWEEP SOUTH ACROSS THE OHIO VALLEY. OVR NRN MI...850MB TEMPS DROP
FROM AROUND 0C/+1C WEDNESDAY NIGHT TO -3C THURSDAY. MODEL SOUNDINGS
SHOWING ABOVE FREEZING LAYER EXTENDING FROM THE SFC THRU 4K FT
WEDNESDAY NIGHT DROPPING TO AROUND 2500 FEET BY 00Z FRIDAY. WILL
TREND TWD ALL RAIN EVENT WEDNESDAY NIGHT AND MUCH OF THURSDAY
AFTERNOON. WILL MENTION A MIX RAIN/SNOW TO ALL SNOW THURSDAY
NIGHT...WHEN VERTICAL TEMP PROFILE ON SOUNDINGS SHOW ABV FREEZING
LAYER DROPPING UNDER 1500 FEET. HIGHS THURSDAY GENERALLY AROUND 40
MOST LOCATIONS.
SWR
&&
.MARINE.../ISSUED AT 429 AM/
WINDS AND WAVES EXPECTED TO REMAIN BELOW SCA CRITERIA TODAY
THROUGH TUESDAY...WITH WINDS PRIMARILY FROM THE SOUTHEAST.
STRONGEST WINDS AND HIGHEST WAVES TODAY EXPECTED IN THE STRAITS
AND BTWN THE BRIDGE AND DETOUR...HOWEVER EXPECTED TO REMAIN BELOW
SCA. FOG THIS MORNING TO DIMINISH AS SFC HIGH PRESSURE AND DRY AIR
LINGER ACROSS THE ERN LAKES. CLEARING SLOWEST OVER THE ERN LAKES
ONCE AGAIN TODAY WITH OVERALL SE FLOW ACROSS THE REGION AND LATE
NOV SUN ANGLE. NEXT CHANCE OF RAIN OVER THE NRN LAKES NEARSHORE
WATERS...WILL BE TUESDAY NIGHT AND WEDNESDAY AS A PLAINS STORM
SYSTEM LIFTS NORTH INTO NRN MI.
SWR
&&
.AVIATION.../ISSUED AT 1142 AM/...VALID FOR 18Z TAFS
WILL TREND CONSIDERABLY MORE PESSIMISTIC WITH THE FORECASTS...
PARTICULARLY IN REGARD TO CLOUD COVER. LOW STRATUS (IFR) ONCE
AGAIN DEVELOPED OVERNIGHT AND PERSISTS THIS MORNING. BUT UNLIKE
PREVIOUS DAYS...INCREASING WARM ADVECTION/STRENGTHENING INVERSION
AND INCREASING HIGH CLOUD COVER LIMITING HEATING...WILL CONSPIRE
TO KEEP STRATUS LAYER INTACT THROUGH TODAY AND POSSIBLY THROUGH
TONIGHT. THINNING/LIFTING OF THE LOW CLOUDS NOT COMPLETELY OUT OF
THE QUESTION...BUT NOT BANKING ON IT. THUS HIGH IFR/LOW MVFR
ANTICIPATED THROUGH THE PERIOD.
ADAM
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KAPX 231536
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1035 AM EST MON NOV 23 2009
.SYNOPSIS.../ISSUED AT 429 AM/
HIGH PRESSURE TO OUR EAST WILL MAINTAIN MILD AND QUIET WEATHER
THROUGH TUESDAY. LOW PRESSURE WILL START TO ORGANIZE IN THE CENTRAL
PLAINS TONIGHT...AND THEN SLOWLY MOVE TOWARD NORTHERN MICHIGAN THRU
THANKSGIVING DAY. THIS SYSTEM WILL BRING COOLER AND WETTER WEATHER
BY WEDNESDAY AND THURSDAY...THOUGH LITTLE IN THE WAY OF SNOW IS
EXPECTED.
JZ
&&
.SHORT TERM.../ISSUED AT 1035 AM/...TODAY
DEPARTING HIGH PRESSURE WILL REMAIN IN CONTROL OF NRN MICHIGAN/S
WEATHER THROUGH TODAY BEFORE GIVING WAY TO MORE UNSETTLE WEATHER
OVER THE NEXT FEW DAYS. PERSISTENT WITH THE LAST FEW MORNINGS...LOW
STRATUS/PATCHY FOG ONCE AGAIN WIDESPREAD ACROSS NRN MICHIGAN.
SHALLOW TO BE SURE...LESS THAN 1000 FEET IN DEPTH PER 12Z APX
SOUNDING. DIFFERENCE TODAY VERSUS THE LAST FEW DAYS RESTS IN WARM
ADVECTION HIGH CLOUD COVER WHICH HAS INCHED INTO THE STATE ON THE
BACKSIDE OF THE SLOWLY DEPARTING HIGH PRESSURE SYSTEM...AS WELL AS A
SLIGHTLY STRONGER INVERSION SITTING AT 900 MB. COMBINED...WILL BE A
BIT MORE DIFFICULT TO THIN/ERODE THE LOW STRATUS LAYER TODAY VERSUS
THE PREVIOUS FEW DAYS. HEATING/MIXING MAY ULTIMATELY THIN OUT THE
LOW LAYER TO SOME EXTENT. BUT HAVING SERIOUS DOUBTS ABOUT THAT AND
PLAN FOR NOW IS TO NUDGE THE FORECAST TOWARD THE CLOUDIER SIDE OF
THINGS...TODAY AS WELL AS THROUGH TONIGHT. THIS WILL OF COURSE HAVE
OBVIOUS IMPLICATIONS ON TODAY/S MAX TEMPS AND WILL TWEAK EXPECTED
HIGHS DOWNWARD ACCORDINGLY.
ADAM
&&
.LONG TERM.../ISSUED AT 429 AM/...TONIGHT AND BEYOND
HIGH PRESSURE AND DRY AIR OVER THE ERN LAKES TO REMAIN IN CONTROL
MONDAY NIGHT THROUGH TUESDAY AFTERNOON...WHILE A SRN PLAINS STORM
SYSTEM LIFTS INTO THE CENTRAL PLAINS AND AN UPPER TROUGH DIGS INTO
THE CENTRAL PLAINS. MODEL SOUNDINGS AND MSTR PROGS SHOW 850/500MB
RH LINGERING AROUND 40 PCT THRU 00Z WED. WILL CONTINUE A DRY FCST
OVER THE NRN LAKES MONDAY NIGHT AND TUESDAY. LOW TEMPS TUESDAY IN
THE MID 30S AS AIRMASS REMAINS UNCHANGED...AFTN TEMPS IN THE 45 TO
50 DEGREE RANGE AS SOME UPPER CLOUDS INCREASE OVER THE STATE IN
ADVANCE OF APPROACHING SFC AND UPPER LEVELS FEATURES.
TUESDAY NIGHT AND WEDNESDAY...CENTRAL PLAINS STORM SYSTEM LIFTS
NORTH INTO THE UPPER MIDWEST TUESDAY NIGHT BEFORE LIFTING NORTH INTO
THE STRAITS AND ERN UPPER MICHIGAN WEDNESDAY. MODEL SOUNDINGS AND
MSTR PROGS SHOWING MSTR INCREASE OVER THE NRN LAKES THROUGH THE PD
AS THE STORM SYSTEM LIFTS INTO NRN MI. 850/500MB RH WILL INCREASE TO
AROUND 80 PCT WHILE 850MB DEW PTS INCREASE FROM -8C TUESDAY TO 0C BY
12Z WEDNESDAY. MODEL SOUNDINGS SHOWING ABV FREEZING LAYER FROM THE
SFC TO ARND 4000 FT TUESDAY NIGHT...EXTENDING TO 5500 FEET
WEDNESDAY. THEREFORE PCPN ALL IN THE FORM OF RAIN THROUGH THIS
PERIOD. LOW TEMPS IN THE 30S TUESDAY NIGHT WITH HIGHS IN THE MID 40S
WEDNESDAY.
WEDNESDAY NIGHT AND THURSDAY...STORM SYSTEM OVER THE NRN LAKES
LINGERS BUT BECOMES STRETCHED OUT ACROSS THE STATE...AS THE LOW
TRIES TO LIFT NORTH TWD HUDSON BAY. THE DIGGING 500MB TROUGH DROPS
SOUTH OF THE STATE AND MOVES EAST OVER THE OHIO VALLEY. MODEL
SOUNDINGS SHOWING COLDEST 850MB AIR TO LINGER WEST OF THE REGION AND
SWEEP SOUTH ACROSS THE OHIO VALLEY. OVR NRN MI...850MB TEMPS DROP
FROM AROUND 0C/+1C WEDNESDAY NIGHT TO -3C THURSDAY. MODEL SOUNDINGS
SHOWING ABOVE FREEZING LAYER EXTENDING FROM THE SFC THRU 4K FT
WEDNESDAY NIGHT DROPPING TO AROUND 2500 FEET BY 00Z FRIDAY. WILL
TREND TWD ALL RAIN EVENT WEDNESDAY NIGHT AND MUCH OF THURSDAY
AFTERNOON. WILL MENTION A MIX RAIN/SNOW TO ALL SNOW THURSDAY
NIGHT...WHEN VERTICAL TEMP PROFILE ON SOUNDINGS SHOW ABV FREEZING
LAYER DROPPING UNDER 1500 FEET. HIGHS THURSDAY GENERALLY AROUND 40
MOST LOCATIONS.
SWR
&&
.MARINE.../ISSUED AT 429 AM/
WINDS AND WAVES EXPECTED TO REMAIN BELOW SCA CRITERIA TODAY
THROUGH TUESDAY...WITH WINDS PRIMARILY FROM THE SOUTHEAST.
STRONGEST WINDS AND HIGHEST WAVES TODAY EXPECTED IN THE STRAITS
AND BTWN THE BRIDGE AND DETOUR...HOWEVER EXPECTED TO REMAIN BELOW
SCA. FOG THIS MORNING TO DIMINISH AS SFC HIGH PRESSURE AND DRY AIR
LINGER ACROSS THE ERN LAKES. CLEARING SLOWEST OVER THE ERN LAKES
ONCE AGAIN TODAY WITH OVERALL SE FLOW ACROSS THE REGION AND LATE
NOV SUN ANGLE. NEXT CHANCE OF RAIN OVER THE NRN LAKES NEARSHORE
WATERS...WILL BE TUESDAY NIGHT AND WEDNESDAY AS A PLAINS STORM
SYSTEM LIFTS NORTH INTO NRN MI.
SWR
&&
.AVIATION.../ISSUED AT 645 AM/...VALID FOR 12Z TAFS
CURRENT SFC OBS SHOWING GENERALLY MVFR CIGS AND VSBYS OVR NRN MI
THIS MORNING...OCCASIONALLY IFR VSBYS AT KAPN. MVFR CONDS EXPECTED
TO IMPROVE TO VFR ARND 14Z/15Z OVER KPLN/KTVC AS SUN HELPS MIX DRIER
AIR TO SFC. SLOWER RECOVERY AT KAPN AS SFC WINDS TURN SE WITH MVFR
CIGS AND VSBY POSSIBLE THRU MUCH OF THE AFTN. FOG/STRATUS EXPECTED
TO REDEVELOP AGAIN TONIGHT...GENERALLY AFT 06Z.
SWR
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KGRR 231150
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
650 AM EST MON NOV 23 2009
LATEST UPDATE...AVIATION...
.SYNOPSIS...(438 AM EST MON NOV 23 2009)
THE WARMER THAN NORMAL TEMPERATURES WILL CONTINUE INTO MID WEEK AS
SOUTHERLY WINDS PREVAIL. THE CHANCE OF RAIN RETURNS BY TUESDAY
NIGHT INTO WEDNESDAY AS LOW PRESSURE ENTERS THE WESTERN GREAT
LAKES. IT WILL BECOME COOLER BEHIND THIS SYSTEM AND SOME SNOW COULD
MIX IN WITH THE RAIN BY LATE WEDNESDAY NIGHT INTO THANKSGIVING DAY.
AT THIS POINT LITTLE TO NO SNOW ACCUMULATION IS EXPECTED.
&&
.SHORT TERM...(438 AM EST MON NOV 23 2009)
(TODAY THROUGH WEDNESDAY)
THE MAIN FOCUS EARLY IN THE SHORT TERM WAS ON FOG POTENTIAL. THEN
ATTENTION TURNS TO THE RAIN CHANCES THAT WILL ARRIVE TUESDAY NIGHT
INTO WEDNESDAY.
LIGHT FOG WAS WIDESPREAD ACROSS THE CWA THIS MORNING...HOWEVER WINDS
OF 20-25 KNOTS IN THE BOUNDARY LAYER WAS KEEPING ANY DENSE FOG AT A
MINIMUM. THE MIXING HAS RESULTED IN A STRATUS DECK THAT COVERS MUCH
OF THE AREA EARLY THIS MORNING. THESE CLOUDS ARE RATHER SHALLOW AND
IT WILL BE A TOUGH CALL AS TO WHETHER THE LOW NOVEMBER SUN ANGLE
WILL BE ABLE TO BURN OFF THESE LOW CLOUDS THROUGH THE DAY. THIS
APPEARS MOST DOUBTFUL ACROSS AREAS SOUTH OF I-96 WHERE MOISTURE WILL
ADVECT NORTHWARD FROM THE WAVE OVER SOUTHERN OH. IN FACT...I HAVE
ADDED THE POSSIBILITY OF A SPRINKLE TO THE SE CWA BY LATE
AFTERNOON/EARLY EVENING. A FEW PEAKS OF THE SUN MAY OCCUR OVER THE
NE CWA HOWEVER...WHERE THE MOISTURE WILL REMAIN SHALLOW AND ENOUGH
MIXING MAY SCOUR OUT SOME OF THE CLOUDS.
BY LATE TONIGHT WEAK UPPER RIDGING WILL SLIDE THROUGH. THIS WILL
HELP RELAX THE PRESSURE GRADIENT AND FOG APPEARS LIKE A GOOD BET
AGAIN TONIGHT. THIS COULD BECOME DENSE ACROSS ANY AREA THAT BRIEFLY
CLEARS.
WILL REMOVE ALL POPS IN THE WESTERN CWA FOR TUESDAY AS A SLOWER
TREND CONTINUES WITH THE EJECTION OF THE PLAINS LOW. THIS SHOULD BE
ANOTHER REPEAT OF TODAY WHERE...WITH LITTLE FLOW...WE MAY STRUGGLE
TO SEE MUCH DAYTIME CLEARING.
A STACKED LOW PRESSURE WILL BE OVER SE IA BY TUESDAY EVENING. IT
WILL MOVE SLOWLY NE TO NORTHERN LAKE MICHIGAN BY WEDNESDAY EVENING.
WITH IT REMAINING TO OUR WEST WE WILL STAY ON IT/S WARM SIDE AND
ONLY RAIN IS EXPECTED INITIALLY. AS WITH SYSTEMS OF THIS TYPE...A
SLOWER SOLUTION USUALLY WINS OUT. SO HAVE BUMPED BACK THE
LIKELY/CATEGORICAL POPS UNTIL LATE TUESDAY NIGHT AND CONTINUED THEM
INTO WEDNESDAY. IT APPEARS THAT THE LEFT EXIT REGION OF THE UPPER
JET STAYS TO OUR WEST...SO HEAVY RAIN IS NOT EXPECTED.
&&
.LONG TERM...(438 AM EST MON NOV 23 2009)
(WEDNESDAY NIGHT THROUGH SUNDAY)
100-130 KT UPPER LEVEL JET DIVING SOUTH FROM CENTRAL CANADA THROUGH
THE NRN PLAINS WILL HELP CARVE OUT A LONG WAVE TROUGH OVER THE GREAT
LAKES REGION FOR THANKSGIVING. THE RESULT WILL BE COLDER AIR AND
SHOWERY PCPN IN THE FORM OF MIXED RAIN AND SNOW SHOWERS.
WHILE THE AIR PROGGED AT H8 AROUND -5C SUPPORTS SNOW ON
THANKSGIVING...THE SFC TEMPS ARE STILL PROGGED TO BE NEAR 40F WHICH
SUPPORTS MOSTLY RAIN. THE BEST OPPORTUNITY TO EXPERIENCE ANY WET
SNOW WOULD BE THURSDAY NIGHT AND EARLY FRIDAY WHEN SFC TEMPS WILL BE
A LITTLE COOLER AND THE CLOSED UPPER LOW WILL STILL BE NEARBY.
NOTHING SIGNIFICANT IN TERMS OF ACCUMULATION IS EXPECTED AT THIS
POINT.
THE LONGWAVE TROUGH/COLD AIR IS PROGGED TO MOVE EAST OF THE AREA
FRIDAY AND FRIDAY NIGHT AS THE NEXT UPSTREAM SYSTEM DIGS INTO THE
NRN ROCKIES. UPPER RIDGING IN BETWEEN THESE TWO TROUGHS WILL RESIDE
OVER THE GREAT LAKES REGION SATURDAY AND SUNDAY...WHICH SHOULD
PROMOTE DRY CONDITIONS WITH SLIGHTLY ABOVE NORMAL TEMPS.
&&
.AVIATION...(650 AM EST MON NOV 23 2009)
WIDESPREAD IFR/LIFR STRATUS WITH BASES BELOW 1K FEET FORMED
OVERNIGHT AND WILL LIKELY LINGER THROUGH 14-16Z. IT/S UNCERTAIN
HOWEVER WHETHER THE STRATUS WILL TOTALLY SCATTER OUT AND GO VFR BY
18Z OR JUST GRADUALLY LIFT TO AN MVFR DECK WITH A FEW BREAKS IN IT.
HAVE OPTED TO FCST THE LATTER IN THE TAFS SINCE IT IS LATE NOVEMBER
AND THE SUN ANGLE DOES LITTLE TO HELP WITH MIXING OUT STRATUS.
IT IS WORTH NOTING THE IDEA SHOWN BY THE HRRR RUC MODEL AND THAT IS
THAT THE STRATUS WILL CLEAR FROM SOUTHEAST TO NORTHWEST THIS
MORNING. THIS SOLUTION IS CERTAINLY GAINING SOME CREDENCE SINCE
CURRENT SATELLITE FOG IMAGERY SHOWS THAT MOST OF OHIO IS FOG/STRATUS
FREE AND LOW LEVEL TRAJECTORIES ARE FROM THE SOUTHEAST. IF THIS
STARTS TO HAPPEN... WILL AMEND THE TAFS AND TIME THE CLEARING LINE
INTO THE AREA.
MORE FOG/STRATUS ISSUES ARE LIKELY AGAIN TONIGHT... WITH IFR
CATEGORY OR LOWER A POSSIBILITY AGAIN.
&&
.MARINE...(438 AM EST MON NOV 23 2009)
AREAS OF FOG WILL BE AN ISSUE EARLY THIS MORNING AND AGAIN LATE
TONIGHT. WINDS AND WAVES HOWEVER WILL REMAIN FAIRLY LOW...
ESPECIALLY FOR NOV.
&&
.HYDROLOGY...(438 AM EST MON NOV 23 2009)
RAINFALL FROM TUESDAY NIGHT AND WEDNESDAY WILL BE RATHER LIGHT WITH
MOST AREAS RECEIVING BETWEEN A QUARTER AND A HALF INCH OF RAIN.
THIS SHOULD HAVE LITTLE IMPACT ON HYDRO.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: JK
SHORT TERM: JK
LONG TERM: MEADE
AVIATION: MEADE
MARINE: JK
HYDROLOGY: JK
000
FXUS63 KAPX 231147
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
645 AM EST MON NOV 23 2009
.SYNOPSIS.../ISSUED AT 429 AM/
HIGH PRESSURE TO OUR EAST WILL MAINTAIN MILD AND QUIET WEATHER
THROUGH TUESDAY. LOW PRESSURE WILL START TO ORGANIZE IN THE CENTRAL
PLAINS TONIGHT...AND THEN SLOWLY MOVE TOWARD NORTHERN MICHIGAN THRU
THANKSGIVING DAY. THIS SYSTEM WILL BRING COOLER AND WETTER WEATHER
BY WEDNESDAY AND THURSDAY...THOUGH LITTLE IN THE WAY OF SNOW IS
EXPECTED.
JZ
&&
.SHORT TERM.../ISSUED AT 429 AM/...TODAY
PERSISTENT FOR THE PAST SEVERAL NIGHTS...LOCAL OBS SHOWING AREAS OF
FOG ACROSS MUCH OF NRN MI...WITH VSBYS RANGING FROM 1 MILE TO 5
MILES. DO NOT EXPECT WIDESPREAD DENSE FOG THIS MORNING...AS SOME MID
AND UPPER LEVEL CLOUD COVER SPREAD INTO THE REGION COMBINED WITH SE
WINDS BTWN 5 AND 10 MPH. HOWEVER WILL KEEP A MENTION OF MORNING FOG
IN MOST ZONES EARLY THIS MORNING.
OTHERWISE HIGH PRESSURE STRETCHING FROM THE NORTH ATLANTIC INTO THE
ERN LAKES...TO REMAIN A DOMINATE FEATURE THROUGH THE AFTN. DRY AIR
ASSOCIATED WITH THIS SYSTEM WILL REMAIN AN INFLUENCE OVER MUCH OF
THE STATE...AS 850/500MB RH LINGERS AROUND 30 PCT WHILE SFC DEW PTS
LINGER IN THE UPPER 30S AND 850MB DEW PT REMAIN BELOW 0C. OVERALL
AIRMASS AND SYNOPTIC PATTERN OVER THE NRN LAKES TODAY...SIMILAR TO
SUNDAY...SO WILL TREND FORECAST TODAY TWDS SUNDAYS OUTCOME. OVERALL
EXPECT MOSTLY SUNNY SKIES ONCE AGAIN TODAY WITH HIGHS WARMING INTO
THE 50S. WINDS TURN MORE TWD THE SE THIS AFTN...SO WILL MENTION
COOLEST TEMPS OVER THE ERN LAKES WITH SLIGHTLY WARMER TEMPS OVR THE
WRN LAKES DO TO DOWNSLOPING.
SWR
&&
.LONG TERM.../ISSUED AT 429 AM/...TONIGHT AND BEYOND
HIGH PRESSURE AND DRY AIR OVER THE ERN LAKES TO REMAIN IN CONTROL
MONDAY NIGHT THROUGH TUESDAY AFTERNOON...WHILE A SRN PLAINS STORM
SYSTEM LIFTS INTO THE CENTRAL PLAINS AND AN UPPER TROUGH DIGS INTO
THE CENTRAL PLAINS. MODEL SOUNDINGS AND MSTR PROGS SHOW 850/500MB
RH LINGERING AROUND 40 PCT THRU 00Z WED. WILL CONTINUE A DRY FCST
OVER THE NRN LAKES MONDAY NIGHT AND TUESDAY. LOW TEMPS TUESDAY IN
THE MID 30S AS AIRMASS REMAINS UNCHANGED...AFTN TEMPS IN THE 45 TO
50 DEGREE RANGE AS SOME UPPER CLOUDS INCREASE OVER THE STATE IN
ADVANCE OF APPROACHING SFC AND UPPER LEVELS FEATURES.
TUESDAY NIGHT AND WEDNESDAY...CENTRAL PLAINS STORM SYSTEM LIFTS
NORTH INTO THE UPPER MIDWEST TUESDAY NIGHT BEFORE LIFTING NORTH INTO
THE STRAITS AND ERN UPPER MICHIGAN WEDNESDAY. MODEL SOUNDINGS AND
MSTR PROGS SHOWING MSTR INCREASE OVER THE NRN LAKES THROUGH THE PD
AS THE STORM SYSTEM LIFTS INTO NRN MI. 850/500MB RH WILL INCREASE TO
AROUND 80 PCT WHILE 850MB DEW PTS INCREASE FROM -8C TUESDAY TO 0C BY
12Z WEDNESDAY. MODEL SOUNDINGS SHOWING ABV FREEZING LAYER FROM THE
SFC TO ARND 4000 FT TUESDAY NIGHT...EXTENDING TO 5500 FEET
WEDNESDAY. THEREFORE PCPN ALL IN THE FORM OF RAIN THROUGH THIS
PERIOD. LOW TEMPS IN THE 30S TUESDAY NIGHT WITH HIGHS IN THE MID 40S
WEDNESDAY.
WEDNESDAY NIGHT AND THURSDAY...STORM SYSTEM OVER THE NRN LAKES
LINGERS BUT BECOMES STRETCHED OUT ACROSS THE STATE...AS THE LOW
TRIES TO LIFT NORTH TWD HUDSON BAY. THE DIGGING 500MB TROUGH DROPS
SOUTH OF THE STATE AND MOVES EAST OVER THE OHIO VALLEY. MODEL
SOUNDINGS SHOWING COLDEST 850MB AIR TO LINGER WEST OF THE REGION AND
SWEEP SOUTH ACROSS THE OHIO VALLEY. OVR NRN MI...850MB TEMPS DROP
FROM AROUND 0C/+1C WEDNESDAY NIGHT TO -3C THURSDAY. MODEL SOUNDINGS
SHOWING ABOVE FREEZING LAYER EXTENDING FROM THE SFC THRU 4K FT
WEDNESDAY NIGHT DROPPING TO AROUND 2500 FEET BY 00Z FRIDAY. WILL
TREND TWD ALL RAIN EVENT WEDNESDAY NIGHT AND MUCH OF THURSDAY
AFTERNOON. WILL MENTION A MIX RAIN/SNOW TO ALL SNOW THURSDAY
NIGHT...WHEN VERTICAL TEMP PROFILE ON SOUNDINGS SHOW ABV FREEZING
LAYER DROPPING UNDER 1500 FEET. HIGHS THURSDAY GENERALLY AROUND 40
MOST LOCATIONS.
SWR
&&
.MARINE.../ISSUED AT 429 AM/
WINDS AND WAVES EXPECTED TO REMAIN BELOW SCA CRITERIA TODAY
THROUGH TUESDAY...WITH WINDS PRIMARILY FROM THE SOUTHEAST.
STRONGEST WINDS AND HIGHEST WAVES TODAY EXPECTED IN THE STRAITS
AND BTWN THE BRIDGE AND DETOUR...HOWEVER EXPECTED TO REMAIN BELOW
SCA. FOG THIS MORNING TO DIMINISH AS SFC HIGH PRESSURE AND DRY AIR
LINGER ACROSS THE ERN LAKES. CLEARING SLOWEST OVER THE ERN LAKES
ONCE AGAIN TODAY WITH OVERALL SE FLOW ACROSS THE REGION AND LATE
NOV SUN ANGLE. NEXT CHANCE OF RAIN OVER THE NRN LAKES NEARSHORE
WATERS...WILL BE TUESDAY NIGHT AND WEDNESDAY AS A PLAINS STORM
SYSTEM LIFTS NORTH INTO NRN MI.
SWR
&&
.AVIATION.../ISSUED AT 645 AM/...VALID FOR 12Z TAFS
CURRENT SFC OBS SHOWING GENERALLY MVFR CIGS AND VSBYS OVR NRN MI
THIS MORNING...OCCASIONALLY IFR VSBYS AT KAPN. MVFR CONDS EXPECTED
TO IMPROVE TO VFR ARND 14Z/15Z OVER KPLN/KTVC AS SUN HELPS MIX DRIER
AIR TO SFC. SLOWER RECOVERY AT KAPN AS SFC WINDS TURN SE WITH MVFR
CIGS AND VSBY POSSIBLE THRU MUCH OF THE AFTN. FOG/STRATUS EXPECTED
TO REDEVELOP AGAIN TONIGHT...GENERALLY AFT 06Z.
SWR
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KMQT 231130 AAA
AFDMQT
AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE MARQUETTE MI
630 AM EST MON NOV 23 2009
UPDATED FOR 12Z TAF ISSUANCE
.DISCUSSION...
.TODAY THROUGH TUESDAY...SURFACE RIDGING EXTENDING WESTWARD FROM
NOVA SCOTIA CONTINUES TO INFLUENCE THE GREAT LAKES. LATEST WV
IMAGERY SHOWS MOISTURE STREAMING NORTHEASTWARD AROUND THE
PERIPHERY OF THIS RIDGE AS A COLD FRONT TRACKS EAST ACROSS THE
SOUTHERN CANADIAN PRAIRIES...REMAINING NORTHWEST OF UPPER
MICHIGAN. BROAD AREA OF SHOWERS HAVE DEVELOPED WITHIN THIS
MOISTURE PLUME AIDED BY WEAK ISENTROPIC LIFT NOTED ON 305
THETA-E/PRESSURE ANALYSIS. SHORT TERM GUIDANCE AGREES THESE
SHOWERS WILL REMAIN WEST OF LINE FROM L`ANSE TO WATERSMEET...WITH
THE HEAVIER SHOWERS REMAINING OFFSHORE. EXPECT CLOUDS TO REMAIN
OVER THE FAR WEST MOST OF THE DAY WITH PARTIAL CLEARING AND
PERIODS OF SUNSHINE EXPECTED OVER THE REMAINDER OF UPPER MICHIGAN.
EXPECT AREAS OF DENSE FOG EARLY THIS MORNING UNDER THIS CLEARING.
THIS SHOULD ALSO ALLOW FOR ANOTHER MILD DAY WITH HIGH TEMPERATURES
IN THE LOW 50S...SOME 15 TO 20 DEGREES ABOVE NORMAL. A WEAK S/W
TROUGH NOTED IN THE 500MB FLOW WILL PASS THROUGH THE CWA
TONIGHT...HOWEVER WITH LIMITED MOISTURE DON/T EXPECT MEASURABLE
RAINFALL. IN FACT EXPECT A DRY FORECAST THROUGH TUESDAY.
.TUESDAY NIGHT INTO FRIDAY...BY TUESDAY NIGHT ATTENTION TURNS TO
S/W TROUGH CURRENTLY SITUATED OVER EASTERN COLORADO. THIS FEATURE
IS PROGGED TO SHIFT NORTHEAST OUT THE CENTRAL PLAINS ON
TUESDAY...CROSSING NORTHERN LAKE MICHIGAN ON WEDNESDAY NIGHT WHILE
STRENGTHENING SLIGHTLY. GOING FORECAST APPEARS TO HANDLE
INCREASING POPS WELL...WITH LIKELY POPS BY WEDNESDAY AS DEEPER
MOISTURE/BEST 500MB HEIGHT FALLS ARRIVE OVER UPPER MICHIGAN. MAIN
CHANGES WERE RELATED TO RAIN/SNOW COVERAGE. ATTM IT APPEARS THE
EASTERN ZONES WILL STAY MOSTLY RAIN PER BUFKIT SOUNDINGS/CRITICAL
THICKNESS VALUES. COLD AIR IS LACKING AND IN FACT THE NECESSARY
COLD AIR IS SITUATED WELL TO OUR NORTH ON WEDNESDAY OVER HUDSON
BAY AND NORTHERN MANITOBA. EXPECT SOME SNOW FLAKES THOUGH BY
WEDNESDAY NIGHT OVER SOME OF THE HIGHER TERRAIN AIDED BY DIABATIC
COOLING PROCESSES WITH A RAIN/SNOW MIX ELSEWHERE EXCEPT THE EAST
WHERE ALL RAIN IS EXPECTED THROUGH THURSDAY. ADJUSTED WORDING IN
HWO TO REFLECT LESSER POTENTIAL FOR SIGNIFICANT ACCUMULATING
SNOWFALL.
STILL DISAGREEMENT AMONG LONG TERM GUIDANCE MODELS AS TO WHETHER
ENOUGH COLD AIR IS AVAILABLE FOR LAKE EFFECT SNOW BEHIND THIS
SYSTEM. 23/00Z GFS GUIDANCE BRINGS 850MB TEMPERATURES AS COLD AS
-9C...WHICH GIVEN THE CURRENT LAKE SUPERIOR WATER TEMPERATURE OF
5C WOULD BE JUST ENOUGH FOR LAKE PROCESSES TO BEGIN. THE PREFERRED
ECMWF SOLUTION OFFERS A MUCH WARMER AIRMASS WITH 850MB
TEMPERATURES NEVER FALLING BELOW -4C. A QUICK GLANCE AT 850MB
TEMPERATURES ACROSS THE NORTHERN HEMISPHERE SHOWS COLD AIR IS
NOWHERE TO BE FOUND OVER THE WESTERN HEMISPHERE WITH VIRTUALLY ALL
THE COLD AIR...-20 OR COLDER...LOCKED UP OVER SIBERIA.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
EXPECT LO CLDS/FOG THIS MRNG TO IMPACT BOTH SAW/CMX THIS MRNG WITH
MOIST SSE FLOW ARND HI PRES TO THE E. COMBINATION OF SOME DAYTIME
HEATING/DRY ADVECTION IN THE H95-9 LYR SHOULD RESULT IN GRADUAL
IMPROVEMENT SO THAT A PD OF VFR CONDITIONS IS LIKELY IN THE AFTN.
MORE FOG/ST WL REDEVELOP AGAIN THIS EVNG WITH LGT WINDS/NOCTURNAL
COOLING. PLAN ON THE WORST LIFR CONDITIONS AT SAW AFT MIDNIGHT WITH
FAVORABLE UPSLOPE SE FLOW.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
EXPECT HI PRES TO REMAIN NEARLY STATIONARY OVER SE CANADA AND THE
NE STATES INTO WED WHILE LO PRES DEVELOPING IN THE PLAINS MOVES
SLOWLY NE TO WISCONSIN. WINDS WILL BE UNDER 25 KTS THRU THIS TIME.
AS THE HI FINALLY RETREATS...THE LO CENTER WILL MOVE GRADUALLY E TO
OVER SE ONTARIO ON FRI. PLAN ON A PERIOD OF STRONGER N WINDS TO 30
KTS ON WED NIGHT INTO FRI ON THE NW FLANK OF THIS LO. SINCE THIS LO
NOW APPEARS WILL DEVELOP MORE SLOWLY THAN EXPECTED BEFORE...THE N
GALES PREVIOUSLY FORECAST APPEAR LESS LIKELY. LOOK FOR A HI PRES
RIDGE TO BUILD TOWARD THE WESTERN GREAT LAKES ON FRI AND BRING
DIMINISHING WINDS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
DISCUSSION...PEARSON
AVIATION...KC
MARINE...KC
000
FXUS63 KDTX 231057
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
557 AM EST MON NOV 23 2009
.AVIATION...
PRETTY WIDE AREA OF LOW STRATUS HAS FORMED AGAIN OVERNIGHT...BUT THE
RAGGED EASTERN EDGE JUST HAPPENS TO FALL NEAR DTW/DET...SO THE EARLY
PART OF THE FORECAST COULD SEE WIDELY VARYING CONDITIONS AT THESE
TWO SITES. MBS/FNT ARE DEEPER INTO THIS STRATUS DECK AND WILL REMAIN
IFR UNTIL MIDDAY AS THIS LOW LEVEL MOISTURE BURNS OFF/MIXES OUT. PTK
WILL PROBABLY REMAIN IFR AS WELL...BUT MAY BREAK OUT A BIT EARLIER
IN THE MID/LATE MORNING. AS LOW PRESSURE TO THE SOUTH EDGES SLOWLY
IN THIS DIRECTION...THE MOIST SOUTHEAST FLOW WILL PERSIST...SO ANY
CLEARING DURING THE DAY WILL BE REPLACED BY THE RE-EXPANSION OF THE
STRATUS BACK OVER THE AREA FROM LATE EVENING ON INTO THE OVERNIGHT
HOURS. SO...PERSISTENCE WILL BE THE FORECAST TO END THIS FORECAST
PERIOD.
&&
.PREV DISCUSSION...ISSUED 341 AM EST MON NOV 23 2009
SHORT TERM...TODAY
LOW STRATUS/AREAS OF FOG WILL BE PREVALENT AGAIN THIS MORNING...AND
EXPECT IT TO TAKE MUCH OF THE MORNING TO BURN THIS OFF. EVEN BY THE
AFTERNOON...SKIES WILL BE PARTLY/MOSTLY CLOUDY AS CLOUDS LIFT NORTH
INTO THE REGION AS LOW PRESSURE BEGINS EDGING TOWARDS THE AREA. THE
HIGHS WILL CLIMB TO BETWEEN 50 AND 55 DEGREES AGAIN...SO NO MAJOR
CHANGES WILL BE NEEDED TO THE GOING FORECAST.
LONG TERM...TONIGHT THROUGH NEXT SUNDAY
ONE MORE MORNING OF FOG TO AFFECT LOWER MICHIGAN BEFORE THE NEXT
STORM SYSTEM MOVES IN...BRINGING RAIN AND SNOW WITH IT. HIGH
PRESSURE STRETCHING FROM THE GREAT LAKES TO THE NEW ENGLAND STATES
WILL CONTINUE ITS TRACK EASTWARD THROUGH TUESDAY WHEN IT WILL
FINALLY LOSE ITS INFLUENCE ON THE WEATHER IN SE MICHIGAN. THE
HIGH PRESSURE WILL AGAIN GIVE US A WEAK EASTERLY WIND FIELD OFF THE
LAKES REINFORCING THE ALREADY HIGH MOISTURE VALUES IN THE LOW
LEVELS. SURFACE DEWPOINTS WILL REMAIN NEAR 40F UNDER A STRONG
INVERSION LOCATED AROUND 975MB. MODEL SOUNDINGS SHOW HIGHER
POTENTIAL TO THE NORTH AROUND FNT/MBS BUT DUE TO THE PERSISTENCE OF
THIS PATTERN WITH MOISTURE AMOUNTS AND FOG DEVELOPMENT...WILL LEAVE
MENTION FOR ALL AREAS.
MODELS COMING INTO BETTER AGREEMENT WITH EACH NEW RUN RECENTLY IN
REGARDS TO THE MID WEEK STORM SYSTEM HEADING FOR THE GREAT LAKES
REGION. THE GFS IS TRENDING A BIT SLOWER EACH RUN BECOMING MORE IN
PHASE WITH THE ECMWF...WHICH HAS BEEN THE MOST CONSISTENT MODEL IN
HANDLING THIS SYSTEM. THE NAM DIGS THE TROUGH/LOW DEEPER INTO THE
PLAINS THEN BOTH THE GFS AND ECMWF WHICH ALSO ACTS TO SLOW IT DOWN.
THIS SURFACE LOW SHOULD TRACK NORTH ALONG LAKE MICHIGAN ON WEDNESDAY
LEADING TO PRECIP CHANCES BEGINNING OVERNIGHT TUESDAY. THIS INITIAL
UPPER WAVE LOOKS TO WEAKEN A BIT AS IT MOVES OVER MI BUT WILL BE
QUICKLY REINFORCED BY A SECOND STRONGER WAVE DIGGING INTO THE
CENTRAL PLAINS FROM THE NORTHERN BRANCH OF THE JET STREAM ON
WEDNESDAY. MODELS ARE ONCE AGAIN SHOWING A FAIRLY COLD AIRMASS BEING
BROUGHT IN WITH THIS SECOND IMPULSE. 850MB TEMPS AROUND -5C ARE
BEING ADVERTISED FOR THURSDAY INTO FRIDAY WITH MOST MODELS
NOW...GFS/DGEX/ECMWF. TEMPS HAVE ALREADY BEEN HEDGED LOWER TO TAKE
THIS INTO ACCOUNT SO WILL WAIT TO SEE IF THIS BECOMES A MORE
CONSISTENT SOLUTION BEFORE ACTING FURTHER ON IT. AS THE MODELS SEEM
SLOWER WITH EACH SUCCESSIVE RUN...STILL BELIEVE THANKSGIVING DAY
WILL BE A RAIN EVENT CHANGING OVER TO RAIN/SNOW OVERNIGHT INTO
FRIDAY THOUGH AMOUNTS SHOULD STAY ON THE LOW SIDE.
UPPER LEVEL RIDGING WILL MOVE IN BEHIND THIS SYSTEM ON SATURDAY
PUTTING AN END TO PRECIP CHANCES ALTHOUGH IT LOOKS LIKE THE COLDER
TEMPS...HIGHS IN THE LOWER 40S...WILL REMAIN WITH US.
MARINE...
LIGHT SOUTHEAST WINDS WILL INCREASE SLIGHTLY INTO TUESDAY AS HIGH
PRESSURE RETREATS EAST...AWAY FROM THE AREA. THE PATTERN BECOMES
MORE ACTIVE MID/LATE NEXT WEEK AS AN UPPER LEVEL STORM SYSTEM LIFTS
INTO THE REGION LATE TUESDAY INTO WEDNESDAY AND BRINGS THE CHANCE OF
RAIN AS WELL AS INCREASED WINDS. ANOTHER MORE AGGRESSIVE DISTURBANCE
WILL THEN DIVE SOUTHEAST INTO THE SOUTHERN GREAT LAKES AND OHIO
VALLEY BRINGING COLDER TEMPERATURES AND A MIX OF RAIN/SNOW SHOWERS
LATE IN THE WEEK. WINDS/WAVES WILL BE MUCH MORE TURBULENT AS THIS
SYSTEM WAFFLES THROUGH THE AREA.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....DG
SHORT TERM...DG
LONG TERM....DRK
MARINE.......DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KGRR 230938
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
438 AM EST MON NOV 23 2009
LATEST UPDATE...SHORT TERM...
.SYNOPSIS...(438 AM EST MON NOV 23 2009)
THE WARMER THAN NORMAL TEMPERATURES WILL CONTINUE INTO MID WEEK AS
SOUTHERLY WINDS PREVAIL. THE CHANCE OF RAIN RETURNS BY TUESDAY
NIGHT INTO WEDNESDAY AS LOW PRESSURE ENTERS THE WESTERN GREAT
LAKES. IT WILL BECOME COOLER BEHIND THIS SYSTEM AND SOME SNOW COULD
MIX IN WITH THE RAIN BY LATE WEDNESDAY NIGHT INTO THANKSGIVING DAY.
AT THIS POINT LITTLE TO NO SNOW ACCUMULATION IS EXPECTED.
&&
.SHORT TERM...(438 AM EST MON NOV 23 2009)
(TODAY THROUGH WEDNESDAY)
THE MAIN FOCUS EARLY IN THE SHORT TERM WAS ON FOG POTENTIAL. THEN
ATTENTION TURNS TO THE RAIN CHANCES THAT WILL ARRIVE TUESDAY NIGHT
INTO WEDNESDAY.
LIGHT FOG WAS WIDESPREAD ACROSS THE CWA THIS MORNING...HOWEVER WINDS
OF 20-25 KNOTS IN THE BOUNDARY LAYER WAS KEEPING ANY DENSE FOG AT A
MINIMUM. THE MIXING HAS RESULTED IN A STRATUS DECK THAT COVERS MUCH
OF THE AREA EARLY THIS MORNING. THESE CLOUDS ARE RATHER SHALLOW AND
IT WILL BE A TOUGH CALL AS TO WHETHER THE LOW NOVEMBER SUN ANGLE
WILL BE ABLE TO BURN OFF THESE LOW CLOUDS THROUGH THE DAY. THIS
APPEARS MOST DOUBTFUL ACROSS AREAS SOUTH OF I-96 WHERE MOISTURE WILL
ADVECT NORTHWARD FROM THE WAVE OVER SOUTHERN OH. IN FACT...I HAVE
ADDED THE POSSIBILITY OF A SPRINKLE TO THE SE CWA BY LATE
AFTERNOON/EARLY EVENING. A FEW PEAKS OF THE SUN MAY OCCUR OVER THE
NE CWA HOWEVER...WHERE THE MOISTURE WILL REMAIN SHALLOW AND ENOUGH
MIXING MAY SCOUR OUT SOME OF THE CLOUDS.
BY LATE TONIGHT WEAK UPPER RIDGING WILL SLIDE THROUGH. THIS WILL
HELP RELAX THE PRESSURE GRADIENT AND FOG APPEARS LIKE A GOOD BET
AGAIN TONIGHT. THIS COULD BECOME DENSE ACROSS ANY AREA THAT BRIEFLY
CLEARS.
WILL REMOVE ALL POPS IN THE WESTERN CWA FOR TUESDAY AS A SLOWER
TREND CONTINUES WITH THE EJECTION OF THE PLAINS LOW. THIS SHOULD BE
ANOTHER REPEAT OF TODAY WHERE...WITH LITTLE FLOW...WE MAY STRUGGLE
TO SEE MUCH DAYTIME CLEARING.
A STACKED LOW PRESSURE WILL BE OVER SE IA BY TUESDAY EVENING. IT
WILL MOVE SLOWLY NE TO NORTHERN LAKE MICHIGAN BY WEDNESDAY EVENING.
WITH IT REMAINING TO OUR WEST WE WILL STAY ON IT/S WARM SIDE AND
ONLY RAIN IS EXPECTED INITIALLY. AS WITH SYSTEMS OF THIS TYPE...A
SLOWER SOLUTION USUALLY WINS OUT. SO HAVE BUMPED BACK THE
LIKELY/CATEGORICAL POPS UNTIL LATE TUESDAY NIGHT AND CONTINUED THEM
INTO WEDNESDAY. IT APPEARS THAT THE LEFT EXIT REGION OF THE UPPER
JET STAYS TO OUR WEST...SO HEAVY RAIN IS NOT EXPECTED.
&&
.LONG TERM...(438 AM EST MON NOV 23 2009)
(WEDNESDAY NIGHT THROUGH SUNDAY)
100-130 KT UPPER LEVEL JET DIVING SOUTH FROM CENTRAL CANADA THROUGH
THE NRN PLAINS WILL HELP CARVE OUT A LONG WAVE TROUGH OVER THE GREAT
LAKES REGION FOR THANKSGIVING. THE RESULT WILL BE COLDER AIR AND
SHOWERY PCPN IN THE FORM OF MIXED RAIN AND SNOW SHOWERS.
WHILE THE AIR PROGGED AT H8 AROUND -5C SUPPORTS SNOW ON
THANKSGIVING...THE SFC TEMPS ARE STILL PROGGED TO BE NEAR 40F WHICH
SUPPORTS MOSTLY RAIN. THE BEST OPPORTUNITY TO EXPERIENCE ANY WET
SNOW WOULD BE THURSDAY NIGHT AND EARLY FRIDAY WHEN SFC TEMPS WILL BE
A LITTLE COOLER AND THE CLOSED UPPER LOW WILL STILL BE NEARBY.
NOTHING SIGNIFICANT IN TERMS OF ACCUMULATION IS EXPECTED AT THIS
POINT.
THE LONGWAVE TROUGH/COLD AIR IS PROGGED TO MOVE EAST OF THE AREA
FRIDAY AND FRIDAY NIGHT AS THE NEXT UPSTREAM SYSTEM DIGS INTO THE
NRN ROCKIES. UPPER RIDGING IN BETWEEN THESE TWO TROUGHS WILL RESIDE
OVER THE GREAT LAKES REGION SATURDAY AND SUNDAY...WHICH SHOULD
PROMOTE DRY CONDITIONS WITH SLIGHTLY ABOVE NORMAL TEMPS.
&&
.AVIATION...(1200 AM EST MON NOV 23 2009)
SOME LOW CLOUDS HAVE FORMED DOWNWIND OF LAKE ERIE AND WITH SOUTHEAST
FLOW AROUND THE HIGH PRESSURE...THESE CLOUDS SHOULD BE AFFECTING
JXN...AZO AND BTL AFTER 06Z AND AREAS FURTHER NORTH LATER TONIGHT.
THE CLOUDS...ALONG WITH SOME HIGHER WINDS WILL MEAN LESS FOG
FORMATION THAN LAST NIGHT. FOG AND LOW CLOUDS SHOULD MIX OUT BY 15Z.
&&
.MARINE...(438 AM EST MON NOV 23 2009)
AREAS OF FOG WILL BE AN ISSUE EARLY THIS MORNING AND AGAIN LATE
TONIGHT. WINDS AND WAVES HOWEVER WILL REMAIN FAIRLY LOW...
ESPECIALLY FOR NOV.
&&
.HYDROLOGY...(438 AM EST MON NOV 23 2009)
RAINFALL FROM TUESDAY NIGHT AND WEDNESDAY WILL BE RATHER LIGHT WITH
MOST AREAS RECEIVING BETWEEN A QUARTER AND A HALF INCH OF RAIN.
THIS SHOULD HAVE LITTLE IMPACT ON HYDRO.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: JK
SHORT TERM: JK
LONG TERM: MEADE
AVIATION: OSTUNO
MARINE: JK
HYDROLOGY: JK
000
FXUS63 KAPX 230928
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
428 AM EST MON NOV 23 2009
.SYNOPSIS.../ISSUED AT 429 AM/
HIGH PRESSURE TO OUR EAST WILL MAINTAIN MILD AND QUIET WEATHER
THROUGH TUESDAY. LOW PRESSURE WILL START TO ORGANIZE IN THE CENTRAL
PLAINS TONIGHT...AND THEN SLOWLY MOVE TOWARD NORTHERN MICHIGAN THRU
THANKSGIVING DAY. THIS SYSTEM WILL BRING COOLER AND WETTER WEATHER
BY WEDNESDAY AND THURSDAY...THOUGH LITTLE IN THE WAY OF SNOW IS
EXPECTED.
JZ
&&
.SHORT TERM.../ISSUED AT 429 AM/...TODAY
PERSISTENT FOR THE PAST SEVERAL NIGHTS...LOCAL OBS SHOWING AREAS OF
FOG ACROSS MUCH OF NRN MI...WITH VSBYS RANGING FROM 1 MILE TO 5
MILES. DO NOT EXPECT WIDESPREAD DENSE FOG THIS MORNING...AS SOME MID
AND UPPER LEVEL CLOUD COVER SPREAD INTO THE REGION COMBINED WITH SE
WINDS BTWN 5 AND 10 MPH. HOWEVER WILL KEEP A MENTION OF MORNING FOG
IN MOST ZONES EARLY THIS MORNING.
OTHERWISE HIGH PRESSURE STRETCHING FROM THE NORTH ATLANTIC INTO THE
ERN LAKES...TO REMAIN A DOMINATE FEATURE THROUGH THE AFTN. DRY AIR
ASSOCIATED WITH THIS SYSTEM WILL REMAIN AN INFLUENCE OVER MUCH OF
THE STATE...AS 850/500MB RH LINGERS AROUND 30 PCT WHILE SFC DEW PTS
LINGER IN THE UPPER 30S AND 850MB DEW PT REMAIN BELOW 0C. OVERALL
AIRMASS AND SYNOPTIC PATTERN OVER THE NRN LAKES TODAY...SIMILAR TO
SUNDAY...SO WILL TREND FORECAST TODAY TWDS SUNDAYS OUTCOME. OVERALL
EXPECT MOSTLY SUNNY SKIES ONCE AGAIN TODAY WITH HIGHS WARMING INTO
THE 50S. WINDS TURN MORE TWD THE SE THIS AFTN...SO WILL MENTION
COOLEST TEMPS OVER THE ERN LAKES WITH SLIGHTLY WARMER TEMPS OVR THE
WRN LAKES DO TO DOWNSLOPING.
SWR
&&
.LONG TERM.../ISSUED AT 429 AM/...TONIGHT AND BEYOND
HIGH PRESSURE AND DRY AIR OVER THE ERN LAKES TO REMAIN IN CONTROL
MONDAY NIGHT THROUGH TUESDAY AFTERNOON...WHILE A SRN PLAINS STORM
SYSTEM LIFTS INTO THE CENTRAL PLAINS AND AN UPPER TROUGH DIGS INTO
THE CENTRAL PLAINS. MODEL SOUNDINGS AND MSTR PROGS SHOW 850/500MB
RH LINGERING AROUND 40 PCT THRU 00Z WED. WILL CONTINUE A DRY FCST
OVER THE NRN LAKES MONDAY NIGHT AND TUESDAY. LOW TEMPS TUESDAY IN
THE MID 30S AS AIRMASS REMAINS UNCHANGED...AFTN TEMPS IN THE 45 TO
50 DEGREE RANGE AS SOME UPPER CLOUDS INCREASE OVER THE STATE IN
ADVANCE OF APPROACHING SFC AND UPPER LEVELS FEATURES.
TUESDAY NIGHT AND WEDNESDAY...CENTRAL PLAINS STORM SYSTEM LIFTS
NORTH INTO THE UPPER MIDWEST TUESDAY NIGHT BEFORE LIFTING NORTH INTO
THE STRAITS AND ERN UPPER MICHIGAN WEDNESDAY. MODEL SOUNDINGS AND
MSTR PROGS SHOWING MSTR INCREASE OVER THE NRN LAKES THROUGH THE PD
AS THE STORM SYSTEM LIFTS INTO NRN MI. 850/500MB RH WILL INCREASE TO
AROUND 80 PCT WHILE 850MB DEW PTS INCREASE FROM -8C TUESDAY TO 0C BY
12Z WEDNESDAY. MODEL SOUNDINGS SHOWING ABV FREEZING LAYER FROM THE
SFC TO ARND 4000 FT TUESDAY NIGHT...EXTENDING TO 5500 FEET
WEDNESDAY. THEREFORE PCPN ALL IN THE FORM OF RAIN THROUGH THIS
PERIOD. LOW TEMPS IN THE 30S TUESDAY NIGHT WITH HIGHS IN THE MID 40S
WEDNESDAY.
WEDNESDAY NIGHT AND THURSDAY...STORM SYSTEM OVER THE NRN LAKES
LINGERS BUT BECOMES STRETCHED OUT ACROSS THE STATE...AS THE LOW
TRIES TO LIFT NORTH TWD HUDSON BAY. THE DIGGING 500MB TROUGH DROPS
SOUTH OF THE STATE AND MOVES EAST OVER THE OHIO VALLEY. MODEL
SOUNDINGS SHOWING COLDEST 850MB AIR TO LINGER WEST OF THE REGION AND
SWEEP SOUTH ACROSS THE OHIO VALLEY. OVR NRN MI...850MB TEMPS DROP
FROM AROUND 0C/+1C WEDNESDAY NIGHT TO -3C THURSDAY. MODEL SOUNDINGS
SHOWING ABOVE FREEZING LAYER EXTENDING FROM THE SFC THRU 4K FT
WEDNESDAY NIGHT DROPPING TO AROUND 2500 FEET BY 00Z FRIDAY. WILL
TREND TWD ALL RAIN EVENT WEDNESDAY NIGHT AND MUCH OF THURSDAY
AFTERNOON. WILL MENTION A MIX RAIN/SNOW TO ALL SNOW THURSDAY
NIGHT...WHEN VERTICAL TEMP PROFILE ON SOUNDINGS SHOW ABV FREEZING
LAYER DROPPING UNDER 1500 FEET. HIGHS THURSDAY GENERALLY AROUND 40
MOST LOCATIONS.
SWR
&&
.MARINE.../ISSUED AT 429 AM/
WINDS AND WAVES EXPECTED TO REMAIN BELOW SCA CRITERIA TODAY
THROUGH TUESDAY...WITH WINDS PRIMARILY FROM THE SOUTHEAST.
STRONGEST WINDS AND HIGHEST WAVES TODAY EXPECTED IN THE STRAITS
AND BTWN THE BRIDGE AND DETOUR...HOWEVER EXPECTED TO REMAIN BELOW
SCA. FOG THIS MORNING TO DIMINISH AS SFC HIGH PRESSURE AND DRY AIR
LINGER ACROSS THE ERN LAKES. CLEARING SLOWEST OVER THE ERN LAKES
ONCE AGAIN TODAY WITH OVERALL SE FLOW ACROSS THE REGION AND LATE
NOV SUN ANGLE. NEXT CHANCE OF RAIN OVER THE NRN LAKES NEARSHORE
WATERS...WILL BE TUESDAY NIGHT AND WEDNESDAY AS A PLAINS STORM
SYSTEM LIFTS NORTH INTO NRN MI.
SWR
&&
.AVIATION.../ISSUED AT 1205 AM/...VALID FOR 06Z TAFS
TREND OVER THE LAST COUPLE OF HOURS HAS BEEN FOR STRATUS/LIGHT FOG
TO REDEVELOP AT ALL TAF SITES. WILL THEN BANK ON TREND TO CONTINUE
INTO MID MORNING. OVERALL CONFIDENCE NOT GREAT...AND INCREASING
SOUTHERLY FLOW COULD KEEP STRATUS AND/OR FOG AT BAY...AT LEAST KEEP
FOG FROM BECOMING DENSE. VRF CONDITIONS THEN EXPECTED TO REEMERGE
LATER THIS MORNING INTO THIS AFTERNOON. FOG/STRATUS THEN EXPECTED TO
REDEVELOP AGAIN THIS EVENING.
AJS
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KMQT 230842
AFDMQT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
342 AM EST MON NOV 23 2009
.DISCUSSION...
.TODAY THROUGH TUESDAY...SURFACE RIDGING EXTENDING WESTWARD FROM
NOVA SCOTIA CONTINUES TO INFLUENCE THE GREAT LAKES. LATEST WV
IMAGERY SHOWS MOISTURE STREAMING NORTHEASTWARD AROUND THE
PERIPHERY OF THIS RIDGE AS A COLD FRONT TRACKS EAST ACROSS THE
SOUTHERN CANADIAN PRAIRIES...REMAINING NORTHWEST OF UPPER
MICHIGAN. BROAD AREA OF SHOWERS HAVE DEVELOPED WITHIN THIS
MOISTURE PLUME AIDED BY WEAK ISENTROPIC LIFT NOTED ON 305
THETA-E/PRESSURE ANALYSIS. SHORT TERM GUIDANCE AGREES THESE
SHOWERS WILL REMAIN WEST OF LINE FROM L`ANSE TO WATERSMEET...WITH
THE HEAVIER SHOWERS REMAINING OFFSHORE. EXPECT CLOUDS TO REMAIN
OVER THE FAR WEST MOST OF THE DAY WITH PARTIAL CLEARING AND
PERIODS OF SUNSHINE EXPECTED OVER THE REMAINDER OF UPPER MICHIGAN.
EXPECT AREAS OF DENSE FOG EARLY THIS MORNING UNDER THIS CLEARING.
THIS SHOULD ALSO ALLOW FOR ANOTHER MILD DAY WITH HIGH TEMPERATURES
IN THE LOW 50S...SOME 15 TO 20 DEGREES ABOVE NORMAL. A WEAK S/W
TROUGH NOTED IN THE 500MB FLOW WILL PASS THROUGH THE CWA
TONIGHT...HOWEVER WITH LIMITED MOISTURE DON/T EXPECT MEASURABLE
RAINFALL. IN FACT EXPECT A DRY FORECAST THROUGH TUESDAY.
.TUESDAY NIGHT INTO FRIDAY...BY TUESDAY NIGHT ATTENTION TURNS TO
S/W TROUGH CURRENTLY SITUATED OVER EASTERN COLORADO. THIS FEATURE
IS PROGGED TO SHIFT NORTHEAST OUT THE CENTRAL PLAINS ON
TUESDAY...CROSSING NORTHERN LAKE MICHIGAN ON WEDNESDAY NIGHT WHILE
STRENGTHENING SLIGHTLY. GOING FORECAST APPEARS TO HANDLE
INCREASING POPS WELL...WITH LIKELY POPS BY WEDNESDAY AS DEEPER
MOISTURE/BEST 500MB HEIGHT FALLS ARRIVE OVER UPPER MICHIGAN. MAIN
CHANGES WERE RELATED TO RAIN/SNOW COVERAGE. ATTM IT APPEARS THE
EASTERN ZONES WILL STAY MOSTLY RAIN PER BUFKIT SOUNDINGS/CRITICAL
THICKNESS VALUES. COLD AIR IS LACKING AND IN FACT THE NECESSARY
COLD AIR IS SITUATED WELL TO OUR NORTH ON WEDNESDAY OVER HUDSON
BAY AND NORTHERN MANITOBA. EXPECT SOME SNOW FLAKES THOUGH BY
WEDNESDAY NIGHT OVER SOME OF THE HIGHER TERRAIN AIDED BY DIABATIC
COOLING PROCESSES WITH A RAIN/SNOW MIX ELSEWHERE EXCEPT THE EAST
WHERE ALL RAIN IS EXPECTED THROUGH THURSDAY. ADJUSTED WORDING IN
HWO TO REFLECT LESSER POTENTIAL FOR SIGNIFICANT ACCUMULATING
SNOWFALL.
STILL DISAGREEMENT AMONG LONG TERM GUIDANCE MODELS AS TO WHETHER
ENOUGH COLD AIR IS AVAILABLE FOR LAKE EFFECT SNOW BEHIND THIS
SYSTEM. 23/00Z GFS GUIDANCE BRINGS 850MB TEMPERATURES AS COLD AS
-9C...WHICH GIVEN THE CURRENT LAKE SUPERIOR WATER TEMPERATURE OF
5C WOULD BE JUST ENOUGH FOR LAKE PROCESSES TO BEGIN. THE PREFERRED
ECMWF SOLUTION OFFERS A MUCH WARMER AIRMASS WITH 850MB
TEMPERATURES NEVER FALLING BELOW -4C. A QUICK GLANCE AT 850MB
TEMPERATURES ACROSS THE NORTHERN HEMISPHERE SHOWS COLD AIR IS
NOWHERE TO BE FOUND OVER THE WESTERN HEMISPHERE WITH VIRTUALLY ALL
THE COLD AIR...-20 OR COLDER...LOCKED UP OVER SIBERIA.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
A MOIST LOW-LVL SOUTHERLY FLOW CONTINUES OVER THE AREA AND SHOULD
CONTRIBUTE TO ANOTHER ROUND OF FOG LATE TONIGHT INTO MON MORNING.
THE UPSLOPE FLOW WILL FAVOR KSAW FOR THE THICKER FOG WHERE I EXPECT
CONDITIONS TO LOWER TO IFR TOWARD SUNRISE. AT KCMX...LESS FAVORABLE
SRLY FLOW SHOULD KEEP PREVAILING CONDITIONS VFR UNTIL AROUND
SUNRISE...AT WHICH TIME WINDS SHIFT SE AND COULD BRING IN SOME MVFR
STRATUS/FOG CONDITIONS. DIURNAL MIXING SHOULD ALLOW CONDITIONS TO
IMPROVE TO VFR AT BOTH TAF SITES BY EARLY MON AFTERNOON.
CONTINUED SE FLOW THIS EVENING WILL ALLOW FOR SOME MVFR STRATUS/FOG
TO REDEVELOP AT KSAW AROUND 03Z.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
EXPECT HI PRES TO REMAIN NEARLY STATIONARY OVER SE CANADA AND THE
NE STATES INTO WED WHILE LO PRES DEVELOPING IN THE PLAINS MOVES
SLOWLY NE TO WISCONSIN. WINDS WILL BE UNDER 25 KTS THRU THIS TIME.
AS THE HI FINALLY RETREATS...THE LO CENTER WILL MOVE GRADUALLY E TO
OVER SE ONTARIO ON FRI. PLAN ON A PERIOD OF STRONGER N WINDS TO 30
KTS ON WED NIGHT INTO FRI ON THE NW FLANK OF THIS LO. SINCE THIS LO
NOW APPEARS WILL DEVELOP MORE SLOWLY THAN EXPECTED BEFORE...THE N
GALES PREVIOUSLY FORECAST APPEAR LESS LIKELY. LOOK FOR A HI PRES
RIDGE TO BUILD TOWARD THE WESTERN GREAT LAKES ON FRI AND BRING
DIMINISHING WINDS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
DISCUSSION...PEARSON
AVIATION...VOSS
MARINE...KC
000
FXUS63 KDTX 230841
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
341 AM EST MON NOV 23 2009
.SHORT TERM...TODAY
LOW STRATUS/AREAS OF FOG WILL BE PREVALENT AGAIN THIS MORNING...AND
EXPECT IT TO TAKE MUCH OF THE MORNING TO BURN THIS OFF. EVEN BY THE
AFTERNOON...SKIES WILL BE PARTLY/MOSTLY CLOUDY AS CLOUDS LIFT NORTH
INTO THE REGION AS LOW PRESSURE BEGINS EDGING TOWARDS THE AREA. THE
HIGHS WILL CLIMB TO BETWEEN 50 AND 55 DEGREES AGAIN...SO NO MAJOR
CHANGES WILL BE NEEDED TO THE GOING FORECAST.
&&
.LONG TERM...TONIGHT THROUGH NEXT SUNDAY
ONE MORE MORNING OF FOG TO AFFECT LOWER MICHIGAN BEFORE THE NEXT
STORM SYSTEM MOVES IN...BRINGING RAIN AND SNOW WITH IT. HIGH
PRESSURE STRETCHING FROM THE GREAT LAKES TO THE NEW ENGLAND STATES
WILL CONTINUE ITS TRACK EASTWARD THROUGH TUESDAY WHEN IT WILL
FINALLY LOSE ITS INFLUENCE ON THE WEATHER IN SE MICHIGAN. THE
HIGH PRESSURE WILL AGAIN GIVE US A WEAK EASTERLY WIND FIELD OFF THE
LAKES REINFORCING THE ALREADY HIGH MOISTURE VALUES IN THE LOW
LEVELS. SURFACE DEWPOINTS WILL REMAIN NEAR 40F UNDER A STRONG
INVERSION LOCATED AROUND 975MB. MODEL SOUNDINGS SHOW HIGHER
POTENTIAL TO THE NORTH AROUND FNT/MBS BUT DUE TO THE PERSISTENCE OF
THIS PATTERN WITH MOISTURE AMOUNTS AND FOG DEVELOPMENT...WILL LEAVE
MENTION FOR ALL AREAS.
MODELS COMING INTO BETTER AGREEMENT WITH EACH NEW RUN RECENTLY IN
REGARDS TO THE MID WEEK STORM SYSTEM HEADING FOR THE GREAT LAKES
REGION. THE GFS IS TRENDING A BIT SLOWER EACH RUN BECOMING MORE IN
PHASE WITH THE ECMWF...WHICH HAS BEEN THE MOST CONSISTENT MODEL IN
HANDLING THIS SYSTEM. THE NAM DIGS THE TROUGH/LOW DEEPER INTO THE
PLAINS THEN BOTH THE GFS AND ECMWF WHICH ALSO ACTS TO SLOW IT DOWN.
THIS SURFACE LOW SHOULD TRACK NORTH ALONG LAKE MICHIGAN ON WEDNESDAY
LEADING TO PRECIP CHANCES BEGINNING OVERNIGHT TUESDAY. THIS INITIAL
UPPER WAVE LOOKS TO WEAKEN A BIT AS IT MOVES OVER MI BUT WILL BE
QUICKLY REINFORCED BY A SECOND STRONGER WAVE DIGGING INTO THE
CENTRAL PLAINS FROM THE NORTHERN BRANCH OF THE JET STREAM ON
WEDNESDAY. MODELS ARE ONCE AGAIN SHOWING A FAIRLY COLD AIRMASS BEING
BROUGHT IN WITH THIS SECOND IMPULSE. 850MB TEMPS AROUND -5C ARE
BEING ADVERTISED FOR THURSDAY INTO FRIDAY WITH MOST MODELS
NOW...GFS/DGEX/ECMWF. TEMPS HAVE ALREADY BEEN HEDGED LOWER TO TAKE
THIS INTO ACCOUNT SO WILL WAIT TO SEE IF THIS BECOMES A MORE
CONSISTENT SOLUTION BEFORE ACTING FURTHER ON IT. AS THE MODELS SEEM
SLOWER WITH EACH SUCCESSIVE RUN...STILL BELIEVE THANKSGIVING DAY
WILL BE A RAIN EVENT CHANGING OVER TO RAIN/SNOW OVERNIGHT INTO
FRIDAY THOUGH AMOUNTS SHOULD STAY ON THE LOW SIDE.
UPPER LEVEL RIDGING WILL MOVE IN BEHIND THIS SYSTEM ON SATURDAY
PUTTING AN END TO PRECIP CHANCES ALTHOUGH IT LOOKS LIKE THE COLDER
TEMPS...HIGHS IN THE LOWER 40S...WILL REMAIN WITH US.
&&
.MARINE...
LIGHT SOUTHEAST WINDS WILL INCREASE SLIGHTLY INTO TUESDAY AS HIGH
PRESSURE RETREATS EAST...AWAY FROM THE AREA. THE PATTERN BECOMES
MORE ACTIVE MID/LATE NEXT WEEK AS AN UPPER LEVEL STORM SYSTEM LIFTS
INTO THE REGION LATE TUESDAY INTO WEDNESDAY AND BRINGS THE CHANCE OF
RAIN AS WELL AS INCREASED WINDS. ANOTHER MORE AGGRESSIVE DISTURBANCE
WILL THEN DIVE SOUTHEAST INTO THE SOUTHERN GREAT LAKES AND OHIO
VALLEY BRINGING COLDER TEMPERATURES AND A MIX OF RAIN/SNOW SHOWERS
LATE IN THE WEEK. WINDS/WAVES WILL BE MUCH MORE TURBULENT AS THIS
SYSTEM WAFFLES THROUGH THE AREA.
&&
.PREV DISCUSSION...ISSUED 1155 PM EST SUN NOV 22 2009
AVIATION...
A BROAD AREA OF MVFR FOG NOW IN PLACE AREAWIDE AS THE NEAR SURFACE
LAYER CONTINUES TO SATURATE. PERSISTENT 3-6 KT EASTERLY FLOW
MAINTAINING JUST ENOUGH MIXING TO PREVENT A MORE RAPID DROP IN
VISIBILITY. THIS NOW LOOKS TO BE THE CASE THROUGH THE
NIGHT...ALTHOUGH WILL NOT RULE OUT INTERMITTENT TIMES WHERE WINDS
CAN GO CALM. THIS WILL LOCALLY ENHANCE THE FOG POTENTIAL...MOST
LIKELY DURING THE 10-14Z TIME WINDOW WHERE LIFR CONDITIONS REMAIN
POSSIBLE. ALSO NOTING THE MOST RECENT SATELLITE IMAGERY WHICH
DEPICTS A SMALL AREA OF STRATUS DEVELOPING ON THE NORTHWEST SIDE OF
LAKE ERIE INTO ONTARIO. THIS ADDED MOISTURE FLUX WILL CONTRIBUTE TO
ADDITIONAL STRATUS DEVELOPMENT DOWNSTREAM WITH THE WIND FIELD
MAINTAINING AN EASTERLY COMPONENT. THEREFORE IFR/LIFR CIGS NOT OUT
OF THE QUESTION EITHER...ESPECIALLY IN THE DETROIT AREA. ANY
RESIDUAL STRATUS WILL STRUGGLE TO LIFT/SCATTER INTO EARLY AFTERNOON
GIVEN THE STRENGTH OF THE INVERSION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...DG
LONG TERM....DRK
MARINE.......DG
AVIATION.....MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KMQT 230518 AAB
AFDMQT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MARQUETTE MI
1217 AM EST MON NOV 23 2009
UPDATED FOR 06Z AVIATION DISCUSSION
.SYNOPSIS...
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN UPPER RIDGE AXIS
OVER WESTERN QUEBEC AND A LONGWAVE TROUGH OVER THE NORTHERN AND
CENTRAL PLAINS AND INTO CENTRAL CANADA. ANOTHER TROUGH CONTINUES TO
DIG OVER THE PACIFIC NORTHWEST. A WEAK SHORTWAVE IS OVER THE EAST
END OF THE FORECAST AREA THIS AFTERNOON...WITH OTHERS OVER EASTERN
DAKOTAS AND MINNESOTA. SURFACE ANALYSIS SUGGEST A COLD FRONT
EXTENDING FROM CENTRAL HUDSON BAY SOUTH THROUGH MINNESOTA TO A WEAK
LOW OVER EASTERN NEBRASKA AND A LARGE HIGH OVER THE CANADIAN
MARITIME CAUSING A SOUTHERLY FLOW ACROSS THE FORECAST AREA. THIS
SOUTHERLY FLOW BROUGHT ABNORMALLY WARM AIR AND SOME LOW LEVEL
MOISTURE INTO THE AREA WHICH CAUSED CONSIDERABLE FOG THIS MORNING.
THIS MORNING AREA RAOBS INDICATED THE AIR MASS WAS QUITE DRY ABOVE
800MB. QUITE A BIT OF HIGH CLOUDS ARE STREAMING INTO THIS AREA AHEAD
OF OF THE FRONT. A LOW LEVEL JET OVER THE AIR CONTINUES TO MIX TO
SURFACE OVER THE LAKE.
&&
.SHORT TERM...
THE MAIN CONCERN FOR TONIGHT AND MONDAY WILL BE WITH THE POTENTIAL
FOR RAIN AND FOG.
THE MID LEVEL RIDGE WILL PUSH INTO EASTERN QUEBEC WITH THE
ASSOCIATED HIGH WEAKENING AS IT REACHES NEW ENGLAND TONIGHT. THE MID
LEVEL TROUGH OVER THE NORTHERN PLAINS WILL WEAKEN AND SETTLE OVER
HUDSON BAY TONIGHT. THE ASSOCIATED SHORTWAVE WILL WEAKEN AS WELL AS
IT STALLS OUT OVER THE UPPER MISSISSIPPI RIVER VALLEY.
MEANWHILE...THE TROUGH OVER THE PACIFIC NORTHWEST CONTINUE TO DEEPEN
AS IT MOVES INTO THE NORTHERN HIGH PLAINS. THE COLD FRONT OVER
MINNESOTA WILL REALIGN WITH THE WEAKEN SHORTWAVE OVER CANADA AND
STRETCH FROM SOUTHERN JAMES BAY SOUTHWEST THROUGH THE MINNESOTA
ARROWHEAD TO EASTERN SOUTH DAKOTA. SURFACE DEW POINT ARE IN THE LOW
TO MID 40S ACROSS THE CWA THIS AFTERNOON. AFTER SUNDOWN WITH THE
CLEARING SKIES OVER THE EAST...TEMPERATURES WILL FALL RAPIDLY WILL
BE FAVORABLE FOR FOG DEVELOPMENT OVERNIGHT. INCREASE HUMIDITY AHEAD
OF THE COLD FRONT WILL INCREASE THE POSSIBILITY OF RAIN AND FOG
THERE AS WELL. THUS WILL TENDED TO GO WITH THE A LITTLE POPS LATER
TONIGHT WITH INFLUX OF MOISTURE AND SOME ISENTROPIC ASCENT AHEAD OF
THE FRONT.
THE MID LEVEL TROUGH OVER THE HIGH PLAINS WILL DEEPEN INTO A CUTOFF
LOW OVER THE CENTRAL PLAINS ON MONDAY. WEAK SHORTWAVES EJECTED OUT
OF THE BASE OF THIS LOW WILL SWEEP ACROSS THE FORECAST AREA ON
MONDAY. THE FINAL REMNANT OF THE WEAKENING TROUGH WILL SHIFT INTO
WISCONSIN. THE NEBRASKA SURFACE LOW WILL DEEPEN AS IT INCHES INTO
EASTERN NEBRASKA. A STRONG SOUTHERLY FLOW AND THE ALIGNMENT OF THE
LOW LEVEL JET WILL HOLD THE FRONTAL SYSTEM STATIONARY JUST TO THE
NORTH OF LAKE SUPERIOR. AS WITH THIS MORNING...PATCHY FOG SHOULD
LAST THROUGH THE EARLY MORNING HOURS AFTER SUNRISE. DRY AIR
ADVECTING INTO THE AREA AHEAD OF THE NEBRASKA LOW WILL END THE FOG
AND LIMIT ANY PRECIPITATION ACROSS THE AREA ON MONDAY.
&&
LONGER TERM 00Z TUE ONWARD...
FORECAST PROBLEM CONTINUES TO BE THE UPCOMING STORM AND WHAT IT WILL
DO...PCPN TYPE AND WHEN IT WILL OCCUR. THE STORM SYSTEM IS CURRENTLY
IN THE PACIFIC NW NOW AND WILL DIG SE AND FORM A CLOSED LOW WITH IT
THIS FORECAST PERIOD. NAM BRINGS IN ANOTHER TROUGH INTO THE PACIFIC
NW MON NIGHT AND THEN MOVES IT EAST BEFORE DIGGING IT INTO THE
TROUGH ON TUE. WHAT THIS DOES THEN IS KICKS THE CLOSED LOW OUT
SLOWLY ENE AND ANOTHER CLOSED 500 MB LOW FORMS OVER THE NORTHERN
PLAINS TUE NIGHT AND DIGS SE INTO THE MISSOURI RIVER VALLEY NEAR
SIOUX CITY IA 00Z THU WHILE THE OTHER LOW IS IN CENTRAL LOWER
MICHIGAN. DEEPER MOISTURE DOES NOT ARRIVE UNTIL TUE NIGHT ALONG WITH
SOME BETTER DYNAMICS ACCORDING TO THE NAM. GFS IS FAIRLY SIMILAR TO
THE NAM EXCEPT BRINGS PCPN IN A BIT QUICKER. BASICALLY...WITH MODELS
STILL NOT CONSISTENT ON SOLUTION...WILL NOT MAKE VERY MANY CHANGES
TO THE GOING FORECAST. KEPT LIKELY POPS IN FOR WED THROUGH THU WITH
DECENT MOISTURE AROUND. ONLY CHANGE I DID MAKE WAS TO REMOVE SNOW
FROM WED AS COLD AIR DOES NOT COME IN UNTIL WED NIGHT. SYSTEM REALLY
DOES NOT HAVE MUCH COLD AIR TO WORK WITH AND WILL HAVE TO
MANUFACTURE ITS OWN COLD AIR TO DO SO.
IN THE EXTENDED...CONTINUED TO GO WITH THE 00Z ECMWF FOR THIS
FORECAST PERIOD AS IT HAS BEEN THE MOST CONSISTENT MODEL FOR THE
PAST SEVERAL DAYS. ECMWF SHOWS A TROUGH AND CLOSED LOW AFFECTING THE
AREA FOR THU AND THEN RIDGING FOR FRI AND SAT AND INTO SUN AS WELL.
DID NOT MAKE ANY CHANGES TO THE EXTENDED AT ALL. STILL HAVE LIKELY
POPS IN FOR THU AND THEN DRY FOR FRI NIGHT THROUGH SUN EVEN AS A
COLD FRONT MOVES THROUGH ON SUN. TEMPERATURES CONTINUE TO BE MILD
AND NORMAL TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
A MOIST LOW-LVL SOUTHERLY FLOW CONTINUES OVER THE AREA AND SHOULD
CONTRIBUTE TO ANOTHER ROUND OF FOG LATE TONIGHT INTO MON MORNING.
THE UPSLOPE FLOW WILL FAVOR KSAW FOR THE THICKER FOG WHERE I EXPECT
CONDITIONS TO LOWER TO IFR TOWARD SUNRISE. AT KCMX...LESS FAVORABLE
SRLY FLOW SHOULD KEEP PREVAILING CONDITIONS VFR UNTIL AROUND
SUNRISE...AT WHICH TIME WINDS SHIFT SE AND COULD BRING IN SOME MVFR
STRATUS/FOG CONDITIONS. DIURNAL MIXING SHOULD ALLOW CONDITIONS TO
IMPROVE TO VFR AT BOTH TAF SITES BY EARLY MON AFTERNOON.
CONTINUED SE FLOW THIS EVENING WILL ALLOW FOR SOME MVFR STRATUS/FOG
TO REDEVELOP AT KSAW AROUND 03Z.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
WITH LAKE SUPERIOR IN BETWEEN LOW PRESSURE OVER THE CENTRAL PLAINS
AND THE HIGH OVER THE NORTHEAST STATES...SOUTHERLY WINDS TO 25 KNOTS
WILL PREVAIL INTO MONDAY MORNING. A FEW WIND GUSTS TO 28 KNOTS WILL
BE POSSIBLE TONIGHT MAINLY OVER THE EASTERN LAKE. WINDS WILL REMAIN
UNDER 20 KNOTS INTO WEDNESDAY...WHEN A STORM SYSTEM APPROACHES THE
UPPER GREAT LAKES AND WINDS BEGIN TO INCREASE OUT OF THE NORTH AND
NORTHEAST WITH GALES POSSIBLE LATE WEDNESDAY THROUGH FRIDAY MORNING.
LOCALLY DENSE PATCHY FOG IS POSSIBLE TONIGHT ACROSS LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS/SHORT TERM...DLG
LONG TERM...07
AVIATION...JV
MARINE...DLG
000
FXUS63 KAPX 230506
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1205 AM EST MON NOV 23 2009
.SYNOPSIS.../ISSUED AT 316 PM/
HIGH PRESSURE OVER NEW ENGLAND WILL MAINTAIN ITS INFLUENCE OVER THE
GREAT LAKES THROUGH MONDAY EVEN AS IT DRIFTS INTO THE CANADIAN
MARITIME PROVINCES. THIS WILL RESULT IN A CONTINUATION OF THE
CURRENT PATTERN...WITH NIGHTTIME AND MORNING FOG GRADUALLY GIVING
WAY TO SUNNY SKIES. BUT THERE COULD BE SOME LOCATIONS WHERE LOW
CLOUDS NEVER DISSIPATE. THE NEXT CHANCE OF RAIN WILL ARRIVE TUESDAY
NIGHT AND WEDNESDAY AS A STORM SYSTEM LIFTS INTO THE REGION.
TEMPERATURES WILL REMAIN WARMER THAN NORMAL THROUGH MID-NEXT WEEK
AND THEN TURN COLDER BEHIND THIS SYSTEM.
JH
&&
.SHORT TERM.../ISSUED AT 1017 PM/...TONIGHT
ON THE LATEST SURFACE WEATHER MAP...1036 MB HIGH PRESSURE WAS
CENTERED ACROSS NORTHERN NEW ENGLAND WITH 1010 MB LOW PRESSURE OVER
EASTERN WYOMING. THIS LEAVES NORTHERN MICHIGAN IN A SOUTH TO
SOUTHEAST LOW LEVEL FLOW. SURFACE OBSERVATIONS AND SATELLITE
IMAGERY SHOW AN AREA OF STRATUS ACROSS CENTRAL AND EASTERN
SECTIONS OF THE FORECAST AREA. THERE IS SOME LIGHT FOG AS WELL
WITH VISIBILITIES GENERALLY 1 TO 2 MILES OR HIGHER SO FAR. THE
MAIN SHORT TERM FORECAST CONCERN REVOLVES AROUND HOW DENSE AND
WIDESPREAD FOG WILL BE.
PESKY AREA OF STRATUS HAS EXPANDED NORTH/WESTWARD OVER THE LAST
COUPLE OF HOURS. HOWEVER...THIS CLOUD MASS IS MOVING NORTHWARD WITH
SOUTHERN EDGE NOT TO FAR SOUTH OF OUR SOUTHERN FORECAST AREA
BORDER (GENERALLY GLADWIN TO SOUTHEAST OF MANISTEE). SOME MIXING
FROM SOUTHERLY FLOW IN PLACE OVERNIGHT. THE EXPECTATION IS THAT
THIS WILL KEEP FOG FROM BECOMING WIDESPREAD AND DENSE.
OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES WITH LOWS IN THE LOWER
TO MIDDLE 30S FOR THE MOST PART.
SULLIVAN
&&
.LONG TERM.../ISSUED AT 316 PM/...MONDAY AND BEYOND
OUTSIDE OF FOG/STRATUS ISSUES MONDAY/TUESDAY MORNINGS...THE MAIN
FORECAST ISSUES FOR THE UPCOMING WEEK WILL REVOLVE AROUND UPPER
LEVEL ENERGY ROTATING OUT OF THE CENTRAL PLAINS AND SOUTHERN CANADA
WED-THU. THERE APPEARS TO BE SOME CLUSTERING OF MODEL SOLUTIONS
WITH THE SOUTHERN PIECE OF ENERGY ON WEDNESDAY...BUT STILL PLENTY OF
MODEL SPREAD WITH THE HANDLING OF THE SECOND FEATURE FOR
THANKSGIVING DAY. THE OPERATIONAL ECMWF CONTINUES TO BE THE SLOWEST
OF ALL SOLUTIONS...AND WILL TREND TOWARD THE MAJORITY FASTER AND
SLIGHTLY FURTHER NORTH SOLUTIONS.
MONDAY NIGHT/TUESDAY...THE INITIAL SHORTWAVES AHEAD OF THE MAIN
UPPER LOW OVER THE CENTRAL PLAINS WILL DRAW A PLUME OF DEEPER
MOISTURE NORTHWARD FROM THE CENTRAL APPALACHIANS TO THE EASTERN
GREAT LAKES...PASSING EAST OF THE AREA. FOG/STRATUS WILL CONTINUE
TO BE THE MAIN CONCERNS. CIRRUS WILL INHIBIT COOLING TO SOME DEGREE
MONDAY NIGHT...BUT THE GRADIENT WILL ACTUALLY BE A LITTLE WEAKER -
LESS THAN 20KT. I LIKE THE MIDNIGHT SHIFT/S IDEA OF ADDING FOG FOR
MONDAY NIGHT/TUESDAY MORNING...ESPECIALLY OVER EASTERN UPPER WITH
PREVAILING MOIST SOUTHEAST MARINE FLOW.
UPPER LOW MOVES INTO THE CENTRAL MISSISSIPPI VALLEY ON TUESDAY WITH
WARM CONVEYOR BELT HELPING TO SPREAD CLOUDS BUT NOT PCPN INTO
NORTHERN MICHIGAN. UPPER FEATURE SLIDES TOWARD SOUTHWEST MICHIGAN
BY WEDNESDAY MORNING...AND THEN INTO NORTHERN LAKE HURON BY LATE
AFTERNOON. INITIAL SURGE OF RAIN EARLY WEDNESDAY MORNING WILL PUSH
NORTH THROUGH THE AREA THROUGHOUT THE MORNING ON THE NOSE OF H8
THETA-E MOISTURE PLUME...PIVOTING INTO EASTERN UPPER BY MIDDAY. IN
IT/S WAKE...THE HEAVIEST AND MOST STEADY PCPN WILL LIKELY END...AS
DEEPEST MOISTURE AND FORCING SLIDE NORTHEAST. PLENTY OF LOW LEVEL
MOISTURE BENEATH H9 FOR THE AFTERNOON HOURS AND COULD SEE SOME
DRIZZLE. NORTHERN MICHIGAN ON THE WARM SIDE OF THE STORM...SO JUST
LIQUID DURING THE DAY WEDNESDAY /NO SNOW/.
MODEL ISSUES BEGIN TO APPEAR BY WEDNESDAY NIGHT AS UPSTREAM PIECE OF
UPPER LEVEL ENERGY DROPS TOWARD THE MISSISSIPPI VALLEY/NRN OHIO
VALLEY. BEST PCPN CHANCES WILL LIKELY BE TO THE WEST OF
INTERSTATE-75...WITHIN DEVELOPING DEFORMATION AXIS ACROSS LAKE
MICHIGAN. WILL NOT GET TOO DETAILED THIS FAR OUT...GOING WITH HIGH
CHANCE/LOW LIKELY POPS FOR THANKSGIVING DAY. AS FAR AS PCPN
TYPE...RAIN GRADUALLY TURNING TO SNOW ON THANKSGIVING DAY. WHAT
WILL MAKE THIS A DIFFICULT PCPN TYPE CASE IS THAT THE COLDEST CORE
OF TEMPS ASSOCIATED WITH UPPER LOW MAY ACTUALLY FOCUS OVER SOUTHERN
MICHIGAN/NRN OHIO VALLEY - WITH SLIGHTLY WARMER READINGS WRAPPING
BACK OVER NORTHERN MICHIGAN. AT THIS POINT...WAY TOO MANY UNKNOWNS
TO GET VERY SPECIFIC.
SYNOPTIC MOISTURE STRIPS OUT THE EAST THURSDAY NIGHT WITH DRY SLOT
MOVING INTO NORTHERN MICHIGAN...POSSIBLY LEAVING SOME LIGHT PCPN
/FREEZING DRIZZLE?/ FOR LATER THURSDAY NIGHT INTO FRIDAY MORNING.
UPPER RIDGE BUILDS INTO THE AREA FRIDAY/SATURDAY...BRINGING DRIER
WEATHER AND SEASONABLY MILD TEMPERATURES.
JK
&&
.MARINE.../ISSUED AT 316 PM/
GUSTY SOUTH WINDS HAVE PRODUCED SMALL CRAFT WINDS/WAVES ACROSS
WHITEFISH BAY THIS AFTERNOON...WHICH WILL PERSIST INTO THE EVENING
HOURS BEFORE DIMINISHING. OTHERWISE...SOUTHERLY WINDS WILL DOMINATE
ON THE LAKES OVER THE NEXT SEVERAL DAYS WITH CONDITIONS GENERALLY
BELOW SMALL CRAFT ANTICIPATED.
ADAM
&&
.AVIATION.../ISSUED AT 1205 AM/...VALID FOR 06Z TAFS
TREND OVER THE LAST COUPLE OF HOURS HAS BEEN FOR STRATUS/LIGHT FOG
TO REDEVELOP AT ALL TAF SITES. WILL THEN BANK ON TREND TO CONTINUE
INTO MID MORNING. OVERALL CONFIDENCE NOT GREAT...AND INCREASING
SOUTHERLY FLOW COULD KEEP STRATUS AND/OR FOG AT BAY...AT LEAST KEEP
FOG FROM BECOMING DENSE. VRF CONDITIONS THEN EXPECTED TO REEMERGE
LATER THIS MORNING INTO THIS AFTERNOON. FOG/STRATUS THEN EXPECTED TO
REDEVELOP AGAIN THIS EVENING.
AJS
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR LSZ321.
&&
$$
000
FXUS63 KGRR 230500
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1200 AM EST MON NOV 23 2009
LATEST UPDATE...AVIATION...
.SYNOPSIS...(330 PM EST SUN NOV 22 2009)
THE LARGE HIGH PRESSURE SYSTEM THAT WAS OVER THE GREAT LAKES WAS
MOVING OFF INTO THE NORTH ATLANTIC TONIGHT. THAT WILL ALLOW A
DEVELOPING STORM SYSTEM OVER THE SOUTHWEST UNITED STATES TO MOVE
INTO THE SOUTHERN PLAINS TUESDAY AND INTO THE GREAT LAKES WEDNESDAY.
THE SOUTHERLY WINDS AHEAD OF THE STORM WILL CONTINUE THE MILD
WEATHER WITH AREAS OF FOG DURING THE EARLY TO MID MORNING HOURS.
THEN AFTERNOON SUNSHINE WILL PREVAIL MONDAY AND TUESDAY. PERIODS OF
RAIN WILL MOVE INTO THE AREA TUESDAY NIGHT AND CONTINUE INTO
WEDNESDAY. COLDER AIR BEHIND THE STORM MAY MIX SNOW WITH THE RAIN
WEDNESDAY NIGHT.
&&
.SHORT TERM...(1003 PM EST SUN NOV 22 2009)
(TONIGHT THROUGH TUESDAY NIGHT)
WILL LOWER MIN TEMPS IN MOST LOCATIONS GIVEN CURRENT TREND AND
MOSTLY CLEAR SKIES. SOME FOG AND ST STILL EXPECTED LATE...HOWEVER
TEMPS WILL FALL INTO THE 30S BEFORE THIS OCCURS.
OVERALL...THE BIGGEST QUESTION IS JUST HOW FOGGY WILL IT GET TONIGHT
SINCE THERE WILL BE MORE WIND IN THE BOUNDARY LAYER THAT LAST NIGHT.
WITH LESS WIND AND MORE LOW LEVEL MOISTURE AND STILL NOT TOO MUCH IN
THE WAY OF CLOUD COVER...FOG IS LIKELY TUESDAY MORNING. FINALLY...
THERE IS THE ISSUE OF RAIN TUESDAY NIGHT WITH THE SYSTEM FROM THE
SOUTHERN PLAINS.
SOME HIGH CLOUDS FROM THE SYSTEM TO OUR SOUTH SHOULD HAVE LITTLE
IMPACT ON OUR FOG POTENTIAL TONIGHT OR OUR CLEARING THE LOW CLOUDS
OUT BY NOON MONDAY. I EXPECT FOG AGAIN TUESDAY MORNING AS WINDS ARE
LIGHTER IN THE BOUNDARY LAYER AND THE CLOUDS FROM THE SYSTEM TO OUR
WEST WILL NOT HAVE MADE IT HERE YET. THE LOW LEVEL MOISTURE WILL BE
INCREASING THROUGH. SEEMS LIKE A GOOD SET UP FOR MORE FOG.
THE SYSTEM COMING IN TUESDAY NIGHT HAS A LOT OF GOOD THINGS GOING
FOR IT. THERE IS STRONG JET SUPPORT...DECENT GULF MOISTURE AT LOW TO
MID LEVELS... STRONG DYNAMICS AND IS WELL SUPPORTED BY THE ENSEMBLES
NOT TO MENTION THE STRONG INTER-MODEL AGREEMENT. SO I INCREASED POPS
TO LIKELY TUESDAY NIGHT. I DO HAVE TO SAY A SYSTEM LIKE THAT COULD
BE SLOWER TO COME OUT... OTHERWISE I WOULD HAVE GONE WITH
CONDITIONAL POPS .... LIKE 80-90 PCT.
&&
.LONG TERM...(330 PM EST SUN NOV 22 2009)
(WEDNESDAY THROUGH SUNDAY)
MAIN CONCERNS IN THE LONG TERM ARE PCPN CHANCES FROM WED THROUGH
NEXT SATURDAY WITH A COMPLEX PATTERN EVOLVING...AND PCPN TYPE DURING
THIS PERIOD AS COLD AIR FILTERS INTO THE AREA.
MODEL CONSENSUS INDICATES THAT THE SYSTEM COMING IN FROM THE SW WILL
HAVE PUSHED THE OCCLUDED FRONT OVER THE AREA OR JUST NORTH OF THE
AREA BY THE BEGINNING OF THE PERIOD WED MORNING. DEEPER MOISTURE
WILL BE MOVING OUT AND MORE SHOWERY TYPE WEATHER CAN BE EXPECTED.
PCPN AT THIS POINT ON WED SHOULD STILL BE ALL RAIN AS THE PUSH OF
COLDER AIR WILL STILL BE WEST OF THE AREA.
THE INITIAL TROUGH THAT PUSHES THE FRONT THROUGH ON WED WILL LINGER
ENOUGH WED NIGHT AND THU TO ALLOW ADDITIONAL ENERGY TO DIVE SE AND
CARVE OUT A LONGER WAVE TROUGH. IT WILL BE WITH THIS TROUGH THAT THE
COLDER AIR WILL ARRIVE AND SOME SNOW MAY MIX IN AT TIMES. SHOWERY
WEATHER WILL CONTINUE INTO THU BEFORE SOME LAKE ENHANCEMENT/EFFECT
WILL BEGIN TO DEVELOP. SNOW MAY MIX WITH RAIN OVERNIGHT WED NIGHT
AND THU NIGHT WITH A COOLER BOUNDARY LAYER.
THIS TROUGH WILL HOLD IN INTO FRI NIGHT. GFS IS TRYING TO SHIFT IT
EAST A LITTLE QUICKER...HOWEVER IT LOOKS TOO QUICK GIVEN THE
AMPLITUDE OF THE DEVELOPING PATTERN. FLOW WILL BECOME ANTI-CYCLONIC
SAT MORNING AND THE RIDGE WILL HOLD INTO EARLY SUN. TEMPS WILL
MODERATE SOME. MODELS ARE TRYING TO HAVE A FRONT APPROACH LATE IN
THE DAY ON SUN AS THE NEXT SHORT WAVE TROUGH MOVES IN. THIS LOOKS TO
BE MORE OF A SUN NIGHT ISSUE...JUST PAST THE CURRENT LONG TERM
PERIOD.
&&
.AVIATION...(1200 AM EST MON NOV 23 2009)
SOME LOW CLOUDS HAVE FORMED DOWNWIND OF LAKE ERIE AND WITH SOUTHEAST
FLOW AROUND THE HIGH PRESSURE...THESE CLOUDS SHOULD BE AFFECTING
JXN...AZO AND BTL AFTER 06Z AND AREAS FURTHER NORTH LATER TONIGHT.
THE CLOUDS...ALONG WITH SOME HIGHER WINDS WILL MEAN LESS FOG
FORMATION THAN LAST NIGHT. FOG AND LOW CLOUDS SHOULD MIX OUT BY 15Z.
&&
.MARINE...(330 PM EST SUN NOV 22 2009)
FOG MAY BE AN ISSUE IN THE NEAR SHORE TONIGHT AND TUESDAY MORNING
TOO. WINDS WILL BE LIGHT SO NO ISSUES WITH WAVE HEIGHTS UNTIL
THURSDAY WHEN THE COLD AIR MOVES IN.
&&
.HYDROLOGY...(330 PM EST SUN NOV 22 2009)
NOT ENOUGH RAIN IS EXPECTED WITH THE SYSTEM TUESDAY NIGHT INTO
THURSDAY TO EVEN CAUSE SIGNIFICANT RIVER RISES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: WDM
SHORT TERM: WDM JK
LONG TERM: NJJ
AVIATION: OSTUNO
MARINE: WDM
HYDROLOGY: WDM
000
FXUS63 KDTX 230455
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1155 PM EST SUN NOV 22 2009
.AVIATION...
A BROAD AREA OF MVFR FOG NOW IN PLACE AREAWIDE AS THE NEAR SURFACE
LAYER CONTINUES TO SATURATE. PERSISTENT 3-6 KT EASTERTLY FLOW
MAINTAINING JUST ENOUGH MIXING TO PREVENT A MORE RAPID DROP IN
VISIBILITY. THIS NOW LOOKS TO BE THE CASE THROUGH THE
NIGHT...ALTHOUGH WILL NOT RULE OUT INTERMITTENT TIMES WHERE WINDS
CAN GO CALM. THIS WILL LOCALLY ENHANCE THE FOG POTENTIAL...MOST
LIKELY DURING THE 10-14Z TIME WINDOW WHERE LIFR CONDITIONS REMAIN
POSSIBLE. ALSO NOTING THE MOST RECENT SATELLITE IMAGERY WHICH
DEPICTS A SMALL AREA OF STRATUS DEVELOPING ON THE NORTHWEST SIDE OF
LAKE ERIE INTO ONTARIO. THIS ADDED MOISTURE FLUX WILL CONTRIBUTE TO
ADDITIONAL STRATUS DEVELOPMENT DOWNSTREAM WITH THE WIND FIELD
MAINTAINING AN EASTERLY COMPONENT. THEREFORE IFR/LIFR CIGS NOT OUT
OF THE QUESTION EITHER...ESPECIALLY IN THE DETROIT AREA. ANY
RESIDUAL STRATUS WILL STRUGGLE TO LIFT/SCATTER INTO EARLY AFTERNOON
GIVEN THE STRENGTH OF THE INVERSION.
&&
.PREV DISCUSSION...ISSUED 331 PM EST SUN NOV 22 2009
SHORT TERM...TONIGHT
ONCE AGAIN WITH SURFACE DEW POINTS HOVERING IN THE LOW TO MID
40S...SOUTHEAST MICHIGAN APPEARS PRIMED FOR FOG ONCE AGAIN...AS LOW
STRATUS IS EXPECTED TO DISSIPATE AROUND SUNSET...SETTING US UP FOR
GOOD RADIATIONAL COOLING WITH THE UPPER LEVEL RIDGE AXIS REMAINING
OVERHEAD. THE DIFFERENCE TONIGHT IS A BETTER GRADIENT/SOUTHEAST WIND
IN THE LOW LEVELS...WHICH AGAIN BEGS THE QUESTION OF LOW STRATUS VS
FOG. THE FLIP SIDE IS THIS EAST-SOUTHEAST FLOW IS FAVORABLE...AS
LAKE ERIE/LAKE ST CLAIR/SOUTHERN LAKE HURON PROVIDES SOME ADDITIONAL
MOISTURE FLUX. WILL BE CARRYING AREAS OF DENSE FOG DEVELOPING IN THE
ZONES...AND WILL DEFER TO THE EVENING SHIFT TO PULL THE TRIGGER ON
AN ADVISORY (IF NEED BE) BASED ON TRENDS. WITH SURFACE WINDS MORE
THAN LIKELY STAYING UP JUST A BIT AND BETTER CHANCE FOR QUICKER LOW
STRATUS DEVELOPMENT...WOULD BE SURPRISED IF MINS ARE AS COLD AS THIS
MORNING...AND WILL CARRY MINS PREDOMINATELY IN THE MID 30S.
LONG TERM...MONDAY THROUGH NEXT SUNDAY
AN ELONGATED SURFACE RIDGE IS FORECAST TO REMAIN OVER THE EASTERN
GREAT LAKES THROUGH TUESDAY. THE LACK OF LOW LEVEL DRY AIR ADVECTION
AND LIMITED MIXING DEPTHS WILL CONTINUE TO MAKE FOG AND LOW CLOUDS
PROBLEMATIC OVER THE NEXT COUPLE OF DAYS...ESPECIALLY WHEN
CONSIDERING THE CONTINUED EASTERLY MOISTURE FLUX OFF LAKE ERIE. WEAK
SHALLOW COLD AIR ADVECTION ON MONDAY MAY PROVE SUFFICIENT ENOUGH TO
STRENGTHEN THE LOW LEVEL INVERSION. THIS RAISES CONCERNS THAT
RESIDUAL MOISTURE FROM MORNING FOG/LOW STRATUS WILL REMAINED TRAPPED
UNDER THE INVERSION WELL INTO THE AFTERNOON /LIKE WHAT HAS
HAPPENED TODAY/. HAVE THEREFORE RAISED AFTERNOON CLOUD COVER AND
LOWERED TEMPS A FEW DEGREES BELOW GUIDANCE /NEAR 50/. SLIGHTLY
BETTER MOISTURE ADVECTION BELOW 925MB ON MON NIGHT WITH THE HELP
OF A WEAK SHORT WAVE TRACKING THROUGH THE OHIO VALLEY SHOULD
RESULT IN A MUCH THICKER AND MORE PERSISTENT STRATUS DECK. HAVE
ACCOUNTED FOR THIS IN BOTH MON NIGHT/TUESDAYS SKY COVER AND TEMPS
/KEEPING MAX TEMPS IN THE UPPER 40S TO NEAR 50 ON TUES/.
THE UPPER WAVE SHOWN ON THE CURRENT WATER VAPOR LOOP OVER THE
PACIFIC NORTHWEST WILL BE THE NEXT CHALLENGE IN THE LONG TERM. THIS
WAVE IS FORECAST TO AMPLIFY ACROSS THE HIGH PLAINS ON MONDAY AND
THEN DEVELOP INTO A CLOSED CIRCULATION OVER KANSAS BY TUESDAY
MORNING. THE 12Z MODEL SUITE APPEARED WELL INITIALIZED WITH THIS
WAVE. THERE STILL HOWEVER REMAINS SOME MODEL SPREAD WITH RESPECT TO
TIMING. THE 12Z ECMWF AND NAM ARE SLOWER IN COMPARISON TO THE GFS.
IN LIGHT OF MODEL TRENDS OVER THE LAST TWO DAYS...PREFERENCE
CONTINUES TO LIE WITH THE SLOWER ECMWF. THIS SOLUTION INDICATES THE
BEST CHANCE FOR RAIN WILL BE LATE TUES NIGHT INTO WED AS THE COMPACT
UPPER LOW AND ASSOCIATED MID LEVEL HEIGHT FALLS ADVANCE ACROSS THE
STATE.
THE UPPER LOW WILL THEN GET QUICKLY EJECTED TO THE NORTHEAST OF THE
STATE BY THURSDAY AS A FAIRLY STRONG NORTHERN STREAM WAVE DIVES INTO
THE DAKOTAS/UPPER MIDWEST...LEADING TO THE DEVELOPMENT OF A LARGE
CUT OFF CIRCULATION OVER THE EASTERN US BY THE END OF THE WEEK.
THERE IS STILL A DECENT AMOUNT OF MODEL SPREAD AMONG THE 12Z SUITE
WITH RESPECT TO THE AMPLITUDE AND TIMING OF THIS WAVE...WHICH LEAD
TO UNCERTAINTY IN STRENGTH AND LOCATION OF THE LARGE CUT OFF LOW.
HAVE ACTUALLY LOWERED POPS A BIT ON THURSDAY AS THE BULK OF MODEL
SOLUTIONS INDICATE MID LEVEL DRYING IN THE WAKE OF THE FIRST WAVE.
PRECIP CHANCES THEN WILL INCREASE THURS NIGHT INTO FRI WITH THE
POTENTIAL OF THE SECONDARY UPPER LOW IMPACTING THE REGION. IN LIGHT
OF GFS THICKNESS FIELDS...WILL MAINTAIN A CHANCE OF BOTH RAIN AND
SNOW THURS NIGHT INTO FRI /ALTHOUGH THE ECMWF CONTINUES TO SUGGEST
THAT BOUNDARY LAYER TEMPS WILL SUPPORT MAINLY RAIN/.
MARINE...
THERE WILL BE A GRADUAL INCREASE IN SOUTHEAST WINDS MONDAY INTO
TUESDAY AS THE HIGH RETREATS EAST...AWAY FROM THE AREA. THE PATTERN
BECOMES ACTIVE AGAIN MID/LATE NEXT WEEK AS A STRONG SHORTWAVE AND
ASSOCIATED JET STREAK DIG INTO THE UPPER MIDWEST AND LEAD TO THE
DEVELOPMENT OF A LARGE UPPER LEVEL LOW OVER/NEAR THE REGION. THIS
TIME FRAME WILL BRING UNSETTLED WEATHER AND HIGHER WIND AND WAVES.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MR
SHORT TERM...SF
LONG TERM....SC
MARINE.......SF
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KAPX 230328
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1028 PM EST SUN NOV 22 2009
.SYNOPSIS.../ISSUED AT 316 PM/
HIGH PRESSURE OVER NEW ENGLAND WILL MAINTAIN ITS INFLUENCE OVER THE
GREAT LAKES THROUGH MONDAY EVEN AS IT DRIFTS INTO THE CANADIAN
MARITIME PROVINCES. THIS WILL RESULT IN A CONTINUATION OF THE
CURRENT PATTERN...WITH NIGHTTIME AND MORNING FOG GRADUALLY GIVING
WAY TO SUNNY SKIES. BUT THERE COULD BE SOME LOCATIONS WHERE LOW
CLOUDS NEVER DISSIPATE. THE NEXT CHANCE OF RAIN WILL ARRIVE TUESDAY
NIGHT AND WEDNESDAY AS A STORM SYSTEM LIFTS INTO THE REGION.
TEMPERATURES WILL REMAIN WARMER THAN NORMAL THROUGH MID-NEXT WEEK
AND THEN TURN COLDER BEHIND THIS SYSTEM.
JH
&&
.SHORT TERM.../ISSUED AT 1017 PM/...TONIGHT
ON THE LATEST SURFACE WEATHER MAP...1036 MB HIGH PRESSURE WAS
CENTERED ACROSS NORTHERN NEW ENGLAND WITH 1010 MB LOW PRESSURE OVER
EASTERN WYOMING. THIS LEAVES NORTHERN MICHIGAN IN A SOUTH TO
SOUTHEAST LOW LEVEL FLOW. SURFACE OBSERVATIONS AND SATELLITE
IMAGERY SHOW AN AREA OF STRATUS ACROSS CENTRAL AND EASTERN
SECTIONS OF THE FORECAST AREA. THERE IS SOME LIGHT FOG AS WELL
WITH VISIBILITIES GENERALLY 1 TO 2 MILES OR HIGHER SO FAR. THE
MAIN SHORT TERM FORECAST CONCERN REVOLVES AROUND HOW DENSE AND
WIDESPREAD FOG WILL BE.
PESKY AREA OF STRATUS HAS EXPANDED NORTH/WESTWARD OVER THE LAST
COUPLE OF HOURS. HOWEVER...THIS CLOUD MASS IS MOVING NORTHWARD WITH
SOUTHERN EDGE NOT TO FAR SOUTH OF OUR SOUTHERN FORECAST AREA
BORDER (GENERALLY GLADWIN TO SOUTHEAST OF MANISTEE). SOME MIXING
FROM SOUTHERLY FLOW IN PLACE OVERNIGHT. THE EXPECTATION IS THAT
THIS WILL KEEP FOG FROM BECOMING WIDESPREAD AND DENSE.
OTHERWISE...PARTLY TO MOSTLY CLOUDY SKIES WITH LOWS IN THE LOWER
TO MIDDLE 30S FOR THE MOST PART.
SULLIVAN
&&
.LONG TERM.../ISSUED AT 316 PM/...MONDAY AND BEYOND
OUTSIDE OF FOG/STRATUS ISSUES MONDAY/TUESDAY MORNINGS...THE MAIN
FORECAST ISSUES FOR THE UPCOMING WEEK WILL REVOLVE AROUND UPPER
LEVEL ENERGY ROTATING OUT OF THE CENTRAL PLAINS AND SOUTHERN CANADA
WED-THU. THERE APPEARS TO BE SOME CLUSTERING OF MODEL SOLUTIONS
WITH THE SOUTHERN PIECE OF ENERGY ON WEDNESDAY...BUT STILL PLENTY OF
MODEL SPREAD WITH THE HANDLING OF THE SECOND FEATURE FOR
THANKSGIVING DAY. THE OPERATIONAL ECMWF CONTINUES TO BE THE SLOWEST
OF ALL SOLUTIONS...AND WILL TREND TOWARD THE MAJORITY FASTER AND
SLIGHTLY FURTHER NORTH SOLUTIONS.
MONDAY NIGHT/TUESDAY...THE INITIAL SHORTWAVES AHEAD OF THE MAIN
UPPER LOW OVER THE CENTRAL PLAINS WILL DRAW A PLUME OF DEEPER
MOISTURE NORTHWARD FROM THE CENTRAL APPALACHIANS TO THE EASTERN
GREAT LAKES...PASSING EAST OF THE AREA. FOG/STRATUS WILL CONTINUE
TO BE THE MAIN CONCERNS. CIRRUS WILL INHIBIT COOLING TO SOME DEGREE
MONDAY NIGHT...BUT THE GRADIENT WILL ACTUALLY BE A LITTLE WEAKER -
LESS THAN 20KT. I LIKE THE MIDNIGHT SHIFT/S IDEA OF ADDING FOG FOR
MONDAY NIGHT/TUESDAY MORNING...ESPECIALLY OVER EASTERN UPPER WITH
PREVAILING MOIST SOUTHEAST MARINE FLOW.
UPPER LOW MOVES INTO THE CENTRAL MISSISSIPPI VALLEY ON TUESDAY WITH
WARM CONVEYOR BELT HELPING TO SPREAD CLOUDS BUT NOT PCPN INTO
NORTHERN MICHIGAN. UPPER FEATURE SLIDES TOWARD SOUTHWEST MICHIGAN
BY WEDNESDAY MORNING...AND THEN INTO NORTHERN LAKE HURON BY LATE
AFTERNOON. INITIAL SURGE OF RAIN EARLY WEDNESDAY MORNING WILL PUSH
NORTH THROUGH THE AREA THROUGHOUT THE MORNING ON THE NOSE OF H8
THETA-E MOISTURE PLUME...PIVOTING INTO EASTERN UPPER BY MIDDAY. IN
IT/S WAKE...THE HEAVIEST AND MOST STEADY PCPN WILL LIKELY END...AS
DEEPEST MOISTURE AND FORCING SLIDE NORTHEAST. PLENTY OF LOW LEVEL
MOISTURE BENEATH H9 FOR THE AFTERNOON HOURS AND COULD SEE SOME
DRIZZLE. NORTHERN MICHIGAN ON THE WARM SIDE OF THE STORM...SO JUST
LIQUID DURING THE DAY WEDNESDAY /NO SNOW/.
MODEL ISSUES BEGIN TO APPEAR BY WEDNESDAY NIGHT AS UPSTREAM PIECE OF
UPPER LEVEL ENERGY DROPS TOWARD THE MISSISSIPPI VALLEY/NRN OHIO
VALLEY. BEST PCPN CHANCES WILL LIKELY BE TO THE WEST OF
INTERSTATE-75...WITHIN DEVELOPING DEFORMATION AXIS ACROSS LAKE
MICHIGAN. WILL NOT GET TOO DETAILED THIS FAR OUT...GOING WITH HIGH
CHANCE/LOW LIKELY POPS FOR THANKSGIVING DAY. AS FAR AS PCPN
TYPE...RAIN GRADUALLY TURNING TO SNOW ON THANKSGIVING DAY. WHAT
WILL MAKE THIS A DIFFICULT PCPN TYPE CASE IS THAT THE COLDEST CORE
OF TEMPS ASSOCIATED WITH UPPER LOW MAY ACTUALLY FOCUS OVER SOUTHERN
MICHIGAN/NRN OHIO VALLEY - WITH SLIGHTLY WARMER READINGS WRAPPING
BACK OVER NORTHERN MICHIGAN. AT THIS POINT...WAY TOO MANY UNKNOWNS
TO GET VERY SPECIFIC.
SYNOPTIC MOISTURE STRIPS OUT THE EAST THURSDAY NIGHT WITH DRY SLOT
MOVING INTO NORTHERN MICHIGAN...POSSIBLY LEAVING SOME LIGHT PCPN
/FREEZING DRIZZLE?/ FOR LATER THURSDAY NIGHT INTO FRIDAY MORNING.
UPPER RIDGE BUILDS INTO THE AREA FRIDAY/SATURDAY...BRINGING DRIER
WEATHER AND SEASONABLY MILD TEMPERATURES.
JK
&&
.MARINE.../ISSUED AT 316 PM/
GUSTY SOUTH WINDS HAVE PRODUCED SMALL CRAFT WINDS/WAVES ACROSS
WHITEFISH BAY THIS AFTERNOON...WHICH WILL PERSIST INTO THE EVENING
HOURS BEFORE DIMINISHING. OTHERWISE...SOUTHERLY WINDS WILL DOMINATE
ON THE LAKES OVER THE NEXT SEVERAL DAYS WITH CONDITIONS GENERALLY
BELOW SMALL CRAFT ANTICIPATED.
ADAM
&&
.AVIATION.../ISSUED AT 633 PM/...VALID FOR 00Z TAFS
MVFR CONDITIONS EXPECTED TO CONTINUE AT APN OVER THE NEXT COUPLE
OF HOURS AND VFR AT TVC AND PLN. WILL THEN BANK ON STRATUS/FOG
REDEVELOPING LATER THIS EVENING AND BECOMING SUBSTANTIAL
OVERNIGHT INTO MONDAY MORNING. OVERALL CONFIDENCE NOT GREAT...AND
INCREASING SOUTHERLY FLOW COULD KEEP STRATUS AND/OR FOG AT BAY.
BUT WILL CONTINUE WITH IFR CONDITIONS DURING THE OVERNIGHT PERIOD.
VRF CONDITIONS THEN EXPECTED TO REEMERGE LATER MONDAY MORNING INTO
MONDAY AFTERNOON.
AJS
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR LSZ321.
&&
$$
000
FXUS63 KGRR 230303
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1003 PM EST SUN NOV 22 2009
LATEST UPDATE...SHORT TERM...
.SYNOPSIS...(330 PM EST SUN NOV 22 2009)
THE LARGE HIGH PRESSURE SYSTEM THAT WAS OVER THE GREAT LAKES WAS
MOVING OFF INTO THE NORTH ATLANTIC TONIGHT. THAT WILL ALLOW A
DEVELOPING STORM SYSTEM OVER THE SOUTHWEST UNITED STATES TO MOVE
INTO THE SOUTHERN PLAINS TUESDAY AND INTO THE GREAT LAKES WEDNESDAY.
THE SOUTHERLY WINDS AHEAD OF THE STORM WILL CONTINUE THE MILD
WEATHER WITH AREAS OF FOG DURING THE EARLY TO MID MORNING HOURS.
THEN AFTERNOON SUNSHINE WILL PREVAIL MONDAY AND TUESDAY. PERIODS OF
RAIN WILL MOVE INTO THE AREA TUESDAY NIGHT AND CONTINUE INTO
WEDNESDAY. COLDER AIR BEHIND THE STORM MAY MIX SNOW WITH THE RAIN
WEDNESDAY NIGHT.
&&
.SHORT TERM...(1003 PM EST SUN NOV 22 2009)
(TONIGHT THROUGH TUESDAY NIGHT)
WILL LOWER MIN TEMPS IN MOST LOCATIONS GIVEN CURRENT TREND AND
MOSTLY CLEAR SKIES. SOME FOG AND ST STILL EXPECTED LATE...HOWEVER
TEMPS WILL FALL INTO THE 30S BEFORE THIS OCCURS.
OVERALL...THE BIGGEST QUESTION IS JUST HOW FOGGY WILL IT GET TONIGHT
SINCE THERE WILL BE MORE WIND IN THE BOUNDARY LAYER THAT LAST NIGHT.
WITH LESS WIND AND MORE LOW LEVEL MOISTURE AND STILL NOT TOO MUCH IN
THE WAY OF CLOUD COVER...FOG IS LIKELY TUESDAY MORNING. FINALLY...
THERE IS THE ISSUE OF RAIN TUESDAY NIGHT WITH THE SYSTEM FROM THE
SOUTHERN PLAINS.
SOME HIGH CLOUDS FROM THE SYSTEM TO OUR SOUTH SHOULD HAVE LITTLE
IMPACT ON OUR FOG POTENTIAL TONIGHT OR OUR CLEARING THE LOW CLOUDS
OUT BY NOON MONDAY. I EXPECT FOG AGAIN TUESDAY MORNING AS WINDS ARE
LIGHTER IN THE BOUNDARY LAYER AND THE CLOUDS FROM THE SYSTEM TO OUR
WEST WILL NOT HAVE MADE IT HERE YET. THE LOW LEVEL MOISTURE WILL BE
INCREASING THROUGH. SEEMS LIKE A GOOD SET UP FOR MORE FOG.
THE SYSTEM COMING IN TUESDAY NIGHT HAS A LOT OF GOOD THINGS GOING
FOR IT. THERE IS STRONG JET SUPPORT...DECENT GULF MOISTURE AT LOW TO
MID LEVELS... STRONG DYNAMICS AND IS WELL SUPPORTED BY THE ENSEMBLES
NOT TO MENTION THE STRONG INTER-MODEL AGREEMENT. SO I INCREASED POPS
TO LIKELY TUESDAY NIGHT. I DO HAVE TO SAY A SYSTEM LIKE THAT COULD
BE SLOWER TO COME OUT... OTHERWISE I WOULD HAVE GONE WITH
CONDITIONAL POPS .... LIKE 80-90 PCT.
&&
.LONG TERM...(330 PM EST SUN NOV 22 2009)
(WEDNESDAY THROUGH SUNDAY)
MAIN CONCERNS IN THE LONG TERM ARE PCPN CHANCES FROM WED THROUGH
NEXT SATURDAY WITH A COMPLEX PATTERN EVOLVING...AND PCPN TYPE DURING
THIS PERIOD AS COLD AIR FILTERS INTO THE AREA.
MODEL CONSENSUS INDICATES THAT THE SYSTEM COMING IN FROM THE SW WILL
HAVE PUSHED THE OCCLUDED FRONT OVER THE AREA OR JUST NORTH OF THE
AREA BY THE BEGINNING OF THE PERIOD WED MORNING. DEEPER MOISTURE
WILL BE MOVING OUT AND MORE SHOWERY TYPE WEATHER CAN BE EXPECTED.
PCPN AT THIS POINT ON WED SHOULD STILL BE ALL RAIN AS THE PUSH OF
COLDER AIR WILL STILL BE WEST OF THE AREA.
THE INITIAL TROUGH THAT PUSHES THE FRONT THROUGH ON WED WILL LINGER
ENOUGH WED NIGHT AND THU TO ALLOW ADDITIONAL ENERGY TO DIVE SE AND
CARVE OUT A LONGER WAVE TROUGH. IT WILL BE WITH THIS TROUGH THAT THE
COLDER AIR WILL ARRIVE AND SOME SNOW MAY MIX IN AT TIMES. SHOWERY
WEATHER WILL CONTINUE INTO THU BEFORE SOME LAKE ENHANCEMENT/EFFECT
WILL BEGIN TO DEVELOP. SNOW MAY MIX WITH RAIN OVERNIGHT WED NIGHT
AND THU NIGHT WITH A COOLER BOUNDARY LAYER.
THIS TROUGH WILL HOLD IN INTO FRI NIGHT. GFS IS TRYING TO SHIFT IT
EAST A LITTLE QUICKER...HOWEVER IT LOOKS TOO QUICK GIVEN THE
AMPLITUDE OF THE DEVELOPING PATTERN. FLOW WILL BECOME ANTI-CYCLONIC
SAT MORNING AND THE RIDGE WILL HOLD INTO EARLY SUN. TEMPS WILL
MODERATE SOME. MODELS ARE TRYING TO HAVE A FRONT APPROACH LATE IN
THE DAY ON SUN AS THE NEXT SHORT WAVE TROUGH MOVES IN. THIS LOOKS TO
BE MORE OF A SUN NIGHT ISSUE...JUST PAST THE CURRENT LONG TERM
PERIOD.
&&
.AVIATION...(617 PM EST SUN NOV 22 2009)
THERE SHOULD BE ENOUGH LOW LEVEL MOISTURE OVERNIGHT FOR SOME FOG
FORMATION ALTHOUGH THE WINDS WILL BE A BIT HIGHER THAN LAST NIGHT.
THIS WILL KEEP VSBYS FROM CRASHING AS MUCH AS LAST NIGHT...ALTHOUGH
MOSTLY CLEAR SKIES WILL ALLOW ENOUGH RADIATIONAL COOLING TO BRING
SOME IFR CONDITIONS LATE TONIGHT. FOG AND ANY LOW CLOUDS SHOULD MIX
OUT BY 15Z.
&&
.MARINE...(330 PM EST SUN NOV 22 2009)
FOG MAY BE AN ISSUE IN THE NEAR SHORE TONIGHT AND TUESDAY MORNING
TOO. WINDS WILL BE LIGHT SO NO ISSUES WITH WAVE HEIGHTS UNTIL
THURSDAY WHEN THE COLD AIR MOVES IN.
&&
.HYDROLOGY...(330 PM EST SUN NOV 22 2009)
NOT ENOUGH RAIN IS EXPECTED WITH THE SYSTEM TUESDAY NIGHT INTO
THURSDAY TO EVEN CAUSE SIGNIFICANT RIVER RISES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: WDM
SHORT TERM: WDM JK
LONG TERM: NJJ
AVIATION: OSTUNO
MARINE: WDM
HYDROLOGY: WDM
000
FXUS63 KMQT 230029 AAA
AFDMQT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MARQUETTE MI
729 PM EST SUN NOV 22 2009
UPDATED FOR 00Z AVIATION DISCUSSION
.SYNOPSIS...
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN UPPER RIDGE AXIS
OVER WESTERN QUEBEC AND A LONGWAVE TROUGH OVER THE NORTHERN AND
CENTRAL PLAINS AND INTO CENTRAL CANADA. ANOTHER TROUGH CONTINUES TO
DIG OVER THE PACIFIC NORTHWEST. A WEAK SHORTWAVE IS OVER THE EAST
END OF THE FORECAST AREA THIS AFTERNOON...WITH OTHERS OVER EASTERN
DAKOTAS AND MINNESOTA. SURFACE ANALYSIS SUGGEST A COLD FRONT
EXTENDING FROM CENTRAL HUDSON BAY SOUTH THROUGH MINNESOTA TO A WEAK
LOW OVER EASTERN NEBRASKA AND A LARGE HIGH OVER THE CANADIAN
MARITIME CAUSING A SOUTHERLY FLOW ACROSS THE FORECAST AREA. THIS
SOUTHERLY FLOW BROUGHT ABNORMALLY WARM AIR AND SOME LOW LEVEL
MOISTURE INTO THE AREA WHICH CAUSED CONSIDERABLE FOG THIS MORNING.
THIS MORNING AREA RAOBS INDICATED THE AIR MASS WAS QUITE DRY ABOVE
800MB. QUITE A BIT OF HIGH CLOUDS ARE STREAMING INTO THIS AREA AHEAD
OF OF THE FRONT. A LOW LEVEL JET OVER THE AIR CONTINUES TO MIX TO
SURFACE OVER THE LAKE.
&&
.SHORT TERM...
THE MAIN CONCERN FOR TONIGHT AND MONDAY WILL BE WITH THE POTENTIAL
FOR RAIN AND FOG.
THE MID LEVEL RIDGE WILL PUSH INTO EASTERN QUEBEC WITH THE
ASSOCIATED HIGH WEAKENING AS IT REACHES NEW ENGLAND TONIGHT. THE MID
LEVEL TROUGH OVER THE NORTHERN PLAINS WILL WEAKEN AND SETTLE OVER
HUDSON BAY TONIGHT. THE ASSOCIATED SHORTWAVE WILL WEAKEN AS WELL AS
IT STALLS OUT OVER THE UPPER MISSISSIPPI RIVER VALLEY.
MEANWHILE...THE TROUGH OVER THE PACIFIC NORTHWEST CONTINUE TO DEEPEN
AS IT MOVES INTO THE NORTHERN HIGH PLAINS. THE COLD FRONT OVER
MINNESOTA WILL REALIGN WITH THE WEAKEN SHORTWAVE OVER CANADA AND
STRETCH FROM SOUTHERN JAMES BAY SOUTHWEST THROUGH THE MINNESOTA
ARROWHEAD TO EASTERN SOUTH DAKOTA. SURFACE DEW POINT ARE IN THE LOW
TO MID 40S ACROSS THE CWA THIS AFTERNOON. AFTER SUNDOWN WITH THE
CLEARING SKIES OVER THE EAST...TEMPERATURES WILL FALL RAPIDLY WILL
BE FAVORABLE FOR FOG DEVELOPMENT OVERNIGHT. INCREASE HUMIDITY AHEAD
OF THE COLD FRONT WILL INCREASE THE POSSIBILITY OF RAIN AND FOG
THERE AS WELL. THUS WILL TENDED TO GO WITH THE A LITTLE POPS LATER
TONIGHT WITH INFLUX OF MOISTURE AND SOME ISENTROPIC ASCENT AHEAD OF
THE FRONT.
THE MID LEVEL TROUGH OVER THE HIGH PLAINS WILL DEEPEN INTO A CUTOFF
LOW OVER THE CENTRAL PLAINS ON MONDAY. WEAK SHORTWAVES EJECTED OUT
OF THE BASE OF THIS LOW WILL SWEEP ACROSS THE FORECAST AREA ON
MONDAY. THE FINAL REMNANT OF THE WEAKENING TROUGH WILL SHIFT INTO
WISCONSIN. THE NEBRASKA SURFACE LOW WILL DEEPEN AS IT INCHES INTO
EASTERN NEBRASKA. A STRONG SOUTHERLY FLOW AND THE ALIGNMENT OF THE
LOW LEVEL JET WILL HOLD THE FRONTAL SYSTEM STATIONARY JUST TO THE
NORTH OF LAKE SUPERIOR. AS WITH THIS MORNING...PATCHY FOG SHOULD
LAST THROUGH THE EARLY MORNING HOURS AFTER SUNRISE. DRY AIR
ADVECTING INTO THE AREA AHEAD OF THE NEBRASKA LOW WILL END THE FOG
AND LIMIT ANY PRECIPITATION ACROSS THE AREA ON MONDAY.
&&
LONGER TERM 00Z TUE ONWARD...
FORECAST PROBLEM CONTINUES TO BE THE UPCOMING STORM AND WHAT IT WILL
DO...PCPN TYPE AND WHEN IT WILL OCCUR. THE STORM SYSTEM IS CURRENTLY
IN THE PACIFIC NW NOW AND WILL DIG SE AND FORM A CLOSED LOW WITH IT
THIS FORECAST PERIOD. NAM BRINGS IN ANOTHER TROUGH INTO THE PACIFIC
NW MON NIGHT AND THEN MOVES IT EAST BEFORE DIGGING IT INTO THE
TROUGH ON TUE. WHAT THIS DOES THEN IS KICKS THE CLOSED LOW OUT
SLOWLY ENE AND ANOTHER CLOSED 500 MB LOW FORMS OVER THE NORTHERN
PLAINS TUE NIGHT AND DIGS SE INTO THE MISSOURI RIVER VALLEY NEAR
SIOUX CITY IA 00Z THU WHILE THE OTHER LOW IS IN CENTRAL LOWER
MICHIGAN. DEEPER MOISTURE DOES NOT ARRIVE UNTIL TUE NIGHT ALONG WITH
SOME BETTER DYNAMICS ACCORDING TO THE NAM. GFS IS FAIRLY SIMILAR TO
THE NAM EXCEPT BRINGS PCPN IN A BIT QUICKER. BASICALLY...WITH MODELS
STILL NOT CONSISTENT ON SOLUTION...WILL NOT MAKE VERY MANY CHANGES
TO THE GOING FORECAST. KEPT LIKELY POPS IN FOR WED THROUGH THU WITH
DECENT MOISTURE AROUND. ONLY CHANGE I DID MAKE WAS TO REMOVE SNOW
FROM WED AS COLD AIR DOES NOT COME IN UNTIL WED NIGHT. SYSTEM REALLY
DOES NOT HAVE MUCH COLD AIR TO WORK WITH AND WILL HAVE TO
MANUFACTURE ITS OWN COLD AIR TO DO SO.
IN THE EXTENDED...CONTINUED TO GO WITH THE 00Z ECMWF FOR THIS
FORECAST PERIOD AS IT HAS BEEN THE MOST CONSISTENT MODEL FOR THE
PAST SEVERAL DAYS. ECMWF SHOWS A TROUGH AND CLOSED LOW AFFECTING THE
AREA FOR THU AND THEN RIDGING FOR FRI AND SAT AND INTO SUN AS WELL.
DID NOT MAKE ANY CHANGES TO THE EXTENDED AT ALL. STILL HAVE LIKELY
POPS IN FOR THU AND THEN DRY FOR FRI NIGHT THROUGH SUN EVEN AS A
COLD FRONT MOVES THROUGH ON SUN. TEMPERATURES CONTINUE TO BE MILD
AND NORMAL TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /FOR THE 00Z TAF ISSUANCE/...
A MOIST LOW-LVL SOUTHERLY FLOW CONTINUES OVER THE AREA AND SHOULD
CONTRIBUTE TO ANOTHER ROUND OF FOG LATE THIS EVENING AND OVERNIGHT.
THE UPSLOPE FLOW WILL FAVOR KSAW FOR THE THICKER FOG WHERE I EXPECT
CONDITIONS TO LOWER TO NEAR IFR BY LATE EVENING AND THEN LIFR BY
06Z. AT KCMX...LESS FAVORABLE FLOW SHOULD KEEP PREVAILING CONDITIONS
THERE VFR...BUT GIVEN MOIST DEWPOINTS PUT IN A TEMPO GRP 10-14Z FOR
MVFR CONDITIONS. DIURNAL MIXING SHOULD ALLOW CONDITIONS TO IMPROVE
TO VFR AT SAW BY EARLY MON AFTERNOON.
LLWS CAN BE EXPECTED AT BOTH TAF SITES UNTIL 06Z WITH LOW-LVL JET
MAX AROUND 1KFT OFF THE SFC.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
WITH LAKE SUPERIOR IN BETWEEN LOW PRESSURE OVER THE CENTRAL PLAINS
AND THE HIGH OVER THE NORTHEAST STATES...SOUTHERLY WINDS TO 25 KNOTS
WILL PREVAIL INTO MONDAY MORNING. A FEW WIND GUSTS TO 28 KNOTS WILL
BE POSSIBLE TONIGHT MAINLY OVER THE EASTERN LAKE. WINDS WILL REMAIN
UNDER 20 KNOTS INTO WEDNESDAY...WHEN A STORM SYSTEM APPROACHES THE
UPPER GREAT LAKES AND WINDS BEGIN TO INCREASE OUT OF THE NORTH AND
NORTHEAST WITH GALES POSSIBLE LATE WEDNESDAY THROUGH FRIDAY MORNING.
LOCALLY DENSE PATCHY FOG IS POSSIBLE TONIGHT ACROSS LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS/SHORT TERM...DLG
LONG TERM...07
AVIATION...JV
MARINE...DLG
000
FXUS63 KDTX 222349
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
649 PM EST SUN NOV 22 2009
.AVIATION...
THE AMBIENT CONDITIONS REMAIN VIRTUALLY UNCHANGED FROM LAST NIGHT.
AMPLE BOUNDARY LAYER MOISTURE WILL EXIST TO PROMOTE FOG/STRATUS
DEVELOPMENT THROUGH THE NIGHT AS GOOD RADIATIONAL COOLING
STRENGTHENS THE INVERSION. A SLIGHTLY STRONGER EAST-SOUTHEAST LOW
LEVEL GRADIENT DOES EXIST TONIGHT. THIS MAY PRECLUDE A MORE
WIDESPREAD DENSE FOG PROBLEM BUT AID IN THE MOISTURE FLUX
/ESPECIALLY OFF LAKE ERIE/. THIS WOULD SUGGEST A COMBINATION OF
FOG/STRATUS EVENTUALLY LEADING TO IFR/LIFR CONDITIONS...PRIMARILY
BETWEEN 09-14Z. ONCE AGAIN ANY RESIDUAL STRATUS WILL STRUGGLE TO
LIFT/SCATTER INTO MONDAY AFTERNOON GIVEN THE STRENGTH OF THE
INVERSION.
&&
.PREV DISCUSSION...ISSUED 331 PM EST SUN NOV 22 2009
SHORT TERM...TONIGHT
ONCE AGAIN WITH SURFACE DEW POINTS HOVERING IN THE LOW TO MID
40S...SOUTHEAST MICHIGAN APPEARS PRIMED FOR FOG ONCE AGAIN...AS LOW
STRATUS IS EXPECTED TO DISSIPATE AROUND SUNSET...SETTING US UP FOR
GOOD RADIATIONAL COOLING WITH THE UPPER LEVEL RIDGE AXIS REMAINING
OVERHEAD. THE DIFFERENCE TONIGHT IS A BETTER GRADIENT/SOUTHEAST WIND
IN THE LOW LEVELS...WHICH AGAIN BEGS THE QUESTION OF LOW STRATUS VS
FOG. THE FLIP SIDE IS THIS EAST-SOUTHEAST FLOW IS FAVORABLE...AS
LAKE ERIE/LAKE ST CLAIR/SOUTHERN LAKE HURON PROVIDES SOME ADDITIONAL
MOISTURE FLUX. WILL BE CARRYING AREAS OF DENSE FOG DEVELOPING IN THE
ZONES...AND WILL DEFER TO THE EVENING SHIFT TO PULL THE TRIGGER ON
AN ADVISORY (IF NEED BE) BASED ON TRENDS. WITH SURFACE WINDS MORE
THAN LIKELY STAYING UP JUST A BIT AND BETTER CHANCE FOR QUICKER LOW
STRATUS DEVELOPMENT...WOULD BE SURPRISED IF MINS ARE AS COLD AS THIS
MORNING...AND WILL CARRY MINS PREDOMINATELY IN THE MID 30S.
LONG TERM...MONDAY THROUGH NEXT SUNDAY
AN ELONGATED SURFACE RIDGE IS FORECAST TO REMAIN OVER THE EASTERN
GREAT LAKES THROUGH TUESDAY. THE LACK OF LOW LEVEL DRY AIR ADVECTION
AND LIMITED MIXING DEPTHS WILL CONTINUE TO MAKE FOG AND LOW CLOUDS
PROBLEMATIC OVER THE NEXT COUPLE OF DAYS...ESPECIALLY WHEN
CONSIDERING THE CONTINUED EASTERLY MOISTURE FLUX OFF LAKE ERIE. WEAK
SHALLOW COLD AIR ADVECTION ON MONDAY MAY PROVE SUFFICIENT ENOUGH TO
STRENGTHEN THE LOW LEVEL INVERSION. THIS RAISES CONCERNS THAT
RESIDUAL MOISTURE FROM MORNING FOG/LOW STRATUS WILL REMAINED TRAPPED
UNDER THE INVERSION WELL INTO THE AFTERNOON /LIKE WHAT HAS
HAPPENED TODAY/. HAVE THEREFORE RAISED AFTERNOON CLOUD COVER AND
LOWERED TEMPS A FEW DEGREES BELOW GUIDANCE /NEAR 50/. SLIGHTLY
BETTER MOISTURE ADVECTION BELOW 925MB ON MON NIGHT WITH THE HELP
OF A WEAK SHORT WAVE TRACKING THROUGH THE OHIO VALLEY SHOULD
RESULT IN A MUCH THICKER AND MORE PERSISTENT STRATUS DECK. HAVE
ACCOUNTED FOR THIS IN BOTH MON NIGHT/TUESDAYS SKY COVER AND TEMPS
/KEEPING MAX TEMPS IN THE UPPER 40S TO NEAR 50 ON TUES/.
THE UPPER WAVE SHOWN ON THE CURRENT WATER VAPOR LOOP OVER THE
PACIFIC NORTHWEST WILL BE THE NEXT CHALLENGE IN THE LONG TERM. THIS
WAVE IS FORECAST TO AMPLIFY ACROSS THE HIGH PLAINS ON MONDAY AND
THEN DEVELOP INTO A CLOSED CIRCULATION OVER KANSAS BY TUESDAY
MORNING. THE 12Z MODEL SUITE APPEARED WELL INITIALIZED WITH THIS
WAVE. THERE STILL HOWEVER REMAINS SOME MODEL SPREAD WITH RESPECT TO
TIMING. THE 12Z ECMWF AND NAM ARE SLOWER IN COMPARISON TO THE GFS.
IN LIGHT OF MODEL TRENDS OVER THE LAST TWO DAYS...PREFERENCE
CONTINUES TO LIE WITH THE SLOWER ECMWF. THIS SOLUTION INDICATES THE
BEST CHANCE FOR RAIN WILL BE LATE TUES NIGHT INTO WED AS THE COMPACT
UPPER LOW AND ASSOCIATED MID LEVEL HEIGHT FALLS ADVANCE ACROSS THE
STATE.
THE UPPER LOW WILL THEN GET QUICKLY EJECTED TO THE NORTHEAST OF THE
STATE BY THURSDAY AS A FAIRLY STRONG NORTHERN STREAM WAVE DIVES INTO
THE DAKOTAS/UPPER MIDWEST...LEADING TO THE DEVELOPMENT OF A LARGE
CUT OFF CIRCULATION OVER THE EASTERN US BY THE END OF THE WEEK.
THERE IS STILL A DECENT AMOUNT OF MODEL SPREAD AMONG THE 12Z SUITE
WITH RESPECT TO THE AMPLITUDE AND TIMING OF THIS WAVE...WHICH LEAD
TO UNCERTAINTY IN STRENGTH AND LOCATION OF THE LARGE CUT OFF LOW.
HAVE ACTUALLY LOWERED POPS A BIT ON THURSDAY AS THE BULK OF MODEL
SOLUTIONS INDICATE MID LEVEL DRYING IN THE WAKE OF THE FIRST WAVE.
PRECIP CHANCES THEN WILL INCREASE THURS NIGHT INTO FRI WITH THE
POTENTIAL OF THE SECONDARY UPPER LOW IMPACTING THE REGION. IN LIGHT
OF GFS THICKNESS FIELDS...WILL MAINTAIN A CHANCE OF BOTH RAIN AND
SNOW THURS NIGHT INTO FRI /ALTHOUGH THE ECMWF CONTINUES TO SUGGEST
THAT BOUNDARY LAYER TEMPS WILL SUPPORT MAINLY RAIN/.
MARINE...
THERE WILL BE A GRADUAL INCREASE IN SOUTHEAST WINDS MONDAY INTO
TUESDAY AS THE HIGH RETREATS EAST...AWAY FROM THE AREA. THE PATTERN
BECOMES ACTIVE AGAIN MID/LATE NEXT WEEK AS A STRONG SHORTWAVE AND
ASSOCIATED JET STREAK DIG INTO THE UPPER MIDWEST AND LEAD TO THE
DEVELOPMENT OF A LARGE UPPER LEVEL LOW OVER/NEAR THE REGION. THIS
TIME FRAME WILL BRING UNSETTLED WEATHER AND HIGHER WIND AND WAVES.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MR
SHORT TERM...SF
LONG TERM....SC
MARINE.......SF
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KAPX 222341
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
641 PM EST SUN NOV 22 2009
.SYNOPSIS.../ISSUED AT 316 PM/
HIGH PRESSURE OVER NEW ENGLAND WILL MAINTAIN ITS INFLUENCE OVER THE
GREAT LAKES THROUGH MONDAY EVEN AS IT DRIFTS INTO THE CANADIAN
MARITIME PROVINCES. THIS WILL RESULT IN A CONTINUATION OF THE
CURRENT PATTERN...WITH NIGHTTIME AND MORNING FOG GRADUALLY GIVING
WAY TO SUNNY SKIES. BUT THERE COULD BE SOME LOCATIONS WHERE LOW
CLOUDS NEVER DISSIPATE. THE NEXT CHANCE OF RAIN WILL ARRIVE TUESDAY
NIGHT AND WEDNESDAY AS A STORM SYSTEM LIFTS INTO THE REGION.
TEMPERATURES WILL REMAIN WARMER THAN NORMAL THROUGH MID-NEXT WEEK
AND THEN TURN COLDER BEHIND THIS SYSTEM.
JH
&&
.SHORT TERM.../ISSUED AT 316 PM/...TONIGHT
HIGH PRESSURE WILL REMAIN DOMINANT ACROSS THE GREAT LAKES/NEW
ENGLAND THROUGH TONIGHT UNDER STEADIER S/SE LOW LEVEL FLOW. SAME
ISSUES AS THE PREVIOUS FEW NIGHTS...HOW MUCH STRATUS/FOG CAN WE
EXPECT. NO SIMPLE ANSWERS. BAND OF LOW CLOUD COVER AND REDUCED VSBYS
STILL INTACT ACROSS A PORTION OF NE LOWER MICHIGAN INTO EASTERN
UPPER MICHIGAN WITH 1/4SM TO 1/2SM VSBYS STILL BEING REPORTED OVER A
PORTION OF EASTERN UPPER. THIS CLOUD COVER HAS BEEN STEADILY ERODING
ALTHOUGH ANOTHER BATCH OF LOW CLOUD/MOISTURE EVIDENT ON SATELLITE
IMAGERY ACROSS SE LOWER MICHIGAN SHOWING SIGNS OF SWINGING BACK UP
INTO NE LOWER MICHIGAN OVER THE NEXT SEVERAL HOURS. OVER NW LOWER
MICHIGAN...OBS CONTINUE TO REPORT SOME RESTRICTION TO VSBYS (HZ)
ALONG WITH HIGHER DEWPOINTS THAN SATURDAY.
UPSHOT TO ALL THIS...APPEARS LIKELY THAT STRATUS/FOG WILL ONCE AGAIN
DEVELOP THIS EVENING AND OVERNIGHT ESPECIALLY ACROSS NE LOWER
MICHIGAN AS AFOREMENTIONED LOW CLOUD SWINGS UP THROUGH THE REGION.
NEGATIVES AGAINST WIDESPREAD DENSE FOG INCLUDE INCREASING S/SE FLOW
AND GIVEN THAT...WILL REFRAIN FROM ISSUING ANY FOG RELATED HEADLINES
AT THIS POINT. AS USUAL...EVENING SHIFT WILL NEED TO MONITOR.
ADAM
&&
.LONG TERM.../ISSUED AT 316 PM/...MONDAY AND BEYOND
OUTSIDE OF FOG/STRATUS ISSUES MONDAY/TUESDAY MORNINGS...THE MAIN
FORECAST ISSUES FOR THE UPCOMING WEEK WILL REVOLVE AROUND UPPER
LEVEL ENERGY ROTATING OUT OF THE CENTRAL PLAINS AND SOUTHERN CANADA
WED-THU. THERE APPEARS TO BE SOME CLUSTERING OF MODEL SOLUTIONS
WITH THE SOUTHERN PIECE OF ENERGY ON WEDNESDAY...BUT STILL PLENTY OF
MODEL SPREAD WITH THE HANDLING OF THE SECOND FEATURE FOR
THANKSGIVING DAY. THE OPERATIONAL ECMWF CONTINUES TO BE THE SLOWEST
OF ALL SOLUTIONS...AND WILL TREND TOWARD THE MAJORITY FASTER AND
SLIGHTLY FURTHER NORTH SOLUTIONS.
MONDAY NIGHT/TUESDAY...THE INITIAL SHORTWAVES AHEAD OF THE MAIN
UPPER LOW OVER THE CENTRAL PLAINS WILL DRAW A PLUME OF DEEPER
MOISTURE NORTHWARD FROM THE CENTRAL APPALACHIANS TO THE EASTERN
GREAT LAKES...PASSING EAST OF THE AREA. FOG/STRATUS WILL CONTINUE
TO BE THE MAIN CONCERNS. CIRRUS WILL INHIBIT COOLING TO SOME DEGREE
MONDAY NIGHT...BUT THE GRADIENT WILL ACTUALLY BE A LITTLE WEAKER -
LESS THAN 20KT. I LIKE THE MIDNIGHT SHIFT/S IDEA OF ADDING FOG FOR
MONDAY NIGHT/TUESDAY MORNING...ESPECIALLY OVER EASTERN UPPER WITH
PREVAILING MOIST SOUTHEAST MARINE FLOW.
UPPER LOW MOVES INTO THE CENTRAL MISSISSIPPI VALLEY ON TUESDAY WITH
WARM CONVEYOR BELT HELPING TO SPREAD CLOUDS BUT NOT PCPN INTO
NORTHERN MICHIGAN. UPPER FEATURE SLIDES TOWARD SOUTHWEST MICHIGAN
BY WEDNESDAY MORNING...AND THEN INTO NORTHERN LAKE HURON BY LATE
AFTERNOON. INITIAL SURGE OF RAIN EARLY WEDNESDAY MORNING WILL PUSH
NORTH THROUGH THE AREA THROUGHOUT THE MORNING ON THE NOSE OF H8
THETA-E MOISTURE PLUME...PIVOTING INTO EASTERN UPPER BY MIDDAY. IN
IT/S WAKE...THE HEAVIEST AND MOST STEADY PCPN WILL LIKELY END...AS
DEEPEST MOISTURE AND FORCING SLIDE NORTHEAST. PLENTY OF LOW LEVEL
MOISTURE BENEATH H9 FOR THE AFTERNOON HOURS AND COULD SEE SOME
DRIZZLE. NORTHERN MICHIGAN ON THE WARM SIDE OF THE STORM...SO JUST
LIQUID DURING THE DAY WEDNESDAY /NO SNOW/.
MODEL ISSUES BEGIN TO APPEAR BY WEDNESDAY NIGHT AS UPSTREAM PIECE OF
UPPER LEVEL ENERGY DROPS TOWARD THE MISSISSIPPI VALLEY/NRN OHIO
VALLEY. BEST PCPN CHANCES WILL LIKELY BE TO THE WEST OF
INTERSTATE-75...WITHIN DEVELOPING DEFORMATION AXIS ACROSS LAKE
MICHIGAN. WILL NOT GET TOO DETAILED THIS FAR OUT...GOING WITH HIGH
CHANCE/LOW LIKELY POPS FOR THANKSGIVING DAY. AS FAR AS PCPN
TYPE...RAIN GRADUALLY TURNING TO SNOW ON THANKSGIVING DAY. WHAT
WILL MAKE THIS A DIFFICULT PCPN TYPE CASE IS THAT THE COLDEST CORE
OF TEMPS ASSOCIATED WITH UPPER LOW MAY ACTUALLY FOCUS OVER SOUTHERN
MICHIGAN/NRN OHIO VALLEY - WITH SLIGHTLY WARMER READINGS WRAPPING
BACK OVER NORTHERN MICHIGAN. AT THIS POINT...WAY TOO MANY UNKNOWNS
TO GET VERY SPECIFIC.
SYNOPTIC MOISTURE STRIPS OUT THE EAST THURSDAY NIGHT WITH DRY SLOT
MOVING INTO NORTHERN MICHIGAN...POSSIBLY LEAVING SOME LIGHT PCPN
/FREEZING DRIZZLE?/ FOR LATER THURSDAY NIGHT INTO FRIDAY MORNING.
UPPER RIDGE BUILDS INTO THE AREA FRIDAY/SATURDAY...BRINGING DRIER
WEATHER AND SEASONABLY MILD TEMPERATURES.
JK
&&
.MARINE.../ISSUED AT 316 PM/
GUSTY SOUTH WINDS HAVE PRODUCED SMALL CRAFT WINDS/WAVES ACROSS
WHITEFISH BAY THIS AFTERNOON...WHICH WILL PERSIST INTO THE EVENING
HOURS BEFORE DIMINISHING. OTHERWISE...SOUTHERLY WINDS WILL DOMINATE
ON THE LAKES OVER THE NEXT SEVERAL DAYS WITH CONDITIONS GENERALLY
BELOW SMALL CRAFT ANTICIPATED.
ADAM
&&
.AVIATION.../ISSUED AT 633 PM/...VALID FOR 00Z TAFS
MVFR CONDITIONS EXPECTED TO CONTINUE AT APN OVER THE NEXT COUPLE
OF HOURS AND VFR AT TVC AND PLN. WILL THEN BANK ON STRATUS/FOG
REDEVELOPING LATER THIS EVENING AND BECOMING SUBSTANTIAL
OVERNIGHT INTO MONDAY MORNING. OVERALL CONFIDENCE NOT GREAT...AND
INCREASING SOUTHERLY FLOW COULD KEEP STRATUS AND/OR FOG AT BAY.
BUT WILL CONTINUE WITH IFR CONDITIONS DURING THE OVERNIGHT PERIOD.
VRF CONDITIONS THEN EXPECTED TO REEMERGE LATER MONDAY MORNING INTO
MONDAY AFTERNOON.
AJS
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR LSZ321.
&&
$$
000
FXUS63 KGRR 222317
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
617 PM EST SUN NOV 22 2009
LATEST UPDATE...AVIATION...
.SYNOPSIS...(330 PM EST SUN NOV 22 2009)
THE LARGE HIGH PRESSURE SYSTEM THAT WAS OVER THE GREAT LAKES IS
MOVING OFF INTO THE NORTH ATLANTIC TONIGHT. THAT WILL ALLOW A
DEVELOPING STORM SYSTEM OVER THE SOUTHWEST UNITED STATES TO MOVE
INTO THE SOUTHERN PLAINS TUESDAY AND INTO THE GREAT LAKES WEDNESDAY.
THE SOUTHERLY WINDS AHEAD OF THE STORM WILL CONTINUE THE MILD
WEATHER WITH AREAS OF FOG DURING THE EARLY TO MID MORNING HOURS THEN
AFTERNOON SUNSHINE MONDAY AND TUESDAY. PERIODS OF RAIN WILL MOVE
INTO THE AREA TUESDAY NIGHT AND CONTINUE INTO WEDNESDAY. COLDER AIR
BEHIND THE STORM MAY MIX THE SNOW WITH THE RAIN WEDNESDAY NIGHT.
&&
.SHORT TERM...(330 PM EST SUN NOV 22 2009)
(TONIGHT THROUGH TUESDAY NIGHT)
OVERALL THE BIGGEST QUESTION IS JUST HOW FOGGY WILL IT GET TONIGHT
SINCE THERE WILL BE MORE WIND IN THE BOUNDARY LAYER THAT LAST NIGHT?
WITH LESS WIND AND MORE LOW LEVEL MOISTURE AND STILL NOT TO MUCH IN
THE WAY OF CLOUD COVER... FOG IS LIKELY TUESDAY MORNING TOO. FINALLY
THERE IS THE ISSUE OF RAIN TUESDAY NIGHT WITH THE SYSTEM FROM THE
SOUTHERN PLAINS.
THE AREA OF LOW CLOUDS OVER THE EASTERN PART OF THE STATE IS TRYING
TO MIX OUT LATE THIS AFTERNOON BUT WITH THE SUN SETTING IN LESS THAN
THREE HOURS...IT WOULD SEEMS IT WILL NOT BE ABLE TO TOTALLY MIX OUT.
WITH THE SOUTHEAST WINDS BELOW 3000 FT AGL INTO MONDAY NIGHT THOSE
CLOUDS SHOULD OVERSPREAD THE CWA BY LATE TONIGHT. ADD TO THAT THE 30
KNOT WINDS AT 1000 FT AGL AROUND MIDNIGHT AND ONE DOES WONDER JUST
HOW MUCH FOG THERE CAN BE. STILL THE BOUNDARY LAYER RH IS HIGHER
TONIGHT THEN LAST NIGHT SO I HAVE CONTINUED THE AREAS OF FOG
OVERNIGHT BUT KEPT THE DENSE FOG WORDING OUT OF THE ZONES.
SOME HIGH CLOUDS FROM THE SYSTEM TO OUR SOUTH SHOULD HAVE LITTLE
IMPACT ON OUR FOG POTENTIAL TONIGHT OR OUR CLEARING THE LOW CLOUDS
OUT BY NOON MONDAY. I EXPECT FOG AGAIN TUESDAY MORNING AS WINDS ARE
LIGHTER IN THE BOUNDARY LAYER AND THE CLOUDS FROM THE SYSTEM TO OUR
WEST WILL NOT HAVE MADE IT HERE YET. THE LOW LEVEL MOISTURE WILL BE
INCREASING THROUGH. SEEMS LIKE A GOOD SET UP FOR MORE FOG.
THE SYSTEM COMING IN TUESDAY NIGHT HAS A LOT OF GOOD THINGS GOING
FOR IT. THERE IS STRONG JET SUPPORT...DECENT GULF MOISTURE AT LOW TO
MID LEVELS... STRONG DYNAMICS AND IS WELL SUPPORTED BY THE ENSEMBLES
NOT TO MENTION THE STRONG INTER-MODEL AGREEMENT. SO I INCREASED POPS
TO LIKELY TUESDAY NIGHT. I DO HAVE TO SAY A SYSTEM LIKE THAT COULD
BE SLOWER TO COME OUT... OTHERWISE I WOULD HAVE GONE WITH
CONDITIONAL POPS .... LIKE 80-90 PCT.
&&
.LONG TERM...(330 PM EST SUN NOV 22 2009)
(WEDNESDAY THROUGH SUNDAY)
MAIN CONCERNS IN THE LONG TERM ARE PCPN CHANCES FROM WED THROUGH
NEXT SATURDAY WITH A COMPLEX PATTERN EVOLVING...AND PCPN TYPE DURING
THIS PERIOD AS COLD AIR FILTERS INTO THE AREA.
MODEL CONSENSUS INDICATES THAT THE SYSTEM COMING IN FROM THE SW WILL
HAVE PUSHED THE OCCLUDED FRONT OVER THE AREA OR JUST NORTH OF THE
AREA BY THE BEGINNING OF THE PERIOD WED MORNING. DEEPER MOISTURE
WILL BE MOVING OUT AND MORE SHOWERY TYPE WEATHER CAN BE EXPECTED.
PCPN AT THIS POINT ON WED SHOULD STILL BE ALL RAIN AS THE PUSH OF
COLDER AIR WILL STILL BE WEST OF THE AREA.
THE INITIAL TROUGH THAT PUSHES THE FRONT THROUGH ON WED WILL LINGER
ENOUGH WED NIGHT AND THU TO ALLOW ADDITIONAL ENERGY TO DIVE SE AND
CARVE OUT A LONGER WAVE TROUGH. IT WILL BE WITH THIS TROUGH THAT THE
COLDER AIR WILL ARRIVE AND SOME SNOW MAY MIX IN AT TIMES. SHOWERY
WEATHER WILL CONTINUE INTO THU BEFORE SOME LAKE ENHANCEMENT/EFFECT
WILL BEGIN TO DEVELOP. SNOW MAY MIX WITH RAIN OVERNIGHT WED NIGHT
AND THU NIGHT WITH A COOLER BOUNDARY LAYER.
THIS TROUGH WILL HOLD IN INTO FRI NIGHT. GFS IS TRYING TO SHIFT IT
EAST A LITTLE QUICKER...HOWEVER IT LOOKS TOO QUICK GIVEN THE
AMPLITUDE OF THE DEVELOPING PATTERN. FLOW WILL BECOME ANTI-CYCLONIC
SAT MORNING AND THE RIDGE WILL HOLD INTO EARLY SUN. TEMPS WILL
MODERATE SOME. MODELS ARE TRYING TO HAVE A FRONT APPROACH LATE IN
THE DAY ON SUN AS THE NEXT SHORT WAVE TROUGH MOVES IN. THIS LOOKS TO
BE MORE OF A SUN NIGHT ISSUE...JUST PAST THE CURRENT LONG TERM
PERIOD.
&&
.AVIATION...(617 PM EST SUN NOV 22 2009)
THERE SHOULD BE ENOUGH LOW LEVEL MOISTURE OVERNIGHT FOR SOME FOG
FORMATION ALTHOUGH THE WINDS WILL BE A BIT HIGHER THAN LAST NIGHT.
THIS WILL KEEP VSBYS FROM CRASHING AS MUCH AS LAST NIGHT...ALTHOUGH
MOSTLY CLEAR SKIES WILL ALLOW ENOUGH RADIATIONAL COOLING TO BRING
SOME IFR CONDITIONS LATE TONIGHT. FOG AND ANY LOW CLOUDS SHOULD MIX
OUT BY 15Z.
&&
.MARINE...(330 PM EST SUN NOV 22 2009)
FOG MAY BE AN ISSUE IN THE NEAR SHORE TONIGHT AND TUESDAY MORNING
TOO. WINDS WILL BE LIGHT SO NO ISSUES WITH WAVE HEIGHTS UNTIL
THURSDAY WHEN THE COLD AIR MOVES IN.
&&
.HYDROLOGY...(330 PM EST SUN NOV 22 2009)
NOT ENOUGH RAIN IS EXPECTED WITH THE SYSTEM TUESDAY NIGHT INTO
THURSDAY TO EVEN CAUSE SIGNIFICANT RIVER RISES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: WDM
SHORT TERM: WDM
LONG TERM: NJJ
AVIATION: OSTUNO
MARINE: WDM
HYDROLOGY: WDM
000
FXUS63 KMQT 222049
AFDMQT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
350 PM EST SUN NOV 22 2009
.SYNOPSIS...
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN UPPER RIDGE AXIS
OVER WESTERN QUEBEC AND A LONGWAVE TROUGH OVER THE NORTHERN AND
CENTRAL PLAINS AND INTO CENTRAL CANADA. ANOTHER TROUGH CONTINUES TO
DIG OVER THE PACIFIC NORTHWEST. A WEAK SHORTWAVE IS OVER THE EAST
END OF THE FORECAST AREA THIS AFTERNOON...WITH OTHERS OVER EASTERN
DAKOTAS AND MINNESOTA. SURFACE ANALYSIS SUGGEST A COLD FRONT
EXTENDING FROM CENTRAL HUDSON BAY SOUTH THROUGH MINNESOTA TO A WEAK
LOW OVER EASTERN NEBRASKA AND A LARGE HIGH OVER THE CANADIAN
MARITIME CAUSING A SOUTHERLY FLOW ACROSS THE FORECAST AREA. THIS
SOUTHERLY FLOW BROUGHT ABNORMALLY WARM AIR AND SOME LOW LEVEL
MOISTURE INTO THE AREA WHICH CAUSED CONSIDERABLE FOG THIS MORNING.
THIS MORNING AREA RAOBS INDICATED THE AIR MASS WAS QUITE DRY ABOVE
800MB. QUITE A BIT OF HIGH CLOUDS ARE STREAMING INTO THIS AREA AHEAD
OF OF THE FRONT. A LOW LEVEL JET OVER THE AIR CONTINUES TO MIX TO
SURFACE OVER THE LAKE.
&&
.SHORT TERM...
THE MAIN CONCERN FOR TONIGHT AND MONDAY WILL BE WITH THE POTENTIAL
FOR RAIN AND FOG.
THE MID LEVEL RIDGE WILL PUSH INTO EASTERN QUEBEC WITH THE
ASSOCIATED HIGH WEAKENING AS IT REACHES NEW ENGLAND TONIGHT. THE MID
LEVEL TROUGH OVER THE NORTHERN PLAINS WILL WEAKEN AND SETTLE OVER
HUDSON BAY TONIGHT. THE ASSOCIATED SHORTWAVE WILL WEAKEN AS WELL AS
IT STALLS OUT OVER THE UPPER MISSISSIPPI RIVER VALLEY.
MEANWHILE...THE TROUGH OVER THE PACIFIC NORTHWEST CONTINUE TO DEEPEN
AS IT MOVES INTO THE NORTHERN HIGH PLAINS. THE COLD FRONT OVER
MINNESOTA WILL REALIGN WITH THE WEAKEN SHORTWAVE OVER CANADA AND
STRETCH FROM SOUTHERN JAMES BAY SOUTHWEST THROUGH THE MINNESOTA
ARROWHEAD TO EASTERN SOUTH DAKOTA. SURFACE DEW POINT ARE IN THE LOW
TO MID 40S ACROSS THE CWA THIS AFTERNOON. AFTER SUNDOWN WITH THE
CLEARING SKIES OVER THE EAST...TEMPERATURES WILL FALL RAPIDLY WILL
BE FAVORABLE FOR FOG DEVELOPMENT OVERNIGHT. INCREASE HUMIDITY AHEAD
OF THE COLD FRONT WILL INCREASE THE POSSIBILITY OF RAIN AND FOG
THERE AS WELL. THUS WILL TENDED TO GO WITH THE A LITTLE POPS LATER
TONIGHT WITH INFLUX OF MOISTURE AND SOME ISENTROPIC ASCENT AHEAD OF
THE FRONT.
THE MID LEVEL TROUGH OVER THE HIGH PLAINS WILL DEEPEN INTO A CUTOFF
LOW OVER THE CENTRAL PLAINS ON MONDAY. WEAK SHORTWAVES EJECTED OUT
OF THE BASE OF THIS LOW WILL SWEEP ACROSS THE FORECAST AREA ON
MONDAY. THE FINAL REMNANT OF THE WEAKENING TROUGH WILL SHIFT INTO
WISCONSIN. THE NEBRASKA SURFACE LOW WILL DEEPEN AS IT INCHES INTO
EASTERN NEBRASKA. A STRONG SOUTHERLY FLOW AND THE ALIGNMENT OF THE
LOW LEVEL JET WILL HOLD THE FRONTAL SYSTEM STATIONARY JUST TO THE
NORTH OF LAKE SUPERIOR. AS WITH THIS MORNING...PATCHY FOG SHOULD
LAST THROUGH THE EARLY MORNING HOURS AFTER SUNRISE. DRY AIR
ADVECTING INTO THE AREA AHEAD OF THE NEBRASKA LOW WILL END THE FOG
AND LIMIT ANY PRECIPITATION ACROSS THE AREA ON MONDAY.
&&
LONGER TERM 00Z TUE ONWARD...
FORECAST PROBLEM CONTINUES TO BE THE UPCOMING STORM AND WHAT IT WILL
DO...PCPN TYPE AND WHEN IT WILL OCCUR. THE STORM SYSTEM IS CURRENTLY
IN THE PACIFIC NW NOW AND WILL DIG SE AND FORM A CLOSED LOW WITH IT
THIS FORECAST PERIOD. NAM BRINGS IN ANOTHER TROUGH INTO THE PACIFIC
NW MON NIGHT AND THEN MOVES IT EAST BEFORE DIGGING IT INTO THE
TROUGH ON TUE. WHAT THIS DOES THEN IS KICKS THE CLOSED LOW OUT
SLOWLY ENE AND ANOTHER CLOSED 500 MB LOW FORMS OVER THE NORTHERN
PLAINS TUE NIGHT AND DIGS SE INTO THE MISSOURI RIVER VALLEY NEAR
SIOUX CITY IA 00Z THU WHILE THE OTHER LOW IS IN CENTRAL LOWER
MICHIGAN. DEEPER MOISTURE DOES NOT ARRIVE UNTIL TUE NIGHT ALONG WITH
SOME BETTER DYNAMICS ACCORDING TO THE NAM. GFS IS FAIRLY SIMILAR TO
THE NAM EXCEPT BRINGS PCPN IN A BIT QUICKER. BASICALLY...WITH MODELS
STILL NOT CONSISTENT ON SOLUTION...WILL NOT MAKE VERY MANY CHANGES
TO THE GOING FORECAST. KEPT LIKELY POPS IN FOR WED THROUGH THU WITH
DECENT MOISTURE AROUND. ONLY CHANGE I DID MAKE WAS TO REMOVE SNOW
FROM WED AS COLD AIR DOES NOT COME IN UNTIL WED NIGHT. SYSTEM REALLY
DOES NOT HAVE MUCH COLD AIR TO WORK WITH AND WILL HAVE TO
MANUFACTURE ITS OWN COLD AIR TO DO SO.
IN THE EXTENDED...CONTINUED TO GO WITH THE 00Z ECMWF FOR THIS
FORECAST PERIOD AS IT HAS BEEN THE MOST CONSISTENT MODEL FOR THE
PAST SEVERAL DAYS. ECMWF SHOWS A TROUGH AND CLOSED LOW AFFECTING THE
AREA FOR THU AND THEN RIDGING FOR FRI AND SAT AND INTO SUN AS WELL.
DID NOT MAKE ANY CHANGES TO THE EXTENDED AT ALL. STILL HAVE LIKELY
POPS IN FOR THU AND THEN DRY FOR FRI NIGHT THROUGH SUN EVEN AS A
COLD FRONT MOVES THROUGH ON SUN. TEMPERATURES CONTINUE TO BE MILD
AND NORMAL TO SLIGHTLY ABOVE NORMAL.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
THE REMAINING MIST SHOULD DISSIPATE EARLY THIS AFTERNOON. A FEW
SPRINKLES ARE SHOWING UP ON RADAR AND WERE REPORTED AT KCMX...SO
HAVE ADDED IT TO THE TAF. AFTER THE MIST DISSIPATED...BOTH SITES
WILL BE VFR UNTIL LATER TONIGHT WHEN FOG WILL LIKELY REDEVELOP AS
LOW LEVEL HUMIDITY INCREASES OVER THE AREA. AT BOTH LOCATIONS
SIMILAR CONDITIONS TO LAST NIGHT WILL AGAIN OCCUR WITH DOWNSLOPING
SOUTHERLY WINDS LIMITING LOWER VISIBILITIES AND CEILINGS TO LIFR.
LLWS CAN BE EXPECTED AT BOTH TAF SITES AFTER SUNSET UNTIL LATE
MORNING ON MONDAY WHEN THE LOW LEVEL JET SHIFT EAST.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
WITH LAKE SUPERIOR IN BETWEEN LOW PRESSURE OVER THE CENTRAL PLAINS
AND THE HIGH OVER THE NORTHEAST STATES...SOUTHERLY WINDS TO 25 KNOTS
WILL PREVAIL INTO MONDAY MORNING. A FEW WIND GUSTS TO 28 KNOTS WILL
BE POSSIBLE TONIGHT MAINLY OVER THE EASTERN LAKE. WINDS WILL REMAIN
UNDER 20 KNOTS INTO WEDNESDAY...WHEN A STORM SYSTEM APPROACHES THE
UPPER GREAT LAKES AND WINDS BEGIN TO INCREASE OUT OF THE NORTH AND
NORTHEAST WITH GALES POSSIBLE LATE WEDNESDAY THROUGH FRIDAY MORNING.
LOCALLY DENSE PATCHY FOG IS POSSIBLE TONIGHT ACROSS LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS/SHORT TERM...DLG
LONG TERM...07
AVIATION...DLG
MARINE...DLG
000
FXUS63 KDTX 222031
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
331 PM EST SUN NOV 22 2009
.SHORT TERM...TONIGHT
ONCE AGAIN WITH SURFACE DEW POINTS HOVERING IN THE LOW TO MID
40S...SOUTHEAST MICHIGAN APPEARS PRIMED FOR FOG ONCE AGAIN...AS LOW
STRATUS IS EXPECTED TO DISSIPATE AROUND SUNSET...SETTING US UP FOR
GOOD RADIATIONAL COOLING WITH THE UPPER LEVEL RIDGE AXIS REMAINING
OVERHEAD. THE DIFFERENCE TONIGHT IS A BETTER GRADIENT/SOUTHEAST WIND
IN THE LOW LEVELS...WHICH AGAIN BEGS THE QUESTION OF LOW STRATUS VS
FOG. THE FLIP SIDE IS THIS EAST-SOUTHEAST FLOW IS FAVORABLE...AS
LAKE ERIE/LAKE ST CLAIR/SOUTHERN LAKE HURON PROVIDES SOME ADDITIONAL
MOISTURE FLUX. WILL BE CARRYING AREAS OF DENSE FOG DEVELOPING IN THE
ZONES...AND WILL DEFER TO THE EVENING SHIFT TO PULL THE TRIGGER ON
AN ADVISORY (IF NEED BE) BASED ON TRENDS. WITH SURFACE WINDS MORE
THAN LIKELY STAYING UP JUST A BIT AND BETTER CHANCE FOR QUICKER LOW
STRATUS DEVELOPMENT...WOULD BE SURPRISED IF MINS ARE AS COLD AS THIS
MORNING...AND WILL CARRY MINS PREDOMINATELY IN THE MID 30S.
&&
.LONG TERM...MONDAY THROUGH NEXT SUNDAY
AN ELONGATED SURFACE RIDGE IS FORECAST TO REMAIN OVER THE EASTERN
GREAT LAKES THROUGH TUESDAY. THE LACK OF LOW LEVEL DRY AIR ADVECTION
AND LIMITED MIXING DEPTHS WILL CONTINUE TO MAKE FOG AND LOW CLOUDS
PROBLEMATIC OVER THE NEXT COUPLE OF DAYS...ESPECIALLY WHEN
CONSIDERING THE CONTINUED EASTERLY MOISTURE FLUX OFF LAKE ERIE. WEAK
SHALLOW COLD AIR ADVECTION ON MONDAY MAY PROVE SUFFICIENT ENOUGH TO
STRENGTHEN THE LOW LEVEL INVERSION. THIS RAISES CONCERNS THAT
RESIDUAL MOISTURE FROM MORNING FOG/LOW STRATUS WILL REMAINED TRAPPED
UNDER THE INVERSION WELL INTO THE AFTERNOON /LIKE WHAT HAS
HAPPENED TODAY/. HAVE THEREFORE RAISED AFTERNOON CLOUD COVER AND
LOWERED TEMPS A FEW DEGREES BELOW GUIDANCE /NEAR 50/. SLIGHTLY
BETTER MOISTURE ADVECTION BELOW 925MB ON MON NIGHT WITH THE HELP
OF A WEAK SHORT WAVE TRACKING THROUGH THE OHIO VALLEY SHOULD
RESULT IN A MUCH THICKER AND MORE PERSISTENT STRATUS DECK. HAVE
ACCOUNTED FOR THIS IN BOTH MON NIGHT/TUESDAYS SKY COVER AND TEMPS
/KEEPING MAX TEMPS IN THE UPPER 40S TO NEAR 50 ON TUES/.
THE UPPER WAVE SHOWN ON THE CURRENT WATER VAPOR LOOP OVER THE
PACIFIC NORTHWEST WILL BE THE NEXT CHALLENGE IN THE LONG TERM. THIS
WAVE IS FORECAST TO AMPLIFY ACROSS THE HIGH PLAINS ON MONDAY AND
THEN DEVELOP INTO A CLOSED CIRCULATION OVER KANSAS BY TUESDAY
MORNING. THE 12Z MODEL SUITE APPEARED WELL INITIALIZED WITH THIS
WAVE. THERE STILL HOWEVER REMAINS SOME MODEL SPREAD WITH RESPECT TO
TIMING. THE 12Z ECMWF AND NAM ARE SLOWER IN COMPARISON TO THE GFS.
IN LIGHT OF MODEL TRENDS OVER THE LAST TWO DAYS...PREFERENCE
CONTINUES TO LIE WITH THE SLOWER ECMWF. THIS SOLUTION INDICATES THE
BEST CHANCE FOR RAIN WILL BE LATE TUES NIGHT INTO WED AS THE COMPACT
UPPER LOW AND ASSOCIATED MID LEVEL HEIGHT FALLS ADVANCE ACROSS THE
STATE.
THE UPPER LOW WILL THEN GET QUICKLY EJECTED TO THE NORTHEAST OF THE
STATE BY THURSDAY AS A FAIRLY STRONG NORTHERN STREAM WAVE DIVES INTO
THE DAKOTAS/UPPER MIDWEST...LEADING TO THE DEVELOPMENT OF A LARGE
CUT OFF CIRCULATION OVER THE EASTERN US BY THE END OF THE WEEK.
THERE IS STILL A DECENT AMOUNT OF MODEL SPREAD AMONG THE 12Z SUITE
WITH RESPECT TO THE AMPLITUDE AND TIMING OF THIS WAVE...WHICH LEAD
TO UNCERTAINTY IN STRENGTH AND LOCATION OF THE LARGE CUT OFF LOW.
HAVE ACTUALLY LOWERED POPS A BIT ON THURSDAY AS THE BULK OF MODEL
SOLUTIONS INDICATE MID LEVEL DRYING IN THE WAKE OF THE FIRST WAVE.
PRECIP CHANCES THEN WILL INCREASE THURS NIGHT INTO FRI WITH THE
POTENTIAL OF THE SECONDARY UPPER LOW IMPACTING THE REGION. IN LIGHT
OF GFS THICKNESS FIELDS...WILL MAINTAIN A CHANCE OF BOTH RAIN AND
SNOW THURS NIGHT INTO FRI /ALTHOUGH THE ECMWF CONTINUES TO SUGGEST
THAT BOUNDARY LAYER TEMPS WILL SUPPORT MAINLY RAIN/.
&&
.MARINE...
THERE WILL BE A GRADUAL INCREASE IN SOUTHEAST WINDS MONDAY INTO
TUESDAY AS THE HIGH RETREATS EAST...AWAY FROM THE AREA. THE PATTERN
BECOMES ACTIVE AGAIN MID/LATE NEXT WEEK AS A STRONG SHORTWAVE AND
ASSOCIATED JET STREAK DIG INTO THE UPPER MIDWEST AND LEAD TO THE
DEVELOPMENT OF A LARGE UPPER LEVEL LOW OVER/NEAR THE REGION. THIS
TIME FRAME WILL BRING UNSETTLE WEATHER AND HIGHER WIND AND WAVES.
&&
.PREV DISCUSSION...ISSUED 1201 PM EST SUN NOV 22 2009
AVIATION...
MUCH LIKE YESTERDAY...IT WILL TAKE MOST OF THE AFTERNOON FOR
VSBYS AND CEILINGS TO IMPROVE INTO VFR CATEGORY. ONCE THE SUN
SETS...GOOD RADITIONAL COOLING WILL KICK IN...ALLOWING SURFACE
VISIBILITIES TO BEGIN TO CRASH...AS SURFACE DEW POINTS ARE RUNNING
HIGH EARLY THIS AFTERNOON (MID 40S). TONIGHT THERE WILL BE A
STRONGER SOUTHEAST WIND...WHICH MAY LEAD TO LIFR CEILINGS VS
VSBYS...BUT EITHER WAY WE APPEAR DESTINED TO FALL INTO THE LIFR
CATEGORY AS SOUTHEAST FLOW COMES OF LAKE ERIE/ST CLAIR/SOUTHERN
LAKE HURON. IMPROVEMENTS IN THE VIS/CEILINGS WILL BE SLOW
TOMORROW...AND PROBABLY WON`T SEE VFR CONDITIONS UNTIL AFT 18Z.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...SF
LONG TERM....SC
MARINE.......SF
AVIATION.....SF
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KGRR 222028
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
330 PM EST SUN NOV 22 2009
LATEST UPDATE...ALL BUT AVIATION...
.SYNOPSIS...(330 PM EST SUN NOV 22 2009)
THE LARGE HIGH PRESSURE SYSTEM THAT WAS OVER THE GREAT LAKES IS
MOVING OFF INTO THE NORTH ATLANTIC TONIGHT. THAT WILL ALLOW A
DEVELOPING STORM SYSTEM OVER THE SOUTHWEST UNITED STATES TO MOVE
INTO THE SOUTHERN PLAINS TUESDAY AND INTO THE GREAT LAKES WEDNESDAY.
THE SOUTHERLY WINDS AHEAD OF THE STORM WILL CONTINUE THE MILD
WEATHER WITH AREAS OF FOG DURING THE EARLY TO MID MORNING HOURS THEN
AFTERNOON SUNSHINE MONDAY AND TUESDAY. PERIODS OF RAIN WILL MOVE
INTO THE AREA TUESDAY NIGHT AND CONTINUE INTO WEDNESDAY. COLDER AIR
BEHIND THE STORM MAY MIX THE SNOW WITH THE RAIN WEDNESDAY NIGHT.
&&
.SHORT TERM...(330 PM EST SUN NOV 22 2009)
(TONIGHT THROUGH TUESDAY NIGHT)
OVERALL THE BIGGEST QUESTION IS JUST HOW FOGGY WILL IT GET TONIGHT
SINCE THERE WILL BE MORE WIND IN THE BOUNDARY LAYER THAT LAST NIGHT?
WITH LESS WIND AND MORE LOW LEVEL MOISTURE AND STILL NOT TO MUCH IN
THE WAY OF CLOUD COVER... FOG IS LIKELY TUESDAY MORNING TOO. FINALLY
THERE IS THE ISSUE OF RAIN TUESDAY NIGHT WITH THE SYSTEM FROM THE
SOUTHERN PLAINS.
THE AREA OF LOW CLOUDS OVER THE EASTERN PART OF THE STATE IS TRYING
TO MIX OUT LATE THIS AFTERNOON BUT WITH THE SUN SETTING IN LESS THAN
THREE HOURS...IT WOULD SEEMS IT WILL NOT BE ABLE TO TOTALLY MIX OUT.
WITH THE SOUTHEAST WINDS BELOW 3000 FT AGL INTO MONDAY NIGHT THOSE
CLOUDS SHOULD OVERSPREAD THE CWA BY LATE TONIGHT. ADD TO THAT THE 30
KNOT WINDS AT 1000 FT AGL AROUND MIDNIGHT AND ONE DOES WONDER JUST
HOW MUCH FOG THERE CAN BE. STILL THE BOUNDARY LAYER RH IS HIGHER
TONIGHT THEN LAST NIGHT SO I HAVE CONTINUED THE AREAS OF FOG
OVERNIGHT BUT KEPT THE DENSE FOG WORDING OUT OF THE ZONES.
SOME HIGH CLOUDS FROM THE SYSTEM TO OUR SOUTH SHOULD HAVE LITTLE
IMPACT ON OUR FOG POTENTIAL TONIGHT OR OUR CLEARING THE LOW CLOUDS
OUT BY NOON MONDAY. I EXPECT FOG AGAIN TUESDAY MORNING AS WINDS ARE
LIGHTER IN THE BOUNDARY LAYER AND THE CLOUDS FROM THE SYSTEM TO OUR
WEST WILL NOT HAVE MADE IT HERE YET. THE LOW LEVEL MOISTURE WILL BE
INCREASING THROUGH. SEEMS LIKE A GOOD SET UP FOR MORE FOG.
THE SYSTEM COMING IN TUESDAY NIGHT HAS A LOT OF GOOD THINGS GOING
FOR IT. THERE IS STRONG JET SUPPORT...DECENT GULF MOISTURE AT LOW TO
MID LEVELS... STRONG DYNAMICS AND IS WELL SUPPORTED BY THE ENSEMBLES
NOT TO MENTION THE STRONG INTER-MODEL AGREEMENT. SO I INCREASED POPS
TO LIKELY TUESDAY NIGHT. I DO HAVE TO SAY A SYSTEM LIKE THAT COULD
BE SLOWER TO COME OUT... OTHERWISE I WOULD HAVE GONE WITH
CONDITIONAL POPS .... LIKE 80-90 PCT.
&&
.LONG TERM...(330 PM EST SUN NOV 22 2009)
(WEDNESDAY THROUGH SUNDAY)
MAIN CONCERNS IN THE LONG TERM ARE PCPN CHANCES FROM WED THROUGH
NEXT SATURDAY WITH A COMPLEX PATTERN EVOLVING...AND PCPN TYPE DURING
THIS PERIOD AS COLD AIR FILTERS INTO THE AREA.
MODEL CONSENSUS INDICATES THAT THE SYSTEM COMING IN FROM THE SW WILL
HAVE PUSHED THE OCCLUDED FRONT OVER THE AREA OR JUST NORTH OF THE
AREA BY THE BEGINNING OF THE PERIOD WED MORNING. DEEPER MOISTURE
WILL BE MOVING OUT AND MORE SHOWERY TYPE WEATHER CAN BE EXPECTED.
PCPN AT THIS POINT ON WED SHOULD STILL BE ALL RAIN AS THE PUSH OF
COLDER AIR WILL STILL BE WEST OF THE AREA.
THE INITIAL TROUGH THAT PUSHES THE FRONT THROUGH ON WED WILL LINGER
ENOUGH WED NIGHT AND THU TO ALLOW ADDITIONAL ENERGY TO DIVE SE AND
CARVE OUT A LONGER WAVE TROUGH. IT WILL BE WITH THIS TROUGH THAT THE
COLDER AIR WILL ARRIVE AND SOME SNOW MAY MIX IN AT TIMES. SHOWERY
WEATHER WILL CONTINUE INTO THU BEFORE SOME LAKE ENHANCEMENT/EFFECT
WILL BEGIN TO DEVELOP. SNOW MAY MIX WITH RAIN OVERNIGHT WED NIGHT
AND THU NIGHT WITH A COOLER BOUNDARY LAYER.
THIS TROUGH WILL HOLD IN INTO FRI NIGHT. GFS IS TRYING TO SHIFT IT
EAST A LITTLE QUICKER...HOWEVER IT LOOKS TOO QUICK GIVEN THE
AMPLITUDE OF THE DEVELOPING PATTERN. FLOW WILL BECOME ANTI-CYCLONIC
SAT MORNING AND THE RIDGE WILL HOLD INTO EARLY SUN. TEMPS WILL
MODERATE SOME. MODELS ARE TRYING TO HAVE A FRONT APPROACH LATE IN
THE DAY ON SUN AS THE NEXT SHORT WAVE TROUGH MOVES IN. THIS LOOKS TO
BE MORE OF A SUN NIGHT ISSUE...JUST PAST THE CURRENT LONG TERM
PERIOD.
&&
.AVIATION...(1234 PM EST SUN NOV 22 2009)
COMPLICATED AND UNCERTAIN FORECAST FOR THE NEXT 24 HOURS...
ESPECIALLY CONCERNING FOG AND LOW CLOUD POTENTIAL FOR TONIGHT. MOST
LOCATIONS SHOULD REMAIN VFR THROUGH 23Z THIS EVENING WITH JUST A FEW
CUMULUS CLOUDS EXPECTED FOR THE MOST PART. SOME OF THE STRATUS EAST
OF THE AREA IS TRYING TO MOVE IN. SOME OF THIS WILL IMPACT KJXN AND
KLAN WITH A SCT015-020 LAYER...BUT WE DO NOT EXPECT IT TO GO BKN AS
IT IS MIXING OUT.
WE WILL START OUT A BIT BETTER ON VSBYS THIS EVENING AS VSBYS ARE
ALREADY BETTER THAN THEY WERE ALL DAY ON SAT. MOISTURE IS STILL
HANGING AROUND AND WE ARE MIXING HIGHER DEW POINTS DOWN...SO FOG
POTENTIAL REMAINS. WINDS WILL BE HIGHER THAN LAST NIGHT WHICH SHOULD
NEGATE FOG SOMEWHAT. WE ARE ALSO WATCHING THE LOWER CLOUDS TO THE
EAST COMING IN OFF OF LAKE ERIE. THIS IS EXPECTED TO SPREAD WESTWARD
AFTER SUNSET AS MIXING DIMINISHES. THIS ALSO SHOULD EXPAND AS THE
MOIST AIR WILL CONDENSE FAIRLY QUICKLY AFTER SUNSET. THE LOW CLOUDS
SHOULD ALSO NEGATE THE FOG SOME...BUT WE COULD VERY WELL END UP
SEEING IFR CIGS DEVELOP...EARLIER TO THE EAST. CONDITIONS WILL BE
SLOW TO IMPROVE AFTER SUNRISE ON MON AND THEN THROUGH 16-17Z MON.
&&
.MARINE...(330 PM EST SUN NOV 22 2009)
FOG MAY BE AN ISSUE IN THE NEAR SHORE TONIGHT AND TUESDAY MORNING
TOO. WINDS WILL BE LIGHT SO NO ISSUES WITH WAVE HEIGHTS UNTIL
THURSDAY WHEN THE COLD AIR MOVES IN.
&&
.HYDROLOGY...(330 PM EST SUN NOV 22 2009)
NOT ENOUGH RAIN IS EXPECTED WITH THE SYSTEM TUESDAY NIGHT INTO
THURSDAY TO EVEN CAUSE SIGNIFICANT RIVER RISES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: WDM
SHORT TERM: WDM
LONG TERM: NJJ
AVIATION: NJJ
MARINE: WDM
HYDROLOGY: WDM
000
FXUS63 KAPX 222017
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
316 PM EST SUN NOV 22 2009
.SYNOPSIS.../ISSUED AT 316 PM/
HIGH PRESSURE OVER NEW ENGLAND WILL MAINTAIN ITS INFLUENCE OVER THE
GREAT LAKES THROUGH MONDAY EVEN AS IT DRIFTS INTO THE CANADIAN
MARITIME PROVINCES. THIS WILL RESULT IN A CONTINUATION OF THE
CURRENT PATTERN...WITH NIGHTTIME AND MORNING FOG GRADUALLY GIVING
WAY TO SUNNY SKIES. BUT THERE COULD BE SOME LOCATIONS WHERE LOW
CLOUDS NEVER DISSIPATE. THE NEXT CHANCE OF RAIN WILL ARRIVE TUESDAY
NIGHT AND WEDNESDAY AS A STORM SYSTEM LIFTS INTO THE REGION.
TEMPERATURES WILL REMAIN WARMER THAN NORMAL THROUGH MID-NEXT WEEK
AND THEN TURN COLDER BEHIND THIS SYSTEM.
JH
&&
.SHORT TERM.../ISSUED AT 316 PM/...TONIGHT
HIGH PRESSURE WILL REMAIN DOMINANT ACROSS THE GREAT LAKES/NEW
ENGLAND THROUGH TONIGHT UNDER STEADIER S/SE LOW LEVEL FLOW. SAME
ISSUES AS THE PREVIOUS FEW NIGHTS...HOW MUCH STRATUS/FOG CAN WE
EXPECT. NO SIMPLE ANSWERS. BAND OF LOW CLOUD COVER AND REDUCED VSBYS
STILL INTACT ACROSS A PORTION OF NE LOWER MICHIGAN INTO EASTERN
UPPER MICHIGAN WITH 1/4SM TO 1/2SM VSBYS STILL BEING REPORTED OVER A
PORTION OF EASTERN UPPER. THIS CLOUD COVER HAS BEEN STEADILY ERODING
ALTHOUGH ANOTHER BATCH OF LOW CLOUD/MOISTURE EVIDENT ON SATELLITE
IMAGERY ACROSS SE LOWER MICHIGAN SHOWING SIGNS OF SWINGING BACK UP
INTO NE LOWER MICHIGAN OVER THE NEXT SEVERAL HOURS. OVER NW LOWER
MICHIGAN...OBS CONTINUE TO REPORT SOME RESTRICTION TO VSBYS (HZ)
ALONG WITH HIGHER DEWPOINTS THAN SATURDAY.
UPSHOT TO ALL THIS...APPEARS LIKELY THAT STRATUS/FOG WILL ONCE AGAIN
DEVELOP THIS EVENING AND OVERNIGHT ESPECIALLY ACROSS NE LOWER
MICHIGAN AS AFOREMENTIONED LOW CLOUD SWINGS UP THROUGH THE REGION.
NEGATIVES AGAINST WIDESPREAD DENSE FOG INCLUDE INCREASING S/SE FLOW
AND GIVEN THAT...WILL REFRAIN FROM ISSUING ANY FOG RELATED HEADLINES
AT THIS POINT. AS USUAL...EVENING SHIFT WILL NEED TO MONITOR.
ADAM
&&
.LONG TERM.../ISSUED AT 316 PM/...MONDAY AND BEYOND
OUTSIDE OF FOG/STRATUS ISSUES MONDAY/TUESDAY MORNINGS...THE MAIN
FORECAST ISSUES FOR THE UPCOMING WEEK WILL REVOLVE AROUND UPPER
LEVEL ENERGY ROTATING OUT OF THE CENTRAL PLAINS AND SOUTHERN CANADA
WED-THU. THERE APPEARS TO BE SOME CLUSTERING OF MODEL SOLUTIONS
WITH THE SOUTHERN PIECE OF ENERGY ON WEDNESDAY...BUT STILL PLENTY OF
MODEL SPREAD WITH THE HANDLING OF THE SECOND FEATURE FOR
THANKSGIVING DAY. THE OPERATIONAL ECMWF CONTINUES TO BE THE SLOWEST
OF ALL SOLUTIONS...AND WILL TREND TOWARD THE MAJORITY FASTER AND
SLIGHTLY FURTHER NORTH SOLUTIONS.
MONDAY NIGHT/TUESDAY...THE INITIAL SHORTWAVES AHEAD OF THE MAIN
UPPER LOW OVER THE CENTRAL PLAINS WILL DRAW A PLUME OF DEEPER
MOISTURE NORTHWARD FROM THE CENTRAL APPALACHIANS TO THE EASTERN
GREAT LAKES...PASSING EAST OF THE AREA. FOG/STRATUS WILL CONTINUE
TO BE THE MAIN CONCERNS. CIRRUS WILL INHIBIT COOLING TO SOME DEGREE
MONDAY NIGHT...BUT THE GRADIENT WILL ACTUALLY BE A LITTLE WEAKER -
LESS THAN 20KT. I LIKE THE MIDNIGHT SHIFT/S IDEA OF ADDING FOG FOR
MONDAY NIGHT/TUESDAY MORNING...ESPECIALLY OVER EASTERN UPPER WITH
PREVAILING MOIST SOUTHEAST MARINE FLOW.
UPPER LOW MOVES INTO THE CENTRAL MISSISSIPPI VALLEY ON TUESDAY WITH
WARM CONVEYOR BELT HELPING TO SPREAD CLOUDS BUT NOT PCPN INTO
NORTHERN MICHIGAN. UPPER FEATURE SLIDES TOWARD SOUTHWEST MICHIGAN
BY WEDNESDAY MORNING...AND THEN INTO NORTHERN LAKE HURON BY LATE
AFTERNOON. INITIAL SURGE OF RAIN EARLY WEDNESDAY MORNING WILL PUSH
NORTH THROUGH THE AREA THROUGHOUT THE MORNING ON THE NOSE OF H8
THETA-E MOISTURE PLUME...PIVOTING INTO EASTERN UPPER BY MIDDAY. IN
IT/S WAKE...THE HEAVIEST AND MOST STEADY PCPN WILL LIKELY END...AS
DEEPEST MOISTURE AND FORCING SLIDE NORTHEAST. PLENTY OF LOW LEVEL
MOISTURE BENEATH H9 FOR THE AFTERNOON HOURS AND COULD SEE SOME
DRIZZLE. NORTHERN MICHIGAN ON THE WARM SIDE OF THE STORM...SO JUST
LIQUID DURING THE DAY WEDNESDAY /NO SNOW/.
MODEL ISSUES BEGIN TO APPEAR BY WEDNESDAY NIGHT AS UPSTREAM PIECE OF
UPPER LEVEL ENERGY DROPS TOWARD THE MISSISSIPPI VALLEY/NRN OHIO
VALLEY. BEST PCPN CHANCES WILL LIKELY BE TO THE WEST OF
INTERSTATE-75...WITHIN DEVELOPING DEFORMATION AXIS ACROSS LAKE
MICHIGAN. WILL NOT GET TOO DETAILED THIS FAR OUT...GOING WITH HIGH
CHANCE/LOW LIKELY POPS FOR THANKSGIVING DAY. AS FAR AS PCPN
TYPE...RAIN GRADUALLY TURNING TO SNOW ON THANKSGIVING DAY. WHAT
WILL MAKE THIS A DIFFICULT PCPN TYPE CASE IS THAT THE COLDEST CORE
OF TEMPS ASSOCIATED WITH UPPER LOW MAY ACTUALLY FOCUS OVER SOUTHERN
MICHIGAN/NRN OHIO VALLEY - WITH SLIGHTLY WARMER READINGS WRAPPING
BACK OVER NORTHERN MICHIGAN. AT THIS POINT...WAY TOO MANY UNKNOWNS
TO GET VERY SPECIFIC.
SYNOPTIC MOISTURE STRIPS OUT THE EAST THURSDAY NIGHT WITH DRY SLOT
MOVING INTO NORTHERN MICHIGAN...POSSIBLY LEAVING SOME LIGHT PCPN
/FREEZING DRIZZLE?/ FOR LATER THURSDAY NIGHT INTO FRIDAY MORNING.
UPPER RIDGE BUILDS INTO THE AREA FRIDAY/SATURDAY...BRINGING DRIER
WEATHER AND SEASONABLY MILD TEMPERATURES.
JK
&&
.MARINE.../ISSUED AT 316 PM/
GUSTY SOUTH WINDS HAVE PRODUCED SMALL CRAFT WINDS/WAVES ACROSS
WHITEFISH BAY THIS AFTERNOON...WHICH WILL PERSIST INTO THE EVENING
HOURS BEFORE DIMINISHING. OTHERWISE...SOUTHERLY WINDS WILL DOMINATE
ON THE LAKES OVER THE NEXT SEVERAL DAYS WITH CONDITIONS GENERALLY
BELOW SMALL CRAFT ANTICIPATED.
ADAM
&&
.AVIATION.../ISSUED AT 105 PM/...VALID FOR 18Z TAFS
LOW IFR STRATUS AND REDUCED VSBYS WILL CONTINUE TO IMPACT THE APN
TERMINAL SITE THROUGH AT LEAST 20Z. SATELLITE TRENDS SUGGEST LOW
STRATUS SHOULD ERODE FROM THAT AREA BY 21Z...LEAVING AT LEAST MVFR
CONDITIONS. BUT OVERALL CONFIDENCE IS LOW AS STRATUS COULD HANG
TOUGH THROUGH THE REST OF THE DAY. ELSEWHERE...VFR CONDITIONS
SHOULD PREVAIL UNTIL EVENING.
TONIGHT...HARD TO GO AGAINST PERSISTENCE AT THIS POINT. WILL BANK
OF STRATUS/FOG REDEVELOPING ONCE AGAIN THIS EVENING AND BECOMING
SUBSTANTIAL OVERNIGHT INTO MONDAY MORNING. AGAIN...OVERALL
CONFIDENCE NOT GREAT...AND INCREASING SOUTHERLY FLOW COULD KEEP
STRATUS AND/OR FOG AT BAY. BUT FOR NOW HAVE TRENDED TAFS TO IFR
DURING THE OVERNIGHT PERIOD.
ADAM
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR LSZ321.
&&
$$
000
FXUS63 KAPX 221806
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
106 PM EST SUN NOV 22 2009
.SYNOPSIS.../ISSUED AT 343 AM/
HIGH PRESSURE WHICH LIFTED NORTH INTO THE STATE FROM THE OHIO VALLEY
SATURDAY...WILL BE CENTERED OVER THE EASTERN LAKES INTO THE BEGINNING
OF THE WORK WEEK. THIS PATTERN WILL GENERATE SOME SUN AND WELL ABOVE
NORMAL TEMPERATURES ACROSS NORTHERN MICHIGAN THROUGH MONDAY.
THE NEXT CHANCE OF RAIN WILL BE TUESDAY AND WEDNESDAY...AS A STORM
SYSTEM LIFTS NORTH INTO THE UPPER MIDWEST AND WESTERN GREAT LAKES.
TEMPERATURES WILL REMAIN ABOVE NORMAL TUESDAY AND WEDNESDAY.
MORE SEASONABLE TEMPERATURES AND A CHANCE OF SNOW...MAKE A BRIEF
RETURN TO THE REGION THURSDAY AND FRIDAY...AS COOLER AIR BEGINS TO
FILTER INTO THE REGION.
SWR
&&
.SHORT TERM.../ISSUED AT 1130 AM/...TODAY
ANOTHER MORNING OF STRATUS AND FOG...PARTICULARLY ACROSS EASTERN
UPPER AND NORTHEAST LOWER MICHIGAN. WAY MORE STRATUS/FOG ACROSS NRN
LOWER THAN I ANTICIPATED THIS TIME YESTERDAY. AND SIMILAR TO
YESTERDAY...STRATUS/FOG HAS BEEN STEADILY ERODING THIS MORNING AND
THIS PROCESS REALLY BEGINNING TO ACCELERATE AS HEATING/MIXING
PROCEEDS. NONETHELESS...STILL SOME AREAS IN EASTERN UPPER AND
NORTHEAST LOWER REPORTING 1/4SM OR LESS AT THIS LATE MORNING HOUR
AND ALMOST EXTENDED THE FOG ADVISORY BECAUSE OF THAT. ULTIMATELY
DECIDED TO LET THE FORECAST TEXT SPEAK FOR ITSELF.
THIS AFTERNOON....BROAD HIGH PRESSURE SYSTEM WILL SLOWLY INCH
EASTWARD AWAY FROM THE REGION BRINGING INCREASING S/SW FLOW.
REMAINING STRATUS/FOG SHOULD EVENTUALLY GIVE WAY...BUT PROBABLY NOT
UNTIL LATE IN SOME AREAS AND HAVE STRETCHED OUT FOG/CLOUD COVER
THROUGH A GOOD PORTION OF THE AFTERNOON ACCORDINGLY. WARMEST TEMPS
WILL BE SEEN ACROSS NW LOWER MICHIGAN WHERE GREATEST LENGTH OF
SUNSHINE WILL BE FOUND.
TONIGHT...INCREASING S/SW FLOW CALLS INTO QUESTION JUST HOW HOW
WIDESPREAD FOG/STRATUS GETS. BUT GIVEN RECENT EVENTS...AM RELUCTANT
TO GO AGAINST PERSISTENCE. IN FACT...WILL PUT FOG BACK INTO THE
FORECAST FOR ALL AREAS BY LATE EVENING.
ADAM
&&
.LONG TERM.../ISSUED AT 343 AM/...TONIGHT AND BEYOND
EARLY PART OF THE WEEK STILL LOOKS UNEVENTFUL...BUT THINGS GET A BIT
MORE ACTIVE CLOSE TO THE HOLIDAY. UPPER RIDGING OVERHEAD TODAY WILL
REMAIN PROGRESSIVE...MOVING OFF THE NEW ENGLAND COAST MONDAY. A
COUPLE OF WEAKISH SHORTWAVES WILL LIFT INTO THE OHIO VALLEY AND
CENTRAL/EASTERN LAKES MONDAY/MONDAY NIGHT...IN ADVANCE OF A CLOSED
UPPER LOW DEEPENING IN THE CENTRAL PLAINS. THIS LOW WILL REACH THE
SW LAKES REGION BY WED MORNING...WHILE ANOTHER UPPER LOW DIGS INTO
THE NORTHERN PLAINS. CLOUDS/FOG/TEMPS REMAIN THE MAIN CONCERN EARLY
ON...PRECIP BECOMES THE MAIN ISSUE BEGINNING TUE NIGHT.
MODELS...ARE STARTING TO CLUSTER A BIT WHEN IT COMES TO THE MID-WEEK
SYSTEM. TIMING IS QUITE SIMILAR BETWEEN NAM/GFS/ECMWF/SREF.
HOWEVER...THERE ARE STILL IMPORTANT LATITUDINAL DIFFERENCES. THE GFS
IS FURTHEST SOUTH...WITH AN UPPER LOW NEAR INDY WED MORNING. THE
SREF IS FURTHEST NORTH...NEAR MILWAUKEE. NAM/ECMWF ARE IN BETWEEN...
NEAR THE SOUTHERN TIP OF LAKE MI...AND WILL STEER THE FORECAST IN
THAT MIDDLE-OF-THE-ROAD DIRECTION.
TONIGHT/MONDAY...PRESSURE GRADIENT TIGHTENS A BIT TONIGHT AS HIGH
PRESSURE MOVES ACROSS NEW ENGLAND. AS A RESULT...SOUTHERLY 950MB
WINDS WILL INCREASE TO AROUND 20KT. THIS WILL NOT BE ENOUGH TO
OUTRIGHT PREVENT FOG REDEVELOPMENT...BUT SHOULD PREVENT FOG FROM
BEING AS WIDESPREAD/DENSE AS THE LAST COUPLE OF NIGHTS. MARINE-
INFLUENCED EASTERN UPPER MI HAS THE BEST SHOT OF SEEING THE THICK
STUFF...AS DOES THE IMMEDIATE HURON COAST...THANKS TO SE-ERLY
SUB-950MB WINDS. WILL TWEAK FOG WORDING IN THE GRIDS AND TEXT
PRODUCTS...INCLUDING ADDING DENSE FOG IN THE ABOVE LOCALES.
OTHERWISE...SAME OLD SAME OLD...WITH FOG/STRATUS SLOWING BURNING OFF
DURING THE DAY MONDAY. CLEARING WILL AGAIN TAKE LONGEST IN EASTERN
UPPER AND NE LOWER MI. WE WILL HAVE MORE CIRRUS AROUND ON MONDAY
THAN TODAY...ESPECIALLY IN THE AFTERNOON. THAT MAY BE ENOUGH TO
KNOCK A COUPLE OF DEGREES OFF OF MAX TEMPS...BUT GUIDANCE TEMPS
STILL LOOK A LITTLE TOO COOL IN MANY AREAS.
MONDAY NIGHT/TUESDAY...THE INITIAL SHORTWAVES AHEAD OF THE MAIN
UPPER LOW WILL DRAW A PLUME OF DEEPER MOISTURE NORTHWARD FROM THE
CENTRAL APPALACHIANS TO THE EASTERN GREAT LAKES. THIS WILL PASS EAST
OF US. MEANWHILE...THE WARM CONVEYOR BELT AHEAD OF THE UPSTREAM LOW
WILL ADVANCE INTO IL/WI TUESDAY. IN BETWEEN THESE TWO...WE SHOULD
SEE NO SIGNIFICANT RISK OF PRECIP. INSTEAD...FOG/STRATUS CONTINUE TO
BE THE MAIN CONCERNS. CIRRUS WILL INHIBIT COOLING TO SOME DEGREE
MONDAY NIGHT...BUT THE PRESSURE GRADIENT WILL ACTUALLY BE SOMEWHAT
WEAKER (ESPECIALLY AFTER MIDNIGHT). 950MB WINDS WILL LOWER BELOW
20KT. NAM SOUNDINGS ARE MORE MOIST BELOW 950MB THAN PROGGED TONIGHT.
NUMERICAL GUIDANCE IS MORE BULLISH ON FOG MONDAY NIGHT THAN TONIGHT.
WILL THUS GO AHEAD AND ADD EVEN MORE FOG TO THE LATE MONDAY
NIGHT/TUESDAY MORNING FORECAST...HITTING HARDER IN EASTERN UPPER.
MID AND HIGH CLOUDS WILL BECOME MORE EXTENSIVE TUESDAY...AND THIS
WILL EAT INTO MAX TEMPS...WHICH WILL BE MAINLY IN THE 40S.
REST OF THE FORECAST...MID-WEEK SURFACE LOW NOW LOOKS LIKE IT MAY
PASS JUST SOUTH OF THE FORECAST AREA ON WEDNESDAY. 850MB TEMPS WILL
BE NEAR 0C...BUT THE ENTIRE LAYER BELOW THAT WILL BE ABOVE FREEZING
AND MITIGATE ANY FROZEN PRECIP CONCERNS ON WEDNESDAY. COLDER AIR
WILL GRADUALLY TURN RAIN OVER TO SNOW WED NIGHT INTO TURKEY
DAY...THOUGH MUCH OF THE SYNOPTIC PRECIP WITH THE INITIAL UPPER LOW
WILL BE OVER BY THEN. BUT WHAT DOES THE 2ND ONE DO? THE NEW ECMWF
WOULD OFFER UP A PERIOD OF ACCUMULATING SNOW POSSIBLE...CENTERED ON
THURSDAY NIGHT...AS THAT PASSES TO THE SOUTH.
JZ
&&
.MARINE.../ISSUED AT 343 AM/
HIGH PRESSURE WILL MOVE FROM THE EASTERN LAKES TO OFF THE NEW
ENGLAND COAST. WE WILL SEE SOMETHING OF AN INCREASE IN S-SE WINDS AS
THE HIGH MOVES AWAY. BUT IN THE NEAR TERM...WINDS AND WAVES WILL
REMAIN COMFORTABLY BELOW SMALL CRAFT CRITERIA. LOW LEVEL MOISTURE
AND RELATIVELY LIGHT WINDS WILL STILL RESULT IN AREAS OF FOG THIS
MORNING...LATE TONIGHT INTO MONDAY MORNING...AND LATE MONDAY NIGHT
INTO TUESDAY MORNING.
JZ
&&
.AVIATION.../ISSUED AT 105 PM/...VALID FOR 18Z TAFS
LOW IFR STRATUS AND REDUCED VSBYS WILL CONTINUE TO IMPACT THE APN
TERMINAL SITE THROUGH AT LEAST 20Z. SATELLITE TRENDS SUGGEST LOW
STRATUS SHOULD ERODE FROM THAT AREA BY 21Z...LEAVING AT LEAST MVFR
CONDITIOS. BUT OVERALL CONFIDENCE IS LOW AS STRATUS COULD HANG
TOUGH THROUGH THE REST OF THE DAY. ELSEWHERE...VFR CONDITIONS
SHOULD PREVAIL UNTIL EVENING.
TONIGHT...HARD TO GO AGAINST PERSISTENCE AT THIS POINT. WILL BANK
OF STRATUS/FOG REDEVELOPING ONCE AGAIN THIS EVENING AND BECOMING
SUBSTANTIAL OVERNIGHT INTO MONDAY MORNING. AGAIN...OVERALL
CONFIDENCE NOT GREAT...AND INCREASING SOUTHERLY FLOW COULD KEEP
STRATUS AND/OR FOG AT BAY. BUT FOR NOW HAVE TRENDED TAFS TO IFR
DURING THE OVERNIGHT PERIOD.
ADAM
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR LSZ321.
&&
$$
000
FXUS63 KMQT 221741 AAC
AFDMQT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1242 PM EST SUN NOV 22 2009
UPDATED FOR TAF
.SYNOPSIS...
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW SHARP UPPER RIDGE AXIS
OVER JAMES BAY DOWNSTREAM OF TROUGHING OVER THE NORTHERN AND CENTRAL
PLAINS. ANOTHER TROUGH IS DIGGING OVER THE PACIFIC NORTHWEST. A WEAK
SHORTWAVE IS OVER THE FORECAST AREA THIS MORNING...WITH OTHERS OVER
EASTERN DAKOTAS AND WESTERN MINNESOTA. SURFACE ANALYSIS SUGGEST A
COLD FRONT EXTENDING FROM WESTERN HUDSON BAY SOUTH THROUGH MINNESOTA
TO A WEAK LOW OVER NORTHERN KANSAS AND A LARGE HIGH OVER THE
CANADIAN MARITIME CAUSING A SOUTHERLY FLOW ACROSS THE FORECAST AREA.
THIS SOUTHERLY HAS PUSHED THE 12Z 850MB TEMPERATURES AT PICKLE LAKE
TO AN IMPRESSIVE 4C. THIS FLOW HAS BROUGHT SOME LOW LEVEL MOISTURE
INTO THE AREA WHICH CAUSED CONSIDERABLE FOG THIS MORNING...MOST OF
WHICH HAS BURNED OFF AT THIS TIME. THE AREA RAOBS ARE QUITE DRY
ABOVE 800MB. QUITE A BIT OF HIGH CLOUDS ARE STREAMING INTO THIS AREA
AHEAD OF OF THE FRONT.
&&
.SHORT TERM...
THE MAIN CONCERN WITH THE REST OF TODAY WILL BE THE HIGH TEMPERATURE
ACROSS THE AREA AND POTENTIAL FOR RAIN OVER THE FAR WEST.
THE MID LEVEL RIDGE WILL PUSH INTO WESTERN QUEBEC WITH THE
ASSOCIATED HIGH SETTLING OVER THE LOWER GREAT LAKES. THE WEAK
SHORTWAVE OVER THE FORECAST AREA WILL REACH EASTERN ONTARIO BY LATE
AFTERNOON WHILE THE MID LEVEL TROUGH OVER THE NORTHERN PLAINS SHIFTS
WEAKENS AS IT MOVES THROUGH THE DAKOTAS. THE TROUGH OVER THE PACIFIC
NORTHWEST BEGINS TO DEEPEN. THE COLD FRONT OVER MINNESOTA WILL REACH
THE KDLH AREA BY LATE AFTERNOON. THIS WILL CONTINUE TO DRAW IN MOIST
AIR AHEAD OF THE FRONT INTO THE WEST END OF THE FORECAST AREA. THIS
WILL INCREASE THE PW FROM .5 TO .7 OVER THE IWD AREA. FORECAST
SOUNDINGS SUGGEST A CLOUD DECK AROUND 850MB THIS AFTERNOON MAINLY
OVER THE FAR WEST...INCLUDING WESTERN LAKE SUPERIOR. THUS THIS
INDICATES A POSSIBILITY OF OF SOME SPRINKLES OVER THE FAR WEST. IT
IS QUESTIONABLE IF IT WOULD BE ENOUGH OF SATURATE OUT THE LOWER
LEVELS ENOUGH TO GET ANY MEASURABLE AMOUNTS. THUS WILL STAY WITH
JUST A SLIGHT CHANCE OF FOR NOW.
AS THE FOG AND LOW CLOUDS BURN OFF...TEMPERATURES WILL START
TO CLIMB. WE ARE SEEING RAPID INCREASES IN TEMPERATURES AT LOCATION
WHERE TO THE LOW CLOUDS HAVE BURNED OFF ALREADY. THUS PLAN TO UPDATE
ONLY THE WORDING ON ZONE FORECAST AT THIS TIME.
&&
.LONG TERM...TONIGHT AND LATER PERIODS
RESTRICTED POPS TNGT TO THE FAR WRN CWA AGAIN WHERE FAVORED NAM
SHOWS LO PRES TROF SETTING UP UNDER AXIS OF HIER H85-7 DWPTS. TENDED
TO GO WITH THE HIER POPS LATER AT NGT WITH INFLUX OF MSTR AND SOME
UPR DVGC IN RRQ OF H3 JET MAX IN NW ONTARIO. FARTHER E...RISING MSLP
UNDER PERSISTENT RDG WL RESULT IN A SLACKENING PRES GRADIENT/LIGHTER
WINDS. SO MORE FOG LOOKS LIKE A GOOD BET THERE WHERE DRIER MID LVLS
FAVOR A SHARPER DIURNAL FALL OF TEMP BLO MOS GUIDANCE.
ON MON...NUMERICAL MODELS SHOW DEEPENING TROF IN THE CNTRL PLAINS AS
SHRTWV NOW APRCHG THE PAC NW DIVES ESEWD. WITH THIS DEVELOPMENT
UPSTREAM...MODELS HAVE CONTINUED TREND FOR DRYING TREND DOWNSTREAM
OVER THE FA. GIVEN THIS CONSISTENT TREND...OPTED TO INCRS MAX TEMPS
FCST WITH EXPECTATION FOR MORE AFTN SUNSHINE ONCE MRNG FOG BURNS OFF
WITH DAYTIME MIXING/SFC-H85 DRY ADVECTION. MIXING TO ONLY H9 ON
GFS/NAM FCST SDNGS YIELDS HI TEMPS IN THE LO 50S.
ON MON NGT/TUE...MODELS SHOW OCCLUDED LO IN THE PLAINS MOVING ONLY
SLOWLY NEWD INTO IA BY 00Z WED. WITH ACCOMPANYING DYNAMICS REMAINING
WELL TO THE SW AND HINT OF UPR RDG/DRY MID LVLS LINGERING OVER THE
GRT LKS...PREFER THE DRIER LOOK OF THE NAM. CUT POPS TO ONLY FAR WRN
LK SUP ON MON NGT THRU 18Z TUE. MAINTAINED SCHC POPS AFT 18Z NEAR
THE WI BORDER. WITH DRIER MID LVLS PERSISTING...INCRSD DIURNAL TEMP
RANGE WITH LOWER MINS ON MON NGT AND HIER MAXES ON TUE. MAINTAINED
PATCHY FOG MENTION OVER THE INTERIOR ECNTRL ON MON NGT WITH GRADIENT
FLOW SUFFICIENTLY LGT UNDER LOWER PWAT BLO 0.50 INCH.
MODELS HAVE MAINTAINED LOOK OF MORE PHASING BTWN CUTOFF LO AND
SHRTWVS ARRIVING IN THE NRN BRANCH FLOW FOR MIDWEEK. AS SUCH...GOING
POPS INCRSG TO LIKELY ON WED SEEM APPROPRIATE. ON TUE NGT...REMOVED
MENTION OF SN AS GFS/NAM/ECMWF FCST SDNGS AS WELL AS H100-85 THKNS
FIELDS/MIN TEMPS FCST SUG LLVLS WL BE TOO WARM FOR ANYTHING BUT RA.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
THE REMAINING MIST SHOULD DISSIPATE EALY THIS AFTERNOON. A FEW
SPRINKLES ARE SHOWING UP ON RADAR AND WERE REPORTED AT KCMX...SO
HAVE ADDED IT TO THE TAF. AFTER THE MIST DISSIPATED...BOTH SITES
WILL BE VFR UNTIL TONIGHT WHEN FOG WILL LIKELY REDEVELOP AS LOW
LEVEL MOISTURE WILL STILL BE A CONCERN. AT BOTH LOCATON SIMILAR
CONDITIONS TO LAST NIGHT WILL AGAIN OCCUR WITH DOWNSLOPING SOUTHERLY
WINDS LIMITING LOWER VISIBILITIES AND CEILINGS TO LIFR.
LLWS CAN BE EXPECTED AT BOTH TAF SITES AFTER SUNSET UNTIL LATE
MORNING ON MONDAY WHEN THE LOW LEVEL JET SHIFT EAST.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
WITH LAKE SUPERIOR IN BETWEEN LOW PRESSURE TO THE NORTHWEST AND HIGH
PRESSURE OVER THE LOWER LAKES EXPECT SOUTHERLY WINDS TO 25 KNOTS
INTO MONDAY MORNING. A FEW WIND GUSTS TO 30 KNOTS AREN/T OUT OF THE
QUESTION OVER THE EAST TODAY...HOWEVER...AIRMASS ABOVE THE LAKE
SURFACE IS QUITE STABLE SO DON/T EXPECT WINDS TO GET TOO STRONG.
WINDS WILL THEN REMAIN UNDER 20 KNOTS INTO WEDNESDAY...WHEN A STORM
SYSTEM APPROACHES THE UPPER GREAT LAKES AND WINDS BEGIN TO INCREASE
OUT OF THE NORTH AND NORTHEAST WITH GALES POSSIBLE LATE WEDNESDAY
INTO THURSDAY. LOCALLY DENSE PATCHY FOG IS POSSIBLE THIS MORNING
ACROSS EASTERN LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS/SHORT TERM...DLG
LONG TERM...KC
AVIATION...PEARSON
MARINE...PEARSON
000
FXUS63 KGRR 221734
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1234 PM EST SUN NOV 22 2009
LATEST UPDATE...SYNOPSIS AND AVIATION...
.SYNOPSIS...(1234 PM EST SUN NOV 22 2009)
HIGH PRESSURE WILL PRODUCE FAIR WEATHER TODAY INTO MONDAY BUT FOG
WILL LIKELY REDEVELOP AGAIN LATE TONIGHT. A LOW PRESSURE SYSTEM WILL
BRING RAIN TUESDAY NIGHT AND WEDNESDAY. IT WILL TURN COOLER LATE
THIS WEEK WITH A MIX OF RAIN AND SNOW SHOWERS POSSIBLE FOR OUR
THANKSGIVING HOLIDAY.
&&
.SHORT TERM...(1035 AM EST SUN NOV 22 2009)
(LATE MORNING THROUGH TUESDAY AFTERNOON)
WE HAVE ALLOWED THE FOG ADVISORY TO EXPIRE AT 1000 AM. EVEN
SO...DENSE CONTINUES IN OUR EXTREME NORTHEAST COUNTIES. I EXPECT
THIS WILL MIX OUT BY NOON. HOWEVER... DUE TO THE PREVAILING SOUTH
SOUTHEAST WINDS THROUGH THE BOUNDARY LAYER... I AM CONCERNED ABOUT
THE LARGE AREA OF STRATUS AND FOG OVER LAKE ERIE AND SE LOWER
MICHIGAN AT 10 AM. THE HRRR RUC BRINGS THIS AREA NORTHEAST INTO OUR
EASTERN COUNTIES THIS AFTERNOON. SO I PUT THE CLOUD EDGE IN THE
GRIDS OVER OUR EASTERN COUNTIES THIS AFTERNOON TO ACCOUNT FOR THIS.
I AM CONCERNED ABOUT THE FOG TONIGHT AS THE BOUNDARY LAYER WINDS ARE
TO STRONG OF WIDESPREAD DENSE FOG. TO SOME EXTENT IT WAS FOR THAT
REASON WE DID NOT GET MUCH FOG OVER SOUTH SW COUNTIES EARLY THIS
MORNING. I DID NOT TAKE THE AREAS OF FOG OUT OF OUR ZONES FOR
TONIGHT YET BUT MAY CHANGE THAT TO PATCHY FOG WITH THE AFTERNOON
UPDATE.
THE STORM JUST NOW COMING ONSHORE OVER THE WESTERN UNITED STATES
WILL CURVE OUT A DEEP TROUGH OVER THE CENTRAL UNITED STATES BY
WEDNESDAY BUT WHILE THAT SYSTEM IS DEVELOPING IT WILL BUILD AND
UPSTREAM RIDGE THAT WILL BE CLOSE ENOUGH OR SOUTHWEST LOWER MICHIGAN
TO ASSURE THIS AREA DRY WEATHER THROUGH MOST OF TUESDAY. IT SEEMS TO
ME THE EARLIEST I WOULD THINK RAIN WOULD MOVE INTO OUR AREA IS AFTER
DURING THE EARLY MORNING HOURS OF WEDNESDAY.
&&
.LONG TERM...(400 AM EST SUN NOV 22 2009)
(TUESDAY NIGHT THROUGH SATURDAY)
TWO SYSTEMS/UPPER LOWS ARE THE FOCUS/CHALLENGE OF THE LONG TERM. THE
FIRST TRACKS EAST NORTHEAST FROM THE CENTRAL PLAINS TUESDAY NIGHT
AND WEDNESDAY... TAKING ON A NEGATIVE TILT AS ANOTHER UPPER LOW
DROPS SOUTH THROUGH THE NRN PLAINS.
HANDLING OF THE INITIAL SYSTEM SEEMS RATHER STRAIGHTFORWARD... WITH
A HIGH CHANCE OF RAIN AND PERHAPS EVEN A TSTM. IF THE MODELS REMAIN
CONSISTENT ON TIMING... BELIEVE WE WILL BE ABLE TO RAISE POPS TO
LIKELY OR CATEGORICAL FOR TUESDAY NIGHT AND WEDNESDAY.
THE SECOND SYSTEM IS NOT AS STRAIGHTFORWARD SINCE COLDER H8 AIR NEAR
-4C GETS WRAPPED INTO THE SYSTEM FROM THE SOUTHWEST AS IT TRACKS
ACROSS THE REGION ON THANKSGIVING DAY AND NIGHT. PCPN TYPE IS A
CHALLENGE SINCE BOUNDARY LAYER TEMPS ARE PROGGED TO REMAIN THE MID
TO UPPER 30S DESPITE THE COLDER TEMPS COMING IN ALOFT. WILL CONTINUE
TO CARRY A MIXTURE OF RAIN/SNOW SHOWERS DURING THIS TIME... BUT AM
BECOMING A BIT CONCERNED ABOUT THE POSSIBILITY OF ACCUMULATING WET
SNOW ON THURSDAY NIGHT.
SCATTERED SNOW OR MIXED RAIN AND SNOW SHOWERS MAY LINGER INTO
FRIDAY... BEFORE RIDGING/QUIET WEATHER RETURNS FOR NEXT WEEKEND.
&&
.AVIATION...(1234 PM EST SUN NOV 22 2009)
COMPLICATED AND UNCERTAIN FORECAST FOR THE NEXT 24 HOURS...
ESPECIALLY CONCERNING FOG AND LOW CLOUD POTENTIAL FOR TONIGHT. MOST
LOCATIONS SHOULD REMAIN VFR THROUGH 23Z THIS EVENING WITH JUST A FEW
CUMULUS CLOUDS EXPECTED FOR THE MOST PART. SOME OF THE STRATUS EAST
OF THE AREA IS TRYING TO MOVE IN. SOME OF THIS WILL IMPACT KJXN AND
KLAN WITH A SCT015-020 LAYER...BUT WE DO NOT EXPECT IT TO GO BKN AS
IT IS MIXING OUT.
WE WILL START OUT A BIT BETTER ON VSBYS THIS EVENING AS VSBYS ARE
ALREADY BETTER THAN THEY WERE ALL DAY ON SAT. MOISTURE IS STILL
HANGING AROUND AND WE ARE MIXING HIGHER DEW POINTS DOWN...SO FOG
POTENTIAL REMAINS. WINDS WILL BE HIGHER THAN LAST NIGHT WHICH SHOULD
NEGATE FOG SOMEWHAT. WE ARE ALSO WATCHING THE LOWER CLOUDS TO THE
EAST COMING IN OFF OF LAKE ERIE. THIS IS EXPECTED TO SPREAD WESTWARD
AFTER SUNSET AS MIXING DIMINISHES. THIS ALSO SHOULD EXPAND AS THE
MOIST AIR WILL CONDENSE FAIRLY QUICKLY AFTER SUNSET. THE LOW CLOUDS
SHOULD ALSO NEGATE THE FOG SOME...BUT WE COULD VERY WELL END UP
SEEING IFR CIGS DEVELOP...EARLIER TO THE EAST. CONDITIONS WILL BE
SLOW TO IMPROVE AFTER SUNRISE ON MON AND THEN THROUGH 16-17Z MON.
&&
.MARINE...(400 AM EST SUN NOV 22 2009)
AREAS OF DENSE FOG WILL POSE A HAZARD TO MARINERS THIS MORNING AND
POTENTIALLY ONCE AGAIN ON MONDAY MORNING AND EARLY TUESDAY MORNING
ALSO. OTHERWISE FAIRLY MINIMAL WIND AND WAVE ACTION IS ANTICIPATED
THE NEXT COUPLE OF DAYS.
&&
.HYDROLOGY...(400 AM EST SUN NOV 22 2009)
NO PRECIPITATION THROUGH MONDAY NIGHT AND MUCH OF TUESDAY. NO HYDRO
ISSUES EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: LAURENS/NJJ
SHORT TERM: WDM
LONG TERM: MEADE
AVIATION: NJJ
MARINE: LAURENS
HYDROLOGY: LAURENS
000
FXUS63 KDTX 221701
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1201 PM EST SUN NOV 22 2009
.AVIATION...
MUCH LIKE YESTERDAY...IT WILL TAKE MOST OF THE AFTERNOON FOR
VSBYS AND CEILINGS TO IMPROVE INTO VFR CATEGORY. ONCE THE SUN
SETS...GOOD RADITIONAL COOLING WILL KICK IN...ALLOWING SURFACE
VISIBILITIES TO BEGIN TO CRASH...AS SURFACE DEW POINTS ARE RUNNING
HIGH EARLY THIS AFTERNOON (MID 40S). TONIGHT THERE WILL BE A
STRONGER SOUTHEAST WIND...WHICH MAY LEAD TO LIFR CEILINGS VS
VSBYS...BUT EITHER WAY WE APPEAR DESTINED TO FALL INTO THE LIFR
CATEGORY AS SOUTHEAST FLOW COMES OF LAKE ERIE/ST CLAIR/SOUTHERN
LAKE HURON. IMPROVEMENTS IN THE VIS/CEILINGS WILL BE SLOW
TOMORROW...AND PROBABLY WON`T SEE VFR CONDITIONS UNTIL AFT 18Z.
&&
.PREV DISCUSSION...ISSUED 336 AM EST SUN NOV 22 2009
SHORT TERM...TODAY
LOW STRATUS/FOG CONTINUE TO SLOWLY BUILD SOUTHWEST THROUGH THE CWA
EARLY THIS MORNING...AND EXPECT MOST OF THE AREA TO BE MOSTLY CLOUDY
WITH AREAS OF FOG BY DAYBREAK. WITH WEAK NOVEMBER SUNSHINE...IT WILL
THEN TAKE MUCH OF THE MORNING TO BURN OF THIS STRATUS/FOG...SO ONLY
EXPECT A GRADUAL TRANSITION TO PARTLY SUNNY SKIES BY AFTERNOON. THE
TEMPERATURES WILL BE ABLE TO CLIMB INTO THE LOW/MID 50S AGAIN AS THE
AIRMASS HAS NOT CHANGED APPRECIABLY...BUT THIS WILL BE DEPENDENT ON
THE EVENTUAL EVOLUTION OF THE STRATUS/FOG AND ADJUSTMENTS MAY BE
NEEDED IN SOME AREAS IF CLOUDS TAKE LONGER TO SCOUR OUT.
LONG TERM...TONIGHT THROUGH NEXT SATURDAY
FORECAST CONCERNS FOR THE EXTENDED PERIOD AGAIN CENTER AROUND FOG
DEVELOPMENT MONDAY AND TUESDAY MORNINGS AND THE MID WEEK LOW
PRESSURE SYSTEM THAT WILL AFFECT MICHIGAN.
MID LEVEL RIDGING AND ASSOCIATED SURFACE LOW PRESSURE SYSTEM WILL
CONTINUE TO AFFECT SE MI THROUGH MONDAY EVENING AS IT MOVES EASTWARD
OVER NEW ENGLAND. IT WILL EVENTUALLY BE REPLACED BY A SERIES OF
SHORTWAVES AND AMPLIFIED LONGWAVE TROUGH BY EARLY MIDWEEK. THE MID
LEVELS WILL REMAIN DRY UNTIL THIS TROUGH BEGINS TO INFLUENCE THE
AIRMASS ALOFT EARLY TUESDAY AS SHOWN BY NAM BUFR SOUNDINGS AND
BUFKIT. THE LOW LEVELS ON THE OTHER HAND WILL REMAIN VERY MOIST
LEADING TO POTENTIAL FOG DEVELOPMENT BOTH SUNDAY AND MONDAY NIGHTS.
THE PRESSURE GRADIENT REMAINS WEAK BETWEEN THE OUTGOING HIGH AND
INCOMING LOW PRESSURE SYSTEMS KEEPING THE WINDS WEAK THROUGH THIS
PERIOD. MODEL SOUNDINGS CONTINUE TO SHOW BOUNDARY LAYER DECOUPLING
EACH NIGHT AT AROUND 950MB UNDER THE CONTINUED MID LEVEL SUBSIDENCE
FROM THE EXITING HIGH. A SLIGHT EASTERLY COMPONENT TO THE LOW LEVEL
FLOW WILL ACT TO REINFORCE THE ALREADY MOIST BOUNDARY LAYER.
POTENTIAL DOES EXIST FOR THIS FOG TO BECOME DENSE AS A LACK OF DAY
TIME HEATING WILL ALLOW TEMPS TO DROP FAIRLY QUICKLY AFTER SUNSET.
NOT MUCH HAS CHANGED WITH THE MID WEEK STORM SYSTEM FROM PREVIOUS
MODEL RUNS. IT SEEMS THAT THE GFS IS SLOWING DOWN A BIT BRINGING IT
MORE IN LINE WITH THE ECMWF...WHICH HAS BEEN THE FAVORED MODEL
SOLUTION THUS FAR. THEY BOTH SHOW THE MID LEVEL TROUGH BECOMING
INCREASINGLY AMPLIFIED ON MONDAY OVER THE CENTRAL ROCKIES THEN
BECOMING MORE OF A CUTOFF CIRCULATION OVER THE CENTRAL PLAINS. THERE
ARE STILL MANY QUESTIONS THOUGH REGARDING THE EVOLUTION OF THIS
TROUGH AND LOW AS TO HOW CUTOFF IT WILL BECOME FROM THE MAIN STREAM
AND HOW A SECONDARY SHORTWAVE SLIDING DOWN THE BACKSIDE OF THIS MAIN
LOW WILL AFFECT THE TROUGH. THIS WILL AFFECT THE PROPAGATION SPEED
OF THE TROUGH AND WHEN IT WILL ARRIVE OVER SE MI. IT WILL ALSO
AFFECT HOW COLD THE AIRMASS WILL BE THAT IS BROUGHT IN WITH THE
TROUGH. THE MODELS HAVE BEEN TAPERING BACK THE AMOUNT OF COLD AIR
AND HOLDING IT BACK TIL LATER IN THE AS THEY SLOW THE MAIN FEATURE
DOWN. AT THIS POINT IT LOOKS LIKE THE PRECIP WILL MOVE IN TUESDAY
NIGHT IN THE FORM OF RAIN WITH THE BEST CHANCES DURING THE DAY ON
WEDNESDAY. PRECIP CHANCES REMAIN THROUGH FRIDAY TRANSITIONING TO A
RAIN/SNOW MIX THURSDAY NIGHT AS THE COLDEST AIR MOVES IN ON THE
BACKSIDE OF THE LOW.
MARINE...
HIGH PRESSURE WILL REMAIN IN PLACE OVER THE CENTRAL GREAT LAKES THIS
WEEKEND...RESULTING IN LIGHT/VARIABLE WINDS. THERE WILL BE A GRADUAL
INCREASE IN SOUTHEAST WINDS MONDAY INTO TUESDAY AS THE HIGH RETREATS
EAST AWAY FROM THE AREA. THE PATTERN BECOMES ACTIVE AGAIN MID/LATE
NEXT WEEK AS A STRONG SHORTWAVE AND ASSOCIATED JET STREAK DIG INTO
THE UPPER MIDWEST AND LEAD TO THE DEVELOPMENT OF A LARGE UPPER LEVEL
LOW OVER/NEAR THE REGION. THIS TIME FRAME WILL BRING UNSETTLE
WEATHER AND HIGHER WIND AND WAVES.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....SF
SHORT TERM...DG
LONG TERM....DRK
MARINE.......DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KAPX 221630
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1130 AM EST SAT NOV 21 2009
.SYNOPSIS.../ISSUED AT 343 AM/
HIGH PRESSURE WHICH LIFTED NORTH INTO THE STATE FROM THE OHIO VALLEY
SATURDAY...WILL BE CENTERED OVER THE EASTERN LAKES INTO THE BEGINNING
OF THE WORK WEEK. THIS PATTERN WILL GENERATE SOME SUN AND WELL ABOVE
NORMAL TEMPERATURES ACROSS NORTHERN MICHIGAN THROUGH MONDAY.
THE NEXT CHANCE OF RAIN WILL BE TUESDAY AND WEDNESDAY...AS A STORM
SYSTEM LIFTS NORTH INTO THE UPPER MIDWEST AND WESTERN GREAT LAKES.
TEMPERATURES WILL REMAIN ABOVE NORMAL TUESDAY AND WEDNESDAY.
MORE SEASONABLE TEMPERATURES AND A CHANCE OF SNOW...MAKE A BRIEF
RETURN TO THE REGION THURSDAY AND FRIDAY...AS COOLER AIR BEGINS TO
FILTER INTO THE REGION.
SWR
&&
.SHORT TERM.../ISSUED AT 1130 AM/...TODAY
ANOTHER MORNING OF STRATUS AND FOG...PARTICULARLY ACROSS EASTERN
UPPER AND NORTHEAST LOWER MICHIGAN. WAY MORE STRATUS/FOG ACROSS NRN
LOWER THAN I ANTICIPATED THIS TIME YESTERDAY. AND SIMILAR TO
YESTERDAY...STRATUS/FOG HAS BEEN STEADILY ERODING THIS MORNING AND
THIS PROCESS REALLY BEGINNING TO ACCELERATE AS HEATING/MIXING
PROCEEDS. NONETHELESS...STILL SOME AREAS IN EASTERN UPPER AND
NORTHEAST LOWER REPORTING 1/4SM OR LESS AT THIS LATE MORNING HOUR
AND ALMOST EXTENDED THE FOG ADVISORY BECAUSE OF THAT. ULTIMATELY
DECIDED TO LET THE FORECAST TEXT SPEAK FOR ITSELF.
THIS AFTERNOON....BROAD HIGH PRESSURE SYSTEM WILL SLOWLY INCH
EASTWARD AWAY FROM THE REGION BRINGING INCREASING S/SW FLOW.
REMAINING STRATUS/FOG SHOULD EVENTUALLY GIVE WAY...BUT PROBABLY NOT
UNTIL LATE IN SOME AREAS AND HAVE STRETCHED OUT FOG/CLOUD COVER
THROUGH A GOOD PORTION OF THE AFTERNOON ACCORDINGLY. WARMEST TEMPS
WILL BE SEEN ACROSS NW LOWER MICHIGAN WHERE GREATEST LENGTH OF
SUNSHINE WILL BE FOUND.
TONIGHT...INCREASING S/SW FLOW CALLS INTO QUESTION JUST HOW HOW
WIDESPREAD FOG/STRATUS GETS. BUT GIVEN RECENT EVENTS...AM RELUCTANT
TO GO AGAINST PERSISTENCE. IN FACT...WILL PUT FOG BACK INTO THE
FORECAST FOR ALL AREAS BY LATE EVENING.
ADAM
&&
.LONG TERM.../ISSUED AT 343 AM/...TONIGHT AND BEYOND
EARLY PART OF THE WEEK STILL LOOKS UNEVENTFUL...BUT THINGS GET A BIT
MORE ACTIVE CLOSE TO THE HOLIDAY. UPPER RIDGING OVERHEAD TODAY WILL
REMAIN PROGRESSIVE...MOVING OFF THE NEW ENGLAND COAST MONDAY. A
COUPLE OF WEAKISH SHORTWAVES WILL LIFT INTO THE OHIO VALLEY AND
CENTRAL/EASTERN LAKES MONDAY/MONDAY NIGHT...IN ADVANCE OF A CLOSED
UPPER LOW DEEPENING IN THE CENTRAL PLAINS. THIS LOW WILL REACH THE
SW LAKES REGION BY WED MORNING...WHILE ANOTHER UPPER LOW DIGS INTO
THE NORTHERN PLAINS. CLOUDS/FOG/TEMPS REMAIN THE MAIN CONCERN EARLY
ON...PRECIP BECOMES THE MAIN ISSUE BEGINNING TUE NIGHT.
MODELS...ARE STARTING TO CLUSTER A BIT WHEN IT COMES TO THE MID-WEEK
SYSTEM. TIMING IS QUITE SIMILAR BETWEEN NAM/GFS/ECMWF/SREF.
HOWEVER...THERE ARE STILL IMPORTANT LATITUDINAL DIFFERENCES. THE GFS
IS FURTHEST SOUTH...WITH AN UPPER LOW NEAR INDY WED MORNING. THE
SREF IS FURTHEST NORTH...NEAR MILWAUKEE. NAM/ECMWF ARE IN BETWEEN...
NEAR THE SOUTHERN TIP OF LAKE MI...AND WILL STEER THE FORECAST IN
THAT MIDDLE-OF-THE-ROAD DIRECTION.
TONIGHT/MONDAY...PRESSURE GRADIENT TIGHTENS A BIT TONIGHT AS HIGH
PRESSURE MOVES ACROSS NEW ENGLAND. AS A RESULT...SOUTHERLY 950MB
WINDS WILL INCREASE TO AROUND 20KT. THIS WILL NOT BE ENOUGH TO
OUTRIGHT PREVENT FOG REDEVELOPMENT...BUT SHOULD PREVENT FOG FROM
BEING AS WIDESPREAD/DENSE AS THE LAST COUPLE OF NIGHTS. MARINE-
INFLUENCED EASTERN UPPER MI HAS THE BEST SHOT OF SEEING THE THICK
STUFF...AS DOES THE IMMEDIATE HURON COAST...THANKS TO SE-ERLY
SUB-950MB WINDS. WILL TWEAK FOG WORDING IN THE GRIDS AND TEXT
PRODUCTS...INCLUDING ADDING DENSE FOG IN THE ABOVE LOCALES.
OTHERWISE...SAME OLD SAME OLD...WITH FOG/STRATUS SLOWING BURNING OFF
DURING THE DAY MONDAY. CLEARING WILL AGAIN TAKE LONGEST IN EASTERN
UPPER AND NE LOWER MI. WE WILL HAVE MORE CIRRUS AROUND ON MONDAY
THAN TODAY...ESPECIALLY IN THE AFTERNOON. THAT MAY BE ENOUGH TO
KNOCK A COUPLE OF DEGREES OFF OF MAX TEMPS...BUT GUIDANCE TEMPS
STILL LOOK A LITTLE TOO COOL IN MANY AREAS.
MONDAY NIGHT/TUESDAY...THE INITIAL SHORTWAVES AHEAD OF THE MAIN
UPPER LOW WILL DRAW A PLUME OF DEEPER MOISTURE NORTHWARD FROM THE
CENTRAL APPALACHIANS TO THE EASTERN GREAT LAKES. THIS WILL PASS EAST
OF US. MEANWHILE...THE WARM CONVEYOR BELT AHEAD OF THE UPSTREAM LOW
WILL ADVANCE INTO IL/WI TUESDAY. IN BETWEEN THESE TWO...WE SHOULD
SEE NO SIGNIFICANT RISK OF PRECIP. INSTEAD...FOG/STRATUS CONTINUE TO
BE THE MAIN CONCERNS. CIRRUS WILL INHIBIT COOLING TO SOME DEGREE
MONDAY NIGHT...BUT THE PRESSURE GRADIENT WILL ACTUALLY BE SOMEWHAT
WEAKER (ESPECIALLY AFTER MIDNIGHT). 950MB WINDS WILL LOWER BELOW
20KT. NAM SOUNDINGS ARE MORE MOIST BELOW 950MB THAN PROGGED TONIGHT.
NUMERICAL GUIDANCE IS MORE BULLISH ON FOG MONDAY NIGHT THAN TONIGHT.
WILL THUS GO AHEAD AND ADD EVEN MORE FOG TO THE LATE MONDAY
NIGHT/TUESDAY MORNING FORECAST...HITTING HARDER IN EASTERN UPPER.
MID AND HIGH CLOUDS WILL BECOME MORE EXTENSIVE TUESDAY...AND THIS
WILL EAT INTO MAX TEMPS...WHICH WILL BE MAINLY IN THE 40S.
REST OF THE FORECAST...MID-WEEK SURFACE LOW NOW LOOKS LIKE IT MAY
PASS JUST SOUTH OF THE FORECAST AREA ON WEDNESDAY. 850MB TEMPS WILL
BE NEAR 0C...BUT THE ENTIRE LAYER BELOW THAT WILL BE ABOVE FREEZING
AND MITIGATE ANY FROZEN PRECIP CONCERNS ON WEDNESDAY. COLDER AIR
WILL GRADUALLY TURN RAIN OVER TO SNOW WED NIGHT INTO TURKEY
DAY...THOUGH MUCH OF THE SYNOPTIC PRECIP WITH THE INITIAL UPPER LOW
WILL BE OVER BY THEN. BUT WHAT DOES THE 2ND ONE DO? THE NEW ECMWF
WOULD OFFER UP A PERIOD OF ACCUMULATING SNOW POSSIBLE...CENTERED ON
THURSDAY NIGHT...AS THAT PASSES TO THE SOUTH.
JZ
&&
.MARINE.../ISSUED AT 343 AM/
HIGH PRESSURE WILL MOVE FROM THE EASTERN LAKES TO OFF THE NEW
ENGLAND COAST. WE WILL SEE SOMETHING OF AN INCREASE IN S-SE WINDS AS
THE HIGH MOVES AWAY. BUT IN THE NEAR TERM...WINDS AND WAVES WILL
REMAIN COMFORTABLY BELOW SMALL CRAFT CRITERIA. LOW LEVEL MOISTURE
AND RELATIVELY LIGHT WINDS WILL STILL RESULT IN AREAS OF FOG THIS
MORNING...LATE TONIGHT INTO MONDAY MORNING...AND LATE MONDAY NIGHT
INTO TUESDAY MORNING.
JZ
&&
.AVIATION.../ISSUED AT 620 AM/...VALID FOR 12Z TAFS
IFR/LIFR CONDITIONS WILL IMPROVE THIS MORNING AT ALL TAF SITES...
TAKING LONGEST AT APN...WHICH WILL NOT SEE VFR UNTIL THIS AFTERNOON.
SOME DETERIORATION WILL OCCUR AGAIN TONIGHT AS FOG/STRATUS
REDEVELOPS. PLN/APN WILL LIKELY GO IFR/LIFR AGAIN...WHILE TVC WILL
BE MVFR/IFR.
JZ
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KMQT 221616 AAB
AFDMQT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1116 AM EST SUN NOV 22 2009
UPDATED
.SYNOPSIS...
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW SHARP UPPER RIDGE AXIS
OVER JAMES BAY DOWNSTREAM OF TROUGHING OVER THE NORTHERN AND CENTRAL
PLAINS. ANOTHER TROUGH IS DIGGING OVER THE PACIFIC NORTHWEST. A WEAK
SHORTWAVE IS OVER THE FORECAST AREA THIS MORNING...WITH OTHERS OVER
EASTERN DAKOTAS AND WESTERN MINNESOTA. SURFACE ANALYSIS SUGGEST A
COLD FRONT EXTENDING FROM WESTERN HUDSON BAY SOUTH THROUGH MINNESOTA
TO A WEAK LOW OVER NORTHERN KANSAS AND A LARGE HIGH OVER THE
CANADIAN MARITIME CAUSING A SOUTHERLY FLOW ACROSS THE FORECAST AREA.
THIS SOUTHERLY HAS PUSHED THE 12Z 850MB TEMPERATURES AT PICKLE LAKE
TO AN IMPRESSIVE 4C. THIS FLOW HAS BROUGHT SOME LOW LEVEL MOISTURE
INTO THE AREA WHICH CAUSED CONSIDERABLE FOG THIS MORNING...MOST OF
WHICH HAS BURNED OFF AT THIS TIME. THE AREA RAOBS ARE QUITE DRY
ABOVE 800MB. QUITE A BIT OF HIGH CLOUDS ARE STREAMING INTO THIS AREA
AHEAD OF OF THE FRONT.
&&
.SHORT TERM...
THE MAIN CONCERN WITH THE REST OF TODAY WILL BE THE HIGH TEMPERATURE
ACROSS THE AREA AND POTENTIAL FOR RAIN OVER THE FAR WEST.
THE MID LEVEL RIDGE WILL PUSH INTO WESTERN QUEBEC WITH THE
ASSOCIATED HIGH SETTLING OVER THE LOWER GREAT LAKES. THE WEAK
SHORTWAVE OVER THE FORECAST AREA WILL REACH EASTERN ONTARIO BY LATE
AFTERNOON WHILE THE MID LEVEL TROUGH OVER THE NORTHERN PLAINS SHIFTS
WEAKENS AS IT MOVES THROUGH THE DAKOTAS. THE TROUGH OVER THE PACIFIC
NORTHWEST BEGINS TO DEEPEN. THE COLD FRONT OVER MINNESOTA WILL REACH
THE KDLH AREA BY LATE AFTERNOON. THIS WILL CONTINUE TO DRAW IN MOIST
AIR AHEAD OF THE FRONT INTO THE WEST END OF THE FORECAST AREA. THIS
WILL INCREASE THE PW FROM .5 TO .7 OVER THE IWD AREA. FORECAST
SOUNDINGS SUGGEST A CLOUD DECK AROUND 850MB THIS AFTERNOON MAINLY
OVER THE FAR WEST...INCLUDING WESTERN LAKE SUPERIOR. THUS THIS
INDICATES A POSSIBILITY OF OF SOME SPRINKLES OVER THE FAR WEST. IT
IS QUESTIONABLE IF IT WOULD BE ENOUGH OF SATURATE OUT THE LOWER
LEVELS ENOUGH TO GET ANY MEASURABLE AMOUNTS. THUS WILL STAY WITH
JUST A SLIGHT CHANCE OF FOR NOW.
AS THE FOG AND LOW CLOUDS BURN OFF...TEMPERATURES WILL START
TO CLIMB. WE ARE SEEING RAPID INCREASES IN TEMPERATURES AT LOCATION
WHERE TO THE LOW CLOUDS HAVE BURNED OFF ALREADY. THUS PLAN TO UPDATE
ONLY THE WORDING ON ZONE FORECAST AT THIS TIME.
&&
.LONG TERM...TONIGHT AND LATER PERIODS
RESTRICTED POPS TNGT TO THE FAR WRN CWA AGAIN WHERE FAVORED NAM
SHOWS LO PRES TROF SETTING UP UNDER AXIS OF HIER H85-7 DWPTS. TENDED
TO GO WITH THE HIER POPS LATER AT NGT WITH INFLUX OF MSTR AND SOME
UPR DVGC IN RRQ OF H3 JET MAX IN NW ONTARIO. FARTHER E...RISING MSLP
UNDER PERSISTENT RDG WL RESULT IN A SLACKENING PRES GRADIENT/LIGHTER
WINDS. SO MORE FOG LOOKS LIKE A GOOD BET THERE WHERE DRIER MID LVLS
FAVOR A SHARPER DIURNAL FALL OF TEMP BLO MOS GUIDANCE.
ON MON...NUMERICAL MODELS SHOW DEEPENING TROF IN THE CNTRL PLAINS AS
SHRTWV NOW APRCHG THE PAC NW DIVES ESEWD. WITH THIS DEVELOPMENT
UPSTREAM...MODELS HAVE CONTINUED TREND FOR DRYING TREND DOWNSTREAM
OVER THE FA. GIVEN THIS CONSISTENT TREND...OPTED TO INCRS MAX TEMPS
FCST WITH EXPECTATION FOR MORE AFTN SUNSHINE ONCE MRNG FOG BURNS OFF
WITH DAYTIME MIXING/SFC-H85 DRY ADVECTION. MIXING TO ONLY H9 ON
GFS/NAM FCST SDNGS YIELDS HI TEMPS IN THE LO 50S.
ON MON NGT/TUE...MODELS SHOW OCCLUDED LO IN THE PLAINS MOVING ONLY
SLOWLY NEWD INTO IA BY 00Z WED. WITH ACCOMPANYING DYNAMICS REMAINING
WELL TO THE SW AND HINT OF UPR RDG/DRY MID LVLS LINGERING OVER THE
GRT LKS...PREFER THE DRIER LOOK OF THE NAM. CUT POPS TO ONLY FAR WRN
LK SUP ON MON NGT THRU 18Z TUE. MAINTAINED SCHC POPS AFT 18Z NEAR
THE WI BORDER. WITH DRIER MID LVLS PERSISTING...INCRSD DIURNAL TEMP
RANGE WITH LOWER MINS ON MON NGT AND HIER MAXES ON TUE. MAINTAINED
PATCHY FOG MENTION OVER THE INTERIOR ECNTRL ON MON NGT WITH GRADIENT
FLOW SUFFICIENTLY LGT UNDER LOWER PWAT BLO 0.50 INCH.
MODELS HAVE MAINTAINED LOOK OF MORE PHASING BTWN CUTOFF LO AND
SHRTWVS ARRIVING IN THE NRN BRANCH FLOW FOR MIDWEEK. AS SUCH...GOING
POPS INCRSG TO LIKELY ON WED SEEM APPROPRIATE. ON TUE NGT...REMOVED
MENTION OF SN AS GFS/NAM/ECMWF FCST SDNGS AS WELL AS H100-85 THKNS
FIELDS/MIN TEMPS FCST SUG LLVLS WL BE TOO WARM FOR ANYTHING BUT RA.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
EXPECT REMAINING FOG TO DISSIPATE THIS MORNING...THOUGH FOG WILL
PROBABLY HOLD IN AT KSAW A BIT LONGER...15Z. KSAW WILL THEN BE VFR
UNTIL TONIGHT WHEN FOG WILL LIKELY REDEVELOP AS LOW LEVEL MOISTURE
WILL STILL BE A CONCERN. WENT TO IFR CONDITIONS JUST AFTER SUNSET.
WITH GUSTIER WINDS TODAY THINK SOME MOISTURE COULD BE MIXED OUT SO
DIDN/T GO TO LIFR QUITE YET. AT CMX EXPECT SIMILAR CONDITIONS TO
LAST NIGHT WITH DOWNSLOPING SOUTHERLY WINDS LIMITING LOWER
VISIBILITIES TO MVFR.
LLWS CAN BE EXPECTED AT BOTH TAF SITES AFTER SUNSET.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
WITH LAKE SUPERIOR IN BETWEEN LOW PRESSURE TO THE NORTHWEST AND HIGH
PRESSURE OVER THE LOWER LAKES EXPECT SOUTHERLY WINDS TO 25 KNOTS
INTO MONDAY MORNING. A FEW WIND GUSTS TO 30 KNOTS AREN/T OUT OF THE
QUESTION OVER THE EAST TODAY...HOWEVER...AIRMASS ABOVE THE LAKE
SURFACE IS QUITE STABLE SO DON/T EXPECT WINDS TO GET TOO STRONG.
WINDS WILL THEN REMAIN UNDER 20 KNOTS INTO WEDNESDAY...WHEN A STORM
SYSTEM APPROACHES THE UPPER GREAT LAKES AND WINDS BEGIN TO INCREASE
OUT OF THE NORTH AND NORTHEAST WITH GALES POSSIBLE LATE WEDNESDAY
INTO THURSDAY. LOCALLY DENSE PATCHY FOG IS POSSIBLE THIS MORNING
ACROSS EASTERN LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS/SHORT TERM...DLG
LONG TERM...KC
AVIATION...PEARSON
MARINE...PEARSON
000
FXUS63 KGRR 221538 AAA
AFDGRR
AREA FORECAST DISCUSSION...UPDATED TO DROP FOG ADVISORY
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1035 AM EST SUN NOV 22 2009
LATEST UPDATE...AVIATION...
.SYNOPSIS...(400 AM EST SUN NOV 22 2009)
AREAS OF DENSE FOG WILL DISSIPATE BY LATE THIS MORNING. HIGH
PRESSURE WILL PRODUCE FAIR WEATHER TODAY INTO MONDAY BUT FOG WILL
LIKELY REDEVELOP AGAIN LATE TONIGHT. A LOW PRESSURE SYSTEM WILL
BRING RAIN TUESDAY NIGHT AND WEDNESDAY. IT WILL TURN COOLER LATE
THIS WEEK WITH A MIX OF RAIN AND SNOW SHOWERS POSSIBLE FOR OUR
THANKSGIVING HOLIDAY.
&&
.SHORT TERM...(1035 AM EST SUN NOV 22 2009)
(LATE MORNING THROUGH TUESDAY AFTERNOON)
WE HAVE ALLOWED THE FOG ADVISORY TO EXPIRE AT 1000 AM. EVEN
SO...DENSE CONTINUES IN OUR EXTREME NORTHEAST COUNTIES. I EXPECT
THIS WILL MIX OUT BY NOON. HOWEVER... DUE TO THE PREVAILING SOUTH
SOUTHEAST WINDS THROUGH THE BOUNDARY LAYER... I AM CONCERNED ABOUT
THE LARGE AREA OF STRATUS AND FOG OVER LAKE ERIE AND SE LOWER
MICHIGAN AT 10 AM. THE HRRR RUC BRINGS THIS AREA NORTHEAST INTO OUR
EASTERN COUNTIES THIS AFTERNOON. SO I PUT THE CLOUD EDGE IN THE
GRIDS OVER OUR EASTERN COUNTIES THIS AFTERNOON TO ACCOUNT FOR THIS.
I AM CONCERNED ABOUT THE FOG TONIGHT AS THE BOUNDARY LAYER WINDS ARE
TO STRONG OF WIDESPREAD DENSE FOG. TO SOME EXTENT IT WAS FOR THAT
REASON WE DID NOT GET MUCH FOG OVER SOUTH SW COUNTIES EARLY THIS
MORNING. I DID NOT TAKE THE AREAS OF FOG OUT OF OUR ZONES FOR
TONIGHT YET BUT MAY CHANGE THAT TO PATCHY FOG WITH THE AFTERNOON
UPDATE.
THE STORM JUST NOW COMING ONSHORE OVER THE WESTERN UNITED STATES
WILL CURVE OUT A DEEP TROUGH OVER THE CENTRAL UNITED STATES BY
WEDNESDAY BUT WHILE THAT SYSTEM IS DEVELOPING IT WILL BUILD AND
UPSTREAM RIDGE THAT WILL BE CLOSE ENOUGH OR SOUTHWEST LOWER MICHIGAN
TO ASSURE THIS AREA DRY WEATHER THROUGH MOST OF TUESDAY. IT SEEMS TO
ME THE EARLIEST I WOULD THINK RAIN WOULD MOVE INTO OUR AREA IS AFTER
DURING THE EARLY MORNING HOURS OF WEDNESDAY.
&&
.LONG TERM...(400 AM EST SUN NOV 22 2009)
(TUESDAY NIGHT THROUGH SATURDAY)
TWO SYSTEMS/UPPER LOWS ARE THE FOCUS/CHALLENGE OF THE LONG TERM. THE
FIRST TRACKS EAST NORTHEAST FROM THE CENTRAL PLAINS TUESDAY NIGHT
AND WEDNESDAY... TAKING ON A NEGATIVE TILT AS ANOTHER UPPER LOW
DROPS SOUTH THROUGH THE NRN PLAINS.
HANDLING OF THE INITIAL SYSTEM SEEMS RATHER STRAIGHTFORWARD... WITH
A HIGH CHANCE OF RAIN AND PERHAPS EVEN A TSTM. IF THE MODELS REMAIN
CONSISTENT ON TIMING... BELIEVE WE WILL BE ABLE TO RAISE POPS TO
LIKELY OR CATEGORICAL FOR TUESDAY NIGHT AND WEDNESDAY.
THE SECOND SYSTEM IS NOT AS STRAIGHTFORWARD SINCE COLDER H8 AIR NEAR
-4C GETS WRAPPED INTO THE SYSTEM FROM THE SOUTHWEST AS IT TRACKS
ACROSS THE REGION ON THANKSGIVING DAY AND NIGHT. PCPN TYPE IS A
CHALLENGE SINCE BOUNDARY LAYER TEMPS ARE PROGGED TO REMAIN THE MID
TO UPPER 30S DESPITE THE COLDER TEMPS COMING IN ALOFT. WILL CONTINUE
TO CARRY A MIXTURE OF RAIN/SNOW SHOWERS DURING THIS TIME... BUT AM
BECOMING A BIT CONCERNED ABOUT THE POSSIBILITY OF ACCUMULATING WET
SNOW ON THURSDAY NIGHT.
SCATTERED SNOW OR MIXED RAIN AND SNOW SHOWERS MAY LINGER INTO
FRIDAY... BEFORE RIDGING/QUIET WEATHER RETURNS FOR NEXT WEEKEND.
&&
.AVIATION...(640 PM EST SAT NOV 21 2009)
IFR FOG WILL LINGER THROUGH ABOUT 14-15Z BEFORE IMPROVEMENT TAKES
PLACE... WITH VFR EXPECTED AT MOST SITES BY 18Z. FOG IS EXPECTED TO
REDEVELOP TONIGHT... WITH IFR CONDITIONS POSSIBLE AGAIN.
&&
.MARINE...(400 AM EST SUN NOV 22 2009)
AREAS OF DENSE FOG WILL POSE A HAZARD TO MARINERS THIS MORNING AND
POTENTIALLY ONCE AGAIN ON MONDAY MORNING AND EARLY TUESDAY MORNING
ALSO. OTHERWISE FAIRLY MINIMAL WIND AND WAVE ACTION IS ANTICIPATED
THE NEXT COUPLE OF DAYS.
&&
.HYDROLOGY...(400 AM EST SUN NOV 22 2009)
NO PRECIPITATION THROUGH MONDAY NIGHT AND MUCH OF TUESDAY. NO HYDRO
ISSUES EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: LAURENS
SHORT TERM: WDM
LONG TERM: MEADE
AVIATION: MEADE
MARINE: LAURENS
HYDROLOGY: LAURENS
000
FXUS63 KMQT 221150 AAA
AFDMQT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
650 AM EST SUN NOV 22 2009
UPDATED FOR 12Z TAFS
.SYNOPSIS...
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SHARP UPR RDG AXIS
OVER THE UPR GRT LKS DOWNSTREAM OF TROFFING OVER THE NW CONUS. CWA
IS DOMINATED BY WARM SFC-H85 FLOW BTWN HI PRES OVER SE ONTARIO AND
LO PRES TROF/PACIFIC TYPE COLD FNT IN THE PLAINS TO THE E OF UPR
TROFFING OVER THE NW. THIS SLY FLOW EXTENDS INTO CAN AND HAS PUSHED
THE 00Z H85 TEMP AT PICKLE LAKE ONTARIO TO AN IMPRESSIVE 7C FOR LATE
NOV. THE SLY FLOW IS ADVECTING HIER LLVL MSTR NWD...WITH LO CLD/FOG
DVLPG OVER THE FA UNDER LO INVRN ARND H9 SHOWN ON THE 00Z GRB RAOB
AT TIME OF DIURNAL COOLING. THE FOG IS DENSE AT SOME PLACES...
ESPECIALLY OVER THE E WITH SOME ADDED MOISTENING OFF LK MI AND
DOWNSTREAM OF SOMEWHAT HIER LLVL MSTR DEPICTED ON THE 00Z GRB RAOB
(00Z PWAT THERE IS 0.43 INCH). THE GRB RAOB IS QUITE DRY ABV H8
HOWEVER WITH H7/H5 DWPT DEPRESSION 16C/38C RESPECTIVELY. THE AIRMASS
TO THE W IS EVEN DRIER...WITH 00Z PWAT ARND 0.25 INCH AT INL/MPX.
BUT QUITE A BIT OF HI CLD IS STREAMING EWD INTO THIS AREA AHEAD OF
LO PRES TROF IN THE PLAINS. FARTHER W...A POTENT SHRTWV IN THE
PACIFIC OCEAN APPEARS READY TO CRASH INTO THE PAC NW.
&&
.DISCUSSION...
MAIN FCST CONCERNS NEXT FEW DAYS ARE FOG/ST TRENDS AND CONTINUED ABV
NORMAL TEMPS. FOCUS TOWARD MID WEEK TURNS TO TIMING/IMPACT OF
COMPLEX LO PRES PROGGED TO DVLP IN THE PLAINS AND MOVE NE.
TDAY...SFC HI PRES CENTER IS FCST TO SHIFT E INTO NEW ENGLAND BY 00Z
MON WHILE LO PRES TROF/PACIFIC TYPE COLD FNT MOVES E INTO MN AND
TOWARD WRN LK SUP WHILE WASHING OUT WITH SUPPORTING SHRTWV LIFTING
TO THE NE ARND DOMINANT UPR RDG. ALTHOUGH MORE LLVL MSTR WL ARRIVE
BLO H7 TDAY WITH CONTINUED SSW FLOW...PREFER THE DRIER NAM FCST
GIVEN EXCESSIVE DRYNESS OF THE MID/UPR TROP ASSOCIATED WITH
RESILIENT RDG REINFORCED BY ADVECTION OF VERY WARM AIR WELL INTO CAN
AS NOTED ABV. RETAINED SCHC POPS OVER ONLY THE FAR W IN THE AFTN.
OTRW...EXPECT ST/SC TO BE QUITE RESILIENT WITH ARRIVAL OF CONT
INFLUX OF HIER LLVL MSTR. EVEN WITH THIS LO CLD...TEMPS WL CONT TO
RUN WELL ABV NORMAL WITH MAX TEMPS WITHIN A FEW DEGREES OF 50. THESE
READINGS ARE ABOUT 15 DEGREES ABV NORMAL.
RESTRICTED POPS TNGT TO THE FAR WRN CWA AGAIN WHERE FAVORED NAM
SHOWS LO PRES TROF SETTING UP UNDER AXIS OF HIER H85-7 DWPTS. TENDED
TO GO WITH THE HIER POPS LATER AT NGT WITH INFLUX OF MSTR AND SOME
UPR DVGC IN RRQ OF H3 JET MAX IN NW ONTARIO. FARTHER E...RISING MSLP
UNDER PERSISTENT RDG WL RESULT IN A SLACKENING PRES GRADIENT/LIGHTER
WINDS. SO MORE FOG LOOKS LIKE A GOOD BET THERE WHERE DRIER MID LVLS
FAVOR A SHARPER DIURNAL FALL OF TEMP BLO MOS GUIDANCE.
ON MON...NUMERICAL MODELS SHOW DEEPENING TROF IN THE CNTRL PLAINS AS
SHRTWV NOW APRCHG THE PAC NW DIVES ESEWD. WITH THIS DEVELOPMENT
UPSTREAM...MODELS HAVE CONTINUED TREND FOR DRYING TREND DOWNSTREAM
OVER THE FA. GIVEN THIS CONSISTENT TREND...OPTED TO INCRS MAX TEMPS
FCST WITH EXPECTATION FOR MORE AFTN SUNSHINE ONCE MRNG FOG BURNS OFF
WITH DAYTIME MIXING/SFC-H85 DRY ADVECTION. MIXING TO ONLY H9 ON
GFS/NAM FCST SDNGS YIELDS HI TEMPS IN THE LO 50S.
ON MON NGT/TUE...MODELS SHOW OCCLUDED LO IN THE PLAINS MOVING ONLY
SLOWLY NEWD INTO IA BY 00Z WED. WITH ACCOMPANYING DYNAMICS REMAINING
WELL TO THE SW AND HINT OF UPR RDG/DRY MID LVLS LINGERING OVER THE
GRT LKS...PREFER THE DRIER LOOK OF THE NAM. CUT POPS TO ONLY FAR WRN
LK SUP ON MON NGT THRU 18Z TUE. MAINTAINED SCHC POPS AFT 18Z NEAR
THE WI BORDER. WITH DRIER MID LVLS PERSISTING...INCRSD DIURNAL TEMP
RANGE WITH LOWER MINS ON MON NGT AND HIER MAXES ON TUE. MAINTAINED
PATCHY FOG MENTION OVER THE INTERIOR ECNTRL ON MON NGT WITH GRADIENT
FLOW SUFFICIENTLY LGT UNDER LOWER PWAT BLO 0.50 INCH.
MODELS HAVE MAINTAINED LOOK OF MORE PHASING BTWN CUTOFF LO AND
SHRTWVS ARRIVING IN THE NRN BRANCH FLOW FOR MIDWEEK. AS SUCH...GOING
POPS INCRSG TO LIKELY ON WED SEEM APPROPRIATE. ON TUE NGT...REMOVED
MENTION OF SN AS GFS/NAM/ECMWF FCST SDNGS AS WELL AS H100-85 THKNS
FIELDS/MIN TEMPS FCST SUG LLVLS WL BE TOO WARM FOR ANYTHING BUT RA.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
EXPECT REMAINING FOG TO DISSIPATE THIS MORNING...THOUGH FOG WILL
PROBABLY HOLD IN AT KSAW A BIT LONGER...15Z. KSAW WILL THEN BE VFR
UNTIL TONIGHT WHEN FOG WILL LIKELY REDEVELOP AS LOW LEVEL MOISTURE
WILL STILL BE A CONCERN. WENT TO IFR CONDITIONS JUST AFTER SUNSET.
WITH GUSTIER WINDS TODAY THINK SOME MOISTURE COULD BE MIXED OUT SO
DIDN/T GO TO LIFR QUITE YET. AT CMX EXPECT SIMILAR CONDITIONS TO
LAST NIGHT WITH DOWNSLOPING SOUTHERLY WINDS LIMITING LOWER
VISIBILITIES TO MVFR.
LLWS CAN BE EXPECTED AT BOTH TAF SITES AFTER SUNSET.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
WITH LAKE SUPERIOR IN BETWEEN LOW PRESSURE TO THE NORTHWEST AND HIGH
PRESSURE OVER THE LOWER LAKES EXPECT SOUTHERLY WINDS TO 25 KNOTS
INTO MONDAY MORNING. A FEW WIND GUSTS TO 30 KNOTS AREN/T OUT OF THE
QUESTION OVER THE EAST TODAY...HOWEVER...AIRMASS ABOVE THE LAKE
SURFACE IS QUITE STABLE SO DON/T EXPECT WINDS TO GET TOO STRONG.
WINDS WILL THEN REMAIN UNDER 20 KNOTS INTO WEDNESDAY...WHEN A STORM
SYSTEM APPROACHES THE UPPER GREAT LAKES AND WINDS BEGIN TO INCREASE
OUT OF THE NORTH AND NORTHEAST WITH GALES POSSIBLE LATE WEDNESDAY
INTO THURSDAY. LOCALLY DENSE PATCHY FOG IS POSSIBLE THIS MORNING
ACROSS EASTERN LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS/DISCUSSION...KC
AVIATION...PEARSON
MARINE...PEARSON
000
FXUS63 KGRR 221140
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
640 AM EST SUN NOV 22 2009
LATEST UPDATE...AVIATION...
.SYNOPSIS...(400 AM EST SUN NOV 22 2009)
AREAS OF DENSE FOG WILL DISSIPATE BY LATE THIS MORNING. HIGH
PRESSURE WILL PRODUCE FAIR WEATHER TODAY INTO MONDAY BUT FOG WILL
LIKELY REDEVELOP AGAIN LATE TONIGHT. A LOW PRESSURE SYSTEM WILL
BRING RAIN TUESDAY NIGHT AND WEDNESDAY. IT WILL TURN COOLER LATE
THIS WEEK WITH A MIX OF RAIN AND SNOW SHOWERS POSSIBLE FOR OUR
THANKSGIVING HOLIDAY.
&&
.SHORT TERM...(400 AM EST SUN NOV 22 2009)
(TODAY THROUGH TUESDAY AFTERNOON)
OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO ASSESS FOG POTENTIAL THE
NEXT FEW MORNINGS AND ALSO TO ASSESS PCPN CHANCES FOR TUESDAY. FCST
TWEAKS INCLUDED ADDING MENTION OF PATCHY FOG TO THE FCST DURING THE
EARLY MORNING HOURS TUESDAY AND REMOVAL (OR LOWERING) OF POPS FROM
06Z TUE THROUGH TUE AFTERNOON.
SFC OBS FROM ACROSS OUR CWFA EARLY THIS MORNING INDICATE THAT FOG
CONTINUES TO BECOME MORE DENSE AND WIDESPREAD PARTICULARLY NORTH OF
I-96. HOWEVER AREAS FURTHER SOUTH HAVE ALSO SEEN VISBYS DROP TO A
QUARTER MILE AT TIMES INCLUDING HERE AT GRR. THIS IS OCCURRING DUE
TO CLEAR SKIES... CALM WINDS... AND LINGERING LOW LEVEL MOISTURE
TRAPPED UNDERNEATH A RADIATION INVERSION. THEREFORE THE DENSE FOG
ADVISORY REMAINS IN EFFECT FOR OUR ENTIRE CWFA THROUGH 15Z THIS
MORNING.
FOG SHOULD GRADUALLY DISSIPATE LATE THIS MORNING AND IR SAT TRENDS
AND 00Z MODEL GUIDANCE RH PROGS SUGGEST THAT WE WILL GET QUITE A BIT
OF SUN THIS AFTERNOON. THIS AND SE WINDS OF 5 TO 10 MPH WILL HELP TO
BOOST MAX TEMPS INTO THE MID 50S AT MOST LOCATIONS (SO LONG AS FOG
DOES INDEED MIX OUT AND DISSIPATE BY LATE MORNING).
THE SETUP FOR FOG DEVELOPMENT LATE TONIGHT APPEARS FAVORABLE AND
SIMILAR TO THAT OF EARLY THIS MORNING. A POTENTIAL INHIBITING FACTOR
MAY BE LIGHT ESE WINDS IN THE BOUNDARY LAYER. HOWEVER I DO NOT
BELIEVE THIS WILL PROVIDE SIGNIFICANT ENOUGH MIXING TO INHIBIT FOG
FORMATION. AS A MATTER OF FACT... SREF PROBABILISTIC GUIDANCE OF SFC
VISBYS DROPPING BELOW A MILE SUGGESTS GREATER POTENTIAL FOR FOG LATE
TONIGHT THAN WHAT IT SHOWED FOR EARLY THIS MORNING. BOTTOM LINE...
FOG WILL DEVELOP AGAIN LATE TONIGHT.
OUR TRANQUIL WX WILL CONTINUE MONDAY AFTERNOON THROUGH MONDAY NIGHT
WITH PARTLY CLOUDY SKIES AND RATHER MILD TEMPS FOR THIS TIME OF
YEAR. THE NEXT LOW PRESSURE SYSTEM MOVING IN FROM THE WEST COULD
BRING A FEW SHOWERS BY TUESDAY... ALTHOUGH THE BETTER CHANCE FOR
PCPN SHOULD HOLD OFF UNTIL TUESDAY NIGHT. 21Z SREF POPS ARE OVERDONE
FOR TUESDAY MORNING AND AFTERNOON. WE PREFER THE MORE CONSERVATIVE
00Z GFS/NAM/ECMWF GUIDANCE WHICH SUGGESTS THAT PREDOMINANTLY DRY WX
WILL CONTINUE THROUGH TUESDAY AFTERNOON. WE TWEAKED THE FCST IN THIS
DIRECTION ACCORDINGLY.
&&
.LONG TERM...(400 AM EST SUN NOV 22 2009)
(TUESDAY NIGHT THROUGH SATURDAY)
TWO SYSTEMS/UPPER LOWS ARE THE FOCUS/CHALLENGE OF THE LONG TERM. THE
FIRST TRACKS EAST NORTHEAST FROM THE CENTRAL PLAINS TUESDAY NIGHT
AND WEDNESDAY... TAKING ON A NEGATIVE TILT AS ANOTHER UPPER LOW
DROPS SOUTH THROUGH THE NRN PLAINS.
HANDLING OF THE INITIAL SYSTEM SEEMS RATHER STRAIGHTFORWARD... WITH
A HIGH CHANCE OF RAIN AND PERHAPS EVEN A TSTM. IF THE MODELS REMAIN
CONSISTENT ON TIMING... BELIEVE WE WILL BE ABLE TO RAISE POPS TO
LIKELY OR CATEGORICAL FOR TUESDAY NIGHT AND WEDNESDAY.
THE SECOND SYSTEM IS NOT AS STRAIGHTFORWARD SINCE COLDER H8 AIR NEAR
-4C GETS WRAPPED INTO THE SYSTEM FROM THE SOUTHWEST AS IT TRACKS
ACROSS THE REGION ON THANKSGIVING DAY AND NIGHT. PCPN TYPE IS A
CHALLENGE SINCE BOUNDARY LAYER TEMPS ARE PROGGED TO REMAIN THE MID
TO UPPER 30S DESPITE THE COLDER TEMPS COMING IN ALOFT. WILL CONTINUE
TO CARRY A MIXTURE OF RAIN/SNOW SHOWERS DURING THIS TIME... BUT AM
BECOMING A BIT CONCERNED ABOUT THE POSSIBILITY OF ACCUMULATING WET
SNOW ON THURSDAY NIGHT.
SCATTERED SNOW OR MIXED RAIN AND SNOW SHOWERS MAY LINGER INTO
FRIDAY... BEFORE RIDGING/QUIET WEATHER RETURNS FOR NEXT WEEKEND.
&&
.AVIATION...(640 PM EST SAT NOV 21 2009)
IFR FOG WILL LINGER THROUGH ABOUT 14-15Z BEFORE IMPROVEMENT TAKES
PLACE... WITH VFR EXPECTED AT MOST SITES BY 18Z. FOG IS EXPECTED TO
REDEVELOP TONIGHT... WITH IFR CONDITIONS POSSIBLE AGAIN.
&&
.MARINE...(400 AM EST SUN NOV 22 2009)
AREAS OF DENSE FOG WILL POSE A HAZARD TO MARINERS THIS MORNING AND
POTENTIALLY ONCE AGAIN ON MONDAY MORNING AND EARLY TUESDAY MORNING
ALSO. OTHERWISE FAIRLY MINIMAL WIND AND WAVE ACTION IS ANTICIPATED
THE NEXT COUPLE OF DAYS.
&&
.HYDROLOGY...(400 AM EST SUN NOV 22 2009)
NO PRECIPITATION THROUGH MONDAY NIGHT AND MUCH OF TUESDAY. NO HYDRO
ISSUES EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...DENSE FOG ADVISORY FOR OUR ENTIRE CWFA THROUGH 10 AM TODAY.
LM...NONE.
&&
$$
SYNOPSIS: LAURENS
SHORT TERM: LAURENS
LONG TERM: MEADE
AVIATION: MEADE
MARINE: LAURENS
HYDROLOGY: LAURENS
000
FXUS63 KAPX 221119
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
620 AM EST SAT NOV 21 2009
.SYNOPSIS.../ISSUED AT 343 AM/
HIGH PRESSURE WHICH LIFTED NORTH INTO THE STATE FROM THE OHIO VALLEY
SATURDAY...WILL BE CENTERED OVER THE EASTERN LAKES INTO THE BEGINNING
OF THE WORK WEEK. THIS PATTERN WILL GENERATE SOME SUN AND WELL ABOVE
NORMAL TEMPERATURES ACROSS NORTHERN MICHIGAN THROUGH MONDAY.
THE NEXT CHANCE OF RAIN WILL BE TUESDAY AND WEDNESDAY...AS A STORM
SYSTEM LIFTS NORTH INTO THE UPPER MIDWEST AND WESTERN GREAT LAKES.
TEMPERATURES WILL REMAIN ABOVE NORMAL TUESDAY AND WEDNESDAY.
MORE SEASONABLE TEMPERATURES AND A CHANCE OF SNOW...MAKE A BRIEF
RETURN TO THE REGION THURSDAY AND FRIDAY...AS COOLER AIR BEGINS TO
FILTER INTO THE REGION.
SWR
&&
.SHORT TERM.../ISSUED AT 343 AM/...TODAY
HIGH PRESSURE CENTERED NEAR LK ONTARIO...WITH A WEAK PRESSURE
GRADIENT OVER NORTHERN MI. FOG AND STRATUS QUICKLY REDEVELOPED AFTER
SUNRISE...THICKEST (PER FOG IMAGERY) IN NE LOWER AND EASTERN UPPER
MI. FOG/CLOUDS AND TEMPS ARE THE MAIN CONCERNS TODAY.
VSBYS ARE NOT ON THE FLOOR EVERYWHERE...BUT ARE LESS THAN 1/2 MILE
IN MANY...MANY LOCALES. ONGOING DENSE FOG ADVISORY IS FINE.
NEAR-SURFACE WINDS WILL REMAIN SE-ERLY TODAY. THUS...DOWNSLOPING
WILL HELP FOG/STRATUS BREAK UP FIRST NEAR THE LAKE MI COAST OF NW
LOWER MI. THIS SHOULD HAPPEN BY MID-MORNING...EXPANDING ACROSS MOST
OF NORTHERN MI BY MID-AFTERNOON. GIVEN A MOISTENING MARINE
INFLUENCE...AM NOT AT ALL CONVINCED THAT EASTERN UPPER MI...AND THE
IMMEDIATE NE LOWER MI COAST...WILL BREAK OUT AT ALL.
WILL LEAN TOWARD THE WARM END OF GUIDANCE IN NW LOWER (MID
50S)...THE COOL END IN EASTERN UPPER (MID/UPPER 40S)...IN BETWEEN IN
NE LOWER (LOWER 50S).
JZ
&&
.LONG TERM.../ISSUED AT 343 AM/...TONIGHT AND BEYOND
EARLY PART OF THE WEEK STILL LOOKS UNEVENTFUL...BUT THINGS GET A BIT
MORE ACTIVE CLOSE TO THE HOLIDAY. UPPER RIDGING OVERHEAD TODAY WILL
REMAIN PROGRESSIVE...MOVING OFF THE NEW ENGLAND COAST MONDAY. A
COUPLE OF WEAKISH SHORTWAVES WILL LIFT INTO THE OHIO VALLEY AND
CENTRAL/EASTERN LAKES MONDAY/MONDAY NIGHT...IN ADVANCE OF A CLOSED
UPPER LOW DEEPENING IN THE CENTRAL PLAINS. THIS LOW WILL REACH THE
SW LAKES REGION BY WED MORNING...WHILE ANOTHER UPPER LOW DIGS INTO
THE NORTHERN PLAINS. CLOUDS/FOG/TEMPS REMAIN THE MAIN CONCERN EARLY
ON...PRECIP BECOMES THE MAIN ISSUE BEGINNING TUE NIGHT.
MODELS...ARE STARTING TO CLUSTER A BIT WHEN IT COMES TO THE MID-WEEK
SYSTEM. TIMING IS QUITE SIMILAR BETWEEN NAM/GFS/ECMWF/SREF.
HOWEVER...THERE ARE STILL IMPORTANT LATITUDINAL DIFFERENCES. THE GFS
IS FURTHEST SOUTH...WITH AN UPPER LOW NEAR INDY WED MORNING. THE
SREF IS FURTHEST NORTH...NEAR MILWAUKEE. NAM/ECMWF ARE IN BETWEEN...
NEAR THE SOUTHERN TIP OF LAKE MI...AND WILL STEER THE FORECAST IN
THAT MIDDLE-OF-THE-ROAD DIRECTION.
TONIGHT/MONDAY...PRESSURE GRADIENT TIGHTENS A BIT TONIGHT AS HIGH
PRESSURE MOVES ACROSS NEW ENGLAND. AS A RESULT...SOUTHERLY 950MB
WINDS WILL INCREASE TO AROUND 20KT. THIS WILL NOT BE ENOUGH TO
OUTRIGHT PREVENT FOG REDEVELOPMENT...BUT SHOULD PREVENT FOG FROM
BEING AS WIDESPREAD/DENSE AS THE LAST COUPLE OF NIGHTS. MARINE-
INFLUENCED EASTERN UPPER MI HAS THE BEST SHOT OF SEEING THE THICK
STUFF...AS DOES THE IMMEDIATE HURON COAST...THANKS TO SE-ERLY
SUB-950MB WINDS. WILL TWEAK FOG WORDING IN THE GRIDS AND TEXT
PRODUCTS...INCLUDING ADDING DENSE FOG IN THE ABOVE LOCALES.
OTHERWISE...SAME OLD SAME OLD...WITH FOG/STRATUS SLOWING BURNING OFF
DURING THE DAY MONDAY. CLEARING WILL AGAIN TAKE LONGEST IN EASTERN
UPPER AND NE LOWER MI. WE WILL HAVE MORE CIRRUS AROUND ON MONDAY
THAN TODAY...ESPECIALLY IN THE AFTERNOON. THAT MAY BE ENOUGH TO
KNOCK A COUPLE OF DEGREES OFF OF MAX TEMPS...BUT GUIDANCE TEMPS
STILL LOOK A LITTLE TOO COOL IN MANY AREAS.
MONDAY NIGHT/TUESDAY...THE INITIAL SHORTWAVES AHEAD OF THE MAIN
UPPER LOW WILL DRAW A PLUME OF DEEPER MOISTURE NORTHWARD FROM THE
CENTRAL APPALACHIANS TO THE EASTERN GREAT LAKES. THIS WILL PASS EAST
OF US. MEANWHILE...THE WARM CONVEYOR BELT AHEAD OF THE UPSTREAM LOW
WILL ADVANCE INTO IL/WI TUESDAY. IN BETWEEN THESE TWO...WE SHOULD
SEE NO SIGNIFICANT RISK OF PRECIP. INSTEAD...FOG/STRATUS CONTINUE TO
BE THE MAIN CONCERNS. CIRRUS WILL INHIBIT COOLING TO SOME DEGREE
MONDAY NIGHT...BUT THE PRESSURE GRADIENT WILL ACTUALLY BE SOMEWHAT
WEAKER (ESPECIALLY AFTER MIDNIGHT). 950MB WINDS WILL LOWER BELOW
20KT. NAM SOUNDINGS ARE MORE MOIST BELOW 950MB THAN PROGGED TONIGHT.
NUMERICAL GUIDANCE IS MORE BULLISH ON FOG MONDAY NIGHT THAN TONIGHT.
WILL THUS GO AHEAD AND ADD EVEN MORE FOG TO THE LATE MONDAY
NIGHT/TUESDAY MORNING FORECAST...HITTING HARDER IN EASTERN UPPER.
MID AND HIGH CLOUDS WILL BECOME MORE EXTENSIVE TUESDAY...AND THIS
WILL EAT INTO MAX TEMPS...WHICH WILL BE MAINLY IN THE 40S.
REST OF THE FORECAST...MID-WEEK SURFACE LOW NOW LOOKS LIKE IT MAY
PASS JUST SOUTH OF THE FORECAST AREA ON WEDNESDAY. 850MB TEMPS WILL
BE NEAR 0C...BUT THE ENTIRE LAYER BELOW THAT WILL BE ABOVE FREEZING
AND MITIGATE ANY FROZEN PRECIP CONCERNS ON WEDNESDAY. COLDER AIR
WILL GRADUALLY TURN RAIN OVER TO SNOW WED NIGHT INTO TURKEY
DAY...THOUGH MUCH OF THE SYNOPTIC PRECIP WITH THE INITIAL UPPER LOW
WILL BE OVER BY THEN. BUT WHAT DOES THE 2ND ONE DO? THE NEW ECMWF
WOULD OFFER UP A PERIOD OF ACCUMULATING SNOW POSSIBLE...CENTERED ON
THURSDAY NIGHT...AS THAT PASSES TO THE SOUTH.
JZ
&&
.MARINE.../ISSUED AT 343 AM/
HIGH PRESSURE WILL MOVE FROM THE EASTERN LAKES TO OFF THE NEW
ENGLAND COAST. WE WILL SEE SOMETHING OF AN INCREASE IN S-SE WINDS AS
THE HIGH MOVES AWAY. BUT IN THE NEAR TERM...WINDS AND WAVES WILL
REMAIN COMFORTABLY BELOW SMALL CRAFT CRITERIA. LOW LEVEL MOISTURE
AND RELATIVELY LIGHT WINDS WILL STILL RESULT IN AREAS OF FOG THIS
MORNING...LATE TONIGHT INTO MONDAY MORNING...AND LATE MONDAY NIGHT
INTO TUESDAY MORNING.
JZ
&&
.AVIATION.../ISSUED AT 620 AM/...VALID FOR 12Z TAFS
IFR/LIFR CONDITIONS WILL IMPROVE THIS MORNING AT ALL TAF SITES...
TAKING LONGEST AT APN...WHICH WILL NOT SEE VFR UNTIL THIS AFTERNOON.
SOME DETERIORATION WILL OCCUR AGAIN TONIGHT AS FOG/STRATUS
REDEVELOPS. PLN/APN WILL LIKELY GO IFR/LIFR AGAIN...WHILE TVC WILL
BE MVFR/IFR.
JZ
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...DENSE FOG ADVISORY UNTIL 10 AM EST TODAY FOR MIZ008-015>036-
041-042.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KDTX 221058
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
558 AM EST SUN NOV 22 2009
.AVIATION...
AREAS OF DENSE FOG AND LOW STRATUS WILL BE PREVALENT TO START THE
FORECAST PERIOD...BUT WILL BE REPLACED BY A LARGER AREA OF HIGHER
BASED STRATUS...1500-2500 FEET...WHICH EXPAND BACK WEST INTO PARTS
OF THE AREA...ESPECIALLY DET/DTW/PTK...THIS MORNING. VISIBILITIES
UNDER THIS SOLID STRATUS DECK AREA 2-4SM...MUCH MORE MANAGEABLE
THAN THE 1/4SM OR LESS DOTTING THE REGION ATTM. CLEARING WILL BE
SLOW LATE THIS MORNING/EARLY THIS AFTERNOON...BUT WILL HOLD ONTO A
PERIOD OF FEW-SCT BY AFTERNOON WITH CLEAR SKIES PERHAPS DURING THE
EVENING BEFORE FOG/STRATUS REFORM TONIGHT TO SOME DEGREE. WILL NOT
BRING VISIBILITIES DOWN AS MUCH TONIGHT AS BETTER GRADIENT WILL BE
IN PLACE TO KEEP EAST/SOUTHEAST WINDS AT 5 KNOTS OR SO. TOUGH CALL
THOUGH AS ABUNDANT LOW LEVEL MOISTURE WILL CONTINUE TO FEED INTO
SOUTHEAST MICHIGAN ON THIS LOW LEVEL FLOW.
&&
.PREV DISCUSSION...ISSUED 336 AM EST SUN NOV 22 2009
SHORT TERM...TODAY
LOW STRATUS/FOG CONTINUE TO SLOWLY BUILD SOUTHWEST THROUGH THE CWA
EARLY THIS MORNING...AND EXPECT MOST OF THE AREA TO BE MOSTLY CLOUDY
WITH AREAS OF FOG BY DAYBREAK. WITH WEAK NOVEMBER SUNSHINE...IT WILL
THEN TAKE MUCH OF THE MORNING TO BURN OF THIS STRATUS/FOG...SO ONLY
EXPECT A GRADUAL TRANSITION TO PARTLY SUNNY SKIES BY AFTERNOON. THE
TEMPERATURES WILL BE ABLE TO CLIMB INTO THE LOW/MID 50S AGAIN AS THE
AIRMASS HAS NOT CHANGED APPRECIABLY...BUT THIS WILL BE DEPENDENT ON
THE EVENTUAL EVOLUTION OF THE STRATUS/FOG AND ADJUSTMENTS MAY BE
NEEDED IN SOME AREAS IF CLOUDS TAKE LONGER TO SCOUR OUT.
LONG TERM...TONIGHT THROUGH NEXT SATURDAY
FORECAST CONCERNS FOR THE EXTENDED PERIOD AGAIN CENTER AROUND FOG
DEVELOPMENT MONDAY AND TUESDAY MORNINGS AND THE MID WEEK LOW
PRESSURE SYSTEM THAT WILL AFFECT MICHIGAN.
MID LEVEL RIDGING AND ASSOCIATED SURFACE LOW PRESSURE SYSTEM WILL
CONTINUE TO AFFECT SE MI THROUGH MONDAY EVENING AS IT MOVES EASTWARD
OVER NEW ENGLAND. IT WILL EVENTUALLY BE REPLACED BY A SERIES OF
SHORTWAVES AND AMPLIFIED LONGWAVE TROUGH BY EARLY MIDWEEK. THE MID
LEVELS WILL REMAIN DRY UNTIL THIS TROUGH BEGINS TO INFLUENCE THE
AIRMASS ALOFT EARLY TUESDAY AS SHOWN BY NAM BUFR SOUNDINGS AND
BUFKIT. THE LOW LEVELS ON THE OTHER HAND WILL REMAIN VERY MOIST
LEADING TO POTENTIAL FOG DEVELOPMENT BOTH SUNDAY AND MONDAY NIGHTS.
THE PRESSURE GRADIENT REMAINS WEAK BETWEEN THE OUTGOING HIGH AND
INCOMING LOW PRESSURE SYSTEMS KEEPING THE WINDS WEAK THROUGH THIS
PERIOD. MODEL SOUNDINGS CONTINUE TO SHOW BOUNDARY LAYER DECOUPLING
EACH NIGHT AT AROUND 950MB UNDER THE CONTINUED MID LEVEL SUBSIDENCE
FROM THE EXITING HIGH. A SLIGHT EASTERLY COMPONENT TO THE LOW LEVEL
FLOW WILL ACT TO REINFORCE THE ALREADY MOIST BOUNDARY LAYER.
POTENTIAL DOES EXIST FOR THIS FOG TO BECOME DENSE AS A LACK OF DAY
TIME HEATING WILL ALLOW TEMPS TO DROP FAIRLY QUICKLY AFTER SUNSET.
NOT MUCH HAS CHANGED WITH THE MID WEEK STORM SYSTEM FROM PREVIOUS
MODEL RUNS. IT SEEMS THAT THE GFS IS SLOWING DOWN A BIT BRINGING IT
MORE IN LINE WITH THE ECMWF...WHICH HAS BEEN THE FAVORED MODEL
SOLUTION THUS FAR. THEY BOTH SHOW THE MID LEVEL TROUGH BECOMING
INCREASINGLY AMPLIFIED ON MONDAY OVER THE CENTRAL ROCKIES THEN
BECOMING MORE OF A CUTOFF CIRCULATION OVER THE CENTRAL PLAINS. THERE
ARE STILL MANY QUESTIONS THOUGH REGARDING THE EVOLUTION OF THIS
TROUGH AND LOW AS TO HOW CUTOFF IT WILL BECOME FROM THE MAIN STREAM
AND HOW A SECONDARY SHORTWAVE SLIDING DOWN THE BACKSIDE OF THIS MAIN
LOW WILL AFFECT THE TROUGH. THIS WILL AFFECT THE PROPAGATION SPEED
OF THE TROUGH AND WHEN IT WILL ARRIVE OVER SE MI. IT WILL ALSO
AFFECT HOW COLD THE AIRMASS WILL BE THAT IS BROUGHT IN WITH THE
TROUGH. THE MODELS HAVE BEEN TAPERING BACK THE AMOUNT OF COLD AIR
AND HOLDING IT BACK TIL LATER IN THE AS THEY SLOW THE MAIN FEATURE
DOWN. AT THIS POINT IT LOOKS LIKE THE PRECIP WILL MOVE IN TUESDAY
NIGHT IN THE FORM OF RAIN WITH THE BEST CHANCES DURING THE DAY ON
WEDNESDAY. PRECIP CHANCES REMAIN THROUGH FRIDAY TRANSITIONING TO A
RAIN/SNOW MIX THURSDAY NIGHT AS THE COLDEST AIR MOVES IN ON THE
BACKSIDE OF THE LOW.
MARINE...
HIGH PRESSURE WILL REMAIN IN PLACE OVER THE CENTRAL GREAT LAKES THIS
WEEKEND...RESULTING IN LIGHT/VARIABLE WINDS. THERE WILL BE A GRADUAL
INCREASE IN SOUTHEAST WINDS MONDAY INTO TUESDAY AS THE HIGH RETREATS
EAST AWAY FROM THE AREA. THE PATTERN BECOMES ACTIVE AGAIN MID/LATE
NEXT WEEK AS A STRONG SHORTWAVE AND ASSOCIATED JET STREAK DIG INTO
THE UPPER MIDWEST AND LEAD TO THE DEVELOPMENT OF A LARGE UPPER LEVEL
LOW OVER/NEAR THE REGION. THIS TIME FRAME WILL BRING UNSETTLE
WEATHER AND HIGHER WIND AND WAVES.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...DENSE FOG ADVISORY...MIZ047-MIZ048-MIZ049-MIZ053-MIZ054-MIZ055-
MIZ060-MIZ061-MIZ062-MIZ063-MIZ068-MIZ069-MIZ070-MIZ075-MIZ076-
MIZ082-MIZ083...UNTIL 10 AM SUNDAY.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....DG
SHORT TERM...DG
LONG TERM....DRK
MARINE.......DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
000
FXUS63 KGRR 220900
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
400 AM EST SUN NOV 22 2009
LATEST UPDATE...ALL EXCEPT AVIATION...
.SYNOPSIS...(400 AM EST SUN NOV 22 2009)
AREAS OF DENSE FOG WILL DISSIPATE BY LATE THIS MORNING. HIGH
PRESSURE WILL PRODUCE FAIR WEATHER TODAY INTO MONDAY BUT FOG WILL
LIKELY REDEVELOP AGAIN LATE TONIGHT. A LOW PRESSURE SYSTEM WILL
BRING RAIN TUESDAY NIGHT AND WEDNESDAY. IT WILL TURN COOLER LATE
THIS WEEK WITH A MIX OF RAIN AND SNOW SHOWERS POSSIBLE FOR OUR
THANKSGIVING HOLIDAY.
&&
.SHORT TERM...(400 AM EST SUN NOV 22 2009)
(TODAY THROUGH TUESDAY AFTERNOON)
OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO ASSESS FOG POTENTIAL THE
NEXT FEW MORNINGS AND ALSO TO ASSESS PCPN CHANCES FOR TUESDAY. FCST
TWEAKS INCLUDED ADDING MENTION OF PATCHY FOG TO THE FCST DURING THE
EARLY MORNING HOURS TUESDAY AND REMOVAL (OR LOWERING) OF POPS FROM
06Z TUE THROUGH TUE AFTERNOON.
SFC OBS FROM ACROSS OUR CWFA EARLY THIS MORNING INDICATE THAT FOG
CONTINUES TO BECOME MORE DENSE AND WIDESPREAD PARTICULARLY NORTH OF
I-96. HOWEVER AREAS FURTHER SOUTH HAVE ALSO SEEN VISBYS DROP TO A
QUARTER MILE AT TIMES INCLUDING HERE AT GRR. THIS IS OCCURRING DUE
TO CLEAR SKIES... CALM WINDS... AND LINGERING LOW LEVEL MOISTURE
TRAPPED UNDERNEATH A RADIATION INVERSION. THEREFORE THE DENSE FOG
ADVISORY REMAINS IN EFFECT FOR OUR ENTIRE CWFA THROUGH 15Z THIS
MORNING.
FOG SHOULD GRADUALLY DISSIPATE LATE THIS MORNING AND IR SAT TRENDS
AND 00Z MODEL GUIDANCE RH PROGS SUGGEST THAT WE WILL GET QUITE A BIT
OF SUN THIS AFTERNOON. THIS AND SE WINDS OF 5 TO 10 MPH WILL HELP TO
BOOST MAX TEMPS INTO THE MID 50S AT MOST LOCATIONS (SO LONG AS FOG
DOES INDEED MIX OUT AND DISSIPATE BY LATE MORNING).
THE SETUP FOR FOG DEVELOPMENT LATE TONIGHT APPEARS FAVORABLE AND
SIMILAR TO THAT OF EARLY THIS MORNING. A POTENTIAL INHIBITING FACTOR
MAY BE LIGHT ESE WINDS IN THE BOUNDARY LAYER. HOWEVER I DO NOT
BELIEVE THIS WILL PROVIDE SIGNIFICANT ENOUGH MIXING TO INHIBIT FOG
FORMATION. AS A MATTER OF FACT... SREF PROBABALISTIC GUIDANCE OF SFC
VISBYS DROPPING BELOW A MILE SUGGESTS GREATER POTENTIAL FOR FOG LATE
TONIGHT THAN WHAT IT SHOWED FOR EARLY THIS MORNING. BOTTOM LINE...
FOG WILL DEVELOP AGAIN LATE TONIGHT.
OUR TRANQUIL WX WILL CONTINUE MONDAY AFTERNOON THROUGH MONDAY NIGHT
WITH PARTLY CLOUDY SKIES AND RATHER MILD TEMPS FOR THIS TIME OF
YEAR. THE NEXT LOW PRESSURE SYSTEM MOVING IN FROM THE WEST COULD
BRING A FEW SHOWERS BY TUESDAY... ALTHOUGH THE BETTER CHANCE FOR
PCPN SHOULD HOLD OFF UNTIL TUESDAY NIGHT. 21Z SREF POPS ARE OVERDONE
FOR TUESDAY MORNING AND AFTERNOON. WE PREFER THE MORE CONSERVATIVE
00Z GFS/NAM/ECMWF GUIDANCE WHICH SUGGESTS THAT PREDOMINANTELY DRY WX
WILL CONTINUE THROUGH TUESDAY AFTERNOON. WE TWEAKED THE FCST IN THIS
DIRECTION ACCORDINGLY.
&&
.LONG TERM...(400 AM EST SUN NOV 22 2009)
(TUESDAY NIGHT THROUGH SATURDAY)
TWO SYSTEMS/UPPER LOWS ARE THE FOCUS/CHALLENGE OF THE LONG TERM. THE
FIRST TRACKS EAST NORTHEAST FROM THE CENTRAL PLAINS TUESDAY NIGHT
AND WEDNESDAY... TAKING ON A NEGATIVE TILT AS ANOTHER UPPER LOW
DROPS SOUTH THROUGH THE NRN PLAINS.
HANDLING OF THE INITIAL SYSTEM SEEMS RATHER STRAIGHTFORWARD... WITH
A HIGH CHANCE OF RAIN AND PERHAPS EVEN A TSTM. IF THE MODELS REMAIN
CONSISTENT ON TIMING... BELIEVE WE WILL BE ABLE TO RAISE POPS TO
LIKELY OR CATEGORICAL FOR TUESDAY NIGHT AND WEDNESDAY.
THE SECOND SYSTEM IS NOT AS STRAIGHTFORWARD SINCE COLDER H8 AIR NEAR
-4C GETS WRAPPED INTO THE SYSTEM FROM THE SOUTHWEST AS IT TRACKS
ACROSS THE REGION ON THANKSGIVING DAY AND NIGHT. PCPN TYPE IS A
CHALLENGE SINCE BOUNDARY LAYER TEMPS ARE PROGGED TO REMAIN THE MID
TO UPPER 30S DESPITE THE COLDER TEMPS COMING IN ALOFT. WILL CONTINUE
TO CARRY A MIXTURE OF RAIN/SNOW SHOWERS DURING THIS TIME... BUT AM
BECOMING A BIT CONCERNED ABOUT THE POSSIBILITY OF ACCUMULATING WET
SNOW ON THURSDAY NIGHT.
SCATTERED SNOW OR MIXED RAIN AND SNOW SHOWERS MAY LINGER INTO
FRIDAY... BEFORE RIDGING/QUIET WEATHER RETURNS FOR NEXT WEEKEND.
&&
.AVIATION...(1130 PM EST SAT NOV 21 2009)
FOG CONTINUES TO DEVELOP AND BECOME MORE DENSE AND WIDESPREAD ACROSS
LWR MI. VISBYS OF A QUARTER MILE OR LESS ARE REPORTED AT MKG AND
VISBYS ARE ALSO ON A SLOW DOWNWARD TREND AT THE REMAINDER OF OUR TAF
SITES.
VLIFR CONDITIONS WILL CONTINUE AT MKG OVERNIGHT THROUGH MID MORNING
SUNDAY IN DENSE FOG. IFR TO MVFR CONDITIONS AT THE REST OF OUR TAF
SITES WILL DETERIORATE INTO THE IFR TO VLIFR FLIGHT CATEGORY DURING
THE NEXT SEVERAL HOURS. THIS AS FOG CONTINUES TO BECOME MORE DENSE
AND WIDESPREAD WITH DECENT LOW LEVEL MOISTURE TRAPPED UNDERNEATH THE
RADIATION INVERSION.
FOG WILL LINGER THROUGH MID MORNING SUNDAY AT ALL TAF SITES BEFORE
DISSIPATING.
&&
.MARINE...(400 AM EST SUN NOV 22 2009)
AREAS OF DENSE FOG WILL POSE A HAZARD TO MARINERS THIS MORNING AND
POTENTIALLY ONCE AGAIN ON MONDAY MORNING AND EARLY TUESDAY MORNING
ALSO. OTHERWISE FAIRLY MINIMAL WIND AND WAVE ACTION IS ANTICIPATED
THE NEXT COUPLE OF DAYS.
&&
.HYDROLOGY...(400 AM EST SUN NOV 22 2009)
NO PRECIPITATION THROUGH MONDAY NIGHT AND MUCH OF TUESDAY. NO HYDRO
ISSUES EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...DENSE FOG ADVISORY FOR OUR ENTIRE CWFA THROUGH 10 AM TODAY.
LM...NONE.
&&
$$
SYNOPSIS: LAURENS
SHORT TERM: LAURENS
LONG TERM: MEADE
AVIATION: LAURENS
MARINE: LAURENS
HYDROLOGY: LAURENS
000
FXUS63 KMQT 220851
AFDMQT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
350 AM EST SUN NOV 22 2009
.SYNOPSIS...
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SHARP UPR RDG AXIS
OVER THE UPR GRT LKS DOWNSTREAM OF TROFFING OVER THE NW CONUS. CWA
IS DOMINATED BY WARM SFC-H85 FLOW BTWN HI PRES OVER SE ONTARIO AND
LO PRES TROF/PACIFIC TYPE COLD FNT IN THE PLAINS TO THE E OF UPR
TROFFING OVER THE NW. THIS SLY FLOW EXTENDS INTO CAN AND HAS PUSHED
THE 00Z H85 TEMP AT PICKLE LAKE ONTARIO TO AN IMPRESSIVE 7C FOR LATE
NOV. THE SLY FLOW IS ADVECTING HIER LLVL MSTR NWD...WITH LO CLD/FOG
DVLPG OVER THE FA UNDER LO INVRN ARND H9 SHOWN ON THE 00Z GRB RAOB
AT TIME OF DIURNAL COOLING. THE FOG IS DENSE AT SOME PLACES...
ESPECIALLY OVER THE E WITH SOME ADDED MOISTENING OFF LK MI AND
DOWNSTREAM OF SOMEWHAT HIER LLVL MSTR DEPICTED ON THE 00Z GRB RAOB
(00Z PWAT THERE IS 0.43 INCH). THE GRB RAOB IS QUITE DRY ABV H8
HOWEVER WITH H7/H5 DWPT DEPRESSION 16C/38C RESPECTIVELY. THE AIRMASS
TO THE W IS EVEN DRIER...WITH 00Z PWAT ARND 0.25 INCH AT INL/MPX.
BUT QUITE A BIT OF HI CLD IS STREAMING EWD INTO THIS AREA AHEAD OF
LO PRES TROF IN THE PLAINS. FARTHER W...A POTENT SHRTWV IN THE
PACIFIC OCEAN APPEARS READY TO CRASH INTO THE PAC NW.
&&
.DISCUSSION...
MAIN FCST CONCERNS NEXT FEW DAYS ARE FOG/ST TRENDS AND CONTINUED ABV
NORMAL TEMPS. FOCUS TOWARD MID WEEK TURNS TO TIMING/IMPACT OF
COMPLEX LO PRES PROGGED TO DVLP IN THE PLAINS AND MOVE NE.
TDAY...SFC HI PRES CENTER IS FCST TO SHIFT E INTO NEW ENGLAND BY 00Z
MON WHILE LO PRES TROF/PACIFIC TYPE COLD FNT MOVES E INTO MN AND
TOWARD WRN LK SUP WHILE WASHING OUT WITH SUPPORTING SHRTWV LIFTING
TO THE NE ARND DOMINANT UPR RDG. ALTHOUGH MORE LLVL MSTR WL ARRIVE
BLO H7 TDAY WITH CONTINUED SSW FLOW...PREFER THE DRIER NAM FCST
GIVEN EXCESSIVE DRYNESS OF THE MID/UPR TROP ASSOCIATED WITH
RESILIENT RDG REINFORCED BY ADVECTION OF VERY WARM AIR WELL INTO CAN
AS NOTED ABV. RETAINED SCHC POPS OVER ONLY THE FAR W IN THE AFTN.
OTRW...EXPECT ST/SC TO BE QUITE RESILIENT WITH ARRIVAL OF CONT
INFLUX OF HIER LLVL MSTR. EVEN WITH THIS LO CLD...TEMPS WL CONT TO
RUN WELL ABV NORMAL WITH MAX TEMPS WITHIN A FEW DEGREES OF 50. THESE
READINGS ARE ABOUT 15 DEGREES ABV NORMAL.
RESTRICTED POPS TNGT TO THE FAR WRN CWA AGAIN WHERE FAVORED NAM
SHOWS LO PRES TROF SETTING UP UNDER AXIS OF HIER H85-7 DWPTS. TENDED
TO GO WITH THE HIER POPS LATER AT NGT WITH INFLUX OF MSTR AND SOME
UPR DVGC IN RRQ OF H3 JET MAX IN NW ONTARIO. FARTHER E...RISING MSLP
UNDER PERSISTENT RDG WL RESULT IN A SLACKENING PRES GRADIENT/LIGHTER
WINDS. SO MORE FOG LOOKS LIKE A GOOD BET THERE WHERE DRIER MID LVLS
FAVOR A SHARPER DIURNAL FALL OF TEMP BLO MOS GUIDANCE.
ON MON...NUMERICAL MODELS SHOW DEEPENING TROF IN THE CNTRL PLAINS AS
SHRTWV NOW APRCHG THE PAC NW DIVES ESEWD. WITH THIS DEVELOPMENT
UPSTREAM...MODELS HAVE CONTINUED TREND FOR DRYING TREND DOWNSTREAM
OVER THE FA. GIVEN THIS CONSISTENT TREND...OPTED TO INCRS MAX TEMPS
FCST WITH EXPECTATION FOR MORE AFTN SUNSHINE ONCE MRNG FOG BURNS OFF
WITH DAYTIME MIXING/SFC-H85 DRY ADVECTION. MIXING TO ONLY H9 ON
GFS/NAM FCST SDNGS YIELDS HI TEMPS IN THE LO 50S.
ON MON NGT/TUE...MODELS SHOW OCCLUDED LO IN THE PLAINS MOVING ONLY
SLOWLY NEWD INTO IA BY 00Z WED. WITH ACCOMPANYING DYNAMICS REMAINING
WELL TO THE SW AND HINT OF UPR RDG/DRY MID LVLS LINGERING OVER THE
GRT LKS...PREFER THE DRIER LOOK OF THE NAM. CUT POPS TO ONLY FAR WRN
LK SUP ON MON NGT THRU 18Z TUE. MAINTAINED SCHC POPS AFT 18Z NEAR
THE WI BORDER. WITH DRIER MID LVLS PERSISTING...INCRSD DIURNAL TEMP
RANGE WITH LOWER MINS ON MON NGT AND HIER MAXES ON TUE. MAINTAINED
PATCHY FOG MENTION OVER THE INTERIOR ECNTRL ON MON NGT WITH GRADIENT
FLOW SUFFICIENTLY LGT UNDER LOWER PWAT BLO 0.50 INCH.
MODELS HAVE MAINTAINED LOOK OF MORE PHASING BTWN CUTOFF LO AND
SHRTWVS ARRIVING IN THE NRN BRANCH FLOW FOR MIDWEEK. AS SUCH...GOING
POPS INCRSG TO LIKELY ON WED SEEM APPROPRIATE. ON TUE NGT...REMOVED
MENTION OF SN AS GFS/NAM/ECMWF FCST SDNGS AS WELL AS H100-85 THKNS
FIELDS/MIN TEMPS FCST SUG LLVLS WL BE TOO WARM FOR ANYTHING BUT RA.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
LOW LEVEL MOISTURE TRAPPED UNDER A SUBSIDENCE INVERSION HAS RESULTED
IN STRATUS AND PATCHY FOG OVER PORTIONS OF WEST AND CENTRAL UPR MI
TONIGHT. WITH A S-SE FLOW EXPECT COMBINATION OF STRATUS/FOG TO LWR
CONDITIONS DOWN TO LIFR OVERNIGHT AT KSAW. AT KCMX...SE (DOWNSLOPE)
FLOW SHOULD ONLY YIELD MVFR CONDITIONS AT KCMX. DIURNAL MIXING WILL
CAUSE SOUTH WINDS TO PICK UP EVEN MORE BY LATE SUNDAY MORNING WHICH
SHOULD DISSIPATE THE FOG BUT MVFR STRATUS CIGS SHOULD PERSIST INTO
EARLY/MID AFTERNOON BEFORE LIFTING.
LLWS CAN BE EXPECTED AT BOTH TAF SITES UNTIL AROUND 14Z SUNDAY.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
WITH LAKE SUPERIOR IN BETWEEN LOW PRESSURE TO THE NORTHWEST AND HIGH
PRESSURE OVER THE LOWER LAKES EXPECT SOUTHERLY WINDS TO 25 KNOTS
INTO MONDAY MORNING. A FEW WIND GUSTS TO 30 KNOTS AREN/T OUT OF THE
QUESTION OVER THE EAST TODAY...HOWEVER...AIRMASS ABOVE THE LAKE
SURFACE IS QUITE STABLE SO DON/T EXPECT WINDS TO GET TOO STRONG.
WINDS WILL THEN REMAIN UNDER 20 KNOTS INTO WEDNESDAY...WHEN A STORM
SYSTEM APPROACHES THE UPPER GREAT LAKES AND WINDS BEGIN TO INCREASE
OUT OF THE NORTH AND NORTHEAST WITH GALES POSSIBLE LATE WEDNESDAY
INTO THURSDAY. LOCALLY DENSE PATCHY FOG IS POSSIBLE THIS MORNING
ACROSS EASTERN LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS/DISCUSSION...KC
AVIATION...JV
MARINE...PEARSON
000
FXUS63 KAPX 220842
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
343 AM EST SAT NOV 21 2009
.SYNOPSIS.../ISSUED AT 343 AM/
HIGH PRESSURE WHICH LIFTED NORTH INTO THE STATE FROM THE OHIO VALLEY
SATURDAY...WILL BE CENTERED OVER THE EASTERN LAKES INTO THE BEGINNING
OF THE WORK WEEK. THIS PATTERN WILL GENERATE SOME SUN AND WELL ABOVE
NORMAL TEMPERATURES ACROSS NORTHERN MICHIGAN THROUGH MONDAY.
THE NEXT CHANCE OF RAIN WILL BE TUESDAY AND WEDNESDAY...AS A STORM
SYSTEM LIFTS NORTH INTO THE UPPER MIDWEST AND WESTERN GREAT LAKES.
TEMPERATURES WILL REMAIN ABOVE NORMAL TUESDAY AND WEDNESDAY.
MORE SEASONABLE TEMPERATURES AND A CHANCE OF SNOW...MAKE A BRIEF
RETURN TO THE REGION THURSDAY AND FRIDAY...AS COOLER AIR BEGINS TO
FILTER INTO THE REGION.
SWR
&&
.SHORT TERM.../ISSUED AT 343 AM/...TODAY
HIGH PRESSURE CENTERED NEAR LK ONTARIO...WITH A WEAK PRESSURE
GRADIENT OVER NORTHERN MI. FOG AND STRATUS QUICKLY REDEVELOPED AFTER
SUNRISE...THICKEST (PER FOG IMAGERY) IN NE LOWER AND EASTERN UPPER
MI. FOG/CLOUDS AND TEMPS ARE THE MAIN CONCERNS TODAY.
VSBYS ARE NOT ON THE FLOOR EVERYWHERE...BUT ARE LESS THAN 1/2 MILE
IN MANY...MANY LOCALES. ONGOING DENSE FOG ADVISORY IS FINE.
NEAR-SURFACE WINDS WILL REMAIN SE-ERLY TODAY. THUS...DOWNSLOPING
WILL HELP FOG/STRATUS BREAK UP FIRST NEAR THE LAKE MI COAST OF NW
LOWER MI. THIS SHOULD HAPPEN BY MID-MORNING...EXPANDING ACROSS MOST
OF NORTHERN MI BY MID-AFTERNOON. GIVEN A MOISTENING MARINE
INFLUENCE...AM NOT AT ALL CONVINCED THAT EASTERN UPPER MI...AND THE
IMMEDIATE NE LOWER MI COAST...WILL BREAK OUT AT ALL.
WILL LEAN TOWARD THE WARM END OF GUIDANCE IN NW LOWER (MID
50S)...THE COOL END IN EASTERN UPPER (MID/UPPER 40S)...IN BETWEEN IN
NE LOWER (LOWER 50S).
JZ
&&
.LONG TERM.../ISSUED AT 343 AM/...TONIGHT AND BEYOND
EARLY PART OF THE WEEK STILL LOOKS UNEVENTFUL...BUT THINGS GET A BIT
MORE ACTIVEW CLOSE TO THE HOLIDAY. UPPER RIDGING OVERHEAD TODAY WILL
REMAIN PROGRESSIVE...MOVING OFF THE NEW ENGLAND COAST MONDAY. A
COUPLE OF WEAKISH SHORTWAVES WILL LIFT INTO THE OHIO VALLEY AND
CENTRAL/EASTERN LAKES MONDAY/MONDAY NIGHT...IN ADVANCE OF A CLOSED
UPPER LOW DEEPENING IN THE CENTRAL PLAINS. THIS LOW WILL REACH THE
SW LAKES REGION BY WED MORNING...WHILE ANOTHER UPPER LOW DIGS INTO
THE NORTHERN PLAINS. CLOUDS/FOG/TEMPS REMAIN THE MAIN CONCERN EARLY
ON...PRECIP BECOMES THE MAIN ISSUE BEGINNING TUE NIGHT.
MODELS...ARE STARTING TO CLUSTER A BIT WHEN IT COMES TO THE MID-WEEK
SYSTEM. TIMING IS QUITE SIMILAR BETWEEN NAM/GFS/ECMWF/SREF.
HOWEVER...THERE ARE STILL IMPORTANT LATITUDINAL DIFFERENCES. THE GFS
IS FURTHEST SOUTH...WITH AN UPPER LOW NEAR INDY WED MORNING. THE
SREF IS FURTHEST NORTH...NEAR MILWAUKEE. NAM/ECMWF ARE IN BETWEEN...
NEAR THE SOUTHERN TIP OF LAKE MI...AND WILL STEER THE FORECAST IN
THAT MIDDLE-OF-THE-ROAD DIRECTION.
TONIGHT/MONDAY...PRESSURE GRADIENT TIGHTENS A BIT TONIGHT AS HIGH
PRESSURE MOVES ACROSS NEW ENGLAND. AS A RESULT...SOUTHERLY 950MB
WINDS WILL INCREASE TO AROUND 20KT. THIS WILL NOT BE ENOUGH TO
OUTRIGHT PREVENT FOG REDEVELOPMENT...BUT SHOULD PREVENT FOG FROM
BEING AS WIDESPREAD/DENSE AS THE LAST COUPLE OF NIGHTS. MARINE-
INFLUENCED EASTERN UPPER MI HAS THE BEST SHOT OF SEEING THE THICK
STUFF...AS DOES THE IMMEDIATE HURON COAST...THANKS TO SE-ERLY
SUB-950MB WINDS. WILL TWEAK FOG WORDING IN THE GRIDS AND TEXT
PRODUCTS...INCLUDING ADDING DENSE FOG IN THE ABOVE LOCALES.
OTHERWISE...SAME OLD SAME OLD...WITH FOG/STRATUS SLOWING BURNING OFF
DURING THE DAY MONDAY. CLEARING WILL AGAIN TAKE LONGEST IN EASTERN
UPPER AND NE LOWER MI. WE WILL HAVE MORE CIRRUS AROUND ON MONDAY
THAN TODAY...ESPECIALLY IN THE AFTERNOON. THAT MAY BE ENOUGH TO
KNOCK A COUPLE OF DEGREES OFF OF MAX TEMPS...BUT GUIDANCE TEMPS
STILL LOOK A LITTLE TOO COOL IN MANY AREAS.
MONDAY NIGHT/TUESDAY...THE INTIAL SHORTWAVES AHEAD OF THE MAIN UPPER
LOW WILL DRAW A PLUME OF DEEPER MOISTURE NORTHWARD FROM THE CENTRAL
APPALACHIANS TO THE EASTERN GREAT LAKES. THIS WILL PASS EAST OF US.
MEANWHILE...THE WARM CONVEYOR BELT AHEAD OF THE UPSTREAM LOW WILL
ADVANCE INTO IL/WI TUESDAY. IN BETWEEN THESE TWO...WE SHOULD SEE NO
SIGNIFICANT RISK OF PRECIP. INSTEAD...FOG/STRATUS CONTINUE TO BE THE
MAIN CONCERNS. CIRRUS WILL INHIBIT COOLING TO SOME DEGREE MONDAY
NIGHT...BUT THE PRESSURE GRADIENT WILL ACTUALLY BE SOMEWHAT WEAKER
(ESPECIALLY AFTER MIDNIGHT). 950MB WINDS WILL LOWER BELOW 20KT. NAM
SOUNDINGS ARE MORE MOIST BELOW 950MB THAN PROGGED TONIGHT. NUMERICAL
GUIDANCE IS MORE BULLISH ON FOG MONDAY NIGHT THAN TONIGHT. WILL THUS
GO AHEAD AND ADD EVEN MORE FOG TO THE LATE MONDAY NIGHT/TUESDAY
MORNING FORECAST...HITTING HARDER IN EASTERN UPPER.
MID AND HIGH CLOUDS WILL BECOME MORE EXTENSIVE TUESDAY...AND THIS
WILL EAT INTO MAX TEMPS...WHICH WILL BE MAINLY IN THE 40S.
REST OF THE FORECAST...MID-WEEK SURFACE LOW NOW LOOKS LIKE IT MAY
PASS JUST SOUTH OF THE FORECAST AREA ON WEDNESDAY. 850MB TEMPS WILL
BE NEAR 0C...BUT THE ENTIRE LAYER BELOW THAT WILL BE ABOVE FREEZING
AND MITIGATE ANY FROZEN PRECIP CONCERNS ON WEDNESDAY. COLDER AIR
WILL GRADUALLY TURN RAIN OVER TO SNOW WED NIGHT INTO TURKEY
DAY...THOUGH MUCH OF THE SYNOPTIC PRECIP WITH THE INITIAL UPPER LOW
WILL BE OVER BY THEN. BUT WHAT DOES THE 2ND ONE DO? THE NEW ECMWF
WOULD OFFER UP A PERIOD OF ACCUMULATING SNOW POSSIBLE...CENTERED ON
THURSDAY NIGHT...AS THAT PASSES TO THE SOUTH.
JZ
&&
.MARINE.../ISSUED AT 343 AM/
HIGH PRESSURE WILL MOVE FROM THE EASTERN LAKES TO OFF THE NEW
ENGLAND COAST. WE WILL SEE SOMETHING OF AN INCREASE IN S-SE WINDS AS
THE HIGH MOVES AWAY. BUT IN THE NEAR TERM...WINDS AND WAVES WILL
REMAIN COMFORTABLY BELOW SMALL CRAFT CRITERIA. LOW LEVEL MOISTURE
AND RELATIVELY LIGHT WINDS WILL STILL RESULT IN AREAS OF FOG THIS
MORNING...LATE TONIGHT INTO MONDAY MORNING...AND LATE MONDAY NIGHT
INTO TUESDAY MORNING.
JZ
&&
.AVIATION.../ISSUED AT 1150 PM/...VALID FOR 06Z TAFS
WIDESPREAD LOW STRATUS/IFR/LIFR CIGS WILL PERSIST OVERNIGHT AND FOR
JUST A FEW HOURS AFTER SUNRISE. DIURNAL MIXING AND INCREASING LOW
LEVEL WIND SPEEDS WILL DISSIPATE THE FOG BY MID TO LATE MORNING...
LEAVING VFR CONDITIONS FOR THE REMAINDER OF THE DAY AND THE EVENING
HOURS.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...DENSE FOG ADVISORY UNTIL 10 AM EST TODAY FOR MIZ008-015>036-
041-042.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KDTX 220836
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
336 AM EST SUN NOV 22 2009
.SHORT TERM...TODAY
LOW STRATUS/FOG CONTINUE TO SLOWLY BUILD SOUTHWEST THROUGH THE CWA
EARLY THIS MORNING...AND EXPECT MOST OF THE AREA TO BE MOSTLY CLOUDY
WITH AREAS OF FOG BY DAYBREAK. WITH WEAK NOVEMBER SUNSHINE...IT WILL
THEN TAKE MUCH OF THE MORNING TO BURN OF THIS STRATUS/FOG...SO ONLY
EXPECT A GRADUAL TRANSITION TO PARTLY SUNNY SKIES BY AFTERNOON. THE
TEMPERATURES WILL BE ABLE TO CLIMB INTO THE LOW/MID 50S AGAIN AS THE
AIRMASS HAS NOT CHANGED APPRECIABLY...BUT THIS WILL BE DEPENDENT ON
THE EVENTUAL EVOLUTION OF THE STRATUS/FOG AND ADJUSTMENTS MAY BE
NEEDED IN SOME AREAS IF CLOUDS TAKE LONGER TO SCOUR OUT.
&&
.LONG TERM...TONIGHT THROUGH NEXT SATURDAY
FORECAST CONCERNS FOR THE EXTENDED PERIOD AGAIN CENTER AROUND FOG
DEVELOPMENT MONDAY AND TUESDAY MORNINGS AND THE MID WEEK LOW
PRESSURE SYSTEM THAT WILL AFFECT MICHIGAN.
MID LEVEL RIDGING AND ASSOCIATED SURFACE LOW PRESSURE SYSTEM WILL
CONTINUE TO AFFECT SE MI THROUGH MONDAY EVENING AS IT MOVES EASTWARD
OVER NEW ENGLAND. IT WILL EVENTUALLY BE REPLACED BY A SERIES OF
SHORTWAVES AND AMPLIFIED LONGWAVE TROUGH BY EARLY MIDWEEK. THE MID
LEVELS WILL REMAIN DRY UNTIL THIS TROUGH BEGINS TO INFLUENCE THE
AIRMASS ALOFT EARLY TUESDAY AS SHOWN BY NAM BUFR SOUNDINGS AND
BUFKIT. THE LOW LEVELS ON THE OTHER HAND WILL REMAIN VERY MOIST
LEADING TO POTENTIAL FOG DEVELOPMENT BOTH SUNDAY AND MONDAY NIGHTS.
THE PRESSURE GRADIENT REMAINS WEAK BETWEEN THE OUTGOING HIGH AND
INCOMING LOW PRESSURE SYSTEMS KEEPING THE WINDS WEAK THROUGH THIS
PERIOD. MODEL SOUNDINGS CONTINUE TO SHOW BOUNDARY LAYER DECOUPLING
EACH NIGHT AT AROUND 950MB UNDER THE CONTINUED MID LEVEL SUBSIDENCE
FROM THE EXITING HIGH. A SLIGHT EASTERLY COMPONENT TO THE LOW LEVEL
FLOW WILL ACT TO REINFORCE THE ALREADY MOIST BOUNDARY LAYER.
POTENTIAL DOES EXIST FOR THIS FOG TO BECOME DENSE AS A LACK OF DAY
TIME HEATING WILL ALLOW TEMPS TO DROP FAIRLY QUICKLY AFTER SUNSET.
NOT MUCH HAS CHANGED WITH THE MID WEEK STORM SYSTEM FROM PREVIOUS
MODEL RUNS. IT SEEMS THAT THE GFS IS SLOWING DOWN A BIT BRINGING IT
MORE IN LINE WITH THE ECMWF...WHICH HAS BEEN THE FAVORED MODEL
SOLUTION THUS FAR. THEY BOTH SHOW THE MID LEVEL TROUGH BECOMING
INCREASINGLY AMPLIFIED ON MONDAY OVER THE CENTRAL ROCKIES THEN
BECOMING MORE OF A CUTOFF CIRCULATION OVER THE CENTRAL PLAINS. THERE
ARE STILL MANY QUESTIONS THOUGH REGARDING THE EVOLUTION OF THIS
TROUGH AND LOW AS TO HOW CUTOFF IT WILL BECOME FROM THE MAIN STREAM
AND HOW A SECONDARY SHORTWAVE SLIDING DOWN THE BACKSIDE OF THIS MAIN
LOW WILL AFFECT THE TROUGH. THIS WILL AFFECT THE PROPAGATION SPEED
OF THE TROUGH AND WHEN IT WILL ARRIVE OVER SE MI. IT WILL ALSO
AFFECT HOW COLD THE AIRMASS WILL BE THAT IS BROUGHT IN WITH THE
TROUGH. THE MODELS HAVE BEEN TAPERING BACK THE AMOUNT OF COLD AIR
AND HOLDING IT BACK TIL LATER IN THE AS THEY SLOW THE MAIN FEATURE
DOWN. AT THIS POINT IT LOOKS LIKE THE PRECIP WILL MOVE IN TUESDAY
NIGHT IN THE FORM OF RAIN WITH THE BEST CHANCES DURING THE DAY ON
WEDNESDAY. PRECIP CHANCES REMAIN THROUGH FRIDAY TRANSITIONING TO A
RAIN/SNOW MIX THURSDAY NIGHT AS THE COLDEST AIR MOVES IN ON THE
BACKSIDE OF THE LOW.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN IN PLACE OVER THE CENTRAL GREAT LAKES THIS
WEEKEND...RESULTING IN LIGHT/VARIABLE WINDS. THERE WILL BE A GRADUAL
INCREASE IN SOUTHEAST WINDS MONDAY INTO TUESDAY AS THE HIGH RETREATS
EAST AWAY FROM THE AREA. THE PATTERN BECOMES ACTIVE AGAIN MID/LATE
NEXT WEEK AS A STRONG SHORTWAVE AND ASSOCIATED JET STREAK DIG INTO
THE UPPER MIDWEST AND LEAD TO THE DEVELOPMENT OF A LARGE UPPER LEVEL
LOW OVER/NEAR THE REGION. THIS TIME FRAME WILL BRING UNSETTLE
WEATHER AND HIGHER WIND AND WAVES.
&&
.PREV DISCUSSION...ISSUED 1156 PM EST SAT NOV 21 2009
AVIATION...
VISIBILITY WILL CONTINUE TO DECREASE THROUGH THE EARLY MORNING
HOURS AS BOUNDARY LAYER MOISTURE POOLS BENEATH A STRENGTHENING
NEAR SURFACE BASED NOCTURNAL INVERSION. BASED ON LATEST
OBSERVATIONS...THE AMBIENT CONDITIONS AND OVERALL SETUP STILL
POINT TOWARD SEEING A PERIOD OF LIFR FOG/STRATUS BETWEEN 09-14Z.
MOISTURE WILL SLOWLY MIX OUT AGAIN THROUGH THE LATE MORNING/EARLY
AFTERNOON HOURS WITH CONDITIONS SETTLING BACK INTO VFR FOR MUCH OF
THE AFTERNOON. A MOIST BOUNDARY LAYER WILL REMAIN IN PLACE AGAIN
SUNDAY NIGHT MAINTAINING FAVORABLE CONDITIONS FOR ANOTHER ROUND OF
FOG.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...DENSE FOG ADVISORY...MIZ047-MIZ048-MIZ049-MIZ053-MIZ054-MIZ055-
MIZ060-MIZ061-MIZ062-MIZ063-MIZ068-MIZ069-MIZ070-MIZ075-MIZ076-
MIZ082-MIZ083...UNTIL 10 AM SUNDAY.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...DG
LONG TERM....DRK
MARINE.......DG
AVIATION.....MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
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