[top]
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.
&&
$$
[top]
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
[top]
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
[top]
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).
000
FXUS63 KMQT 220535 AAB
AFDMQT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MARQUETTE MI
1236 AM EST SUN NOV 22 2009
UPDATED FOR 06Z AVIATION DISCUSSION
.DISCUSSION...
.SHORT TERM...
MOST OF UPPER MICHIGAN EXPERIENCED A SUNNY AND MILD DAY BY LATE
NOVEMBER STANDARDS WITH TEMPERATURES RUNNING 10 TO 15 DEGREES ABOVE
NORMAL. THE ONLY EXCEPTION WAS ACROSS EASTERN AREAS WHERE LOW
CLOUDS/FOG HAVE BEEN VERY PERSISTENT ACROSS LUCE AND EASTERN
SCHOOLCRAFT COUNTIES. LOW CLOUDS/FOG WILL CONTINUE TO SLOWLY
DISSIPATE THROUGH THE REMAINDER OF THE AFTERNOON BUT STAGE WILL BE
SET FOR A REPEAT PERFORMANCE TONIGHT.
SFC HIGH CENTERED OVER THE OH VALLEY AND MID ATLANTIC STATES WILL
STILL BE THE MAIN PLAYER ACROSS THE GREAT LAKES INTO THIS EVENING.
SFC/UPPER TROF MAKING SOME PROGRESS THROUGH THE NORTHERN PLAINS WILL
AID IN TIGHTENING THE PRESSURE GRADIENT ACROSS THE AREA
TONIGHT...ESPECIALLY WESTERN SECTIONS. WITH CLEAR SKIES AND LIGHT
WINDS EARLY THIS EVENING TEMPS WILL FALL OFF QUICKLY...LIKELY
REACHING THEIR NIGHT TIME LOWS BY MID TO LATE EVENING. AFTER
THAT...SLOWLY INCREASING SOUTHERLY WINDS SHOULD LIMIT DIURNAL
COOLING. IN ADDITION...WHERE WINDS REMAIN LIGHTEST THE LONGEST IN
THE EAST...ANTICIPATE AREAS OF FOG TO DEVELOP ONCE AGAIN. FURTHER
WEST...FOG WILL NOT BE AS DENSE OR WIDESPREAD...BUT INCREASING 90H
MOISTURE WITH STRONGER SOUTHERLY WINDS JUST OFF THE SURFACE WILL
ALLOW STRATUS TO DEVELOP/MOVE INTO THE WEST TOWARDS DAYBREAK. CLOUDS
AND PERHAPS EVEN A LITTLE DRIZZLE WILL PERSIST THROUGH THE
MORNING...WITH SOME BREAKS LIKELY BY AFTERNOON IN THE EAST.
LEAD S/WV ASSOCIATED WITH NORTHERN PLAINS TROF WILL SHEAR OUT
NORTHEASTWARD LATE SUNDAY AFTERNOON AND GRAZE THE FAR WEST. WILL
MAINTAIN A LOW CHANCE POP FOR WESTERN LAKE SUPERIOR AND EXPECT MOST
AREAS WILL REMAIN DRY DURING THE DAY.
DESPITE THE CLOUDS...TEMPERATURES ON SUNDAY WILL CONTINUE TO BE WELL
ABOVE NORMAL WITH HIGHS EXPECTED IN THE MID 40S TO AROUND 50. WITH
NO SNOW EXPECTED THROUGH TOMORROW...IT LOOKS LIKE WE WILL BREAK OUR
RECORD FOR THE LEAST SNOWIEST START TO THE FALL/WINTER SEASON. IN
ADDITION...IF OUR HIGH TEMPERATURES REMAIN ABOVE 32 DEGREES THROUGH
THE 27TH WE WILL SET A RECORD FOR THE LONGEST PERIOD INTO THE FALL
SEASON WITHOUT A HIGH TEMPERATURE AT OR BELOW 32 DEGREES.
.LONGER TERM...00Z MON ONWARD...
NAM SHOWS A TROUGH IN THE NORTHERN ROCKIES 00Z MON WITH A RIDGE OVER
THE EASTERN U.S. AND CANADA. NAM THEN TAKES THE TROUGH IN THE
ROCKIES AND DIGS IT SOUTHEAST ON MON AND FORMS A CLOSED LOW IN IT
00Z TUE AND THEN CONTINUES TO DIG THE LOW AND TROUGH SOUTHEAST ON
TUE WHILE HAVING ANOTHER SHORTWAVE MOVES ACROSS SOUTHERN CANADA AT
THE SAME TIME. THIS SHORTWAVE IN SOUTHERN CANADA WILL DETERMINE WHAT
THIS SYSTEM WILL DO...WHEN IT WILL KICK OUT THE 500 MB CLOSED LOW
AND TROUGH TO THE SOUTH OF IT...IF THEY WILL MERGE OR NOT OR REMAIN
SEPARATE AND THIS IS WHAT THE MODELS HAVE BEEN HAVING A HARD TIME
FIGURING OUT THE PAST SEVERAL DAYS. WILL FOLLOW CLOSER TOWARDS THE
NAM FOR THIS FORECAST WHICH IS A BIT SLOWER AND BLEND TOWARDS THE
ECMWF LATER ON.
FRONTAL ZONE/TROUGH GETS SHEARED OUT AND WAITS FOR THIS SYSTEM TO
COME IN...BUT IN THE MEANTIME...CANNOT RULE OUT SLIGHT CHANCE POPS
ALONG AND NEAR IT ACROSS THE FAR WESTERN CWA SUN NIGHT THROUGH TUE
BEFORE THE SYSTEM COMES IN FROM THE SW. NOT REAL IMPRESSED WITH RAIN
CHANCES THOUGH AND WILL KEEP SLIGHT CHANCE POPS IN AT THIS TIME.
WILL CONTINUE TO BE MILD WITH FOG AT NIGHT ESPECIALLY OVER THE
CENTRAL AND EAST.
IN THE EXTENDED...FOLLOWED THE 00Z ECMWF FOR THIS FORECAST AS IT HAS
BEEN THE MODEL OF CHOICE FOR A WHILE. THE ECMWF HAS A CLOSED 500 MB
LOW NEAR KANSAS CITY 00Z WED WHICH GOES TO NEAR CHICAGO 00Z THU AND
TO NEAR CLEVELAND 00Z FRI. RIDGING THEN MOVES IN FOR FRI AND SAT.
WITH SYSTEM COMING UP FROM THE SOUTH AND IT HAS TO MAKE ITS OWN COLD
AIR WHICH IT MANAGES TO DO...LOOKS LIKE PCPN WILL BE MIXED WITH THIS
SYSTEM AND START OFF AS RAIN AND THEN GO TO A RAIN/SNOW MIX BEFORE
GOING OVER TO ALL SNOW THU NIGHT. ONE CHANGE IS I BUMPED POPS UP TO
LIKELY FOR WED THROUGH THU AS DEFORMATION ZONE STAYS ACROSS THE AREA
AND WE ARE IN FAVORABLE PART OF STORM TO GET WET. WENT DRY THEN FOR
FRI EXCEPT ACROSS THE EAST AS WRAPAROUND IS STILL THERE AND SAT
EVERYWHERE EVEN AS A COLD FRONT COMES THROUGH THEN. ONE THING IS
THAT THIS SYSTEM REALLY DOES NOT HAVE THAT COLD OF AIR FOR LAKE
EFFECT BEHIND IT AS ECMWF ONLY HAS -4C 850 MB AIR BEHIND IT AND LAKE
TEMPERATURES ARE RUNNING ABOUT 5C TO 6C NOW. TEMPERATURES LOOK TO
STILL STAY NORMAL OR SLIGHTLY ABOVE NORMAL THIS EXTENDED PERIOD.
&&
.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 PM LAKE SUPERIOR FORECAST ISSUANCE/...
WITH TIGHTENING PRESSURE GRADIENT OVERNIGHT TONIGHT AND
SUNDAY...COULD SEE A FEW SOUTHERLY WIND GUSTS UP TO 25 KNOTS FROM
LATE TONIGHT INTO MONDAY MORNING. 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.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...MZ
LONG TERM...07
AVIATION...JV
MARINE...MZ
000
FXUS63 KDTX 220456
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
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.
&&
.PREV DISCUSSION...ISSUED 950 PM EST SAT NOV 21 2009
UPDATE...
TREMENDOUS POST-SUNSET RADITIONAL COOLING RESULTING IN A QUICK
REDUCTION IN DEWPOINT DEPRESSIONS /ESPECIALLY NORTH/ WITH TEMPERATURES
ALREADY IN THE MID-UPPER 30S ACROSS MANY AREAS. GIVEN AMPLE BOUNDARY
LAYER MOISTURE AND THE WEAK WIND FIELD/CLEAR SKIES...SEEING THE
CORRESPONDING FOG FORMATION QUICKLY BECOME DENSE THIS EVENING.
VISIBILITY STILL HOVERS GENERALLY IN THE 2-5 MILE RANGE ACROSS
MANY AREAS SOUTH OF I-69. HOWEVER...THE SETUP POINTS TOWARD THIS
AREA REACHING ADVISORY WORTHY CONDITIONS LATER TONIGHT. AREAS TO
THE NORTH ALREADY AT THIS POINT...AND AN ADVISORY IS OUT NOW FOR
THE ENTIRE AREA THROUGH 10 AM.
ONLY OTHER UPDATE FOR TONIGHT WILL BE TO REALIGN LOWS TO BETTER
CORRELATE WITH CURRENT OBS. THIS TRANSLATES INTO AN ADJUSTMENT
DOWNWARD SLIGHTLY (GENEARLLY 2-3 DEGREES) FOR LOWS...RANGING FROM
MID 30S IN THE COLDEST LOCALES TO AROUND 40 IN DETROIT.
PREV DISCUSSION...ISSUED 317 PM EST SAT NOV 21 2009
SHORT TERM...TONIGHT
WITH SURFACE DEW POINTS STILL HOVERING IN THE LOW TO MID 40S AND
SKIES MOSTLY CLEARED OUT...FOG APPEARS TO BE A GOOD BET TONIGHT AS
ANTI-CYCLONIC FLOW BUILDS INTO LOWER MICHIGAN. EASTERLY FLOW OFF
LAKE ERIE WILL HELP CONTRIBUTE SOME ADDITIONAL MOISTURE ACROSS THE
SOUTH THIRD OF THE CWA. EVEN WITHOUT THIS MOISTURE...RELATIVELY HIGH
CROSSOVER TEMPERATURES SHOULD BE SUFFICIENT FOR FOG WITH MINS
FALLING INTO THE UPPER 30S. A QUICK REDEVELOPMENT OF THE LOW STRATUS
IS ABOUT THE ONLY FLY IN THE OINTMENT...BUT THE ONLY SIGNIFICANT
INVERSION LOOKS TO BE THE SURFACE BASED ONE AND LEANING TOWARD A FOG
SCENARIO...WHICH COULD BECOME DENSE.
LONG TERM...SUNDAY THROUGH NEXT SATURDAY
MID LEVEL RIDGING IS FORECAST TO BUILD ACROSS THE EASTERN GREAT
LAKES ON SUNDAY...ALLOWING THE HIGH NOW CENTERED OVER OHIO TO BUILD
INTO NORTHERN NEW ENGLAND. THE SURFACE HIGH AND ASSOCIATED UPPER
RIDGE IS THEN FORECAST TO SLIDE OFF THE COAST OF NEW ENGLAND ON
MONDAY...WITH SURFACE RIDGING PERSISTING ACROSS THE EASTERN GREAT
LAKES.
WITH NO APPRECIABLE ADVECTION OF LOW LEVEL DRY AIR INTO THE REGION
AND GIVEN THE LIMITED MIXING POTENTIAL THIS TIME OF YEAR...DENSE FOG
WILL BE THE MAIN WEATHER CONCERN OVER THE NEXT SEVERAL DAYS. GIVEN
THE WARM AMBIENT AIRMASS...ONCE FOG IS ABLE TO MIX OUT SUN
AFTERNOON...TEMPS SHOULD ACHIEVE THE LOWER 50S. ALTHOUGH THE LOW
LEVEL GRADIENT IS FORECAST TO INCREASE SUN NIGHT INTO TUES...THE LOW
LEVEL FLOW WILL REMAIN OFF LAKE ERIE. THIS WILL SUPPLY ADDITIONAL
LOW LEVEL MOISTURE INTO THE ALREADY MOISTURE RICH BOUNDARY LAYER.
WHILE THE TIGHTENING GRADIENT RAISES SOME CONCERNS THAT LOW STRATUS
WILL BE FAVORED OVER FOG...MODEL SOUNDINGS AND WIND SPEEDS BELOW
950MB SUGGEST ENOUGH BOUNDARY LAYER DECOUPLING TO ALLOW A CHANCE OF
FOG REDEVELOPMENT BOTH SUN NIGHT AND MONDAY NIGHT. WEAK SHALLOW COLD
AIR ADVECTION ON MONDAY AND PERSISTENT MID LEVEL SUBSIDENCE WILL
STRENGTHEN THE INVERSION. THIS MAY MAKE IT DIFFICULT FOR MORNING
FOG/STRATUS TO COMPLETELY MIX OUT DURING THE AFTERNOON. THUS...HAVE
KEPT MONDAYS MAX TEMPS MAINLY IN THE UPPER 40S.
ATTENTION THEN TURNS TO THE WEATHER SYSTEM EXPECTED TO IMPACT THE
STATE BY MID WEEK. THE 12Z MODEL SUITE CONTINUE TO SHOW MID LEVEL
TROUGH AMPLIFICATION OVER THE CENTRAL ROCKIES ON MONDAY...EVOLVING
INTO A CUT OFF CIRCULATION OVER THE CENTRAL PLAINS BY TUESDAY. BOTH
GFS AND NAM HAVE TRENDED SLOWER WITH THIS SYSTEM /MORE TOWARD THAT
OF THE ECMWF/. SATELLITE REPRESENTATION OF THIS WAVE /NOW OFF THE
COAST OF WASHINGTON STATE/ APPEARS STRONGER THAN WHAT THE GFS
INITIALIZED. THESE FACTORS SEEMS TO SUPPORT THE SLOWER ECMWF. WITH
THE WAVE STILL OFF THE COAST...MODEL CONFIDENCE IS STILL NOT HIGH.
IN LIGHT OF RECENT ECMWF TRENDS HOWEVER...THE BEST CHANCE OF RAIN
ASSOCIATED WITH THE WARM CONVEYOR BELT WILL OCCUR BETWEEN TUES NIGHT
AND WED.
AS THE SYSTEM LIFTS ACROSS MICHIGAN /ROUGHLY IN THE WED TIME PERIOD/
A SECONDARY NORTHERN STREAM WAVE IS FORECAST TO DROP INTO THE
NORTHERN PLAINS/UPPER MISSISSIPPI VALLEY FROM CANADA. THERE REMAINS
A HIGH DEGREE OF UNCERTAINTY WITH RESPECT TO TIMING AND AMPLITUDE OF
THIS WAVE AND WHETHER THERE WILL BE ANY PHASING WITH THE WAVE
PRECEDING IT. IN LIGHT OF RECENT MODEL TRENDS...A CHANCE OF
PRECIPITATION /ALBEIT LIGHT/ CONTINUES TO LOOK WARRANTED THURS
THROUGH FRIDAY. THE MAGNITUDE OF COLD AIR ADVECTION WITH THE
NORTHERN STREAM SYSTEM HAS NOT BEEN SHOWN TO BE AS STRONG OVER THE
LAST COUPLE OF MODEL CYCLES /THE COLDEST AIR NOW DOES NOT LOOK TO
ARRIVE UNTIL THURS NIGHT OR FRIDAY/. SINCE EVEN THE FASTER GFS
SOLUTION IS NOW INDICATING THAT THE COLD AIR ADVECTION WILL NOT BE
STRONG ENOUGH TO OFFSET THE DEPTH OF ABOVE FREEZING AIR IN THE
BOUNDARY LAYER...HAVE REMOVED ALL MENTION OF SNOW ON THANKSGIVING
DAY AND JUST CARRIED A MIX THURS NIGHT INTO FRIDAY.
MARINE...
HIGH PRESSURE WILL REMAIN IN PLACE OVER THE CENTRAL GREAT LAKES
THROUGH TOMORROW...RESULTING IN VERY LIGHT 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.
&S
&&
.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.....MR
UPDATE.......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 220451
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1150 PM EST SAT NOV 21 2009
.SYNOPSIS.../ISSUED AT 401 PM/
HIGH PRESSURE...WILL MAINTAIN ITS INFLUENCE OVER THE REGIONS WEATHER
THROUGH MONDAY...AS IT MOVES FROM THE OHIO VALLEY...ACROSS NEW
ENGLAND...AND INTO THE CANADIAN MARITIME PROVINCES. PATCHY FOG WILL
DEVELOP AGAIN TONIGHT...AND COULD BE BRIEFLY DENSE IN A COUPLE
SPOTS. SUNDAY AND MONDAY WILL BE SIMILAR...WITH PATCHY MORNING FOG
GRADUALLY GIVING WAY TO SUNSHINE.
THE NEXT CHANCE OF RAIN WILL BE TUESDAY...AS A STORM SYSTEM LIFTS
INTO THE UPPER MIDWEST. TEMPERATURES WILL TURN COLDER BEHIND
THIS SYSTEM. SOME PRECIPITATION WILL LINGER INTO WEDNESDAY AND
THURSDAY...AND IT COULD TURN WINTRY THANKSGIVING DAY.
ADAM
&&
.SHORT TERM.../ISSUED AT 913 PM/...OVERNIGHT
HIGH PRESSURE OVERHEAD...LINGERING LOW LEVEL MOISTURE...CLEAR SKIES
AND LIGHT WINDS ARE LEADING TO THE DEVELOPMENT OF LOW STRATUS AND
WIDESPREAD DENSE FOG LATE THIS EVENING. WILL HOIST A DENSE FOG
ADVISORY FOR THE REMAINDER OF THE NIGHT AND INTO SUNDAY MORNING
BEFORE DAYTIME MIXING RESULTS IN DISSIPATION OF THE DENSE FOG BY MID
TO LATE SUNDAY MORNING. OVERNIGHT TEMPS WILL FALL VERY LITTLE FROM
CURRENT TEMPS IN THE LOW TO MID 30S.
&&
.LONG TERM.../ISSUED AT 401 PM/...SUNDAY AND BEYOND
OUTSIDE OF SOME FOG/STRATUS ISSUES SUNDAY/MONDAY MORNINGS...THE MAIN
FORECAST ISSUES FOR THE UPCOMING WEEK WILL REVOLVE AROUND THE UPPER
LEVEL ENERGY MOVING OUT OF THE CENTRAL ROCKIES AND TOWARD THE GREAT
LAKES. MULTITUDE OF MODEL DIFFERENCES IN TIMING/STRENGTH OF
FEATURES...WITH ABOUT A 12 HOUR SPREAD BETWEEN THE FASTER/COLDER GFS
AND THE SLOWER/WARMER ECMWF. THINK THE ECMWF IS TOO SLOW GIVEN THE
LACK OF BACKSIDE JET ENERGY ON THE WESTERN EDGE OF UPPER FEATURE
TUE/WED AND WILL TAKE A BLENDED GFS/ECMWF SOLUTION.
SUNDAY-MONDAY...VERY SIMILAR ISSUES AS FRIDAY NIGHT W/ SHALLOW
/SUB-950MB/ MOISTURE...RELATIVELY WEAK LOW LEVEL FLOW AND ABUNDANT
DRY AIR ALOFT. A BIT MORE RIDGING ALOFT AND MOISTURE NOT QUITE AS
WIDESPREAD...SO FOG/STRATUS MAY BE A BIT PATCHIER THAN FRIDAY NIGHT.
OVERALL...EXPECT AREAS OF STRATUS IN NE LOWER AND EASTERN UPPER
DURING THE OVERNIGHT/EARLY MORNING HOURS. THE STRATUS WILL THIN AND
BREAK UP EACH DAY...LEADING TO AT LAST PARTLY SUNNY SKIES BY
MIDDAY.
UPPER SYSTEM MOVES INTO THE CENTRAL PLAINS ON TUESDAY...THEN TOWARD
THE WESTERN LAKES ON WEDNESDAY. EVEN WITH THE MODEL DIFFERENCES
MENTIONED PREVIOUSLY...THEY ALL AGREE ON NORTHERN MICHIGAN SITTING
IN THE WARM SECTOR OF THIS STORM THROUGH WEDNESDAY...RESULTING IN
JUST RAIN /NO SNOW/. WILL RAISE POPS TO LIKELY FOR SOME AREAS
WED/WED NIGHT GIVEN PLUME OF DEEPER 850MB THETA-E AIR SURGING
NORTHWARD INTO THE AREA ALONG WITH FAVORABLE FORCING. THE RAIN MAY
BEGIN TO CHANGE TO SNOW LATE WEDNESDAY NIGHT OVER WESTERN
AREAS/HIGHER TERRAIN AS COLDER AIR IS DRAWN SOUTHWARD ON THE
BACKSIDE OF UPPER LOW. SURFACE BASED MELT LAYERS DECREASE TOWARD
1.5K BY THANKSGIVING MORNING...WHICH IS SQUARELY ON THE RAIN/SNOW
LINE.
THANKSGIVING...COLD AIR ADVECTION CONTINUES AND THE RAIN WILL CHANGE
TO SNOW ACROSS MUCH OF THE AREA DURING THE DAY /LAKESHORE AREAS MAY
REMAIN MAINLY LIQUID/ AS UPSTREAM UPPER LEVEL ENERGY DROPS INTO THE
SOUTHERN GREAT LAKES. COMBO OF IMPRESSIVE H8-H7 OMEGA AND DEEP
MOISTURE FROM GAYLORD WEST TOWARD LAKE MICHIGAN...AND WILL GO WITH
LIKELY POPS IN THOSE AREAS. WILL HAVE TO KEEP AN EYE ON THIS
SYSTEM...AS IT HAS THE POTENTIAL TO PRODUCE A SNEAKY WINTER EVENT
FOR PARTS OF THE AREA /ACCUMULATING SNOW?/.
RISING UPPER HEIGHTS AND DRIER AIR ADVECTING INTO THE AREA FOR
FRIDAY/SATURDAY...RESULTING IN QUIET WEATHER ONCE AGAIN AS A LOW
AMPLITUDE RIDGE MOVES INTO THE GREAT LAKES.
JK
&&
.MARINE.../ISSUED AT 913 PM/
STRONG HIGH PRESSURE OVER THE GREAT LAKES/EASTERN CONUS WILL RESULT
IN FAIRLY LIGHT WINDS/MINIMAL WAVES TONIGHT. HOWEVER...LIGHT WINDS
AND LINGERING LOW LEVEL MOISTURE WILL LEAD TO WIDESPREAD DENSE FOG
DEVELOPMENT OVERNIGHT AND INTO SUNDAY MORNING. AS THE HIGH NUDGES
EASTWARD ON SUNDAY...STRONGER S/SW RETURN FLOW WILL DEVELOP THROUGH
THE DAY. BUT WINDS/WAVES EXPECTED TO REMAIN BELOW SMALL CRAFT
CRITERIA.
ADAM/RUNYAN
&&
.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 SUNDAY FOR MIZ008-015>036-
041-042.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KGRR 220426
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1130 PM EST SAT NOV 21 2009
LATEST UPDATE...AVIATION...
.SYNOPSIS...(304 PM EST SAT NOV 21 2009)
A LARGE HIGH PRESSURE SYSTEM...CENTERED OVER MICHIGAN EARLY THIS
AFTERNOON WILL SLOWLY MOVE EAST TO THE COAST BY MONDAY MORNING. THAT
WILL PUT SOUTHWEST LOWER MICHIGAN IN A SOUTHERLY FLOW OF AIR THAT
WILL KEEP TEMPERATURES WELL ABOVE NORMAL FOR THIS TIME OF YEAR.
LIGHT WINDS AND MOSTLY CLEAR SKIES DURING THIS EVENING AND SUNDAY
EVENING WILL ALLOW FOR FOG TO FORM AFTER MIDNIGHT TONIGHT AND SUNDAY
NIGHT. A COLD FRONT AND ASSOCIATED STORM SYSTEM WILL BRING RAIN AND
COOLER WEATHER TOWARD MIDWEEK. SOME WET SNOW MAY MIX IN BY WEDNESDAY.
&&
.SHORT TERM...(930 PM EST SAT NOV 21 2009)
(TONIGHT THROUGH MONDAY NIGHT)
WE WILL ISSUE A DENSE FOG ADVISORY FOR OUR ENTIRE CWFA VALID FROM
03Z THIS EVENING THROUGH 15Z SUNDAY. AT 02Z SFC OBS FROM ACROSS LWR
MI INDICATE THAT FOG IS GRADUALLY BECOMING MORE DENSE AND WIDESPREAD.
CLEAR SKIES AND CALM WINDS WILL ALLOW FOG TO CONTINUE TO BECOME MORE
DENSE AND WIDESPREAD OVERNIGHT AS SUGGESTED BY MUCH OF OUR LATEST
NUMERICAL GUIDANCE AND TRENDS IN SFC VISBYS ACROSS OUR CWFA.
REMAINDER OF PREVIOUS SHORT TERM FCST DISCUSSION FOLLOWS... THE
COMBINATION OF LIGHT WINDS TONIGHT AND MOSTLY CLEAR SKIES WILL ALLOW
FOR A CONSIDERABLE AMOUNT OF FOG BY MORNING. OUR FOG PLOT PROCEDURE
INDICATES DENSE FOG ACROSS THE AREA OVERNIGHT. I COULD SEE A STRATUS
DECK FORMING BY SUNRISE.
THE HIGH MOVES TO OUR EAST SUNDAY SO A SOUTHERLY FLOW WILL BECOME
A LITTLE STRONGER (MEAN WIND SURFACE TO 1000 FT AGL 240/04 KNOTS AT
200 PM TODAY COMPARED TO 150/08KT SUNDAY AT 2 PM). ONCE THE LOW
CLOUDS AND FOG BURN OFF IT SHOULD BE A SUNNY DAY ON SUNDAY.
WINDS WILL BE STRONGER IN THE BOUNDARY LAYER SUNDAY NIGHT...STILL IT
WOULD SEEM WITH THE LOW LEVEL MOISTURE INCREASING AND NEARLY CLEAR
SKIES DURING THE EVENING...FOG AND STRATUS WOULD BE A GOOD BET
AGAIN.
MONDAY INTO MONDAY NIGHT A SYSTEM WILL BE PASSING TO OUR SOUTHEAST.
THAT WILL BRING IN SOME MID CLOUDS BUT NOT MUCH ELSE.
&&
.LONG TERM...(304 PM EST SAT NOV 21 2009)
(TUESDAY THROUGH SATURDAY)
WE DIDN/T CHANGE THE FORECAST TOO MUCH. ECMWF/GFS CONTINUE TO SHOW
AN INTRUSION OF COLDER AIR INTO THE GREAT LAKES NEXT WEEK. BUT THE
TREND HAS BEEN TO WRAP THE COLD AIR AROUND THE DEPARTING LOW WITH
THE RESULT BEING THE COLDEST AIR FLOWING SOUTHWEST OF THE CWA. EVEN
SO WE STILL MAY SEE SOME WET SNOW DURING THE END OF THE PERIOD.
RAIN SHOULD DEVELOP TUESDAY IN ADVANCE OF AN OCCLUDING LOW THAT WILL
MOVE FROM THE PLAINS TOWARD LAKE MICHIGAN. THOSE SHOWERS WILL LINGER
INTO WEDNESDAY. A SECOND STRONGER WAVE WILL KICK THE FIRST ONE OUT
AND BRING DOWN THE COLDER AIR FROM CANADA. H8 TEMPS WILL SLOWLY FALL
FROM -2C TO PERHAPS -5C FROM WEDNESDAY THROUGH LATE FRIDAY. THE
COLDEST AIR LOOKS LIKE IT WILL BE ON FRIDAY AS THE THE UPPER LOW
MOVES AWAY SO THAT IS WHEN WE/LL HAVE THE GREATEST CHANCE OF SEEING
SOME SNOW. WE/LL SEE A WARMING TREND BEGIN SATURDAY AS THE LOW PULLS
AWAY.
&&
.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...(304 PM EST SAT NOV 21 2009)
EVEN WITH THE SURFACE HIGH MOVING EAST OF THE AREA BY SUNDAY WINDS
ARE NOT EXPECTED TO BECOME STRONG ENOUGH FOR SMALL CRAFT ADVISORIES
TO BE ISSUES (WAVE HEIGHTS WILL STAY BELOW 4 FEET). AREA OF FOG
ARE EXPECTED DURING THE MORNING HOURS OF SUNDAY AND MONDAY.
&&
.HYDROLOGY...(304 PM EST SAT NOV 21 2009)
NO PRECIPITATION EXPECTED THROUGH MONDAY. NO HYDRO ISSUES ARE
EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...DENSE FOG ADVISORY FOR OUR ENTIRE CWFA THROUGH 10 AM SUNDAY.
LM...NONE.
&&
$$
SYNOPSIS: WDM
SHORT TERM: WDM/LAURENS
LONG TERM: 93
AVIATION: LAURENS
MARINE: WDM
HYDROLOGY: WDM
000
FXUS63 KGRR 220305
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1000 PM EST SAT NOV 21 2009
LATEST UPDATE...AVIATION...
.SYNOPSIS...(304 PM EST SAT NOV 21 2009)
A LARGE HIGH PRESSURE SYSTEM...CENTERED OVER MICHIGAN EARLY THIS
AFTERNOON WILL SLOWLY MOVE EAST TO THE COAST BY MONDAY MORNING. THAT
WILL PUT SOUTHWEST LOWER MICHIGAN IN A SOUTHERLY FLOW OF AIR THAT
WILL KEEP TEMPERATURES WELL ABOVE NORMAL FOR THIS TIME OF YEAR.
LIGHT WINDS AND MOSTLY CLEAR SKIES DURING THIS EVENING AND SUNDAY
EVENING WILL ALLOW FOR FOG TO FORM AFTER MIDNIGHT TONIGHT AND SUNDAY
NIGHT. A COLD FRONT AND ASSOCIATED STORM SYSTEM WILL BRING RAIN AND
COOLER WEATHER TOWARD MIDWEEK. SOME WET SNOW MAY MIX IN BY WEDNESDAY.
&&
.SHORT TERM...(930 PM EST SAT NOV 21 2009)
(TONIGHT THROUGH MONDAY NIGHT)
WE WILL ISSUE A DENSE FOG ADVISORY FOR OUR ENTIRE CWFA VALID FROM
03Z THIS EVENING THROUGH 15Z SUNDAY. AT 02Z SFC OBS FROM ACROSS LWR
MI INDICATE THAT FOG IS GRADUALLY BECOMING MORE DENSE AND WIDESPREAD.
CLEAR SKIES AND CALM WINDS WILL ALLOW FOG TO CONTINUE TO BECOME MORE
DENSE AND WIDESPREAD OVERNIGHT AS SUGGESTED BY MUCH OF OUR LATEST
NUMERICAL GUIDANCE AND TRENDS IN SFC VISBYS ACROSS OUR CWFA.
REMAINDER OF PREVIOUS SHORT TERM FCST DISCUSSION FOLLOWS... THE
COMBINATION OF LIGHT WINDS TONIGHT AND MOSTLY CLEAR SKIES WILL ALLOW
FOR A CONSIDERABLE AMOUNT OF FOG BY MORNING. OUR FOG PLOT PROCEDURE
INDICATES DENSE FOG ACROSS THE AREA OVERNIGHT. I COULD SEE A STRATUS
DECK FORMING BY SUNRISE.
THE HIGH MOVES TO OUR EAST SUNDAY SO A SOUTHERLY FLOW WILL BECOME
A LITTLE STRONGER (MEAN WIND SURFACE TO 1000 FT AGL 240/04 KNOTS AT
200 PM TODAY COMPARED TO 150/08KT SUNDAY AT 2 PM). ONCE THE LOW
CLOUDS AND FOG BURN OFF IT SHOULD BE A SUNNY DAY ON SUNDAY.
WINDS WILL BE STRONGER IN THE BOUNDARY LAYER SUNDAY NIGHT...STILL IT
WOULD SEEM WITH THE LOW LEVEL MOISTURE INCREASING AND NEARLY CLEAR
SKIES DURING THE EVENING...FOG AND STRATUS WOULD BE A GOOD BET
AGAIN.
MONDAY INTO MONDAY NIGHT A SYSTEM WILL BE PASSING TO OUR SOUTHEAST.
THAT WILL BRING IN SOME MID CLOUDS BUT NOT MUCH ELSE.
&&
.LONG TERM...(304 PM EST SAT NOV 21 2009)
(TUESDAY THROUGH SATURDAY)
WE DIDN/T CHANGE THE FORECAST TOO MUCH. ECMWF/GFS CONTINUE TO SHOW
AN INTRUSION OF COLDER AIR INTO THE GREAT LAKES NEXT WEEK. BUT THE
TREND HAS BEEN TO WRAP THE COLD AIR AROUND THE DEPARTING LOW WITH
THE RESULT BEING THE COLDEST AIR FLOWING SOUTHWEST OF THE CWA. EVEN
SO WE STILL MAY SEE SOME WET SNOW DURING THE END OF THE PERIOD.
RAIN SHOULD DEVELOP TUESDAY IN ADVANCE OF AN OCCLUDING LOW THAT WILL
MOVE FROM THE PLAINS TOWARD LAKE MICHIGAN. THOSE SHOWERS WILL LINGER
INTO WEDNESDAY. A SECOND STRONGER WAVE WILL KICK THE FIRST ONE OUT
AND BRING DOWN THE COLDER AIR FROM CANADA. H8 TEMPS WILL SLOWLY FALL
FROM -2C TO PERHAPS -5C FROM WEDNESDAY THROUGH LATE FRIDAY. THE
COLDEST AIR LOOKS LIKE IT WILL BE ON FRIDAY AS THE THE UPPER LOW
MOVES AWAY SO THAT IS WHEN WE/LL HAVE THE GREATEST CHANCE OF SEEING
SOME SNOW. WE/LL SEE A WARMING TREND BEGIN SATURDAY AS THE LOW PULLS
AWAY.
&&
.AVIATION...(1000 PM EST SAT NOV 21 2009)
FOG IS QUICKLY DEVELOPING AND BECOMING MORE DENSE AND WIDESPREAD
ACROSS LWR MI. VISBYS HAVE ALREADY DROPPED TO A QUARTER OF A MILE OR
LESS AT MKG AND ARE ALSO TRENDING DOWNWARD AT ALL THE REST OF OUR
TAF SITES.
WE EXPECT VLIFR CONDITIONS TO CONTINUE AT MKG OVERNIGHT THROUGH MID
MORNING SUNDAY IN DENSE FOG. IFR TO MVFR CONDITIONS AT THE REST OF
OUR TAF SITES DURING THE NEXT HOUR OR TWO WILL DETERIORATE INTO THE
IFR TO VLIFR FLIGHT CATEGORY AFTER MIDNIGHT AS THE FOG CONTINUES TO
BECOME MORE DENSE AND WIDESPREAD.
CLEAR SKIES AND CALM WINDS WITH HIGH PRESSURE OVERHEAD AND LINGERING
LOW LEVEL MOISTURE IN PLACE HAVE LED TO THE FOG DEVELOPMENT. FOG
WILL LINGER THROUGH MID MORNING SUNDAY AT ALL TAF SITES BEFORE
DISSIPATING.
&&
.MARINE...(304 PM EST SAT NOV 21 2009)
EVEN WITH THE SURFACE HIGH MOVING EAST OF THE AREA BY SUNDAY WINDS
ARE NOT EXPECTED TO BECOME STRONG ENOUGH FOR SMALL CRAFT ADVISORIES
TO BE ISSUES (WAVE HEIGHTS WILL STAY BELOW 4 FEET). AREA OF FOG
ARE EXPECTED DURING THE MORNING HOURS OF SUNDAY AND MONDAY.
&&
.HYDROLOGY...(304 PM EST SAT NOV 21 2009)
NO PRECIPITATION EXPECTED THROUGH MONDAY. NO HYDRO ISSUES ARE
EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...DENSE FOG ADVISORY FOR OUR ENTIRE CWFA FROM 10 PM THIS EVENING
THROUGH 10 AM SUNDAY.
LM...NONE.
&&
$$
SYNOPSIS: WDM
SHORT TERM: WDM/LAURENS
LONG TERM: 93
AVIATION: LAURENS
MARINE: WDM
HYDROLOGY: WDM
000
FXUS63 KDTX 220250
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
950 PM EST SAT NOV 21 2009
.UPDATE...
TREMENDOUS POST-SUNSET RADITIONAL COOLING RESULTING IN A QUICK
REDUCTION IN DEWPOINT DEPRESSIONS /ESPECIALLY NORTH/ WITH TEMPERATURES
ALREADY IN THE MID-UPPER 30S ACROSS MANY AREAS. GIVEN AMPLE BOUNDARY
LAYER MOISTURE AND THE WEAK WIND FIELD/CLEAR SKIES...SEEING THE
CORRESPONDING FOG FORMATION QUICKLY BECOME DENSE THIS EVENING.
VISIBILITY STILL HOVERS GENERALLY IN THE 2-5 MILE RANGE ACROSS
MANY AREAS SOUTH OF I-69. HOWEVER...THE SETUP POINTS TOWARD THIS
AREA REACHING ADVISORY WORTHY CONDITIONS LATER TONIGHT. AREAS TO
THE NORTH ALREADY AT THIS POINT...AND AN ADVISORY IS OUT NOW FOR
THE ENTIRE AREA THROUGH 10 AM.
ONLY OTHER UPDATE FOR TONIGHT WILL BE TO REALIGN LOWS TO BETTER
CORRELATE WITH CURRENT OBS. THIS TRANSLATES INTO AN ADJUSTMENT
DOWNWARD SLIGHTLY (GENEARLLY 2-3 DEGREES) FOR LOWS...RANGING FROM
MID 30S IN THE COLDEST LOCALES TO AROUND 40 IN DETROIT.
&&
.PREV DISCUSSION...ISSUED 652 PM EST SAT NOV 21 2009
AVIATION...
MIXING PROVED SUFFICIENT ENOUGH TO SCATTER OUT THE STRATUS DECK THIS
AFTERNOON. HOWEVER...A COOLING BOUNDARY LAYER WITH ALLOW THE COLUMN
TO SATURATE AGAIN BENEATH A STRENGTHENING RADIATION INVERSION
OVERNIGHT. LATEST OBSERVATIONS DISPLAYING THIS NOW IN THE FORM OF
SCATTERED MVFR STRATUS DEVELOPMENT. THE MOIST BOUNDARY LAYER
CONDITIONS AND DECOUPLING WIND FIELD WILL FAVOR AN EXPANSION OF
STRATUS/FOG THROUGHOUT THE NIGHT. MODEL SOUNDINGS INDICATE AN
INVERSION THAT BECOMES MORE SURFACE BASED...AND GIVEN THE WIND FIELD
WILL FAVOR MORE FOG THAN STRATUS...ALTHOUGH IN EITHER CASE THE
POTENTIAL EXISTS FOR A PERIOD OF LIFR WITHIN THE 09Z-14Z WINDOW.
MOISTURE WILL SLOWLY MIX OUT AGAIN THROUGH THE LATE MORNING/EARLY
AFTERNOON.
PREV DISCUSSION...ISSUED 317 PM EST SAT NOV 21 2009
SHORT TERM...TONIGHT
WITH SURFACE DEW POINTS STILL HOVERING IN THE LOW TO MID 40S AND
SKIES MOSTLY CLEARED OUT...FOG APPEARS TO BE A GOOD BET TONIGHT AS
ANTI-CYCLONIC FLOW BUILDS INTO LOWER MICHIGAN. EASTERLY FLOW OFF
LAKE ERIE WILL HELP CONTRIBUTE SOME ADDITIONAL MOISTURE ACROSS THE
SOUTH THIRD OF THE CWA. EVEN WITHOUT THIS MOISTURE...RELATIVELY HIGH
CROSSOVER TEMPERATURES SHOULD BE SUFFICIENT FOR FOG WITH MINS
FALLING INTO THE UPPER 30S. A QUICK REDEVELOPMENT OF THE LOW STRATUS
IS ABOUT THE ONLY FLY IN THE OINTMENT...BUT THE ONLY SIGNIFICANT
INVERSION LOOKS TO BE THE SURFACE BASED ONE AND LEANING TOWARD A FOG
SCENARIO...WHICH COULD BECOME DENSE.
LONG TERM...SUNDAY THROUGH NEXT SATURDAY
MID LEVEL RIDGING IS FORECAST TO BUILD ACROSS THE EASTERN GREAT
LAKES ON SUNDAY...ALLOWING THE HIGH NOW CENTERED OVER OHIO TO BUILD
INTO NORTHERN NEW ENGLAND. THE SURFACE HIGH AND ASSOCIATED UPPER
RIDGE IS THEN FORECAST TO SLIDE OFF THE COAST OF NEW ENGLAND ON
MONDAY...WITH SURFACE RIDGING PERSISTING ACROSS THE EASTERN GREAT
LAKES.
WITH NO APPRECIABLE ADVECTION OF LOW LEVEL DRY AIR INTO THE REGION
AND GIVEN THE LIMITED MIXING POTENTIAL THIS TIME OF YEAR...DENSE FOG
WILL BE THE MAIN WEATHER CONCERN OVER THE NEXT SEVERAL DAYS. GIVEN
THE WARM AMBIENT AIRMASS...ONCE FOG IS ABLE TO MIX OUT SUN
AFTERNOON...TEMPS SHOULD ACHIEVE THE LOWER 50S. ALTHOUGH THE LOW
LEVEL GRADIENT IS FORECAST TO INCREASE SUN NIGHT INTO TUES...THE LOW
LEVEL FLOW WILL REMAIN OFF LAKE ERIE. THIS WILL SUPPLY ADDITIONAL
LOW LEVEL MOISTURE INTO THE ALREADY MOISTURE RICH BOUNDARY LAYER.
WHILE THE TIGHTENING GRADIENT RAISES SOME CONCERNS THAT LOW STRATUS
WILL BE FAVORED OVER FOG...MODEL SOUNDINGS AND WIND SPEEDS BELOW
950MB SUGGEST ENOUGH BOUNDARY LAYER DECOUPLING TO ALLOW A CHANCE OF
FOG REDEVELOPMENT BOTH SUN NIGHT AND MONDAY NIGHT. WEAK SHALLOW COLD
AIR ADVECTION ON MONDAY AND PERSISTENT MID LEVEL SUBSIDENCE WILL
STRENGTHEN THE INVERSION. THIS MAY MAKE IT DIFFICULT FOR MORNING
FOG/STRATUS TO COMPLETELY MIX OUT DURING THE AFTERNOON. THUS...HAVE
KEPT MONDAYS MAX TEMPS MAINLY IN THE UPPER 40S.
ATTENTION THEN TURNS TO THE WEATHER SYSTEM EXPECTED TO IMPACT THE
STATE BY MID WEEK. THE 12Z MODEL SUITE CONTINUE TO SHOW MID LEVEL
TROUGH AMPLIFICATION OVER THE CENTRAL ROCKIES ON MONDAY...EVOLVING
INTO A CUT OFF CIRCULATION OVER THE CENTRAL PLAINS BY TUESDAY. BOTH
GFS AND NAM HAVE TRENDED SLOWER WITH THIS SYSTEM /MORE TOWARD THAT
OF THE ECMWF/. SATELLITE REPRESENTATION OF THIS WAVE /NOW OFF THE
COAST OF WASHINGTON STATE/ APPEARS STRONGER THAN WHAT THE GFS
INITIALIZED. THESE FACTORS SEEMS TO SUPPORT THE SLOWER ECMWF. WITH
THE WAVE STILL OFF THE COAST...MODEL CONFIDENCE IS STILL NOT HIGH.
IN LIGHT OF RECENT ECMWF TRENDS HOWEVER...THE BEST CHANCE OF RAIN
ASSOCIATED WITH THE WARM CONVEYOR BELT WILL OCCUR BETWEEN TUES NIGHT
AND WED.
AS THE SYSTEM LIFTS ACROSS MICHIGAN /ROUGHLY IN THE WED TIME PERIOD/
A SECONDARY NORTHERN STREAM WAVE IS FORECAST TO DROP INTO THE
NORTHERN PLAINS/UPPER MISSISSIPPI VALLEY FROM CANADA. THERE REMAINS
A HIGH DEGREE OF UNCERTAINTY WITH RESPECT TO TIMING AND AMPLITUDE OF
THIS WAVE AND WHETHER THERE WILL BE ANY PHASING WITH THE WAVE
PRECEDING IT. IN LIGHT OF RECENT MODEL TRENDS...A CHANCE OF
PRECIPITATION /ALBEIT LIGHT/ CONTINUES TO LOOK WARRANTED THURS
THROUGH FRIDAY. THE MAGNITUDE OF COLD AIR ADVECTION WITH THE
NORTHERN STREAM SYSTEM HAS NOT BEEN SHOWN TO BE AS STRONG OVER THE
LAST COUPLE OF MODEL CYCLES /THE COLDEST AIR NOW DOES NOT LOOK TO
ARRIVE UNTIL THURS NIGHT OR FRIDAY/. SINCE EVEN THE FASTER GFS
SOLUTION IS NOW INDICATING THAT THE COLD AIR ADVECTION WILL NOT BE
STRONG ENOUGH TO OFFSET THE DEPTH OF ABOVE FREEZING AIR IN THE
BOUNDARY LAYER...HAVE REMOVED ALL MENTION OF SNOW ON THANKSGIVING
DAY AND JUST CARRIED A MIX THURS NIGHT INTO FRIDAY.
MARINE...
HIGH PRESSURE WILL REMAIN IN PLACE OVER THE CENTRAL GREAT LAKES
THROUGH TOMORROW...RESULTING IN VERY LIGHT 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.
&S
&&
.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.
&&
$$
UPDATE.......MR
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 KGRR 220231
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
930 PM EST SAT NOV 21 2009
LATEST UPDATE...SHORT TERM...
.SYNOPSIS...(304 PM EST SAT NOV 21 2009)
A LARGE HIGH PRESSURE SYSTEM...CENTERED OVER MICHIGAN EARLY THIS
AFTERNOON WILL SLOWLY MOVE EAST TO THE COAST BY MONDAY MORNING. THAT
WILL PUT SOUTHWEST LOWER MICHIGAN IN A SOUTHERLY FLOW OF AIR THAT
WILL KEEP TEMPERATURES WELL ABOVE NORMAL FOR THIS TIME OF YEAR.
LIGHT WINDS AND MOSTLY CLEAR SKIES DURING THIS EVENING AND SUNDAY
EVENING WILL ALLOW FOR FOG TO FORM AFTER MIDNIGHT TONIGHT AND SUNDAY
NIGHT. A COLD FRONT AND ASSOCIATED STORM SYSTEM WILL BRING RAIN AND
COOLER WEATHER TOWARD MIDWEEK. SOME WET SNOW MAY MIX IN BY WEDNESDAY.
&&
.SHORT TERM...(930 PM EST SAT NOV 21 2009)
(TONIGHT THROUGH MONDAY NIGHT)
WE WILL ISSUE A DENSE FOG ADVISORY FOR OUR ENTIRE CWFA VALID FROM
03Z THIS EVENING THROUGH 15Z SUNDAY. AT 02Z SFC OBS FROM ACROSS LWR
MI INDICATE THAT FOG IS GRADUALLY BECOMING MORE DENSE AND WIDESPREAD.
CLEAR SKIES AND CALM WINDS WILL ALLOW FOG TO CONTINUE TO BECOME MORE
DENSE AND WIDESPREAD OVERNIGHT AS SUGGESTED BY MUCH OF OUR LATEST
NUMERICAL GUIDANCE AND TRENDS IN SFC VISBYS ACROSS OUR CWFA.
REMAINDER OF PREVIOUS SHORT TERM FCST DISCUSSION FOLLOWS... THE
COMBINATION OF LIGHT WINDS TONIGHT AND MOSTLY CLEAR SKIES WILL ALLOW
FOR A CONSIDERABLE AMOUNT OF FOG BY MORNING. OUR FOG PLOT PROCEDURE
INDICATES DENSE FOG ACROSS THE AREA OVERNIGHT. I COULD SEE A STRATUS
DECK FORMING BY SUNRISE.
THE HIGH MOVES TO OUR EAST SUNDAY SO A SOUTHERLY FLOW WILL BECOME
A LITTLE STRONGER (MEAN WIND SURFACE TO 1000 FT AGL 240/04 KNOTS AT
200 PM TODAY COMPARED TO 150/08KT SUNDAY AT 2 PM). ONCE THE LOW
CLOUDS AND FOG BURN OFF IT SHOULD BE A SUNNY DAY ON SUNDAY.
WINDS WILL BE STRONGER IN THE BOUNDARY LAYER SUNDAY NIGHT...STILL IT
WOULD SEEM WITH THE LOW LEVEL MOISTURE INCREASING AND NEARLY CLEAR
SKIES DURING THE EVENING...FOG AND STRATUS WOULD BE A GOOD BET
AGAIN.
MONDAY INTO MONDAY NIGHT A SYSTEM WILL BE PASSING TO OUR SOUTHEAST.
THAT WILL BRING IN SOME MID CLOUDS BUT NOT MUCH ELSE.
&&
.LONG TERM...(304 PM EST SAT NOV 21 2009)
(TUESDAY THROUGH SATURDAY)
WE DIDN/T CHANGE THE FORECAST TOO MUCH. ECMWF/GFS CONTINUE TO SHOW
AN INTRUSION OF COLDER AIR INTO THE GREAT LAKES NEXT WEEK. BUT THE
TREND HAS BEEN TO WRAP THE COLD AIR AROUND THE DEPARTING LOW WITH
THE RESULT BEING THE COLDEST AIR FLOWING SOUTHWEST OF THE CWA. EVEN
SO WE STILL MAY SEE SOME WET SNOW DURING THE END OF THE PERIOD.
RAIN SHOULD DEVELOP TUESDAY IN ADVANCE OF AN OCCLUDING LOW THAT WILL
MOVE FROM THE PLAINS TOWARD LAKE MICHIGAN. THOSE SHOWERS WILL LINGER
INTO WEDNESDAY. A SECOND STRONGER WAVE WILL KICK THE FIRST ONE OUT
AND BRING DOWN THE COLDER AIR FROM CANADA. H8 TEMPS WILL SLOWLY FALL
FROM -2C TO PERHAPS -5C FROM WEDNESDAY THROUGH LATE FRIDAY. THE
COLDEST AIR LOOKS LIKE IT WILL BE ON FRIDAY AS THE THE UPPER LOW
MOVES AWAY SO THAT IS WHEN WE/LL HAVE THE GREATEST CHANCE OF SEEING
SOME SNOW. WE/LL SEE A WARMING TREND BEGIN SATURDAY AS THE LOW PULLS
AWAY.
&&
.AVIATION...(625 PM EST SAT NOV 21 2009)
HIGH PRESSURE OVERHEAD TONIGHT AND CLEAR SKIES AND CALM WINDS WILL
RESULT IN FOG FORMING. EXPECT VSBYS WILL BE FALLING TO LESS THAN A
MILE LATE TONIGHT. THE FOG WILL LIFT DURING THE MORNING HOURS WITH
VFR EXPECTED BY SUNDAY AFTERNOON.
&&
.MARINE...(304 PM EST SAT NOV 21 2009)
EVEN WITH THE SURFACE HIGH MOVING EAST OF THE AREA BY SUNDAY WINDS
ARE NOT EXPECTED TO BECOME STRONG ENOUGH FOR SMALL CRAFT ADVISORIES
TO BE ISSUES (WAVE HEIGHTS WILL STAY BELOW 4 FEET). AREA OF FOG
ARE EXPECTED DURING THE MORNING HOURS OF SUNDAY AND MONDAY.
&&
.HYDROLOGY...(304 PM EST SAT NOV 21 2009)
NO PRECIPITATION EXPECTED THROUGH MONDAY. NO HYDRO ISSUES ARE
EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...DENSE FOG ADVISORY FOR OUR ENTIRE CWFA FROM 10 PM THIS EVENING
THROUGH 10 AM SUNDAY.
LM...NONE.
&&
$$
SYNOPSIS: WDM
SHORT TERM: WDM/LAURENS
LONG TERM: 93
AVIATION: OSTUNO
MARINE: WDM
HYDROLOGY: WDM
000
FXUS63 KAPX 220213
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
913 PM EST SAT NOV 21 2009
.SYNOPSIS.../ISSUED AT 401 PM/
HIGH PRESSURE...WILL MAINTAIN ITS INFLUENCE OVER THE REGIONS WEATHER
THROUGH MONDAY...AS IT MOVES FROM THE OHIO VALLEY...ACROSS NEW
ENGLAND...AND INTO THE CANADIAN MARITIME PROVINCES. PATCHY FOG WILL
DEVELOP AGAIN TONIGHT...AND COULD BE BRIEFLY DENSE IN A COUPLE
SPOTS. SUNDAY AND MONDAY WILL BE SIMILAR...WITH PATCHY MORNING FOG
GRADUALLY GIVING WAY TO SUNSHINE.
THE NEXT CHANCE OF RAIN WILL BE TUESDAY...AS A STORM SYSTEM LIFTS
INTO THE UPPER MIDWEST. TEMPERATURES WILL TURN COLDER BEHIND
THIS SYSTEM. SOME PRECIPITATION WILL LINGER INTO WEDNESDAY AND
THURSDAY...AND IT COULD TURN WINTRY THANKSGIVING DAY.
ADAM
&&
.SHORT TERM.../ISSUED AT 913 PM/...OVERNIGHT
HIGH PRESSURE OVERHEAD...LINGERING LOW LEVEL MOISTURE...CLEAR SKIES
AND LIGHT WINDS ARE LEADING TO THE DEVELOPMENT OF LOW STRATUS AND
WIDESPREAD DENSE FOG LATE THIS EVENING. WILL HOIST A DENSE FOG
ADVISORY FOR THE REMAINDER OF THE NIGHT AND INTO SUNDAY MORNING
BEFORE DAYTIME MIXING RESULTS IN DISSIPATION OF THE DENSE FOG BY MID
TO LATE SUNDAY MORNING. OVERNIGHT TEMPS WILL FALL VERY LITTLE FROM
CURRENT TEMPS IN THE LOW TO MID 30S.
&&
.LONG TERM.../ISSUED AT 401 PM/...SUNDAY AND BEYOND
OUTSIDE OF SOME FOG/STRATUS ISSUES SUNDAY/MONDAY MORNINGS...THE MAIN
FORECAST ISSUES FOR THE UPCOMING WEEK WILL REVOLVE AROUND THE UPPER
LEVEL ENERGY MOVING OUT OF THE CENTRAL ROCKIES AND TOWARD THE GREAT
LAKES. MULTITUDE OF MODEL DIFFERENCES IN TIMING/STRENGTH OF
FEATURES...WITH ABOUT A 12 HOUR SPREAD BETWEEN THE FASTER/COLDER GFS
AND THE SLOWER/WARMER ECMWF. THINK THE ECMWF IS TOO SLOW GIVEN THE
LACK OF BACKSIDE JET ENERGY ON THE WESTERN EDGE OF UPPER FEATURE
TUE/WED AND WILL TAKE A BLENDED GFS/ECMWF SOLUTION.
SUNDAY-MONDAY...VERY SIMILAR ISSUES AS FRIDAY NIGHT W/ SHALLOW
/SUB-950MB/ MOISTURE...RELATIVELY WEAK LOW LEVEL FLOW AND ABUNDANT
DRY AIR ALOFT. A BIT MORE RIDGING ALOFT AND MOISTURE NOT QUITE AS
WIDESPREAD...SO FOG/STRATUS MAY BE A BIT PATCHIER THAN FRIDAY NIGHT.
OVERALL...EXPECT AREAS OF STRATUS IN NE LOWER AND EASTERN UPPER
DURING THE OVERNIGHT/EARLY MORNING HOURS. THE STRATUS WILL THIN AND
BREAK UP EACH DAY...LEADING TO AT LAST PARTLY SUNNY SKIES BY
MIDDAY.
UPPER SYSTEM MOVES INTO THE CENTRAL PLAINS ON TUESDAY...THEN TOWARD
THE WESTERN LAKES ON WEDNESDAY. EVEN WITH THE MODEL DIFFERENCES
MENTIONED PREVIOUSLY...THEY ALL AGREE ON NORTHERN MICHIGAN SITTING
IN THE WARM SECTOR OF THIS STORM THROUGH WEDNESDAY...RESULTING IN
JUST RAIN /NO SNOW/. WILL RAISE POPS TO LIKELY FOR SOME AREAS
WED/WED NIGHT GIVEN PLUME OF DEEPER 850MB THETA-E AIR SURGING
NORTHWARD INTO THE AREA ALONG WITH FAVORABLE FORCING. THE RAIN MAY
BEGIN TO CHANGE TO SNOW LATE WEDNESDAY NIGHT OVER WESTERN
AREAS/HIGHER TERRAIN AS COLDER AIR IS DRAWN SOUTHWARD ON THE
BACKSIDE OF UPPER LOW. SURFACE BASED MELT LAYERS DECREASE TOWARD
1.5K BY THANKSGIVING MORNING...WHICH IS SQUARELY ON THE RAIN/SNOW
LINE.
THANKSGIVING...COLD AIR ADVECTION CONTINUES AND THE RAIN WILL CHANGE
TO SNOW ACROSS MUCH OF THE AREA DURING THE DAY /LAKESHORE AREAS MAY
REMAIN MAINLY LIQUID/ AS UPSTREAM UPPER LEVEL ENERGY DROPS INTO THE
SOUTHERN GREAT LAKES. COMBO OF IMPRESSIVE H8-H7 OMEGA AND DEEP
MOISTURE FROM GAYLORD WEST TOWARD LAKE MICHIGAN...AND WILL GO WITH
LIKELY POPS IN THOSE AREAS. WILL HAVE TO KEEP AN EYE ON THIS
SYSTEM...AS IT HAS THE POTENTIAL TO PRODUCE A SNEAKY WINTER EVENT
FOR PARTS OF THE AREA /ACCUMULATING SNOW?/.
RISING UPPER HEIGHTS AND DRIER AIR ADVECTING INTO THE AREA FOR
FRIDAY/SATURDAY...RESULTING IN QUIET WEATHER ONCE AGAIN AS A LOW
AMPLITUDE RIDGE MOVES INTO THE GREAT LAKES.
JK
&&
.MARINE.../ISSUED AT 913 PM/
STRONG HIGH PRESSURE OVER THE GREAT LAKES/EASTERN CONUS WILL RESULT
IN FAIRLY LIGHT WINDS/MINIMAL WAVES TONIGHT. HOWEVER...LIGHT WINDS
AND LINGERING LOW LEVEL MOISTURE WILL LEAD TO WIDESPREAD DENSE FOG
DEVELOPMENT OVERNIGHT AND INTO SUNDAY MORNING. AS THE HIGH NUDGES
EASTWARD ON SUNDAY...STRONGER S/SW RETURN FLOW WILL DEVELOP THROUGH
THE DAY. BUT WINDS/WAVES EXPECTED TO REMAIN BELOW SMALL CRAFT
CRITERIA.
ADAM/RUNYAN
&&
.AVIATION.../ISSUED AT 600 PM/...VALID FOR 00Z TAFS
LOW STRATUS/IFR/LIFR CIGS EXPECTED TO REDEVELOP TONIGHT...
PARTICULARLY AT APN. HOWEVER...FORECAST SOUNDINGS/SLIGHTLY DRIER AIR
OVERSPREADING THE REGION SHOULD PRECLUDE WIDESPREAD DENSE FOG
DEVELOPMENT. WHATEVER STRATUS/FOG DEVELOPS WILL MIX OUT AGAIN ON
SUNDAY...LEAVING VFR CONDITIONS FOR MUCH OF THE DAY.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...DENSE FOG ADVISORY UNTIL 10 AM EST SUNDAY FOR MIZ008-015>036-
041-042.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KMQT 220029 AAA
AFDMQT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MARQUETTE MI
729 PM EST SAT NOV 21 2009
UPDATED FOR 00Z AVIATION DISCUSSION
.DISCUSSION...
.SHORT TERM...
MOST OF UPPER MICHIGAN EXPERIENCED A SUNNY AND MILD DAY BY LATE
NOVEMBER STANDARDS WITH TEMPERATURES RUNNING 10 TO 15 DEGREES ABOVE
NORMAL. THE ONLY EXCEPTION WAS ACROSS EASTERN AREAS WHERE LOW
CLOUDS/FOG HAVE BEEN VERY PERSISTENT ACROSS LUCE AND EASTERN
SCHOOLCRAFT COUNTIES. LOW CLOUDS/FOG WILL CONTINUE TO SLOWLY
DISSIPATE THROUGH THE REMAINDER OF THE AFTERNOON BUT STAGE WILL BE
SET FOR A REPEAT PERFORMANCE TONIGHT.
SFC HIGH CENTERED OVER THE OH VALLEY AND MID ATLANTIC STATES WILL
STILL BE THE MAIN PLAYER ACROSS THE GREAT LAKES INTO THIS EVENING.
SFC/UPPER TROF MAKING SOME PROGRESS THROUGH THE NORTHERN PLAINS WILL
AID IN TIGHTENING THE PRESSURE GRADIENT ACROSS THE AREA
TONIGHT...ESPECIALLY WESTERN SECTIONS. WITH CLEAR SKIES AND LIGHT
WINDS EARLY THIS EVENING TEMPS WILL FALL OFF QUICKLY...LIKELY
REACHING THEIR NIGHT TIME LOWS BY MID TO LATE EVENING. AFTER
THAT...SLOWLY INCREASING SOUTHERLY WINDS SHOULD LIMIT DIURNAL
COOLING. IN ADDITION...WHERE WINDS REMAIN LIGHTEST THE LONGEST IN
THE EAST...ANTICIPATE AREAS OF FOG TO DEVELOP ONCE AGAIN. FURTHER
WEST...FOG WILL NOT BE AS DENSE OR WIDESPREAD...BUT INCREASING 90H
MOISTURE WITH STRONGER SOUTHERLY WINDS JUST OFF THE SURFACE WILL
ALLOW STRATUS TO DEVELOP/MOVE INTO THE WEST TOWARDS DAYBREAK. CLOUDS
AND PERHAPS EVEN A LITTLE DRIZZLE WILL PERSIST THROUGH THE
MORNING...WITH SOME BREAKS LIKELY BY AFTERNOON IN THE EAST.
LEAD S/WV ASSOCIATED WITH NORTHERN PLAINS TROF WILL SHEAR OUT
NORTHEASTWARD LATE SUNDAY AFTERNOON AND GRAZE THE FAR WEST. WILL
MAINTAIN A LOW CHANCE POP FOR WESTERN LAKE SUPERIOR AND EXPECT MOST
AREAS WILL REMAIN DRY DURING THE DAY.
DESPITE THE CLOUDS...TEMPERATURES ON SUNDAY WILL CONTINUE TO BE WELL
ABOVE NORMAL WITH HIGHS EXPECTED IN THE MID 40S TO AROUND 50. WITH
NO SNOW EXPECTED THROUGH TOMORROW...IT LOOKS LIKE WE WILL BREAK OUR
RECORD FOR THE LEAST SNOWIEST START TO THE FALL/WINTER SEASON. IN
ADDITION...IF OUR HIGH TEMPERATURES REMAIN ABOVE 32 DEGREES THROUGH
THE 27TH WE WILL SET A RECORD FOR THE LONGEST PERIOD INTO THE FALL
SEASON WITHOUT A HIGH TEMPERATURE AT OR BELOW 32 DEGREES.
.LONGER TERM...00Z MON ONWARD...
NAM SHOWS A TROUGH IN THE NORTHERN ROCKIES 00Z MON WITH A RIDGE OVER
THE EASTERN U.S. AND CANADA. NAM THEN TAKES THE TROUGH IN THE
ROCKIES AND DIGS IT SOUTHEAST ON MON AND FORMS A CLOSED LOW IN IT
00Z TUE AND THEN CONTINUES TO DIG THE LOW AND TROUGH SOUTHEAST ON
TUE WHILE HAVING ANOTHER SHORTWAVE MOVES ACROSS SOUTHERN CANADA AT
THE SAME TIME. THIS SHORTWAVE IN SOUTHERN CANADA WILL DETERMINE WHAT
THIS SYSTEM WILL DO...WHEN IT WILL KICK OUT THE 500 MB CLOSED LOW
AND TROUGH TO THE SOUTH OF IT...IF THEY WILL MERGE OR NOT OR REMAIN
SEPARATE AND THIS IS WHAT THE MODELS HAVE BEEN HAVING A HARD TIME
FIGURING OUT THE PAST SEVERAL DAYS. WILL FOLLOW CLOSER TOWARDS THE
NAM FOR THIS FORECAST WHICH IS A BIT SLOWER AND BLEND TOWARDS THE
ECMWF LATER ON.
FRONTAL ZONE/TROUGH GETS SHEARED OUT AND WAITS FOR THIS SYSTEM TO
COME IN...BUT IN THE MEANTIME...CANNOT RULE OUT SLIGHT CHANCE POPS
ALONG AND NEAR IT ACROSS THE FAR WESTERN CWA SUN NIGHT THROUGH TUE
BEFORE THE SYSTEM COMES IN FROM THE SW. NOT REAL IMPRESSED WITH RAIN
CHANCES THOUGH AND WILL KEEP SLIGHT CHANCE POPS IN AT THIS TIME.
WILL CONTINUE TO BE MILD WITH FOG AT NIGHT ESPECIALLY OVER THE
CENTRAL AND EAST.
IN THE EXTENDED...FOLLOWED THE 00Z ECMWF FOR THIS FORECAST AS IT HAS
BEEN THE MODEL OF CHOICE FOR A WHILE. THE ECMWF HAS A CLOSED 500 MB
LOW NEAR KANSAS CITY 00Z WED WHICH GOES TO NEAR CHICAGO 00Z THU AND
TO NEAR CLEVELAND 00Z FRI. RIDGING THEN MOVES IN FOR FRI AND SAT.
WITH SYSTEM COMING UP FROM THE SOUTH AND IT HAS TO MAKE ITS OWN COLD
AIR WHICH IT MANAGES TO DO...LOOKS LIKE PCPN WILL BE MIXED WITH THIS
SYSTEM AND START OFF AS RAIN AND THEN GO TO A RAIN/SNOW MIX BEFORE
GOING OVER TO ALL SNOW THU NIGHT. ONE CHANGE IS I BUMPED POPS UP TO
LIKELY FOR WED THROUGH THU AS DEFORMATION ZONE STAYS ACROSS THE AREA
AND WE ARE IN FAVORABLE PART OF STORM TO GET WET. WENT DRY THEN FOR
FRI EXCEPT ACROSS THE EAST AS WRAPAROUND IS STILL THERE AND SAT
EVERYWHERE EVEN AS A COLD FRONT COMES THROUGH THEN. ONE THING IS
THAT THIS SYSTEM REALLY DOES NOT HAVE THAT COLD OF AIR FOR LAKE
EFFECT BEHIND IT AS ECMWF ONLY HAS -4C 850 MB AIR BEHIND IT AND LAKE
TEMPERATURES ARE RUNNING ABOUT 5C TO 6C NOW. TEMPERATURES LOOK TO
STILL STAY NORMAL OR SLIGHTLY ABOVE NORMAL THIS EXTENDED PERIOD.
&&
.AVIATION /FOR THE 00Z TAF ISSUANCE/...
LOW LEVEL MOISTURE TRAPPED UNDER A SUBSIDENCE INVERSION HAS RESULTED
IN STRATUS AND PATCHY FOG OVER NRN WI. EXPECT THIS STRATUS/PATCHY
FOG TO SPREAD INTO THE TAF SITES LATE TONIGHT OR TOWARD DAYBREAK ON
THE HEELS OF INCREASING SOUTH WINDS. 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
AFTERNOON.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
WITH TIGHTENING PRESSURE GRADIENT OVERNIGHT TONIGHT AND
SUNDAY...COULD SEE A FEW SOUTHERLY WIND GUSTS UP TO 25 KNOTS FROM
LATE TONIGHT INTO MONDAY MORNING. 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.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...MZ
LONG TERM...07
AVIATION...JV
MARINE...MZ
000
FXUS63 KDTX 212352
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
652 PM EST SAT NOV 21 2009
.AVIATION...
MIXING PROVED SUFFICIENT ENOUGH TO SCATTER OUT THE STRATUS DECK THIS
AFTERNOON. HOWEVER...A COOLING BOUNDARY LAYER WITH ALLOW THE COLUMN
TO SATURATE AGAIN BENEATH A STRENGTHENING RADIATION INVERSION
OVERNIGHT. LATEST OBSERVATIONS DISPLAYING THIS NOW IN THE FORM OF
SCATTERED MVFR STRATUS DEVELOPMENT. THE MOIST BOUNDARY LAYER
CONDITIONS AND DECOUPLING WIND FIELD WILL FAVOR AN EXPANSION OF
STRATUS/FOG THROUGHOUT THE NIGHT. MODEL SOUNDINGS INDICATE AN
INVERSION THAT BECOMES MORE SURFACE BASED...AND GIVEN THE WIND FIELD
WILL FAVOR MORE FOG THAN STRATUS...ALTHOUGH IN EITHER CASE THE
POTENTIAL EXISTS FOR A PERIOD OF LIFR WITHIN THE 09Z-14Z WINDOW.
MOISTURE WILL SLOWLY MIX OUT AGAIN THROUGH THE LATE MORNING/EARLY
AFTERNOON.
&&
.PREV DISCUSSION...ISSUED 317 PM EST SAT NOV 21 2009
SHORT TERM...TONIGHT
WITH SURFACE DEW POINTS STILL HOVERING IN THE LOW TO MID 40S AND
SKIES MOSTLY CLEARED OUT...FOG APPEARS TO BE A GOOD BET TONIGHT AS
ANTI-CYCLONIC FLOW BUILDS INTO LOWER MICHIGAN. EASTERLY FLOW OFF
LAKE ERIE WILL HELP CONTRIBUTE SOME ADDITIONAL MOISTURE ACROSS THE
SOUTH THIRD OF THE CWA. EVEN WITHOUT THIS MOISTURE...RELATIVELY HIGH
CROSSOVER TEMPERATURES SHOULD BE SUFFICIENT FOR FOG WITH MINS
FALLING INTO THE UPPER 30S. A QUICK REDEVELOPMENT OF THE LOW STRATUS
IS ABOUT THE ONLY FLY IN THE OINTMENT...BUT THE ONLY SIGNIFICANT
INVERSION LOOKS TO BE THE SURFACE BASED ONE AND LEANING TOWARD A FOG
SCENARIO...WHICH COULD BECOME DENSE.
LONG TERM...SUNDAY THROUGH NEXT SATURDAY
MID LEVEL RIDGING IS FORECAST TO BUILD ACROSS THE EASTERN GREAT
LAKES ON SUNDAY...ALLOWING THE HIGH NOW CENTERED OVER OHIO TO BUILD
INTO NORTHERN NEW ENGLAND. THE SURFACE HIGH AND ASSOCIATED UPPER
RIDGE IS THEN FORECAST TO SLIDE OFF THE COAST OF NEW ENGLAND ON
MONDAY...WITH SURFACE RIDGING PERSISTING ACROSS THE EASTERN GREAT
LAKES.
WITH NO APPRECIABLE ADVECTION OF LOW LEVEL DRY AIR INTO THE REGION
AND GIVEN THE LIMITED MIXING POTENTIAL THIS TIME OF YEAR...DENSE FOG
WILL BE THE MAIN WEATHER CONCERN OVER THE NEXT SEVERAL DAYS. GIVEN
THE WARM AMBIENT AIRMASS...ONCE FOG IS ABLE TO MIX OUT SUN
AFTERNOON...TEMPS SHOULD ACHIEVE THE LOWER 50S. ALTHOUGH THE LOW
LEVEL GRADIENT IS FORECAST TO INCREASE SUN NIGHT INTO TUES...THE LOW
LEVEL FLOW WILL REMAIN OFF LAKE ERIE. THIS WILL SUPPLY ADDITIONAL
LOW LEVEL MOISTURE INTO THE ALREADY MOISTURE RICH BOUNDARY LAYER.
WHILE THE TIGHTENING GRADIENT RAISES SOME CONCERNS THAT LOW STRATUS
WILL BE FAVORED OVER FOG...MODEL SOUNDINGS AND WIND SPEEDS BELOW
950MB SUGGEST ENOUGH BOUNDARY LAYER DECOUPLING TO ALLOW A CHANCE OF
FOG REDEVELOPMENT BOTH SUN NIGHT AND MONDAY NIGHT. WEAK SHALLOW COLD
AIR ADVECTION ON MONDAY AND PERSISTENT MID LEVEL SUBSIDENCE WILL
STRENGTHEN THE INVERSION. THIS MAY MAKE IT DIFFICULT FOR MORNING
FOG/STRATUS TO COMPLETELY MIX OUT DURING THE AFTERNOON. THUS...HAVE
KEPT MONDAYS MAX TEMPS MAINLY IN THE UPPER 40S.
ATTENTION THEN TURNS TO THE WEATHER SYSTEM EXPECTED TO IMPACT THE
STATE BY MID WEEK. THE 12Z MODEL SUITE CONTINUE TO SHOW MID LEVEL
TROUGH AMPLIFICATION OVER THE CENTRAL ROCKIES ON MONDAY...EVOLVING
INTO A CUT OFF CIRCULATION OVER THE CENTRAL PLAINS BY TUESDAY. BOTH
GFS AND NAM HAVE TRENDED SLOWER WITH THIS SYSTEM /MORE TOWARD THAT
OF THE ECMWF/. SATELLITE REPRESENTATION OF THIS WAVE /NOW OFF THE
COAST OF WASHINGTON STATE/ APPEARS STRONGER THAN WHAT THE GFS
INITIALIZED. THESE FACTORS SEEMS TO SUPPORT THE SLOWER ECMWF. WITH
THE WAVE STILL OFF THE COAST...MODEL CONFIDENCE IS STILL NOT HIGH.
IN LIGHT OF RECENT ECMWF TRENDS HOWEVER...THE BEST CHANCE OF RAIN
ASSOCIATED WITH THE WARM CONVEYOR BELT WILL OCCUR BETWEEN TUES NIGHT
AND WED.
AS THE SYSTEM LIFTS ACROSS MICHIGAN /ROUGHLY IN THE WED TIME PERIOD/
A SECONDARY NORTHERN STREAM WAVE IS FORECAST TO DROP INTO THE
NORTHERN PLAINS/UPPER MISSISSIPPI VALLEY FROM CANADA. THERE REMAINS
A HIGH DEGREE OF UNCERTAINTY WITH RESPECT TO TIMING AND AMPLITUDE OF
THIS WAVE AND WHETHER THERE WILL BE ANY PHASING WITH THE WAVE
PRECEDING IT. IN LIGHT OF RECENT MODEL TRENDS...A CHANCE OF
PRECIPITATION /ALBEIT LIGHT/ CONTINUES TO LOOK WARRANTED THURS
THROUGH FRIDAY. THE MAGNITUDE OF COLD AIR ADVECTION WITH THE
NORTHERN STREAM SYSTEM HAS NOT BEEN SHOWN TO BE AS STRONG OVER THE
LAST COUPLE OF MODEL CYCLES /THE COLDEST AIR NOW DOES NOT LOOK TO
ARRIVE UNTIL THURS NIGHT OR FRIDAY/. SINCE EVEN THE FASTER GFS
SOLUTION IS NOW INDICATING THAT THE COLD AIR ADVECTION WILL NOT BE
STRONG ENOUGH TO OFFSET THE DEPTH OF ABOVE FREEZING AIR IN THE
BOUNDARY LAYER...HAVE REMOVED ALL MENTION OF SNOW ON THANKSGIVING
DAY AND JUST CARRIED A MIX THURS NIGHT INTO FRIDAY.
MARINE...
HIGH PRESSURE WILL REMAIN IN PLACE OVER THE CENTRAL GREAT LAKES
THROUGH TOMORROW...RESULTING IN VERY LIGHT 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.
&S
&&
.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 KGRR 212326
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
625 PM EST SAT NOV 21 2009
LATEST UPDATE...AVIATION...
.SYNOPSIS...(304 PM EST SAT NOV 21 2009)
A LARGE HIGH PRESSURE SYSTEM...CENTERED OVER MICHIGAN EARLY THIS
AFTERNOON WILL SLOWLY MOVE EAST TO THE COAST BY MONDAY MORNING. THAT
WILL PUT SOUTHWEST LOWER MICHIGAN IN A SOUTHERLY FLOW OF AIR THAT
WILL KEEP TEMPERATURES WELL ABOVE NORMAL FOR THIS TIME OF YEAR.
LIGHT WINDS AND MOSTLY CLEAR SKIES DURING THIS EVENING AND SUNDAY
EVENING WILL ALLOW FOR FOG TO FORM AFTER MIDNIGHT TONIGHT AND SUNDAY
NIGHT. A COLD FRONT AND ASSOCIATED STORM SYSTEM WILL BRING RAIN AND
COOLER WEATHER TOWARD MIDWEEK. SOME WET SNOW MAY MIX IN BY WEDNESDAY.
&&
.SHORT TERM...(304 PM EST SAT NOV 21 2009)
(TONIGHT THROUGH MONDAY NIGHT)
THE MAIN ISSUE WITH THIS FORECAST PACKAGE IS THE POTENTIAL FOR FOG
TONIGHT AND SUNDAY NIGHT.
WITH THE HIGH PRESSURE SYSTEM OVERHEAD THIS AFTERNOON AND THE
SHORTWAVE OF LAST NIGHT TO OUR EAST...SKIES WERE MOSTLY SUNNY AT 2
PM. THE COMBINATION OF LIGHT WINDS TONIGHT AND MOSTLY CLEAR SKIES
WILL ALLOW FOR A CONSIDERABLE AMOUNT OF FOG BY MORNING. OUR FOG PLOT
PROCEDURE INDICATES DENSE FOG ACROSS THE AREA OVERNIGHT. I COULD SEE
A STRATUS DECK FORMING BY SUNRISE.
THE HIGH MOVES TO OUR EAST SUNDAY SO A SOUTHERLY FLOW WILL BECOME
A LITTLE STRONGER (MEAN WIND SURFACE TO 1000 FT AGL 240/04 KNOTS AT
200 PM TODAY COMPARED TO 150/08KT SUNDAY AT 2 PM). ONCE THE LOW
CLOUDS AND FOG BURN OFF IT SHOULD BE A SUNNY DAY ON SUNDAY.
WINDS WILL BE STRONGER IN THE BOUNDARY LAYER SUNDAY NIGHT...STILL IT
WOULD SEEM WITH THE LOW LEVEL MOISTURE INCREASING AND NEARLY CLEAR
SKIES DURING THE EVENING...FOG AND STRATUS WOULD BE A GOOD BET
AGAIN.
MONDAY INTO MONDAY NIGHT A SYSTEM WILL BE PASSING TO OUR SOUTHEAST.
THAT WILL BRING IN SOME MID CLOUDS BUT NOT MUCH ELSE.
&&
.LONG TERM...(304 PM EST SAT NOV 21 2009)
(TUESDAY THROUGH SATURDAY)
WE DIDN/T CHANGE THE FORECAST TOO MUCH. ECMWF/GFS CONTINUE TO SHOW
AN INTRUSION OF COLDER AIR INTO THE GREAT LAKES NEXT WEEK. BUT THE
TREND HAS BEEN TO WRAP THE COLD AIR AROUND THE DEPARTING LOW WITH
THE RESULT BEING THE COLDEST AIR FLOWING SOUTHWEST OF THE CWA. EVEN
SO WE STILL MAY SEE SOME WET SNOW DURING THE END OF THE PERIOD.
RAIN SHOULD DEVELOP TUESDAY IN ADVANCE OF AN OCCLUDING LOW THAT WILL
MOVE FROM THE PLAINS TOWARD LAKE MICHIGAN. THOSE SHOWERS WILL LINGER
INTO WEDNESDAY. A SECOND STRONGER WAVE WILL KICK THE FIRST ONE OUT
AND BRING DOWN THE COLDER AIR FROM CANADA. H8 TEMPS WILL SLOWLY FALL
FROM -2C TO PERHAPS -5C FROM WEDNESDAY THROUGH LATE FRIDAY. THE
COLDEST AIR LOOKS LIKE IT WILL BE ON FRIDAY AS THE THE UPPER LOW
MOVES AWAY SO THAT IS WHEN WE/LL HAVE THE GREATEST CHANCE OF SEEING
SOME SNOW. WE/LL SEE A WARMING TREND BEGIN SATURDAY AS THE LOW PULLS
AWAY.
&&
.AVIATION...(625 PM EST SAT NOV 21 2009)
HIGH PRESSURE OVERHEAD TONIGHT AND CLEAR SKIES AND CALM WINDS WILL
RESULT IN FOG FORMING. EXPECT VSBYS WILL BE FALLING TO LESS THAN A
MILE LATE TONIGHT. THE FOG WILL LIFT DURING THE MORNING HOURS WITH
VFR EXPECTED BY SUNDAY AFTERNOON.
&&
.MARINE...(304 PM EST SAT NOV 21 2009)
EVEN WITH THE SURFACE HIGH MOVING EAST OF THE AREA BY SUNDAY WINDS
ARE NOT EXPECTED TO BECOME STRONG ENOUGH FOR SMALL CRAFT ADVISORIES
TO BE ISSUES (WAVE HEIGHTS WILL STAY BELOW 4 FEET). AREA OF FOG
ARE EXPECTED DURING THE MORNING HOURS OF SUNDAY AND MONDAY.
&&
.HYDROLOGY...(304 PM EST SAT NOV 21 2009)
NO PRECIPITATION EXPECTED THROUGH MONDAY. NO HYDRO ISSUES ARE
EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: WDM
SHORT TERM: WDM
LONG TERM: 93
AVIATION: OSTUNO
MARINE: WDM
HYDROLOGY: WDM
000
FXUS63 KAPX 212301
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
600 PM EST SAT NOV 21 2009
.SYNOPSIS.../ISSUED AT 401 PM/
HIGH PRESSURE...WILL MAINTAIN ITS INFLUENCE OVER THE REGIONS WEATHER
THROUGH MONDAY...AS IT MOVES FROM THE OHIO VALLEY...ACROSS NEW
ENGLAND...AND INTO THE CANADIAN MARITIME PROVINCES. PATCHY FOG WILL
DEVELOP AGAIN TONIGHT...AND COULD BE BRIEFLY DENSE IN A COUPLE
SPOTS. SUNDAY AND MONDAY WILL BE SIMILAR...WITH PATCHY MORNING FOG
GRADUALLY GIVING WAY TO SUNSHINE.
THE NEXT CHANCE OF RAIN WILL BE TUESDAY...AS A STORM SYSTEM LIFTS
INTO THE UPPER MIDWEST. TEMPERATURES WILL TURN COLDER BEHIND
THIS SYSTEM. SOME PRECIPITATION WILL LINGER INTO WEDNESDAY AND
THURSDAY...AND IT COULD TURN WINTRY THANKSGIVING DAY.
ADAM
&&
.SHORT TERM.../ISSUED AT 401 PM/...TONIGHT
LARGE AREA OF HIGH PRESSURE CURRENTLY PARKED ACROSS THE EASTERN
CONUS/GREAT LAKES THIS AFTERNOON. WAS A SLOW PROCESS...BUT MID
NOVEMBER SUNSHINE WAS ABLE TO MIX OUT SHALLOW LOW STRATUS ACROSS NRN
LOWER MICHIGAN...ALLOWING TEMPS TO REACH THE 50S. EASTERN UPPER
MICHIGAN NOT SO LUCKY AS SHALLOW STRATUS (LIKELY HELPED BY WEAK FLOW
OFF LAKE MICHIGAN) STILL LINGERS THERE...WITH TEMPS ONLY IN THE
MIDDLE 40S.
TONIGHT...HIGH PRESSURE/LIGHT WINDS WILL CONTINUE TO DOMINATE. MAIN
FORECAST ISSUES REVOLVE AROUND THE REDEVELOPMENT OF FOG/STRATUS.
FAIR AMOUNT OF DRY AIR MIXING FROM ALOFT HAS KNOCKED SFC DEWPOINTS
DOWN INTO THE MIDDLE 30S TO LOWER 40S THIS AFTERNOON ACROSS NRN
LOWER MICHIGAN. GIVEN THAT...DON/T THINK WE WILL SEE QUITE THE
WIDESPREAD STRATUS/FOG DEVELOPMENT THAT WE HAD LAST NIGHT...ALTHOUGH
NOT BRAVE ENOUGH TO YANK IT COMPLETELY. SO...HAVE GONE A BIT MORE
OPTIMISTIC WITH SKY COVER THIS EVENING BEFORE BRINGING SOME STRATUS
BACK INTO THE PICTURE LATER OVERNIGHT TOWARD MORNING.
EASTERN UPPER MICHIGAN IS A BIT MORE PROBLEMATIC AS STRATUS HAS YET
TO LEAVE. BUT...MODEL RH PROGS AND LATE AFTERNOON SATELLITE IMAGERY
DOES SUGGEST THAT STRATUS WILL THIN OUT TO SOME DEGREE BY THIS
EVENING. WILL PLAY IT THAT WAY FOR NOW AND SEE HOW IT GOES.
ADAM
&&
.LONG TERM.../ISSUED AT 401 PM/...SUNDAY AND BEYOND
OUTSIDE OF SOME FOG/STRATUS ISSUES SUNDAY/MONDAY MORNINGS...THE MAIN
FORECAST ISSUES FOR THE UPCOMING WEEK WILL REVOLVE AROUND THE UPPER
LEVEL ENERGY MOVING OUT OF THE CENTRAL ROCKIES AND TOWARD THE GREAT
LAKES. MULTITUDE OF MODEL DIFFERENCES IN TIMING/STRENGTH OF
FEATURES...WITH ABOUT A 12 HOUR SPREAD BETWEEN THE FASTER/COLDER GFS
AND THE SLOWER/WARMER ECMWF. THINK THE ECMWF IS TOO SLOW GIVEN THE
LACK OF BACKSIDE JET ENERGY ON THE WESTERN EDGE OF UPPER FEATURE
TUE/WED AND WILL TAKE A BLENDED GFS/ECMWF SOLUTION.
SUNDAY-MONDAY...VERY SIMILAR ISSUES AS FRIDAY NIGHT W/ SHALLOW
/SUB-950MB/ MOISTURE...RELATIVELY WEAK LOW LEVEL FLOW AND ABUNDANT
DRY AIR ALOFT. A BIT MORE RIDGING ALOFT AND MOISTURE NOT QUITE AS
WIDESPREAD...SO FOG/STRATUS MAY BE A BIT PATCHIER THAN FRIDAY NIGHT.
OVERALL...EXPECT AREAS OF STRATUS IN NE LOWER AND EASTERN UPPER
DURING THE OVERNIGHT/EARLY MORNING HOURS. THE STRATUS WILL THIN AND
BREAK UP EACH DAY...LEADING TO AT LAST PARTLY SUNNY SKIES BY
MIDDAY.
UPPER SYSTEM MOVES INTO THE CENTRAL PLAINS ON TUESDAY...THEN TOWARD
THE WESTERN LAKES ON WEDNESDAY. EVEN WITH THE MODEL DIFFERENCES
MENTIONED PREVIOUSLY...THEY ALL AGREE ON NORTHERN MICHIGAN SITTING
IN THE WARM SECTOR OF THIS STORM THROUGH WEDNESDAY...RESULTING IN
JUST RAIN /NO SNOW/. WILL RAISE POPS TO LIKELY FOR SOME AREAS
WED/WED NIGHT GIVEN PLUME OF DEEPER 850MB THETA-E AIR SURGING
NORTHWARD INTO THE AREA ALONG WITH FAVORABLE FORCING. THE RAIN MAY
BEGIN TO CHANGE TO SNOW LATE WEDNESDAY NIGHT OVER WESTERN
AREAS/HIGHER TERRAIN AS COLDER AIR IS DRAWN SOUTHWARD ON THE
BACKSIDE OF UPPER LOW. SURFACE BASED MELT LAYERS DECREASE TOWARD
1.5K BY THANKSGIVING MORNING...WHICH IS SQUARELY ON THE RAIN/SNOW
LINE.
THANKSGIVING...COLD AIR ADVECTION CONTINUES AND THE RAIN WILL CHANGE
TO SNOW ACROSS MUCH OF THE AREA DURING THE DAY /LAKESHORE AREAS MAY
REMAIN MAINLY LIQUID/ AS UPSTREAM UPPER LEVEL ENERGY DROPS INTO THE
SOUTHERN GREAT LAKES. COMBO OF IMPRESSIVE H8-H7 OMEGA AND DEEP
MOISTURE FROM GAYLORD WEST TOWARD LAKE MICHIGAN...AND WILL GO WITH
LIKELY POPS IN THOSE AREAS. WILL HAVE TO KEEP AN EYE ON THIS
SYSTEM...AS IT HAS THE POTENTIAL TO PRODUCE A SNEAKY WINTER EVENT
FOR PARTS OF THE AREA /ACCUMULATING SNOW?/.
RISING UPPER HEIGHTS AND DRIER AIR ADVECTING INTO THE AREA FOR
FRIDAY/SATURDAY...RESULTING IN QUIET WEATHER ONCE AGAIN AS A LOW
AMPLITUDE RIDGE MOVES INTO THE GREAT LAKES.
JK
&&
.MARINE.../ISSUED AT 401 PM/
STRONG HIGH PRESSURE OVER THE GREAT LAKES/EASTERN CONUS WILL RESULT
IN FAIRLY LIGHT WINDS/MINIMAL WAVES TONIGHT. AS THE HIGH NUDGES
EASTWARD ON SUNDAY...STRONGER S/SW RETURN FLOW WILL DEVELOP THROUGH
THE DAY. BUT WINDS/WAVES EXPECTED TO REMAIN BELOW SMALL CRAFT
CRITERIA.
ADAM
&&
.AVIATION.../ISSUED AT 600 PM/...VALID FOR 00Z TAFS
LOW STRATUS/IFR/LIFR CIGS EXPECTED TO REDEVELOP TONIGHT...
PARTICULARLY AT APN. HOWEVER...FORECAST SOUNDINGS/SLIGHTLY DRIER AIR
OVERSPREADING THE REGION SHOULD PRECLUDE WIDESPREAD DENSE FOG
DEVELOPMENT. WHATEVER STRATUS/FOG DEVELOPS WILL MIX OUT AGAIN ON
SUNDAY...LEAVING VFR CONDITIONS FOR MUCH OF THE DAY.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KAPX 212101
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
401 PM EST SAT NOV 21 2009
.SYNOPSIS.../ISSUED AT 401 PM/
HIGH PRESSURE...WILL MAINTAIN ITS INFLUENCE OVER THE REGIONS WEATHER
THROUGH MONDAY...AS IT MOVES FROM THE OHIO VALLEY...ACROSS NEW
ENGLAND...AND INTO THE CANADIAN MARITIME PROVINCES. PATCHY FOG WILL
DEVELOP AGAIN TONIGHT...AND COULD BE BRIEFLY DENSE IN A COUPLE
SPOTS. SUNDAY AND MONDAY WILL BE SIMILAR...WITH PATCHY MORNING FOG
GRADUALLY GIVING WAY TO SUNSHINE.
THE NEXT CHANCE OF RAIN WILL BE TUESDAY...AS A STORM SYSTEM LIFTS
INTO THE UPPER MIDWEST. TEMPERATURES WILL TURN COLDER BEHIND
THIS SYSTEM. SOME PRECIPITATION WILL LINGER INTO WEDNESDAY AND
THURSDAY...AND IT COULD TURN WINTRY THANKSGIVING DAY.
ADAM
&&
.SHORT TERM.../ISSUED AT 401 PM/...TONIGHT
LARGE AREA OF HIGH PRESSURE CURRENTLY PARKED ACROSS THE EASTERN
CONUS/GREAT LAKES THIS AFTERNOON. WAS A SLOW PROCESS...BUT MID
NOVEMBER SUNSHINE WAS ABLE TO MIX OUT SHALLOW LOW STRATUS ACROSS NRN
LOWER MICHIGAN...ALLOWING TEMPS TO REACH THE 50S. EASTERN UPPER
MICHIGAN NOT SO LUCKY AS SHALLOW STRATUS (LIKELY HELPED BY WEAK FLOW
OFF LAKE MICHIGAN) STILL LINGERS THERE...WITH TEMPS ONLY IN THE
MIDDLE 40S.
TONIGHT...HIGH PRESSURE/LIGHT WINDS WILL CONTINUE TO DOMINATE. MAIN
FORECAST ISSUES REVOLVE AROUND THE REDEVELOPMENT OF FOG/STRATUS.
FAIR AMOUNT OF DRY AIR MIXING FROM ALOFT HAS KNOCKED SFC DEWPOINTS
DOWN INTO THE MIDDLE 30S TO LOWER 40S THIS AFTERNOON ACROSS NRN
LOWER MICHIGAN. GIVEN THAT...DON/T THINK WE WILL SEE QUITE THE
WIDESPREAD STRATUS/FOG DEVELOPMENT THAT WE HAD LAST NIGHT...ALTHOUGH
NOT BRAVE ENOUGH TO YANK IT COMPLETELY. SO...HAVE GONE A BIT MORE
OPTIMISTIC WITH SKY COVER THIS EVENING BEFORE BRINGING SOME STRATUS
BACK INTO THE PICTURE LATER OVERNIGHT TOWARD MORNING.
EASTERN UPPER MICHIGAN IS A BIT MORE PROBLEMATIC AS STRATUS HAS YET
TO LEAVE. BUT...MODEL RH PROGS AND LATE AFTERNOON SATELLITE IMAGERY
DOES SUGGEST THAT STRATUS WILL THIN OUT TO SOME DEGREE BY THIS
EVENING. WILL PLAY IT THAT WAY FOR NOW AND SEE HOW IT GOES.
ADAM
&&
.LONG TERM.../ISSUED AT 401 PM/...SUNDAY AND BEYOND
OUTSIDE OF SOME FOG/STRATUS ISSUES SUNDAY/MONDAY MORNINGS...THE MAIN
FORECAST ISSUES FOR THE UPCOMING WEEK WILL REVOLVE AROUND THE UPPER
LEVEL ENERGY MOVING OUT OF THE CENTRAL ROCKIES AND TOWARD THE GREAT
LAKES. MULTITUDE OF MODEL DIFFERENCES IN TIMING/STRENGTH OF
FEATURES...WITH ABOUT A 12 HOUR SPREAD BETWEEN THE FASTER/COLDER GFS
AND THE SLOWER/WARMER ECMWF. THINK THE ECMWF IS TOO SLOW GIVEN THE
LACK OF BACKSIDE JET ENERGY ON THE WESTERN EDGE OF UPPER FEATURE
TUE/WED AND WILL TAKE A BLENDED GFS/ECMWF SOLUTION.
SUNDAY-MONDAY...VERY SIMILAR ISSUES AS FRIDAY NIGHT W/ SHALLOW
/SUB-950MB/ MOISTURE...RELATIVELY WEAK LOW LEVEL FLOW AND ABUNDANT
DRY AIR ALOFT. A BIT MORE RIDGING ALOFT AND MOISTURE NOT QUITE AS
WIDESPREAD...SO FOG/STRATUS MAY BE A BIT PATCHIER THAN FRIDAY NIGHT.
OVERALL...EXPECT AREAS OF STRATUS IN NE LOWER AND EASTERN UPPER
DURING THE OVERNIGHT/EARLY MORNING HOURS. THE STRATUS WILL THIN AND
BREAK UP EACH DAY...LEADING TO AT LAST PARTLY SUNNY SKIES BY
MIDDAY.
UPPER SYSTEM MOVES INTO THE CENTRAL PLAINS ON TUESDAY...THEN TOWARD
THE WESTERN LAKES ON WEDNESDAY. EVEN WITH THE MODEL DIFFERENCES
MENTIONED PREVIOUSLY...THEY ALL AGREE ON NORTHERN MICHIGAN SITTING
IN THE WARM SECTOR OF THIS STORM THROUGH WEDNESDAY...RESULTING IN
JUST RAIN /NO SNOW/. WILL RAISE POPS TO LIKELY FOR SOME AREAS
WED/WED NITE GIVEN PLUME OF DEEPER 850MB THETA-E AIR SURGING
NORTHWARD INTO THE AREA ALONG WITH FAVORABLE FORCING. THE RAIN MAY
BEGIN TO CHANGE TO SNOW LATE WEDNESDAY NIGHT OVER WESTERN
AREAS/HIGHER TERRAIN AS COLDER AIR IS DRAWN SOUTHWARD ON THE
BACKSIDE OF UPPER LOW. SURFACE BASED MELT LAYERS DECREASE TOWARD
1.5K BY THANKSGIVING MORNING...WHICH IS SQUARELY ON THE RAIN/SNOW
LINE.
THANKSGIVING...COLD AIR ADVECTION CONTINUES AND THE RAIN WILL CHANGE
TO SNOW ACROSS MUCH OF THE AREA DURING THE DAY /LAKESHORE AREAS MAY
REMAIN MAINLY LIQUID/ AS UPSTREAM UPPER LEVEL ENERGY DROPS INTO THE
SOUTHERN GREAT LAKES. COMBO OF IMPRESSIVE H8-H7 OMEGA AND DEEP
MOISTURE FROM GAYLORD WEST TOWARD LAKE MICHIGAN...AND WILL GO WITH
LIKELY POPS IN THOSE AREAS. WILL HAVE TO KEEP AN EYE ON THIS
SYSTEM...AS IT HAS THE POTENTIAL TO PRODUCE A SNEAKY WINTER EVENT
FOR PARTS OF THE AREA /ACCUMULATING SNOW?/.
RISING UPPER HEIGHTS AND DRIER AIR ADVECTING INTO THE AREA FOR
FRIDAY/SATURDAY...RESULTING IN QUIET WEATHER ONCE AGAIN AS A LOW
AMPLITUDE RIDGE MOVES INTO THE GREAT LAKES.
JK
&&
.MARINE.../ISSUED AT 401 PM/
STRONG HIGH PRESSURE OVER THE GREAT LAKES/EASTERN CONUS WILL RESULT
IN FAIRLY LIGHT WINDS/MINIMAL WAVES TONIGHT. AS THE HIGH NUDGES
EASTWARD ON SUNDAY...STRONGER S/SW RETURN FLOW WILL DEVELOP THROUGH
THE DAY. BUT WINDS/WAVES EXPECTED TO REMAIN BELOW SMALL CRAFT
CRITERIA.
ADAM
&&
.AVIATION.../ISSUED AT 129 PM/...VALID FOR 18Z TAFS
IFR STRATUS/FOG DONE FOR THE DAY AT PLN/TVC AND WILL ERODE AT APN
BY 20Z...LEAVING A PERIOD OF VFR CONDITIONS INTO THE EVENING
HOURS. LOW STRATUS/IFR CIGS AGAIN POSSIBLE LATER TONIGHT
PARTICULARLY AT APN. HOWEVER...FORECAST SOUNDINGS/SLIGHTLY DRIER
AIR OVERSPREADING THE REGION SHOULD KEEP STRATUS/FOG AT BAY TO
SOME DEGREE. WHATEVER STRATUS/FOG DEVELOPS WILL MIX OUT AGAIN ON
SUNDAY LEAVING VFR CONDITIONS FOR MUCH OF THE DAY.
ADAM
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KMQT 212050
AFDMQT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
351 PM EST SAT NOV 21 2009
.DISCUSSION...
.SHORT TERM...
MOST OF UPPER MICHIGAN EXPERIENCED A SUNNY AND MILD DAY BY LATE
NOVEMBER STANDARDS WITH TEMPERATURES RUNNING 10 TO 15 DEGREES ABOVE
NORMAL. THE ONLY EXCEPTION WAS ACROSS EASTERN AREAS WHERE LOW
CLOUDS/FOG HAVE BEEN VERY PERSISTENT ACROSS LUCE AND EASTERN
SCHOOLCRAFT COUNTIES. LOW CLOUDS/FOG WILL CONTINUE TO SLOWLY
DISSIPATE THROUGH THE REMAINDER OF THE AFTERNOON BUT STAGE WILL BE
SET FOR A REPEAT PERFORMANCE TONIGHT.
SFC HIGH CENTERED OVER THE OH VALLEY AND MID ATLANTIC STATES WILL
STILL BE THE MAIN PLAYER ACROSS THE GREAT LAKES INTO THIS EVENING.
SFC/UPPER TROF MAKING SOME PROGRESS THROUGH THE NORTHERN PLAINS WILL
AID IN TIGHTENING THE PRESSURE GRADIENT ACROSS THE AREA
TONIGHT...ESPECIALLY WESTERN SECTIONS. WITH CLEAR SKIES AND LIGHT
WINDS EARLY THIS EVENING TEMPS WILL FALL OFF QUICKLY...LIKELY
REACHING THEIR NIGHT TIME LOWS BY MID TO LATE EVENING. AFTER
THAT...SLOWLY INCREASING SOUTHERLY WINDS SHOULD LIMIT DIURNAL
COOLING. IN ADDITION...WHERE WINDS REMAIN LIGHTEST THE LONGEST IN
THE EAST...ANTICIPATE AREAS OF FOG TO DEVELOP ONCE AGAIN. FURTHER
WEST...FOG WILL NOT BE AS DENSE OR WIDESPREAD...BUT INCREASING 90H
MOISTURE WITH STRONGER SOUTHERLY WINDS JUST OFF THE SURFACE WILL
ALLOW STRATUS TO DEVELOP/MOVE INTO THE WEST TOWARDS DAYBREAK. CLOUDS
AND PERHAPS EVEN A LITTLE DRIZZLE WILL PERSIST THROUGH THE
MORNING...WITH SOME BREAKS LIKELY BY AFTERNOON IN THE EAST.
LEAD S/WV ASSOCIATED WITH NORTHERN PLAINS TROF WILL SHEAR OUT
NORTHEASTWARD LATE SUNDAY AFTERNOON AND GRAZE THE FAR WEST. WILL
MAINTAIN A LOW CHANCE POP FOR WESTERN LAKE SUPERIOR AND EXPECT MOST
AREAS WILL REMAIN DRY DURING THE DAY.
DESPITE THE CLOUDS...TEMPERATURES ON SUNDAY WILL CONTINUE TO BE WELL
ABOVE NORMAL WITH HIGHS EXPECTED IN THE MID 40S TO AROUND 50. WITH
NO SNOW EXPECTED THROUGH TOMORROW...IT LOOKS LIKE WE WILL BREAK OUR
RECORD FOR THE LEAST SNOWIEST START TO THE FALL/WINTER SEASON. IN
ADDITION...IF OUR HIGH TEMPERATURES REMAIN ABOVE 32 DEGREES THROUGH
THE 27TH WE WILL SET A RECORD FOR THE LONGEST PERIOD INTO THE FALL
SEASON WITHOUT A HIGH TEMPERATURE AT OR BELOW 32 DEGREES.
.LONGER TERM...00Z MON ONWARD...
NAM SHOWS A TROUGH IN THE NORTHERN ROCKIES 00Z MON WITH A RIDGE OVER
THE EASTERN U.S. AND CANADA. NAM THEN TAKES THE TROUGH IN THE
ROCKIES AND DIGS IT SOUTHEAST ON MON AND FORMS A CLOSED LOW IN IT
00Z TUE AND THEN CONTINUES TO DIG THE LOW AND TROUGH SOUTHEAST ON
TUE WHILE HAVING ANOTHER SHORTWAVE MOVES ACROSS SOUTHERN CANADA AT
THE SAME TIME. THIS SHORTWAVE IN SOUTHERN CANADA WILL DETERMINE WHAT
THIS SYSTEM WILL DO...WHEN IT WILL KICK OUT THE 500 MB CLOSED LOW
AND TROUGH TO THE SOUTH OF IT...IF THEY WILL MERGE OR NOT OR REMAIN
SEPARATE AND THIS IS WHAT THE MODELS HAVE BEEN HAVING A HARD TIME
FIGURING OUT THE PAST SEVERAL DAYS. WILL FOLLOW CLOSER TOWARDS THE
NAM FOR THIS FORECAST WHICH IS A BIT SLOWER AND BLEND TOWARDS THE
ECMWF LATER ON.
FRONTAL ZONE/TROUGH GETS SHEARED OUT AND WAITS FOR THIS SYSTEM TO
COME IN...BUT IN THE MEANTIME...CANNOT RULE OUT SLIGHT CHANCE POPS
ALONG AND NEAR IT ACROSS THE FAR WESTERN CWA SUN NIGHT THROUGH TUE
BEFORE THE SYSTEM COMES IN FROM THE SW. NOT REAL IMPRESSED WITH RAIN
CHANCES THOUGH AND WILL KEEP SLIGHT CHANCE POPS IN AT THIS TIME.
WILL CONTINUE TO BE MILD WITH FOG AT NIGHT ESPECIALLY OVER THE
CENTRAL AND EAST.
IN THE EXTENDED...FOLLOWED THE 00Z ECMWF FOR THIS FORECAST AS IT HAS
BEEN THE MODEL OF CHOICE FOR A WHILE. THE ECMWF HAS A CLOSED 500 MB
LOW NEAR KANSAS CITY 00Z WED WHICH GOES TO NEAR CHICAGO 00Z THU AND
TO NEAR CLEVELAND 00Z FRI. RIDGING THEN MOVES IN FOR FRI AND SAT.
WITH SYSTEM COMING UP FROM THE SOUTH AND IT HAS TO MAKE ITS OWN COLD
AIR WHICH IT MANAGES TO DO...LOOKS LIKE PCPN WILL BE MIXED WITH THIS
SYSTEM AND START OFF AS RAIN AND THEN GO TO A RAIN/SNOW MIX BEFORE
GOING OVER TO ALL SNOW THU NIGHT. ONE CHANGE IS I BUMPED POPS UP TO
LIKELY FOR WED THROUGH THU AS DEFORMATION ZONE STAYS ACROSS THE AREA
AND WE ARE IN FAVORABLE PART OF STORM TO GET WET. WENT DRY THEN FOR
FRI EXCEPT ACROSS THE EAST AS WRAPAROUND IS STILL THERE AND SAT
EVERYWHERE EVEN AS A COLD FRONT COMES THROUGH THEN. ONE THING IS
THAT THIS SYSTEM REALLY DOES NOT HAVE THAT COLD OF AIR FOR LAKE
EFFECT BEHIND IT AS ECMWF ONLY HAS -4C 850 MB AIR BEHIND IT AND LAKE
TEMPERATURES ARE RUNNING ABOUT 5C TO 6C NOW. TEMPERATURES LOOK TO
STILL STAY NORMAL OR SLIGHTLY ABOVE NORMAL THIS EXTENDED PERIOD.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
MORNING FOG HAS DISSIPATED WITH VFR CONDITIONS EXPECTED AT SAW AND
CMX THROUGH THE EVENING HOURS. WITH SFC RIDGE MOVING EAST OF THE
AREA AND PRESSURE GRADIENT TIGHTENING...SOUTHERLY WINDS SHOULD
PREVENT FOG FROM GETTING AS DENSE AS LAST NIGHT. HOWEVER...WITH LOW
LEVEL MOISTURE REMAINING...DO EXPECT SOME FOG TO REDEVELOP AFTER
MIDNIGHT...ESPECIALLY UNTIL SOUTHERLY WINDS BEGIN TO INCREASE
TOWARDS DAYBREAK. IN ADDITION..EXPECT MVFR STRATUS CIGS TO DEVELOP
AT BOTH SITES LATE TONIGHT AND PERSIST THROUGH SUNDAY MORNING.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
WITH TIGHTENING PRESSURE GRADIENT OVERNIGHT TONIGHT AND
SUNDAY...COULD SEE A FEW SOUTHERLY WIND GUSTS UP TO 25 KNOTS FROM
LATE TONIGHT INTO MONDAY MORNING. 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.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...MZ
LONG TERM...07
AVIATION...MZ
MARINE...MZ
000
FXUS63 KDTX 212017
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
317 PM EST SAT NOV 21 2009
.SHORT TERM...TONIGHT
WITH SURFACE DEW POINTS STILL HOVERING IN THE LOW TO MID 40S AND
SKIES MOSTLY CLEARED OUT...FOG APPEARS TO BE A GOOD BET TONIGHT AS
ANTI-CYCLONIC FLOW BUILDS INTO LOWER MICHIGAN. EASTERLY FLOW OFF
LAKE ERIE WILL HELP CONTRIBUTE SOME ADDITIONAL MOISTURE ACROSS THE
SOUTH THIRD OF THE CWA. EVEN WITHOUT THIS MOISTURE...RELATIVELY HIGH
CROSSOVER TEMPERATURES SHOULD BE SUFFICIENT FOR FOG WITH MINS
FALLING INTO THE UPPER 30S. A QUICK REDEVELOPMENT OF THE LOW STRATUS
IS ABOUT THE ONLY FLY IN THE OINTMENT...BUT THE ONLY SIGNIFICANT
INVERSION LOOKS TO BE THE SURFACE BASED ONE AND LEANING TOWARD A FOG
SCENARIO...WHICH COULD BECOME DENSE.
&&
.LONG TERM...SUNDAY THROUGH NEXT SATURDAY
MID LEVEL RIDGING IS FORECAST TO BUILD ACROSS THE EASTERN GREAT
LAKES ON SUNDAY...ALLOWING THE HIGH NOW CENTERED OVER OHIO TO BUILD
INTO NORTHERN NEW ENGLAND. THE SURFACE HIGH AND ASSOCIATED UPPER
RIDGE IS THEN FORECAST TO SLIDE OFF THE COAST OF NEW ENGLAND ON
MONDAY...WITH SURFACE RIDGING PERSISTING ACROSS THE EASTERN GREAT
LAKES.
WITH NO APPRECIABLE ADVECTION OF LOW LEVEL DRY AIR INTO THE REGION
AND GIVEN THE LIMITED MIXING POTENTIAL THIS TIME OF YEAR...DENSE FOG
WILL BE THE MAIN WEATHER CONCERN OVER THE NEXT SEVERAL DAYS. GIVEN
THE WARM AMBIENT AIRMASS...ONCE FOG IS ABLE TO MIX OUT SUN
AFTERNOON...TEMPS SHOULD ACHIEVE THE LOWER 50S. ALTHOUGH THE LOW
LEVEL GRADIENT IS FORECAST TO INCREASE SUN NIGHT INTO TUES...THE LOW
LEVEL FLOW WILL REMAIN OFF LAKE ERIE. THIS WILL SUPPLY ADDITIONAL
LOW LEVEL MOISTURE INTO THE ALREADY MOISTURE RICH BOUNDARY LAYER.
WHILE THE TIGHTENING GRADIENT RAISES SOME CONCERNS THAT LOW STRATUS
WILL BE FAVORED OVER FOG...MODEL SOUNDINGS AND WIND SPEEDS BELOW
950MB SUGGEST ENOUGH BOUNDARY LAYER DECOUPLING TO ALLOW A CHANCE OF
FOG REDEVELOPMENT BOTH SUN NIGHT AND MONDAY NIGHT. WEAK SHALLOW COLD
AIR ADVECTION ON MONDAY AND PERSISTENT MID LEVEL SUBSIDENCE WILL
STRENGTHEN THE INVERSION. THIS MAY MAKE IT DIFFICULT FOR MORNING
FOG/STRATUS TO COMPLETELY MIX OUT DURING THE AFTERNOON. THUS...HAVE
KEPT MONDAYS MAX TEMPS MAINLY IN THE UPPER 40S.
ATTENTION THEN TURNS TO THE WEATHER SYSTEM EXPECTED TO IMPACT THE
STATE BY MID WEEK. THE 12Z MODEL SUITE CONTINUE TO SHOW MID LEVEL
TROUGH AMPLIFICATION OVER THE CENTRAL ROCKIES ON MONDAY...EVOLVING
INTO A CUT OFF CIRCULATION OVER THE CENTRAL PLAINS BY TUESDAY. BOTH
GFS AND NAM HAVE TRENDED SLOWER WITH THIS SYSTEM /MORE TOWARD THAT
OF THE ECMWF/. SATELLITE REPRESENTATION OF THIS WAVE /NOW OFF THE
COAST OF WASHINGTON STATE/ APPEARS STRONGER THAN WHAT THE GFS
INITIALIZED. THESE FACTORS SEEMS TO SUPPORT THE SLOWER ECMWF. WITH
THE WAVE STILL OFF THE COAST...MODEL CONFIDENCE IS STILL NOT HIGH.
IN LIGHT OF RECENT ECMWF TRENDS HOWEVER...THE BEST CHANCE OF RAIN
ASSOCIATED WITH THE WARM CONVEYOR BELT WILL OCCUR BETWEEN TUES NIGHT
AND WED.
AS THE SYSTEM LIFTS ACROSS MICHIGAN /ROUGHLY IN THE WED TIME PERIOD/
A SECONDARY NORTHERN STREAM WAVE IS FORECAST TO DROP INTO THE
NORTHERN PLAINS/UPPER MISSISSIPPI VALLEY FROM CANADA. THERE REMAINS
A HIGH DEGREE OF UNCERTAINTY WITH RESPECT TO TIMING AND AMPLITUDE OF
THIS WAVE AND WHETHER THERE WILL BE ANY PHASING WITH THE WAVE
PRECEDING IT. IN LIGHT OF RECENT MODEL TRENDS...A CHANCE OF
PRECIPITATION /ALBEIT LIGHT/ CONTINUES TO LOOK WARRANTED THURS
THROUGH FRIDAY. THE MAGNITUDE OF COLD AIR ADVECTION WITH THE
NORTHERN STREAM SYSTEM HAS NOT BEEN SHOWN TO BE AS STRONG OVER THE
LAST COUPLE OF MODEL CYCLES /THE COLDEST AIR NOW DOES NOT LOOK TO
ARRIVE UNTIL THURS NIGHT OR FRIDAY/. SINCE EVEN THE FASTER GFS
SOLUTION IS NOW INDICATING THAT THE COLD AIR ADVECTION WILL NOT BE
STRONG ENOUGH TO OFFSET THE DEPTH OF ABOVE FREEZING AIR IN THE
BOUNDARY LAYER...HAVE REMOVED ALL MENTION OF SNOW ON THANKSGIVING
DAY AND JUST CARRIED A MIX THURS NIGHT INTO FRIDAY.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN IN PLACE OVER THE CENTRAL GREAT LAKES
THROUGH TOMORROW...RESULTING IN VERY LIGHT 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.
&S
&&
.PREV DISCUSSION...ISSUED 1201 PM EST SAT NOV 21 2009
AVIATION...
REMNANT LOW LEVEL MOISTURE WITH ILL DEFINED LOW LEVEL INVERSION WILL
MAKE FOR A DIFFICULT TAF FORECAST...AS THE DEBATE WILL BE LOW
STRATUS VS FOG AS CALM/LIGHT WINDS PROMOTE GOOD RADIATIONAL COOLING
TONIGHT. SLOW DRYING OF THE COLUMN THIS AFTERNOON SHOULD ALLOW FOR
PARTIAL CLEARING...BUT BOUNDARY LAYER COOLING WHEN THE SUN SETS
WILL ALLOW FOR EITHER MVFR VSBY`S OR CEILINGS QUICKLY
REDEVELOPING...WITH EITHER IFR VSBY`S OR CEILINGS EXPECTED
OVERNIGHT WITH AT LEAST A STRONG SURFACE BASED INVERSION SETTING
UP AS GENERAL SUBSIDENCE WILL BE THE RULE WITH ANTI-CYCLONIC FLOW
BUILDING IN. SOUTHEAST FLOW OFF LAKE ERIE WILL MAKE DTW ESPECIALLY
SUSCEPTIBLE FOR POSSIBLE DENSE FOG OR LOW STRATUS TOMORROW
MORNING. AS TYPICAL FOR THIS TIME OF YEAR...FOG AND STRATUS WILL
LIKELY TAKE ALL MORNING TO BURN OFF/DISSIPATE WITH THE LIGHT WINDS
AND LIMITED MIXING.
&&
.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 212005
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
304 PM EST SAT NOV 21 2009
LATEST UPDATE...ALL BUT AVIATION...
.SYNOPSIS...(3042 PM EST SAT NOV 21 2009)
A LARGE HIGH PRESSURE SYSTEM...CENTERED OVER MICHIGAN EARLY THIS
AFTERNOON WILL SLOWLY MOVE EAST TO THE COAST BY MONDAY MORNING. THAT
WILL PUT SOUTHWEST LOWER MICHIGAN IN A SOUTHERLY FLOW OF AIR THAT
WILL KEEP TEMPERATURES WELL ABOVE NORMAL FOR THIS TIME OF YEAR.
LIGHT WINDS AND MOSTLY CLEAR SKIES DURING THIS EVENING AND SUNDAY
EVENING WILL ALLOW FOR FOG TO FORM AFTER MIDNIGHT TONIGHT AND SUNDAY
NIGHT. A COLD FRONT AND ASSOCIATED STORM SYSTEM WILL BRING RAIN AND
COOLER WEATHER TOWARD MIDWEEK. SOME WET SNOW MAY MIX IN BY WEDNESDAY.
&&
.SHORT TERM...(304 PM EST SAT NOV 21 2009)
(TONIGHT THROUGH MONDAY NIGHT)
THE MAIN ISSUE WITH THIS FORECAST PACKAGE IS THE POTENTIAL FOR FOG
TONIGHT AND SUNDAY NIGHT.
WITH THE HIGH PRESSURE SYSTEM OVERHEAD THIS AFTERNOON AND THE
SHORTWAVE OF LAST NIGHT TO OUR EAST...SKIES WERE MOSTLY SUNNY AT 2
PM. THE COMBINATION OF LIGHT WINDS TONIGHT AND MOSTLY CLEAR SKIES
WILL ALLOW FOR A CONSIDERABLE AMOUNT OF FOG BY MORNING. OUR FOG PLOT
PROCURE INDICATES DENSE FOG ACROSS THE AREA OVERNIGHT. I COULD SEE A
STRATUS DECK FORMING BY SUNRISE.
THE HIGH MOVES TO OUR EAST SUNDAY SO A SOUTHERLY FLOW WILL BECOME
A LITTLE STRONGER (MEAN WIND SURFACE TO 1000 FT AGL 240/04 KNOTS AT
200 PM TODAY COMPARED TO 150/08KT SUNDAY AT 2 PM). ONCE THE LOW
CLOUDS AND FOG BURN OFF IT SHOULD BE A SUNNY DAY ON SUNDAY.
WINDS WILL BE STRONGER IN THE BOUNDARY LAYER SUNDAY NIGHT...STILL IT
WOULD SEEM WITH THE LOW LEVEL MOISTURE INCREASING AND NEARLY CLEAR
SKIES DURING THE EVENING...FOG AND STRATUS WOULD BE A GOOD BET
AGAIN.
MONDAY INTO MONDAY NIGHT A SYSTEM WILL BE PASSING TO OUR SOUTHEAST.
THAT WILL BRING IN SOME MID CLOUDS BUT NOT MUCH ELSE.
&&
.LONG TERM...(304 PM EST SAT NOV 21 2009)
(TUESDAY THROUGH SATURDAY)
WE DIDN/T CHANGE THE FORECAST TOO MUCH. ECMWF/GFS CONTINUE TO SHOW
AN INTRUSION OF COLDER AIR INTO THE GREAT LAKES NEXT WEEK. BUT THE
TREND HAS BEEN TO WRAP THE COLD AIR AROUND THE DEPARTING LOW WITH
THE RESULT BEING THE COLDEST AIR FLOWING SOUTHWEST OF THE CWA. EVEN
SO WE STILL MAY SEE SOME WET SNOW DURING THE END OF THE PERIOD.
RAIN SHOULD DEVELOP TUESDAY IN ADVANCE OF AN OCCLUDING LOW THAT WILL
MOVE FROM THE PLAINS TOWARD LAKE MICHIGAN. THOSE SHOWERS WILL LINGER
INTO WEDNESDAY. A SECOND STRONGER WAVE WILL KICK THE FIRST ONE OUT
AND BRING DOWN THE COLDER AIR FROM CANADA. H8 TEMPS WILL SLOWLY FALL
FROM -2C TO PERHAPS -5C FROM WEDNESDAY THROUGH LATE FRIDAY. THE
COLDEST AIR LOOKS LIKE IT WILL BE ON FRIDAY AS THE THE UPPER LOW
MOVES AWAY SO THAT IS WHEN WE/LL HAVE THE GREATEST CHANCE OF SEEING
SOME SNOW. WE/LL SEE A WARMING TREND BEGIN SATURDAY AS THE LOW PULLS
AWAY.
&&
.AVIATION...(1258 PM EST SAT NOV 21 2009)
SKIES HAVE BASICALLY CLEARED ACROSS THE TAF SITES BUT SOME CU IS
BEGINNING TO DEVELOP. WATER VAPOR LOOP SHOWS ABUNDANT HIGH MOISTURE
WHICH IS CONTRIBUTING TO THE HAZY SKY. LIGHT WINDS DURING THE NEXT
24 HRS AND GENERALLY CLEAR SKIES TONIGHT WILL RESULT IN VSBYS
FALLING TO LESS THAN A MILE LATE TONIGHT.
&&
.MARINE...(304 PM EST SAT NOV 21 2009)
EVEN WITH THE SURFACE HIGH MOVING EAST OF THE AREA BY SUNDAY WINDS
ARE NOT EXPECTED TO BECOME STRONG ENOUGH FOR SMALL CRAFT ADVISORIES
TO BE ISSUES (WAVE HEIGHTS WILL STAY BELOW 4 FEET). AREA OF FOG
ARE EXPECTED DURING THE MORNING HOURS OF SUNDAY AND MONDAY.
&&
.HYDROLOGY...(304 PM EST SAT NOV 21 2009)
ON PRECIPITATION EXPECTED THROUGH MONDAY. NO HYDRO ISSUES ARE
EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: WDM
SHORT TERM: WDM
LONG TERM: 93
AVIATION: 93
MARINE: WDM
HYDROLOGY: WDM
000
FXUS63 KAPX 211830
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
130 PM EST SAT NOV 21 2009
.SYNOPSIS.../ISSUED AT 350 AM/
HIGH PRESSURE CENTERED OVER THE OHIO VALLEY AND CENTRAL
PLAINS...WILL LIFT NORTH INTO THE GREAT LAKES TODAY. THIS PATTERN
WILL REMAIN IN CONTROL THROUGH THE WEEKEND...GENERATING SOME SUN
AND ABOVE NORMAL TEMPERATURES INTO THE BEGINNING OF NEXT WEEK.
THE NEXT CHANCE OF RAIN WILL BE TUESDAY AND WEDNESDAY...AS A STORM
SYSTEM LIFTS NORTH INTO THE UPPER MIDWEST. TEMPERATURES WILL REMAIN
ABOVE NORMAL TUESDAY AND WEDNESDAY.
SWR
&&
.SHORT TERM.../ISSUED AT 1117 AM/...THIS AFTERNOON
BROAD AREA OF HIGH PRESSURE HAS SET UP ACROSS THE GREAT LAKES AND
MOST OF THE EASTERN CONUS WITH SUBSIDENCE AND LIGHT FLOW DOMINATING.
TRAPPED LOW LEVEL MOISTURE UNDER A STRENGTHENING SUBSIDENCE
INVERSION/LIGHT FLOW AND LOW NOVEMBER SUN ANGLE HAS CONSPIRED TO
PRODUCE WIDESPREAD STRATUS FROM EASTERN UPPER DOWN THROUGH MOST OF
THE LOWER PENINSULA. THERE IS A WEDGE OF DRIER AIR JUST UPSTREAM
WITHIN THE SFC RIDGE AXIS THAT WILL MAKE HEADWAY INTO THE AREA THIS
AFTERNOON. COMBINED WITH CONTINUED "HEATING" OF THE DAY...DO EXPECT
THE STRATUS WILL GRADUALLY THIN...A PROCESS THAT IS ALREADY
OCCURRING IN SPOTS.
SO...FOR THE AFTERNOON UPDATE HAVE TWEAKED GRIDS TO LATEST OBS AND
TRENDS...BUT DO HAVE MOST AREAS TURNING OUT PARTLY SUNNY BY MID TO
LATE AFTERNOON...SAVE FOR PERHAPS THE S/SE COUNTIES WHERE THICKER
CLOUD COVER WILL HOLD ON LATEST. WAS ORIGINALLY PLANNING TO LOWER
TEMPS BASED ON A SLOWER THINNING STRATUS DECK. BUT 16Z OBS COMING IN
ALREADY HAVE MANY SPOTS IN THE MID TO UPPER 40S IN NRN LOWER
MICHIGAN (STILL IN THE UPPER 30S IN EASTERN UPPER). SO HIGH TEMPS
RANGING FROM THE MID 40S IN EASTERN UPPER AND UPPER 40S TO LOWER 50S
IN NRN LOWER MICHIGAN WILL WORK FOR TODAY.
ADAM
&&
.LONG TERM.../ISSUED AT 350 AM/...TONIGHT AND BEYOND
GENERALLY UNEVENTFUL WX WILL CONTINUE. THIS IS NOT THE WAY NOVEMBER
IS SUPPOSED TO WORK AROUND THESE PARTS...BUT SO BE IT. SHORTWAVE
UPPER RIDGING WILL MOVE OVERHEAD TONIGHT...GIVING WAY TO A LENGTHY
PERIOD OF DEEP SW FLOW ALOFT...AHEAD OF A CLOSED LOW MOVING INTO THE
CENTRAL PLAINS BY TUESDAY MORNING. AT THE SURFACE...HIGH PRESSURE
WILL SLOWLY MOVE FROM THE EASTERN LAKES TO THE MARITIME PROVINCES...
EXTENDING RIDGING BACK INTO THE LAKES REGION THRU MONDAY. TEMPS AND
CLOUDS ARE THE MAIN CONCERNS THRU MONDAY.
MODELS...THE MAIN FOCUS IS ON THE SURFACE LOW EXPECTED TO BE BREWING
IN THE CENTRAL PLAINS OR UPPER MS VALLEY BY TUESDAY. MOST OF THE
ENERGY LEADING TO THIS SYSTEM IS STILL WELL OFFSHORE OF THE WEST
COAST. SO THE WIDE MODEL SPREAD (AND RUN-TO-RUN INCONSISTENCIES) ARE
TO BE EXPECTED. HOWEVER...ALL MODELS HAVE US IN THE WARM SECTOR AND
THUS WITH JUST A RAIN EVENT UNTIL COLDER AIR ARRIVES AS THE SYSTEM
PULLS OUT.
TONIGHT/SUNDAY...DEEP AIRMASS REMAINS QUITE DRY. HOWEVER...
DEVELOPING SE FLOW BELOW 950MB (IN A STABLE LAYER RAPIDLY COOLING
TOWARD SATURATION) WILL LIKELY RESULT IN SOME STRATUS REDEVELOPMENT
IN PARTS OF NE/N CENTRAL LOWER AND EASTERN UPPER MI. BOTH THE
NAM/GFS (AND ASSOCIATED NUMERICAL GUIDANCE) PRODUCE SOME LOW CLOUDS.
THE NAM IS MUCH MORE AGGRESSIVE...ALMOST CERTAINLY TOO MUCH SO GIVEN
THE INITIALLY DRY AIRMASS. STILL...WILL NEED TO REORIENT OVERNIGHT
(AND SUNDAY MORNING) CLOUD COVER FOR MORE CLOUDS N/E AND LESS W.
PRESUMING THESE LOW CLOUDS ARE NOT EXTENSIVE...WE/LL BURN THEM OFF
BY EARLY AFTERNOON...WITH MAINLY SUNNY SKIES THEREAFTER. MIN TEMPS
IN THE 30S (AIMING NEAR OR BELOW GUIDANCE). MAX TEMPS UPPER 40S TO
MID 50S.
SUNDAY NIGHT/MONDAY...ACTUALLY VERY SIMILAR ISSUES AS WE HAVE LATE
TONIGHT. SHALLOW (SUB-950MB) SE FLOW WILL ABUNDANT DRY AIR ALOFT
WILL AGAIN SUPPORT AREAS OF STRATUS IN NE LOWER AND EASTERN UPPER
OVERNIGHT INTO MONDAY MORNING. THAT WILL GIVE WAY TO PARTLY (OR EVEN
MOSTLY) SUNNY CONDITIONS BY MONDAY AFTERNOON. BETTER ISENTROPIC
ASCENT/RETURN FLOW WILL REMAIN ANCHORED OVER WESTERN SUPERIOR AND
SURROUNDING AREAS...NO SIGNIFICANT CHANCE FOR PRECIP IS SEEN THIS
FAR EAST. MIN TEMPS 30S...MAX TEMPS UPPER 40S TO LOWER 50S.
REST OF THE FORECAST...TIMING THE NEXT SYSTEM REMAINS A CHALLENGE...
AND WILL CONTINUE TO BE SOMEWHAT BLAND WITH THE MIDWEEK FORECAST.
HOWEVER...MODELS ARE IN AGREEMENT IN A WARMER SOLUTION THAT SLOWS
DOWN ANY REAL RISK OF MIXED PRECIP. WILL GO ALL RAIN WED...A MIX WED
NIGHT...STILL PRIMARILY SNOW ON TURKEY DAY (EVEN THAT IS
UNCERTAIN...AND DOES NOT LOOK LIKE A BIG DEAL REGARDLESS).
JZ
&&
.MARINE.../ISSUED AT 350 AM/
HIGH PRESSURE WILL MOVE FROM THE OHIO VALLEY...TO THE EASTERN GREAT
LAKES...TO THE GULF OF ST LAWRENCE OVER THE NEXT 4 DAYS. WINDS AND
WAVES WILL REMAIN WELL BELOW SMALL CRAFT ADVISORY CRITERIA OVER THE
NEXT 2 DAYS. HOWEVER...FOG COULD CONTINUE TO CAUSE SOME ISSUES ON
THE CONNECTING WATERWAYS...ESPECIALLY IN THE LATE NIGHT AND MORNING
HOURS.
JZ
&&
.AVIATION.../ISSUED AT 129 PM/...VALID FOR 18Z TAFS
IFR STRATUS/FOG DONE FOR THE DAY AT PLN/TVC AND WILL ERODE AT APN
BY 20Z...LEAVING A PERIOD OF VFR CONDITIONS INTO THE EVENING
HOURS. LOW STRATUS/IFR CIGS AGAIN POSSIBLE LATER TONIGHT
PARTICULARLY AT APN. HOWEVER...FORECAST SOUNDINGS/SLIGHTLY DRIER
AIR OVERSPREADING THE REGION SHOULD KEEP STRATUS/FOG AT BAY TO
SOME DEGREE. WHATEVER STRATUS/FOG DEVELOPS WILL MIX OUT AGAIN ON
SUNDAY LEAVING VFR CONDITIONS FOR MUCH OF THE DAY.
ADAM
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KGRR 211758
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1258 PM EST SAT NOV 21 2009
LATEST UPDATE...AVIATION...
.SYNOPSIS...(400 AM EST SAT NOV 21 2009)
HIGH PRESSURE WILL PRODUCE DRY WEATHER AND PARTLY CLOUDY SKIES
THROUGH THE WEEKEND. PATCHY FOG IS ANTICIPATED DURING THE EARLY TO
MID MORNING HOURS OF SATURDAY... SUNDAY AND MONDAY. TEMPERATURES
WILL REMAIN ABOVE NORMAL INTO MID WEEK BEFORE IT TURNS A LITTLE
COOLER LATE IN THE WEEK.
&&
.SHORT TERM...(400 AM EST SAT NOV 21 2009)
(TODAY THROUGH MONDAY AFTERNOON)
SHORT TERM FCST CONCERNS REMAIN FAIRLY MINIMAL. HIGH PRESSURE WILL
PRODUCE DRY WX THROUGH THE WEEKEND. SFC OBS EARLY THIS MORNING SHOW
PATCHY FOG CONTINUES TO DEVELOP WHICH WILL LINGER THROUGH THE EARLY
TO MID MORNING HOURS BEFORE DISSIPATING. LINGERING MORNING CLOUD
COVER WILL GIVE WAY TO PARTIAL SUNSHINE THAT WILL HELP TO BOOST MAX
TEMPS INTO THE LOW TO MID 50S.
00Z MODEL RH PROGS AND NUMERICAL GUIDANCE SUGGESTS MORE CLEARING
WILL OCCUR TONIGHT AS COMPARED TO EARLY THIS MORNING. THIS IN
CONJUNCTION WITH LIGHT AND VARIABLE WINDS WILL ONCE AGAIN SET THE
STAGE FOR PATCHY FOG DEVELOPMENT DURING THE EARLY MORNING HOURS
SUNDAY AND THEN AGAIN ON MONDAY. HIGH TEMPS SUNDAY AND MONDAY WILL
REACH THE LOW TO MID 50S WITH MIN TEMPS MAINLY IN THE UPPER 30S TO
LOWER 40S.
&&
.LONG TERM...(400 AM EST SAT NOV 21 2009)
(MONDAY NIGHT THROUGH FRIDAY)
THE 00Z/21 RUNS OF THE GFS AND ECMWF ARE STILL NOT IN VERY GOOD
AGREEMENT REGARDING THE MID WEEK SYSTEM AND HAVE TRIED TO
INCORPORATE BOTH SOLUTIONS INTO THE FCST GRIDS. A LOW PRESSURE
SYSTEM WILL BE TRACKING FROM THE CNTRL/NRN PLAINS ON TUESDAY... EAST
NORTHEAST THROUGH THE GREAT LAKES REGION ON WED AND THU.
THE FASTER GFS SOLUTION SUPPORTS WAA RAIN MOVING INTO THE REGION ON
TUESDAY WHILE SLOWER ECMWF KEEPS IT DRY AND HOLDS THE RAIN OFF UNTIL
WEDNESDAY. THE COMPROMISE IS TO CARRY CHANCE POPS BOTH DAYS...
ALTHOUGH BELIEVE WEDNESDAY OFFERS THE BETTER PCPN POTENTIAL AND WILL
CARRY SCTD VS CHANCE WORDING ON THAT DAY.
PCPN TYPE BECOMES QUITE PROBLEMATIC BY THANKSGIVING DAY AS THE SFC
LOW MOVES BY AND COOLER AIR IS DRAWN DOWN ON THE BACK SIDE OF THE
SYSTEM. GFS SOLUTION IS STILL COLDER THAN THE ECMWF... ALTHOUGH IT
IS A COMMON BIAS OF THE GFS TO BE COLDER BEYOND DAY 4. EVEN IF ONE
WERE TO RUN WITH THE COOLER GFS SOLUTION... THE 00Z FCST SOUNDINGS
LOOK JUST A TAD TOO WARM IN THE BOUNDARY LAYER TO SUPPORT SNOW. WILL
THEREFORE GO WITH WITH RAIN OR SNOW SHOWER WORDING.
THE CURRENT FCST FOR THURSDAY NIGHT AND FRIDAY CURRENTLY HAS ALL
SNOW FOR PCPN TYPE AND LEFT THAT UNCHANGED... ALTHOUGH THE SPEED OF
THE SYSTEM DEPARTURE WILL DICTATE PCPN CHANCES AND THE DEGREE OF
COLD AIR ON THE BACK SIDE WILL DICTATE PCPN TYPE. THAT/S STILL A BIG
UNCERTAINTY ATTM.
&&
.AVIATION...(1258 PM EST SAT NOV 21 2009)
SKIES HAVE BASICALLY CLEARED ACROSS THE TAF SITES BUT SOME CU IS
BEGINNING TO DEVELOP. WATER VAPOR LOOP SHOWS ABUNDANT HIGH MOISTURE
WHICH IS CONTRIBUTING TO THE HAZY SKY. LIGHT WINDS DURING THE NEXT
24 HRS AND GENERALLY CLEAR SKIES TONIGHT WILL RESULT IN VSBYS
FALLING TO LESS THAN A MILE LATE TONIGHT.
&&
.MARINE...(400 AM EST SAT NOV 21 2009)
HIGH PRESSURE AND LIGHT WINDS WILL RESULT IN MINIMAL WIND/WAVE
ACTION THROUGH THE WEEKEND. SOME PATCHY EARLY TO MID MORNING FOG
THROUGH THE WEEKEND COULD POSE A HAZARD TO MARINERS.
&&
.HYDROLOGY...(400 AM EST SAT NOV 21 2009)
DRY WEATHER IS EXPECTED THROUGH MONDAY. NO HYDRO ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: LAURENS
SHORT TERM: LAURENS
LONG TERM: MEADE
AVIATION: 93
MARINE: LAURENS
HYDROLOGY: LAURENS
000
FXUS63 KMQT 211715 AAB
AFDMQT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MARQUETTE MI
1215 PM EST SAT NOV 21 2009
UPDATED FOR 18Z TAFS
.SYNOPSIS...
00Z RAOBS SHOW RDG ALF BLDG INTO THE WRN GRT LKS DOWNSTREAM OF UPR
TROFFING ALG THE W COAST. AIRMASS UNDER THIS RDG IS QUITE DRY ALF...
WITH 00Z PWAT AS LO AS A MEAGER 0.11 INCH AT INL. SINCE NEAR SFC
MSTR IS MORE ABUNDANT...FOG HAS DEVELOPED OVER THE FA WITH LGT WINDS
ASSOCIATED WITH SFC HI PRES BLDG OVHD UNDER THE RDGING ALF. THE FOG
HAS BECOME LOCALLY DENSE EARLY THIS MRNG. TO THE W...VERY WARM AIR
IS FLOODING NWD INTO THE NRN PLAINS IN THE SLY FLOW BTWN THE HI PRES
RDG NOW OVHD AND LOWER MSLP IN THE ROCKIES. THE 00Z H85 TEMP RANGED
FM 4C AT GRB AND INL TO 9C AT BIS AND AN IMPRESSIVE 14C AT GLASGOW
MT.
&&
.DISCUSSION...
MAIN FCST CONCERNS THIS FCST PD INCLUDE TEMPS THIS WEEKEND AND THEN
PCPN CHCS LATE SUN INTO THE MIDDLE OF NEXT WEEK AS LO PRES BEGINS TO
TAKE SHAPE IN THE PLAINS AND MOVES NE.
TDAY...UPR RDG WILL CONT TO BLD OVER THE UPR LKS WITH FLOOD OF WARM
AIR SURGING INTO CAN AHEAD OF DEEP WRN TROF. WITH DRYNESS OF AIRMASS
MOVING OVHD...EXPECT A MOSUNNY DAY AFT MRNG FOG BURNS OFF. ISSUED
SPS TO HILIGHT PATCHY DENSE FOG EARLY THIS MRNG. MIXING TO H9 ON
FCST SDNGS YIELDS HI TEMPS TOPPING OUT AS HI AS THE LO 50S. GOING
FCST MAX TEMPS SEEM ON TRACK.
FOR TNGT...AS HI PRES RDG SHIFTS TO THE E...SHARPER PRES GRADIENT/
STRENGTHENING SLY FLOW WL DVLP OVER THE CWA...EARLIEST OVER THE W.
WITH THIS STRONGER WIND...EXPECT RELATIVELY LTL DIURNAL FALL OF TEMP
IN THE DOWNSLOPING AREAS NEAR LK SUP...ESPECIALLY OVER THE W FM IWD-
P59. ALTHOUGH THE SHELTERED INTERIOR ECNTRL WL SEE LOWER TEMPS BLO
MOS GUIDANCE WITH DRY MID LVLS AND WEAKER WINDS A BIT LONGER CLOSER
TO DEPARTING SFC HI...BUMPED UP GOING FCST MIN TEMPS THERE A BIT
WITH BOTH GFS/NAM SHOWING A QUICKER RETURN OF H95-9 SPECIFIC
HUMIDITY THAT WL FAVOR FOG AND/OR ST DVLPMENT DURING TIME OF DIURNAL
COOLING.
GFS REMAINS THE MOST AGGRESSIVE MODEL AT GENERATING PCPN OVER THE W
HALF OF THE FA ON SUN AFTN SHOWING MSTR RETURN THRU H7. ALTHOUGH THE
NAM NOW SHOWS HIER SPECIFIC HUMIDITY RETURNING AT H7 AS WELL...THIS
MODEL FOCUSES THE AXIS OF HIER MSTR FARTHER W OVER WRN LK SUP.
CONSIDERING THE FAIRLY HI AMPLITUDE WRN TROF/ERN RDG PATTERN THAT
WOULD FAVOR A SLOWER W-E PROGRESSION...TENDED TOWARD THE NAM AND
GOING FCST. ALTHOUGH THE EXPLICIT GFS FCST SHOWS PCPN...THE GFS MOS
FCST FOR IWD SHOWS ONLY A 10 POP FOR 18Z-24Z SUN...SUPPORTING THE
DRIER NAM AND UKMET. OVER THE E...THERE WL LIKELY BE SOME SUNSHINE
AFT MRNG FOG/ST BURNS OFF WITH MID LVL DRY AIR THRU THE DAY. MORE
PERSISTENT CLD COVER OVER THE W WL LIMIT THE DIURNAL TEMP REBOUND...
BUT BUMPED UP FCST HI TEMPS FARTHER E AWAY FM THE MODERATING
INFLUENCE OF LK MI WITH EXPECTATION FOR MORE AFTN SUNSHINE.
TENDED TO FOLLOW THE LESS PROGRESSIVE NAM/UKMET/12Z ECMWF AGAIN ON
SUN NGT AND CUT BACK ON EWD PROGRESSION OF POPS IN PREVIOUS FCST
GIVEN STRENGTH OF RDG TO THE E AND LINGERING MID LVL DRY AIR. WENT
WITH HIEST POPS OVER WRN LK SUP WHERE NAM SHOWS AXIS OF HIER H85-7
SPECIFIC HUMIDITY AND SOME WEAK UPR DVGC FOR A TIME IN RRQ OF H3 JET
MAX LIFTING NEWD THRU NW ONTARIO. OVER THE E...LOWERED GOING FCST
MIN TEMPS BLO MOS GUIDANCE GIVEN PERSISTENCE OF DRY AIR ALF AND
WHERE NAM SHOWS RISING MSLP/WEAKER GRADIENT FLOW. ALSO ADDED SOME
FOG IN THESE AREAS WHERE DRIER AIR/LIGHTER WINDS WOULD FAVOR THE
SHARPER DIURNAL TEMP FALL. RAISED FCST MIN TEMPS OVER THE W WITH
MORE CLDS/STRONGER WINDS/DOWNSLOPING SLY FLOW.
WITH RDG/ACYC FLOW TENDING TO STRENGTHEN ON MON DOWNSTREAM OF
DEEPENING TROF IN THE PLAINS...TRIMMED GOING POPS TO FCST SCHC POPS
ONLY OVER THE FAR W CLOSER TO LO PRES TROF IN NE MN ON MON AND MON
NGT. WITH TENDENCY FOR DRIER AIR...INCRSD MAX TEMPS ON MON AND
LOWERED FCST FOR MON NGT MINS. ADDED FOG AGAIN OVER THE INTERIOR
ECNTRL WHERE LOWEST TEMPS ARE FAVORED UNDER HIER MSLP. TENDED TO CUT
POPS OVER ESPECIALLY THE NE FA ON TUE AS WELL WITH FAVORED 00Z ECMWF
STILL SHOWING TENACIOUS DRY AIR THERE THRU 00Z WED CLOSER TO SFC HI
IN QUEBEC.
COORDINATED WITH GRB.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
MORNING FOG HAS DISSIPATED WITH VFR CONDITIONS EXPECTED AT SAW AND
CMX THROUGH THE EVENING HOURS. WITH SFC RIDGE MOVING EAST OF THE
AREA AND PRESSURE GRADIENT TIGHTENING...SOUTHERLY WINDS SHOULD
PREVENT FOG FROM GETTING AS DENSE AS LAST NIGHT. HOWEVER...WITH LOW
LEVEL MOISTURE REMAINING...DO EXPECT SOME FOG TO REDEVELOP AFTER
MIDNIGHT...ESPECIALLY UNTIL SOUTHERLY WINDS BEGIN TO INCREASE
TOWARDS DAYBREAK. IN ADDITION..EXPECT MVFR STRATUS CIGS TO DEVELOP
AT BOTH SITES LATE TONIGHT AND PERSIST THROUGH SUNDAY MORNING.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
WINDS WILL REMAIN BELOW 25 KNOTS THROUGH THIS FORECAST PERIOD AS
HIGH PRESSURE REMAINS OVER THE UPPER GREAT LAKES AND KEEPS SYSTEMS
OUT OF THE AREA. WINDS WILL START TO INCREASE WED...POSSIBLY TO GALE
FORCE...AS A STORM SYSTEM COMES UP FROM THE SOUTH.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS/DISCUSSION...KC
AVIATION...MZ
MARINE...PEARSON
000
FXUS63 KDTX 211701
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1201 PM EST SAT NOV 21 2009
.AVIATION...
REMNANT LOW LEVEL MOISTURE WITH ILL DEFINED LOW LEVEL INVERSION WILL
MAKE FOR A DIFFICULT TAF FORECAST...AS THE DEBATE WILL BE LOW
STRATUS VS FOG AS CALM/LIGHT WINDS PROMOTE GOOD RADATIONAL COOLING
TONIGHT. SLOW DRYING OF THE COLUMN THIS AFTERNOON SHOULD ALLOW FOR
PARTIAL CLEARING...BUT BOUNDARY LAYER COOLING WHEN THE SUN SETS
WILL ALLOW FOR EITHER MVFR VSBY`S OR CEILINGS QUICKLY
REDEVELOPING...WITH EITHER IFR VSBY`S OR CEILINGS EXPECTED
OVERNIGHT WITH AT LEAST A STRONG SURFACE BASED INVERSION SETTING
UP AS GENERAL SUBSIDENCE WILL BE THE RULE WITH ANTI-CYCLONIC FLOW
BUILDING IN. SOUTHEAST FLOW OFF LAKE ERIE WILL MAKE DTW ESPECIALLY
SUSCEPTIBLE FOR POSSIBLE DENSE FOG OR LOW STRATUS TOMORROW
MORNING. AS TYPICAL FOR THIS TIME OF YEAR...FOG AND STRATUS WILL
LIKELY TAKE ALL MORNING TO BURN OFF/DISSIPATE WITH THE LIGHT WINDS
AND LIMITED MIXING.
&&
.PREV DISCUSSION...ISSUED 340 AM EST SAT NOV 21 2009
SHORT TERM...TODAY
VERY LITTLE CHANGE TODAY AS CLOUDY SKIES PERSIST MOST IF NOT ALL OF
THE DAY. THE AIRMASS HAS BEEN ABLE TO MODIFY...SO TEMPERATURES WILL
TOP OUT IN THE LOW/MID 50S -VS- FRIDAY/S AROUND 50. THERE WILL BE A
BETTER CHANCE AT A FEW BREAKS IN THE CLOUDS DURING THE AFTERNOON BUT
WITH SUNSET JUST AFTER 5 PM...THE WINDOW WILL CLOSE PRETTY QUICKLY.
NO SIGNIFICANT CHANGES WERE NEEDED TO THE GOING FORECAST.
LONG TERM...TONIGHT THROUGH NEXT FRIDAY
THE CONCERNS IN THE EXTENDED FORECAST REVOLVE AROUND THE POTENTIAL
FOR FOG DEVELOPMENT SUNDAY AND MONDAY MORNINGS AND THEN THE
DEVELOPMENT OF THE LOW PRESSURE SYSTEM THAT WILL HEAD FOR THE AREA
AROUND THANKSGIVING.
A WEAK AREA OF HIGH PRESSURE WILL SLIDE EAST OF THE REGION TONIGHT
GIVING OUR WIND FIELD A SLIGHT EASTERLY COMPONENT. THIS MOIST FLOW
OFF LAKE ERIE WILL ACT TO REINFORCE THE ALREADY MOIST LOW LEVELS.
FAIRLY HIGH SURFACE DEWPOINTS IN THE UPPER 30S TO LOW 40S WILL BE IN
PLACE DURING SUNDAY AND MONDAY MORNINGS. NAMBUFR SOUNDINGS SHOW A
VERY STRONG INVERSION FORMING BETWEEN 925 AND 950MB WHICH WILL TRAP
THIS MOISTURE AT THE SURFACE. SEE NO REASON NOT TO CONTINUE
INHERITED FORECAST MENTION OF FOG FOR BOTH THESE MORNINGS.
TEMPERATURES LOOK TO REMAIN SLIGHTLY ABOVE NORMAL THIS WEEKEND
THROUGH THE EARLY PART OF THE WEEK...44/29 FNT AND 46/32
DTW...THOUGH THERE WILL BE A GRADUAL DECREASE EACH DAY ALONG THE
WAY. TEMPS WILL THEN FALL TO AT OR BELOW NORMAL VALUES AS WE FEEL
THE EFFECTS OF THE NEXT LOW PRESSURE SYSTEM AROUND THANKSGIVING.
THE 00Z MODEL SUITE CONTINUE TO SHOW DISAGREEMENT WITH THE
DEVELOPMENT OF THE MID WEEK LOW AS THEIR PRIOR RUNS HAVE DONE ALL
ALONG AS WELL. THE GFS DEVELOPS A LOW OVER THE NORTHERN PLAINS EARLY
IN THE WEEK AND SHOWS HINTS OF CUTTING OFF THE LOW BUT A FAST MOVING
SHORTWAVE BEHIND THE INITIAL LOW ACTS TO REINFORCE THE LONGWAVE
TROUGH AND NEVER LET IT GET FULLY CUTOFF. THIS SOLUTION KEEPS THINGS
QUITE PROGRESSIVE MEANING PRECIP MOVES IN FASTER ALONG WITH A COLD
CANADIAN AIRMASS. ON THE OTHER HAND YOU HAVE THE ECMWF/NGM/DGEX ALL
HAVE THE LOW BECOMING MORE CUTOFF AND LOCATED FURTHER SOUTH. THIS
LEADS TO A SLOWER PROGRESSION AND HOLDS OFF PRECIP AN EXTRA DAY FOR
THE REGION. ONE THINGS THE MODELS HAVE IN COMMON IS THE COLD AIR
THIS SYSTEM WILL BRING DOWN TO MICHIGAN. 850MB TEMPS WILL FALL FROM
THEIR CURRENT VALUE OF AROUND +4C DOWN TO -5C...AND IF THE GFS PANS
OUT POSSIBLY -10C. THIS EQUATES TO MAX TEMPS ONLY IN THE LOW 40S AND
LOWS IN THE MID 20S. THIS COLD AIRMASS WILL LEAD TO A RAIN/SNOW MIX
THURSDAY AND POSSIBLY ALL SNOW ON FRIDAY ON THE BACKSIDE OF THE
PASSING LOW.
MARINE...
WINDS WILL BE LIGHT TODAY AS HIGH PRESSURE BUILDS OVER THE AREA.
THIS HIGH WILL REMAIN IN PLACE INTO SUNDAY AND THEN ONLY SLOWLY
PROGRESS TO THE EAST EARLY NEXT WEEK...ALLOWING A VERY GRADUAL
INCREASE IN SOUTHEAST FLOW FROM MONDAY INTO TUESDAY. 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 LOW OVER/NEAR THE REGION. THIS TIME
FRAME WILL BRING THE NEXT PERIOD OF HEADLINE WORTHY WINDS/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 211619
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1117 AM EST SAT NOV 21 2009
.SYNOPSIS.../ISSUED AT 350 AM/
HIGH PRESSURE CENTERED OVER THE OHIO VALLEY AND CENTRAL
PLAINS...WILL LIFT NORTH INTO THE GREAT LAKES TODAY. THIS PATTERN
WILL REMAIN IN CONTROL THROUGH THE WEEKEND...GENERATING SOME SUN
AND ABOVE NORMAL TEMPERATURES INTO THE BEGINNING OF NEXT WEEK.
THE NEXT CHANCE OF RAIN WILL BE TUESDAY AND WEDNESDAY...AS A STORM
SYSTEM LIFTS NORTH INTO THE UPPER MIDWEST. TEMPERATURES WILL REMAIN
ABOVE NORMAL TUESDAY AND WEDNESDAY.
SWR
&&
.SHORT TERM.../ISSUED AT 1117 AM/...THIS AFTERNOON
BROAD AREA OF HIGH PRESSURE HAS SET UP ACROSS THE GREAT LAKES AND
MOST OF THE EASTERN CONUS WITH SUBSIDENCE AND LIGHT FLOW DOMINATING.
TRAPPED LOW LEVEL MOISTURE UNDER A STRENGTHENING SUBSIDENCE
INVERSION/LIGHT FLOW AND LOW NOVEMBER SUN ANGLE HAS CONSPIRED TO
PRODUCE WIDESPREAD STRATUS FROM EASTERN UPPER DOWN THROUGH MOST OF
THE LOWER PENINSULA. THERE IS A WEDGE OF DRIER AIR JUST UPSTREAM
WITHIN THE SFC RIDGE AXIS THAT WILL MAKE HEADWAY INTO THE AREA THIS
AFTERNOON. COMBINED WITH CONTINUED "HEATING" OF THE DAY...DO EXPECT
THE STRATUS WILL GRADUALLY THIN...A PROCESS THAT IS ALREADY
OCCURRING IN SPOTS.
SO...FOR THE AFTERNOON UPDATE HAVE TWEAKED GRIDS TO LATEST OBS AND
TRENDS...BUT DO HAVE MOST AREAS TURNING OUT PARTLY SUNNY BY MID TO
LATE AFTERNOON...SAVE FOR PERHAPS THE S/SE COUNTIES WHERE THICKER
CLOUD COVER WILL HOLD ON LATEST. WAS ORIGINALLY PLANNING TO LOWER
TEMPS BASED ON A SLOWER THINNING STRATUS DECK. BUT 16Z OBS COMING IN
ALREADY HAVE MANY SPOTS IN THE MID TO UPPER 40S IN NRN LOWER
MICHIGAN (STILL IN THE UPPER 30S IN EASTERN UPPER). SO HIGH TEMPS
RANGING FROM THE MID 40S IN EASTERN UPPER AND UPPER 40S TO LOWER 50S
IN NRN LOWER MICHIGAN WILL WORK FOR TODAY.
ADAM
&&
.LONG TERM.../ISSUED AT 350 AM/...TONIGHT AND BEYOND
GENERALLY UNEVENTFUL WX WILL CONTINUE. THIS IS NOT THE WAY NOVEMBER
IS SUPPOSED TO WORK AROUND THESE PARTS...BUT SO BE IT. SHORTWAVE
UPPER RIDGING WILL MOVE OVERHEAD TONIGHT...GIVING WAY TO A LENGTHY
PERIOD OF DEEP SW FLOW ALOFT...AHEAD OF A CLOSED LOW MOVING INTO THE
CENTRAL PLAINS BY TUESDAY MORNING. AT THE SURFACE...HIGH PRESSURE
WILL SLOWLY MOVE FROM THE EASTERN LAKES TO THE MARITIME PROVINCES...
EXTENDING RIDGING BACK INTO THE LAKES REGION THRU MONDAY. TEMPS AND
CLOUDS ARE THE MAIN CONCERNS THRU MONDAY.
MODELS...THE MAIN FOCUS IS ON THE SURFACE LOW EXPECTED TO BE BREWING
IN THE CENTRAL PLAINS OR UPPER MS VALLEY BY TUESDAY. MOST OF THE
ENERGY LEADING TO THIS SYSTEM IS STILL WELL OFFSHORE OF THE WEST
COAST. SO THE WIDE MODEL SPREAD (AND RUN-TO-RUN INCONSISTENCIES) ARE
TO BE EXPECTED. HOWEVER...ALL MODELS HAVE US IN THE WARM SECTOR AND
THUS WITH JUST A RAIN EVENT UNTIL COLDER AIR ARRIVES AS THE SYSTEM
PULLS OUT.
TONIGHT/SUNDAY...DEEP AIRMASS REMAINS QUITE DRY. HOWEVER...
DEVELOPING SE FLOW BELOW 950MB (IN A STABLE LAYER RAPIDLY COOLING
TOWARD SATURATION) WILL LIKELY RESULT IN SOME STRATUS REDEVELOPMENT
IN PARTS OF NE/N CENTRAL LOWER AND EASTERN UPPER MI. BOTH THE
NAM/GFS (AND ASSOCIATED NUMERICAL GUIDANCE) PRODUCE SOME LOW CLOUDS.
THE NAM IS MUCH MORE AGGRESSIVE...ALMOST CERTAINLY TOO MUCH SO GIVEN
THE INITIALLY DRY AIRMASS. STILL...WILL NEED TO REORIENT OVERNIGHT
(AND SUNDAY MORNING) CLOUD COVER FOR MORE CLOUDS N/E AND LESS W.
PRESUMING THESE LOW CLOUDS ARE NOT EXTENSIVE...WE/LL BURN THEM OFF
BY EARLY AFTERNOON...WITH MAINLY SUNNY SKIES THEREAFTER. MIN TEMPS
IN THE 30S (AIMING NEAR OR BELOW GUIDANCE). MAX TEMPS UPPER 40S TO
MID 50S.
SUNDAY NIGHT/MONDAY...ACTUALLY VERY SIMILAR ISSUES AS WE HAVE LATE
TONIGHT. SHALLOW (SUB-950MB) SE FLOW WILL ABUNDANT DRY AIR ALOFT
WILL AGAIN SUPPORT AREAS OF STRATUS IN NE LOWER AND EASTERN UPPER
OVERNIGHT INTO MONDAY MORNING. THAT WILL GIVE WAY TO PARTLY (OR EVEN
MOSTLY) SUNNY CONDITIONS BY MONDAY AFTERNOON. BETTER ISENTROPIC
ASCENT/RETURN FLOW WILL REMAIN ANCHORED OVER WESTERN SUPERIOR AND
SURROUNDING AREAS...NO SIGNIFICANT CHANCE FOR PRECIP IS SEEN THIS
FAR EAST. MIN TEMPS 30S...MAX TEMPS UPPER 40S TO LOWER 50S.
REST OF THE FORECAST...TIMING THE NEXT SYSTEM REMAINS A CHALLENGE...
AND WILL CONTINUE TO BE SOMEWHAT BLAND WITH THE MIDWEEK FORECAST.
HOWEVER...MODELS ARE IN AGREEMENT IN A WARMER SOLUTION THAT SLOWS
DOWN ANY REAL RISK OF MIXED PRECIP. WILL GO ALL RAIN WED...A MIX WED
NIGHT...STILL PRIMARILY SNOW ON TURKEY DAY (EVEN THAT IS
UNCERTAIN...AND DOES NOT LOOK LIKE A BIG DEAL REGARDLESS).
JZ
&&
.MARINE.../ISSUED AT 350 AM/
HIGH PRESSURE WILL MOVE FROM THE OHIO VALLEY...TO THE EASTERN GREAT
LAKES...TO THE GULF OF ST LAWRENCE OVER THE NEXT 4 DAYS. WINDS AND
WAVES WILL REMAIN WELL BELOW SMALL CRAFT ADVISORY CRITERIA OVER THE
NEXT 2 DAYS. HOWEVER...FOG COULD CONTINUE TO CAUSE SOME ISSUES ON
THE CONNECTING WATERWAYS...ESPECIALLY IN THE LATE NIGHT AND MORNING
HOURS.
JZ
&&
.AVIATION.../ISSUED AT 633 AM/...VALID FOR 12Z TAFS
WIDESPREAD IFR CONDITIONS THIS MORNING IN FOG/STRATUS. IMPROVEMENT
TO MVFR AND THEN VFR IS EXPECTED MIDDAY AND AFTERNOON AS DRIER AIR
MOVES IN FROM THE WEST. FOG AND LOW CLOUDS COULD RETURN TONIGHT...
ESPECIALLY AT APN...BUT SHOULD NOT BE AS WIDESPREAD.
JZ
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KGRR 211153
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
652 AM EST SAT NOV 21 2009
LATEST UPDATE...AVIATION...
.SYNOPSIS...(400 AM EST SAT NOV 21 2009)
HIGH PRESSURE WILL PRODUCE DRY WEATHER AND PARTLY CLOUDY SKIES
THROUGH THE WEEKEND. PATCHY FOG IS ANTICIPATED DURING THE EARLY TO
MID MORNING HOURS OF SATURDAY... SUNDAY AND MONDAY. TEMPERATURES
WILL REMAIN ABOVE NORMAL INTO MID WEEK BEFORE IT TURNS A LITTLE
COOLER LATE IN THE WEEK.
&&
.SHORT TERM...(400 AM EST SAT NOV 21 2009)
(TODAY THROUGH MONDAY AFTERNOON)
SHORT TERM FCST CONCERNS REMAIN FAIRLY MINIMAL. HIGH PRESSURE WILL
PRODUCE DRY WX THROUGH THE WEEKEND. SFC OBS EARLY THIS MORNING SHOW
PATCHY FOG CONTINUES TO DEVELOP WHICH WILL LINGER THROUGH THE EARLY
TO MID MORNING HOURS BEFORE DISSIPATING. LINGERING MORNING CLOUD
COVER WILL GIVE WAY TO PARTIAL SUNSHINE THAT WILL HELP TO BOOST MAX
TEMPS INTO THE LOW TO MID 50S.
00Z MODEL RH PROGS AND NUMERICAL GUIDANCE SUGGESTS MORE CLEARING
WILL OCCUR TONIGHT AS COMPARED TO EARLY THIS MORNING. THIS IN
CONJUNCTION WITH LIGHT AND VARIABLE WINDS WILL ONCE AGAIN SET THE
STAGE FOR PATCHY FOG DEVELOPMENT DURING THE EARLY MORNING HOURS
SUNDAY AND THEN AGAIN ON MONDAY. HIGH TEMPS SUNDAY AND MONDAY WILL
REACH THE LOW TO MID 50S WITH MIN TEMPS MAINLY IN THE UPPER 30S TO
LOWER 40S.
&&
.LONG TERM...(400 AM EST SAT NOV 21 2009)
(MONDAY NIGHT THROUGH FRIDAY)
THE 00Z/21 RUNS OF THE GFS AND ECMWF ARE STILL NOT IN VERY GOOD
AGREEMENT REGARDING THE MID WEEK SYSTEM AND HAVE TRIED TO
INCORPORATE BOTH SOLUTIONS INTO THE FCST GRIDS. A LOW PRESSURE
SYSTEM WILL BE TRACKING FROM THE CNTRL/NRN PLAINS ON TUESDAY... EAST
NORTHEAST THROUGH THE GREAT LAKES REGION ON WED AND THU.
THE FASTER GFS SOLUTION SUPPORTS WAA RAIN MOVING INTO THE REGION ON
TUESDAY WHILE SLOWER ECMWF KEEPS IT DRY AND HOLDS THE RAIN OFF UNTIL
WEDNESDAY. THE COMPROMISE IS TO CARRY CHANCE POPS BOTH DAYS...
ALTHOUGH BELIEVE WEDNESDAY OFFERS THE BETTER PCPN POTENTIAL AND WILL
CARRY SCTD VS CHANCE WORDING ON THAT DAY.
PCPN TYPE BECOMES QUITE PROBLEMATIC BY THANKSGIVING DAY AS THE SFC
LOW MOVES BY AND COOLER AIR IS DRAWN DOWN ON THE BACK SIDE OF THE
SYSTEM. GFS SOLUTION IS STILL COLDER THAN THE ECMWF... ALTHOUGH IT
IS A COMMON BIAS OF THE GFS TO BE COLDER BEYOND DAY 4. EVEN IF ONE
WERE TO RUN WITH THE COOLER GFS SOLUTION... THE 00Z FCST SOUNDINGS
LOOK JUST A TAD TOO WARM IN THE BOUNDARY LAYER TO SUPPORT SNOW. WILL
THEREFORE GO WITH WITH RAIN OR SNOW SHOWER WORDING.
THE CURRENT FCST FOR THURSDAY NIGHT AND FRIDAY CURRENTLY HAS ALL
SNOW FOR PCPN TYPE AND LEFT THAT UNCHANGED... ALTHOUGH THE SPEED OF
THE SYSTEM DEPARTURE WILL DICTATE PCPN CHANCES AND THE DEGREE OF
COLD AIR ON THE BACK SIDE WILL DICTATE PCPN TYPE. THAT/S STILL A BIG
UNCERTAINTY ATTM.
&&
.AVIATION...(652 AM EST SAT NOV 21 2009)
MID LEVEL CLOUDS WITH BASES AROUND 8K FEET ARE STILL IN PLACE AT 12Z
EAST OF HIGHWAY 131 WHICH IS LIMITING RADIATIONAL FOG FORMATION...
AND VSBYS ARE STILL IN THE 4-6 MILE RANGE FOR THE MOST PART.
MEANWHILE THE MID LEVEL DECK HAS CLEARED ALONG AND WEST OF HIGHWAY
131...WHICH HAS ALLOWED VSBYS TO DROP TO IFR/LIFR IN FOG.
TREND WILL BE FOR GRADUALLY IMPROVING VSBYS THIS MORNING... REACHING
VFR TOWARD 18Z. HOWEVER IFR/LIFR FOG WILL LIKELY FORM AREAWIDE LATE
TONIGHT.
&&
.MARINE...(400 AM EST SAT NOV 21 2009)
HIGH PRESSURE AND LIGHT WINDS WILL RESULT IN MINIMAL WIND/WAVE
ACTION THROUGH THE WEEKEND. SOME PATCHY EARLY TO MID MORNING FOG
THROUGH THE WEEKEND COULD POSE A HAZARD TO MARINERS.
&&
.HYDROLOGY...(400 AM EST SAT NOV 21 2009)
DRY WEATHER IS EXPECTED THROUGH MONDAY. NO HYDRO ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: LAURENS
SHORT TERM: LAURENS
LONG TERM: MEADE
AVIATION: MEADE
MARINE: LAURENS
HYDROLOGY: LAURENS
000
FXUS63 KMQT 211142 AAA
AFDMQT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
642 AM EST SAT NOV 21 2009
UPDATED FOR 12Z TAFS
.SYNOPSIS...
00Z RAOBS SHOW RDG ALF BLDG INTO THE WRN GRT LKS DOWNSTREAM OF UPR
TROFFING ALG THE W COAST. AIRMASS UNDER THIS RDG IS QUITE DRY ALF...
WITH 00Z PWAT AS LO AS A MEAGER 0.11 INCH AT INL. SINCE NEAR SFC
MSTR IS MORE ABUNDANT...FOG HAS DEVELOPED OVER THE FA WITH LGT WINDS
ASSOCIATED WITH SFC HI PRES BLDG OVHD UNDER THE RDGING ALF. THE FOG
HAS BECOME LOCALLY DENSE EARLY THIS MRNG. TO THE W...VERY WARM AIR
IS FLOODING NWD INTO THE NRN PLAINS IN THE SLY FLOW BTWN THE HI PRES
RDG NOW OVHD AND LOWER MSLP IN THE ROCKIES. THE 00Z H85 TEMP RANGED
FM 4C AT GRB AND INL TO 9C AT BIS AND AN IMPRESSIVE 14C AT GLASGOW
MT.
&&
.DISCUSSION...
MAIN FCST CONCERNS THIS FCST PD INCLUDE TEMPS THIS WEEKEND AND THEN
PCPN CHCS LATE SUN INTO THE MIDDLE OF NEXT WEEK AS LO PRES BEGINS TO
TAKE SHAPE IN THE PLAINS AND MOVES NE.
TDAY...UPR RDG WILL CONT TO BLD OVER THE UPR LKS WITH FLOOD OF WARM
AIR SURGING INTO CAN AHEAD OF DEEP WRN TROF. WITH DRYNESS OF AIRMASS
MOVING OVHD...EXPECT A MOSUNNY DAY AFT MRNG FOG BURNS OFF. ISSUED
SPS TO HILIGHT PATCHY DENSE FOG EARLY THIS MRNG. MIXING TO H9 ON
FCST SDNGS YIELDS HI TEMPS TOPPING OUT AS HI AS THE LO 50S. GOING
FCST MAX TEMPS SEEM ON TRACK.
FOR TNGT...AS HI PRES RDG SHIFTS TO THE E...SHARPER PRES GRADIENT/
STRENGTHENING SLY FLOW WL DVLP OVER THE CWA...EARLIEST OVER THE W.
WITH THIS STRONGER WIND...EXPECT RELATIVELY LTL DIURNAL FALL OF TEMP
IN THE DOWNSLOPING AREAS NEAR LK SUP...ESPECIALLY OVER THE W FM IWD-
P59. ALTHOUGH THE SHELTERED INTERIOR ECNTRL WL SEE LOWER TEMPS BLO
MOS GUIDANCE WITH DRY MID LVLS AND WEAKER WINDS A BIT LONGER CLOSER
TO DEPARTING SFC HI...BUMPED UP GOING FCST MIN TEMPS THERE A BIT
WITH BOTH GFS/NAM SHOWING A QUICKER RETURN OF H95-9 SPECIFIC
HUMIDITY THAT WL FAVOR FOG AND/OR ST DVLPMENT DURING TIME OF DIURNAL
COOLING.
GFS REMAINS THE MOST AGGRESSIVE MODEL AT GENERATING PCPN OVER THE W
HALF OF THE FA ON SUN AFTN SHOWING MSTR RETURN THRU H7. ALTHOUGH THE
NAM NOW SHOWS HIER SPECIFIC HUMIDITY RETURNING AT H7 AS WELL...THIS
MODEL FOCUSES THE AXIS OF HIER MSTR FARTHER W OVER WRN LK SUP.
CONSIDERING THE FAIRLY HI AMPLITUDE WRN TROF/ERN RDG PATTERN THAT
WOULD FAVOR A SLOWER W-E PROGRESSION...TENDED TOWARD THE NAM AND
GOING FCST. ALTHOUGH THE EXPLICIT GFS FCST SHOWS PCPN...THE GFS MOS
FCST FOR IWD SHOWS ONLY A 10 POP FOR 18Z-24Z SUN...SUPPORTING THE
DRIER NAM AND UKMET. OVER THE E...THERE WL LIKELY BE SOME SUNSHINE
AFT MRNG FOG/ST BURNS OFF WITH MID LVL DRY AIR THRU THE DAY. MORE
PERSISTENT CLD COVER OVER THE W WL LIMIT THE DIURNAL TEMP REBOUND...
BUT BUMPED UP FCST HI TEMPS FARTHER E AWAY FM THE MODERATING
INFLUENCE OF LK MI WITH EXPECTATION FOR MORE AFTN SUNSHINE.
TENDED TO FOLLOW THE LESS PROGRESSIVE NAM/UKMET/12Z ECMWF AGAIN ON
SUN NGT AND CUT BACK ON EWD PROGRESSION OF POPS IN PREVIOUS FCST
GIVEN STRENGTH OF RDG TO THE E AND LINGERING MID LVL DRY AIR. WENT
WITH HIEST POPS OVER WRN LK SUP WHERE NAM SHOWS AXIS OF HIER H85-7
SPECIFIC HUMIDITY AND SOME WEAK UPR DVGC FOR A TIME IN RRQ OF H3 JET
MAX LIFTING NEWD THRU NW ONTARIO. OVER THE E...LOWERED GOING FCST
MIN TEMPS BLO MOS GUIDANCE GIVEN PERSISTENCE OF DRY AIR ALF AND
WHERE NAM SHOWS RISING MSLP/WEAKER GRADIENT FLOW. ALSO ADDED SOME
FOG IN THESE AREAS WHERE DRIER AIR/LIGHTER WINDS WOULD FAVOR THE
SHARPER DIURNAL TEMP FALL. RAISED FCST MIN TEMPS OVER THE W WITH
MORE CLDS/STRONGER WINDS/DOWNSLOPING SLY FLOW.
WITH RDG/ACYC FLOW TENDING TO STRENGTHEN ON MON DOWNSTREAM OF
DEEPENING TROF IN THE PLAINS...TRIMMED GOING POPS TO FCST SCHC POPS
ONLY OVER THE FAR W CLOSER TO LO PRES TROF IN NE MN ON MON AND MON
NGT. WITH TENDENCY FOR DRIER AIR...INCRSD MAX TEMPS ON MON AND
LOWERED FCST FOR MON NGT MINS. ADDED FOG AGAIN OVER THE INTERIOR
ECNTRL WHERE LOWEST TEMPS ARE FAVORED UNDER HIER MSLP. TENDED TO CUT
POPS OVER ESPECIALLY THE NE FA ON TUE AS WELL WITH FAVORED 00Z ECMWF
STILL SHOWING TENACIOUS DRY AIR THERE THRU 00Z WED CLOSER TO SFC HI
IN QUEBEC.
COORDINATED WITH GRB.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
EXPECT LIFR CONDITIONS TO PERSIST AT KSAW FOR THE NEXT COUPLE HOURS.
EXPECT IMPROVEMENT TO VFR THEREAFTER AS DRIER NOTED ON SATELLITE
WATER VAPOR IMAGERY MOVES OVER THE AIRPORT. AT KCMX ONLY RESIDUAL
FOG LEFT EARLY THIS MORNING WITH VFR CONDITIONS THEREAFTER. SEE NO
REASON WHY FOG WOULDN/T REDEVELOP IN SOME FORM TONIGHT AT BOTH SITES
AS LOW LEVEL MOISTURE REMAINS. SOUTHERLY WINDS WILL BE ON THE
INCREASE LATE TONIGHT BUT SHOULD ACT TO LIMIT VISIBILITIES TO
MVFR/IFR NOT NECESSARILY PRECLUDE DEVELOPMENT.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
WINDS WILL REMAIN BELOW 25 KNOTS THROUGH THIS FORECAST PERIOD AS
HIGH PRESSURE REMAINS OVER THE UPPER GREAT LAKES AND KEEPS SYSTEMS
OUT OF THE AREA. WINDS WILL START TO INCREASE WED...POSSIBLY TO GALE
FORCE...AS A STORM SYSTEM COMES UP FROM THE SOUTH.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS/DISCUSSION...KC
AVIATION...PEARSON
MARINE...PEARSON
000
FXUS63 KAPX 211133
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
633 AM EST SAT NOV 21 2009
.SYNOPSIS.../ISSUED AT 350 AM/
HIGH PRESSURE CENTERED OVER THE OHIO VALLEY AND CENTRAL
PLAINS...WILL LIFT NORTH INTO THE GREAT LAKES TODAY. THIS PATTERN
WILL REMAIN IN CONTROL THROUGH THE WEEKEND...GENERATING SOME SUN
AND ABOVE NORMAL TEMPERATURES INTO THE BEGINNING OF NEXT WEEK.
THE NEXT CHANCE OF RAIN WILL BE TUESDAY AND WEDNESDAY...AS A STORM
SYSTEM LIFTS NORTH INTO THE UPPER MIDWEST. TEMPERATURES WILL REMAIN
ABOVE NORMAL TUESDAY AND WEDNESDAY.
SWR
&&
.SHORT TERM.../ISSUED AT 350 AM/...TODAY
BROAD HIGH PRESSURE IS CENTERED IN THE OHIO VALLEY EARLY THIS
MORNING. THERMALLY-INDUCED TROFS CONTINUE OVER THE LAKES...WITH WEAK
RIDGING OVER LOWER MI. SKIES WERE CLOUDY WITH STRATUS/FOG OVER MOST
OF THE FORECAST AREA...NW CHIPPEWA CO AND PARTS OF THE NE LOWER MI
COAST THE ONLY EXCEPTIONS. EARLIER CLEARING TREND FROM THE W AND NW
HAS SLOWED CONSIDERABLY. CLOUD COVER AND TEMPS ARE THE MAIN CONCERNS.
WEST 1000-850MB WINDS WILL CONTINUE TO ADVECT DRIER AIR INTO THE
REGION THIS MORNING. WE/RE STILL TO HAVE TO MIX OUT THE SHALLOW
FOG/STRATUS THAT HAS FORMED IN THE WAKE OF THE MAIN MASS OF CLOUDS.
GIVEN THE PATHETIC LATE-NOVEMBER SUN ANGLE...THAT WILL TAKE TIME.
WILL SLOW THE CLEARING TREND FROM EARLIER FORECASTS. BY AFTERNOON...
AS HIGH PRESSURE LIFTS TOWARD LAKE ERIE...LOW LEVEL WINDS WILL BACK
SW AND WEAKEN (10KT OR LESS). THIS WILL SLOW THE ADVECTION OF DRIER
AIR...JUST AS IT/S TRYING TO DEPART THE SOUTHERN ZONES. IN
ADDITION...THE COOLEST LOW LEVEL AIR WILL LINGER THERE (850MB TEMPS
AROUND 3C...VS 5-6C IN EASTERN UPPER). STILL EXPECT LOW CLOUDS TO
CLEAR FOR A TIME AROUND MIDDAY...BUT LINGERING MOIST/COOL AIRMASS
WILL ALLOW A DECENT CUMULUS FIELD TO REFIRE (PARTLY CLOUDY).
ELSEWHERE...A MOSTLY SUNNY AFTERNOON IS PLANNED.
WITH CURRENT TEMPS STILL FAIRLY MILD (MAINLY NEAR 40 DEGREES)...AND
A (HOPEFULLY) RESPECTABLE AMOUNT OF SUN...WILL STEER TEMPS TOWARD
THE WARMER END OF GUIDANCE. THUS...MAINLY NEAR 50 TO THE LOWER 50S.
JZ
&&
.LONG TERM.../ISSUED AT 350 AM/...TONIGHT AND BEYOND
GENERALLY UNEVENTFUL WX WILL CONTINUE. THIS IS NOT THE WAY NOVEMBER
IS SUPPOSED TO WORK AROUND THESE PARTS...BUT SO BE IT. SHORTWAVE
UPPER RIDGING WILL MOVE OVERHEAD TONIGHT...GIVING WAY TO A LENGTHY
PERIOD OF DEEP SW FLOW ALOFT...AHEAD OF A CLOSED LOW MOVING INTO THE
CENTRAL PLAINS BY TUESDAY MORNING. AT THE SURFACE...HIGH PRESSURE
WILL SLOWLY MOVE FROM THE EASTERN LAKES TO THE MARITIME PROVINCES...
EXTENDING RIDGING BACK INTO THE LAKES REGION THRU MONDAY. TEMPS AND
CLOUDS ARE THE MAIN CONCERNS THRU MONDAY.
MODELS...THE MAIN FOCUS IS ON THE SURFACE LOW EXPECTED TO BE BREWING
IN THE CENTRAL PLAINS OR UPPER MS VALLEY BY TUESDAY. MOST OF THE
ENERGY LEADING TO THIS SYSTEM IS STILL WELL OFFSHORE OF THE WEST
COAST. SO THE WIDE MODEL SPREAD (AND RUN-TO-RUN INCONSISTENCIES) ARE
TO BE EXPECTED. HOWEVER...ALL MODELS HAVE US IN THE WARM SECTOR AND
THUS WITH JUST A RAIN EVENT UNTIL COLDER AIR ARRIVES AS THE SYSTEM
PULLS OUT.
TONIGHT/SUNDAY...DEEP AIRMASS REMAINS QUITE DRY. HOWEVER...
DEVELOPING SE FLOW BELOW 950MB (IN A STABLE LAYER RAPIDLY COOLING
TOWARD SATURATION) WILL LIKELY RESULT IN SOME STRATUS REDEVELOPMENT
IN PARTS OF NE/N CENTRAL LOWER AND EASTERN UPPER MI. BOTH THE
NAM/GFS (AND ASSOCIATED NUMERICAL GUIDANCE) PRODUCE SOME LOW CLOUDS.
THE NAM IS MUCH MORE AGGRESSIVE...ALMOST CERTAINLY TOO MUCH SO GIVEN
THE INITIALLY DRY AIRMASS. STILL...WILL NEED TO REORIENT OVERNIGHT
(AND SUNDAY MORNING) CLOUD COVER FOR MORE CLOUDS N/E AND LESS W.
PRESUMING THESE LOW CLOUDS ARE NOT EXTENSIVE...WE/LL BURN THEM OFF
BY EARLY AFTERNOON...WITH MAINLY SUNNY SKIES THEREAFTER. MIN TEMPS
IN THE 30S (AIMING NEAR OR BELOW GUIDANCE). MAX TEMPS UPPER 40S TO
MID 50S.
SUNDAY NIGHT/MONDAY...ACTUALLY VERY SIMILAR ISSUES AS WE HAVE LATE
TONIGHT. SHALLOW (SUB-950MB) SE FLOW WILL ABUNDANT DRY AIR ALOFT
WILL AGAIN SUPPORT AREAS OF STRATUS IN NE LOWER AND EASTERN UPPER
OVERNIGHT INTO MONDAY MORNING. THAT WILL GIVE WAY TO PARTLY (OR EVEN
MOSTLY) SUNNY CONDITIONS BY MONDAY AFTERNOON. BETTER ISENTROPIC
ASCENT/RETURN FLOW WILL REMAIN ANCHORED OVER WESTERN SUPERIOR AND
SURROUNDING AREAS...NO SIGNIFICANT CHANCE FOR PRECIP IS SEEN THIS
FAR EAST. MIN TEMPS 30S...MAX TEMPS UPPER 40S TO LOWER 50S.
REST OF THE FORECAST...TIMING THE NEXT SYSTEM REMAINS A CHALLENGE...
AND WILL CONTINUE TO BE SOMEWHAT BLAND WITH THE MIDWEEK FORECAST.
HOWEVER...MODELS ARE IN AGREEMENT IN A WARMER SOLUTION THAT SLOWS
DOWN ANY REAL RISK OF MIXED PRECIP. WILL GO ALL RAIN WED...A MIX WED
NIGHT...STILL PRIMARILY SNOW ON TURKEY DAY (EVEN THAT IS
UNCERTAIN...AND DOES NOT LOOK LIKE A BIG DEAL REGARDLESS).
JZ
&&
.MARINE.../ISSUED AT 350 AM/
HIGH PRESSURE WILL MOVE FROM THE OHIO VALLEY...TO THE EASTERN GREAT
LAKES...TO THE GULF OF ST LAWRENCE OVER THE NEXT 4 DAYS. WINDS AND
WAVES WILL REMAIN WELL BELOW SMALL CRAFT ADVISORY CRITERIA OVER THE
NEXT 2 DAYS. HOWEVER...FOG COULD CONTINUE TO CAUSE SOME ISSUES ON
THE CONNECTING WATERWAYS...ESPECIALLY IN THE LATE NIGHT AND MORNING
HOURS.
JZ
&&
.AVIATION.../ISSUED AT 633 AM/...VALID FOR 12Z TAFS
WIDESPREAD IFR CONDITIONS THIS MORNING IN FOG/STRATUS. IMPROVEMENT
TO MVFR AND THEN VFR IS EXPECTED MIDDAY AND AFTERNOON AS DRIER AIR
MOVES IN FROM THE WEST. FOG AND LOW CLOUDS COULD RETURN TONIGHT...
ESPECIALLY AT APN...BUT SHOULD NOT BE AS WIDESPREAD.
JZ
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KDTX 211102
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
602 AM EST SAT NOV 21 2009
.AVIATION...
VERY DIFFICULT FORECAST AS LOW STRATUS CONTINUES TO HOLD TIGHT ALONG
AND NORTHEAST OF I 75 OR SO...BUT IS BEING SCOURED OUT THIS MORNING
AT FNT AND TO A LESSER DEGREE INTO PTK/DTW/DET. EXPECT RAPID CHANGES
IN CEILINGS HEIGHTS EARLY IN THE FORECAST. AS AN EXAMPLE...FNT IS AT
8KFT WITH MBS AT 500 FEET ATTM. NAM12 HAS BACKED OFF SIGNIFICANTLY
ON LOW LEVEL MOISTURE AND WILL ADJUST FORECAST TO LIFT CEILINGS INTO
LATE MORNING/EARLY AFTERNOON...AND EVEN BRING A PERIOD OF SCT LATER
IN THE DAY AS LOW LEVEL MOISTURE MIXES OUT SOMEWHAT. ANY CLEARING
SHOULD BE TEMPORARY AS CALM WINDS RESULT IN STRONG RADIATIONAL
COOLING...AND THE EXPANSION OF LOW STRATUS AND/OR FOG LATE EVENING
INTO THE OVERNIGHT HOURS.
&&
.PREV DISCUSSION...ISSUED 340 AM EST SAT NOV 21 2009
SHORT TERM...TODAY
VERY LITTLE CHANGE TODAY AS CLOUDY SKIES PERSIST MOST IF NOT ALL OF
THE DAY. THE AIRMASS HAS BEEN ABLE TO MODIFY...SO TEMPERATURES WILL
TOP OUT IN THE LOW/MID 50S -VS- FRIDAY/S AROUND 50. THERE WILL BE A
BETTER CHANCE AT A FEW BREAKS IN THE CLOUDS DURING THE AFTERNOON BUT
WITH SUNSET JUST AFTER 5 PM...THE WINDOW WILL CLOSE PRETTY QUICKLY.
NO SIGNIFICANT CHANGES WERE NEEDED TO THE GOING FORECAST.
LONG TERM...TONIGHT THROUGH NEXT FRIDAY
THE CONCERNS IN THE EXTENDED FORECAST REVOLVE AROUND THE POTENTIAL
FOR FOG DEVELOPMENT SUNDAY AND MONDAY MORNINGS AND THEN THE
DEVELOPMENT OF THE LOW PRESSURE SYSTEM THAT WILL HEAD FOR THE AREA
AROUND THANKSGIVING.
A WEAK AREA OF HIGH PRESSURE WILL SLIDE EAST OF THE REGION TONIGHT
GIVING OUR WIND FIELD A SLIGHT EASTERLY COMPONENT. THIS MOIST FLOW
OFF LAKE ERIE WILL ACT TO REINFORCE THE ALREADY MOIST LOW LEVELS.
FAIRLY HIGH SURFACE DEWPOINTS IN THE UPPER 30S TO LOW 40S WILL BE IN
PLACE DURING SUNDAY AND MONDAY MORNINGS. NAMBUFR SOUNDINGS SHOW A
VERY STRONG INVERSION FORMING BETWEEN 925 AND 950MB WHICH WILL TRAP
THIS MOISTURE AT THE SURFACE. SEE NO REASON NOT TO CONTINUE
INHERITED FORECAST MENTION OF FOG FOR BOTH THESE MORNINGS.
TEMPERATURES LOOK TO REMAIN SLIGHTLY ABOVE NORMAL THIS WEEKEND
THROUGH THE EARLY PART OF THE WEEK...44/29 FNT AND 46/32
DTW...THOUGH THERE WILL BE A GRADUAL DECREASE EACH DAY ALONG THE
WAY. TEMPS WILL THEN FALL TO AT OR BELOW NORMAL VALUES AS WE FEEL
THE EFFECTS OF THE NEXT LOW PRESSURE SYSTEM AROUND THANKSGIVING.
THE 00Z MODEL SUITE CONTINUE TO SHOW DISAGREEMENT WITH THE
DEVELOPMENT OF THE MID WEEK LOW AS THEIR PRIOR RUNS HAVE DONE ALL
ALONG AS WELL. THE GFS DEVELOPS A LOW OVER THE NORTHERN PLAINS EARLY
IN THE WEEK AND SHOWS HINTS OF CUTTING OFF THE LOW BUT A FAST MOVING
SHORTWAVE BEHIND THE INITIAL LOW ACTS TO REINFORCE THE LONGWAVE
TROUGH AND NEVER LET IT GET FULLY CUTOFF. THIS SOLUTION KEEPS THINGS
QUITE PROGRESSIVE MEANING PRECIP MOVES IN FASTER ALONG WITH A COLD
CANADIAN AIRMASS. ON THE OTHER HAND YOU HAVE THE ECMWF/NGM/DGEX ALL
HAVE THE LOW BECOMING MORE CUTOFF AND LOCATED FURTHER SOUTH. THIS
LEADS TO A SLOWER PROGRESSION AND HOLDS OFF PRECIP AN EXTRA DAY FOR
THE REGION. ONE THINGS THE MODELS HAVE IN COMMON IS THE COLD AIR
THIS SYSTEM WILL BRING DOWN TO MICHIGAN. 850MB TEMPS WILL FALL FROM
THEIR CURRENT VALUE OF AROUND +4C DOWN TO -5C...AND IF THE GFS PANS
OUT POSSIBLY -10C. THIS EQUATES TO MAX TEMPS ONLY IN THE LOW 40S AND
LOWS IN THE MID 20S. THIS COLD AIRMASS WILL LEAD TO A RAIN/SNOW MIX
THURSDAY AND POSSIBLY ALL SNOW ON FRIDAY ON THE BACKSIDE OF THE
PASSING LOW.
MARINE...
WINDS WILL BE LIGHT TODAY AS HIGH PRESSURE BUILDS OVER THE AREA.
THIS HIGH WILL REMAIN IN PLACE INTO SUNDAY AND THEN ONLY SLOWLY
PROGRESS TO THE EAST EARLY NEXT WEEK...ALLOWING A VERY GRADUAL
INCREASE IN SOUTHEAST FLOW FROM MONDAY INTO TUESDAY. 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 LOW OVER/NEAR THE REGION. THIS TIME
FRAME WILL BRING THE NEXT PERIOD OF HEADLINE WORTHY WINDS/WAVES.
&&
.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 210857
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
400 AM EST SAT NOV 21 2009
LATEST UPDATE...ALL EXCEPT AVIATION...
.SYNOPSIS...(400 AM EST SAT NOV 21 2009)
HIGH PRESSURE WILL PRODUCE DRY WEATHER AND PARTLY CLOUDY SKIES
THROUGH THE WEEKEND. PATCHY FOG IS ANTICIPATED DURING THE EARLY TO
MID MORNING HOURS OF SATURDAY... SUNDAY AND MONDAY. TEMPERATURES
WILL REMAIN ABOVE NORMAL INTO MID WEEK BEFORE IT TURNS A LITTLE
COOLER LATE IN THE WEEK.
&&
.SHORT TERM...(400 AM EST SAT NOV 21 2009)
(TODAY THROUGH MONDAY AFTERNOON)
SHORT TERM FCST CONCERNS REMAIN FAIRLY MINIMAL. HIGH PRESSURE WILL
PRODUCE DRY WX THROUGH THE WEEKEND. SFC OBS EARLY THIS MORNING SHOW
PATCHY FOG CONTINUES TO DEVELOP WHICH WILL LINGER THROUGH THE EARLY
TO MID MORNING HOURS BEFORE DISSIPATING. LINGERING MORNING CLOUD
COVER WILL GIVE WAY TO PARTIAL SUNSHINE THAT WILL HELP TO BOOST MAX
TEMPS INTO THE LOW TO MID 50S.
00Z MODEL RH PROGS AND NUMERICAL GUIDANCE SUGGESTS MORE CLEARING
WILL OCCUR TONIGHT AS COMPARED TO EARLY THIS MORNING. THIS IN
CONJUNCTION WITH LIGHT AND VARIABLE WINDS WILL ONCE AGAIN SET THE
STAGE FOR PATCHY FOG DEVELOPMENT DURING THE EARLY MORNING HOURS
SUNDAY AND THEN AGAIN ON MONDAY. HIGH TEMPS SUNDAY AND MONDAY WILL
REACH THE LOW TO MID 50S WITH MIN TEMPS MAINLY IN THE UPPER 30S TO
LOWER 40S.
&&
.LONG TERM...(400 AM EST SAT NOV 21 2009)
(MONDAY NIGHT THROUGH FRIDAY)
THE 00Z/21 RUNS OF THE GFS AND ECMWF ARE STILL NOT IN VERY GOOD
AGREEMENT REGARDING THE MID WEEK SYSTEM AND HAVE TRIED TO
INCORPORATE BOTH SOLUTIONS INTO THE FCST GRIDS. A LOW PRESSURE
SYSTEM WILL BE TRACKING FROM THE CNTRL/NRN PLAINS ON TUESDAY... EAST
NORTHEAST THROUGH THE GREAT LAKES REGION ON WED AND THU.
THE FASTER GFS SOLUTION SUPPORTS WAA RAIN MOVING INTO THE REGION ON
TUESDAY WHILE SLOWER ECMWF KEEPS IT DRY AND HOLDS THE RAIN OFF UNTIL
WEDNESDAY. THE COMPROMISE IS TO CARRY CHANCE POPS BOTH DAYS...
ALTHOUGH BELIEVE WEDNESDAY OFFERS THE BETTER PCPN POTENTIAL AND WILL
CARRY SCTD VS CHANCE WORDING ON THAT DAY.
PCPN TYPE BECOMES QUITE PROBLEMATIC BY THANKSGIVING DAY AS THE SFC
LOW MOVES BY AND COOLER AIR IS DRAWN DOWN ON THE BACK SIDE OF THE
SYSTEM. GFS SOLUTION IS STILL COLDER THAN THE ECMWF... ALTHOUGH IT
IS A COMMON BIAS OF THE GFS TO BE COLDER BEYOND DAY 4. EVEN IF ONE
WERE TO RUN WITH THE COOLER GFS SOLUTION... THE 00Z FCST SOUNDINGS
LOOK JUST A TAD TOO WARM IN THE BOUNDARY LAYER TO SUPPORT SNOW. WILL
THEREFORE GO WITH WITH RAIN OR SNOW SHOWER WORDING.
THE CURRENT FCST FOR THURSDAY NIGHT AND FRIDAY CURRENTLY HAS ALL
SNOW FOR PCPN TYPE AND LEFT THAT UNCHANGED... ALTHOUGH THE SPEED OF
THE SYSTEM DEPARTURE WILL DICTATE PCPN CHANCES AND THE DEGREE OF
COLD AIR ON THE BACK SIDE WILL DICTATE PCPN TYPE. THAT/S STILL A BIG
UNCERTAINTY ATTM.
&&
.AVIATION...(400 AM EST SAT NOV 21 2009)
UPDATE... THE LATEST RUC IS HOLDING THE DECK OF MID LEVEL CLOUDS
OVER MOST OF THE AREA FOR THE REMAINDER OF THE NIGHT... WHICH WILL
LIMIT RADIATIONAL FOG FORMATION. WILL UPDATE TAFS TO BE LESS
PESSIMISTIC WITH THE FOG. HOWEVER... SHOULD ANY RANDOM BREAKS IN THE
MID DECK DEVELOP LONG ENOUGH BEFORE DAYBREAK... VSBYS COULD LOWER
ABRUPTLY TO LIFR.
&&
.MARINE...(400 AM EST SAT NOV 21 2009)
HIGH PRESSURE AND LIGHT WINDS WILL RESULT IN MINIMAL WIND/WAVE
ACTION THROUGH THE WEEKEND. SOME PATCHY EARLY TO MID MORNING FOG
THROUGH THE WEEKEND COULD POSE A HAZARD TO MARINERS.
&&
.HYDROLOGY...(400 AM EST SAT NOV 21 2009)
DRY WEATHER IS EXPECTED THROUGH MONDAY. NO HYDRO ISSUES.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS: LAURENS
SHORT TERM: LAURENS
LONG TERM: MEADE
AVIATION: MEADE
MARINE: LAURENS
HYDROLOGY: LAURENS
000
FXUS63 KAPX 210851
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
350 AM EST SAT NOV 21 2009
.SYNOPSIS.../ISSUED AT 350 AM/
HIGH PRESSURE CENTERED OVER THE OHIO VALLEY AND CENTRAL
PLAINS...WILL LIFT NORTH INTO THE GREAT LAKES TODAY. THIS PATTERN
WILL REMAIN IN CONTROL THROUGH THE WEEKEND...GENERATING SOME SUN
AND ABOVE NORMAL TEMPERATURES INTO THE BEGINNING OF NEXT WEEK.
THE NEXT CHANCE OF RAIN WILL BE TUESDAY AND WEDNESDAY...AS A STORM
SYSTEM LIFTS NORTH INTO THE UPPER MIDWEST. TEMPERATURES WILL REMAIN
ABOVE NORMAL TUESDAY AND WEDNESDAY.
SWR
&&
.SHORT TERM.../ISSUED AT 350 AM/...TODAY
BROAD HIGH PRESSURE IS CENTERED IN THE OHIO VALLEY EARLY THIS
MORNING. THERMALLY-INDUCED TROFS CONTINUE OVER THE LAKES...WITH WEAK
RIDGING OVER LOWER MI. SKIES WERE CLOUDY WITH STRATUS/FOG OVER MOST
OF THE FORECAST AREA...NW CHIPPEWA CO AND PARTS OF THE NE LOWER MI
COAST THE ONLY EXCEPTIONS. EARLIER CLEARING TREND FROM THE W AND NW
HAS SLOWED CONSIDERABLY. CLOUD COVER AND TEMPS ARE THE MAIN CONCERNS.
WEST 1000-850MB WINDS WILL CONTINUE TO ADVECT DRIER AIR INTO THE
REGION THIS MORNING. WE/RE STILL TO HAVE TO MIX OUT THE SHALLOW
FOG/STRATUS THAT HAS FORMED IN THE WAKE OF THE MAIN MASS OF CLOUDS.
GIVEN THE PATHETIC LATE-NOVEMBER SUN ANGLE...THAT WILL TAKE TIME.
WILL SLOW THE CLEARING TREND FROM EARLIER FORECASTS. BY AFTERNOON...
AS HIGH PRESSURE LIFTS TOWARD LAKE ERIE...LOW LEVEL WINDS WILL BACK
SW AND WEAKEN (10KT OR LESS). THIS WILL SLOW THE ADVECTION OF DRIER
AIR...JUST AS IT/S TRYING TO DEPART THE SOUTHERN ZONES. IN
ADDITION...THE COOLEST LOW LEVEL AIR WILL LINGER THERE (850MB TEMPS
AROUND 3C...VS 5-6C IN EASTERN UPPER). STILL EXPECT LOW CLOUDS TO
CLEAR FOR A TIME AROUND MIDDAY...BUT LINGERING MOIST/COOL AIRMASS
WILL ALLOW A DECENT CUMULUS FIELD TO REFIRE (PARTLY CLOUDY).
ELSEWHERE...A MOSTLY SUNNY AFTERNOON IS PLANNED.
WITH CURRENT TEMPS STILL FAIRLY MILD (MAINLY NEAR 40 DEGREES)...AND
A (HOPEFULLY) RESPECTABLE AMOUNT OF SUN...WILL STEER TEMPS TOWARD
THE WARMER END OF GUIDANCE. THUS...MAINLY NEAR 50 TO THE LOWER 50S.
JZ
&&
.LONG TERM.../ISSUED AT 350 AM/...TONIGHT AND BEYOND
GENERALLY UNEVENTFUL WX WILL CONTINUE. THIS IS NOT THE WAY NOVEMBER
IS SUPPOSED TO WORK AROUND THESE PARTS...BUT SO BE IT. SHORTWAVE
UPPER RIDGING WILL MOVE OVERHEAD TONIGHT...GIVING WAY TO A LENGTHY
PERIOD OF DEEP SW FLOW ALOFT...AHEAD OF A CLOSED LOW MOVING INTO THE
CENTRAL PLAINS BY TUESDAY MORNING. AT THE SURFACE...HIGH PRESSURE
WILL SLOWLY MOVE FROM THE EASTERN LAKES TO THE MARITIME PROVINCES...
EXTENDING RIDGING BACK INTO THE LAKES REGION THRU MONDAY. TEMPS AND
CLOUDS ARE THE MAIN CONCERNS THRU MONDAY.
MODELS...THE MAIN FOCUS IS ON THE SURFACE LOW EXPECTED TO BE BREWING
IN THE CENTRAL PLAINS OR UPPER MS VALLEY BY TUESDAY. MOST OF THE
ENERGY LEADING TO THIS SYSTEM IS STILL WELL OFFSHORE OF THE WEST
COAST. SO THE WIDE MODEL SPREAD (AND RUN-TO-RUN INCONSISTENCIES) ARE
TO BE EXPECTED. HOWEVER...ALL MODELS HAVE US IN THE WARM SECTOR AND
THUS WITH JUST A RAIN EVENT UNTIL COLDER AIR ARRIVES AS THE SYSTEM
PULLS OUT.
TONIGHT/SUNDAY...DEEP AIRMASS REMAINS QUITE DRY. HOWEVER...
DEVELOPING SE FLOW BELOW 950MB (IN A STABLE LAYER RAPIDLY COOLING
TOWARD SATURATION) WILL LIKELY RESULT IN SOME STRATUS REDEVELOPMENT
IN PARTS OF NE/N CENTRAL LOWER AND EASTERN UPPER MI. BOTH THE
NAM/GFS (AND ASSOCIATED NUMERICAL GUIDANCE) PRODUCE SOME LOW CLOUDS.
THE NAM IS MUCH MORE AGGRESSIVE...ALMOST CERTAINLY TOO MUCH SO GIVEN
THE INITIALLY DRY AIRMASS. STILL...WILL NEED TO REORIENT OVERNIGHT
(AND SUNDAY MORNING) CLOUD COVER FOR MORE CLOUDS N/E AND LESS W.
PRESUMING THESE LOW CLOUDS ARE NOT EXTENSIVE...WE/LL BURN THEM OFF
BY EARLY AFTERNOON...WITH MAINLY SUNNY SKIES THEREAFTER. MIN TEMPS
IN THE 30S (AIMING NEAR OR BELOW GUIDANCE). MAX TEMPS UPPER 40S TO
MID 50S.
SUNDAY NIGHT/MONDAY...ACTUALLY VERY SIMILAR ISSUES AS WE HAVE LATE
TONIGHT. SHALLOW (SUB-950MB) SE FLOW WILL ABUNDANT DRY AIR ALOFT
WILL AGAIN SUPPORT AREAS OF STRATUS IN NE LOWER AND EASTERN UPPER
OVERNIGHT INTO MONDAY MORNING. THAT WILL GIVE WAY TO PARTLY (OR EVEN
MOSTLY) SUNNY CONDITIONS BY MONDAY AFTERNOON. BETTER ISENTROPIC
ASCENT/RETURN FLOW WILL REMAIN ANCHORED OVER WESTERN SUPERIOR AND
SURROUNDING AREAS...NO SIGNIFICANT CHANCE FOR PRECIP IS SEEN THIS
FAR EAST. MIN TEMPS 30S...MAX TEMPS UPPER 40S TO LOWER 50S.
REST OF THE FORECAST...TIMING THE NEXT SYSTEM REMAINS A CHALLENGE...
AND WILL CONTINUE TO BE SOMEWHAT BLAND WITH THE MIDWEEK FORECAST.
HOWEVER...MODELS ARE IN AGREEMENT IN A WARMER SOLUTION THAT SLOWS
DOWN ANY REAL RISK OF MIXED PRECIP. WILL GO ALL RAIN WED...A MIX WED
NIGHT...STILL PRIMARILY SNOW ON TURKEY DAY (EVEN THAT IS
UNCERTAIN...AND DOES NOT LOOK LIKE A BIG DEAL REGARDLESS).
JZ
&&
.MARINE.../ISSUED AT 350 AM/
HIGH PRESSURE WILL MOVE FROM THE OHIO VALLEY...TO THE EASTERN GREAT
LAKES...TO THE GULF OF ST LAWRENCE OVER THE NEXT 4 DAYS. WINDS AND
WAVES WILL REMAIN WELL BELOW SMALL CRAFT ADVISORY CRITERIA OVER THE
NEXT 2 DAYS. HOWEVER...FOG COULD CONTINUE TO CAUSE SOME ISSUES ON
THE CONNECTING WATERWAYS...ESPECIALLY IN THE LATE NIGHT AND MORNING
HOURS.
JZ
&&
.AVIATION.../ISSUED AT 1240 AM/...VALID FOR 06Z TAFS
AMPLE LOW LEVEL MOISTURE HANGING OVER NRN LWR MICHIGAN WILL MAINTAIN
LOW STRATUS AND AREAS OF FOG OVERNIGHT AND THRU THE MORNING. MAINLY
MVFR CONDITIONS WILL GRADUALLY DETERIORATE TO IFR AND EVEN LIFR AT
TIMES OVERNIGHT. CONDITIONS WILL RETURN TO VFR BY MIDDAY SATURDAY AS
DRIER AIR ADVECTS IN FROM THE WEST.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KMQT 210847
AFDMQT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
350 AM EST SAT NOV 21 2009
.SYNOPSIS...
00Z RAOBS SHOW RDG ALF BLDG INTO THE WRN GRT LKS DOWNSTREAM OF UPR
TROFFING ALG THE W COAST. AIRMASS UNDER THIS RDG IS QUITE DRY ALF...
WITH 00Z PWAT AS LO AS A MEAGER 0.11 INCH AT INL. SINCE NEAR SFC
MSTR IS MORE ABUNDANT...FOG HAS DEVELOPED OVER THE FA WITH LGT WINDS
ASSOCIATED WITH SFC HI PRES BLDG OVHD UNDER THE RDGING ALF. THE FOG
HAS BECOME LOCALLY DENSE EARLY THIS MRNG. TO THE W...VERY WARM AIR
IS FLOODING NWD INTO THE NRN PLAINS IN THE SLY FLOW BTWN THE HI PRES
RDG NOW OVHD AND LOWER MSLP IN THE ROCKIES. THE 00Z H85 TEMP RANGED
FM 4C AT GRB AND INL TO 9C AT BIS AND AN IMPRESSIVE 14C AT GLASGOW
MT.
&&
.DISCUSSION...
MAIN FCST CONCERNS THIS FCST PD INCLUDE TEMPS THIS WEEKEND AND THEN
PCPN CHCS LATE SUN INTO THE MIDDLE OF NEXT WEEK AS LO PRES BEGINS TO
TAKE SHAPE IN THE PLAINS AND MOVES NE.
TDAY...UPR RDG WILL CONT TO BLD OVER THE UPR LKS WITH FLOOD OF WARM
AIR SURGING INTO CAN AHEAD OF DEEP WRN TROF. WITH DRYNESS OF AIRMASS
MOVING OVHD...EXPECT A MOSUNNY DAY AFT MRNG FOG BURNS OFF. ISSUED
SPS TO HILIGHT PATCHY DENSE FOG EARLY THIS MRNG. MIXING TO H9 ON
FCST SDNGS YIELDS HI TEMPS TOPPING OUT AS HI AS THE LO 50S. GOING
FCST MAX TEMPS SEEM ON TRACK.
FOR TNGT...AS HI PRES RDG SHIFTS TO THE E...SHARPER PRES GRADIENT/
STRENGTHENING SLY FLOW WL DVLP OVER THE CWA...EARLIEST OVER THE W.
WITH THIS STRONGER WIND...EXPECT RELATIVELY LTL DIURNAL FALL OF TEMP
IN THE DOWNSLOPING AREAS NEAR LK SUP...ESPECIALLY OVER THE W FM IWD-
P59. ALTHOUGH THE SHELTERED INTERIOR ECNTRL WL SEE LOWER TEMPS BLO
MOS GUIDANCE WITH DRY MID LVLS AND WEAKER WINDS A BIT LONGER CLOSER
TO DEPARTING SFC HI...BUMPED UP GOING FCST MIN TEMPS THERE A BIT
WITH BOTH GFS/NAM SHOWING A QUICKER RETURN OF H95-9 SPECIFIC
HUMIDITY THAT WL FAVOR FOG AND/OR ST DVLPMENT DURING TIME OF DIURNAL
COOLING.
GFS REMAINS THE MOST AGGRESSIVE MODEL AT GENERATING PCPN OVER THE W
HALF OF THE FA ON SUN AFTN SHOWING MSTR RETURN THRU H7. ALTHOUGH THE
NAM NOW SHOWS HIER SPECIFIC HUMIDITY RETURNING AT H7 AS WELL...THIS
MODEL FOCUSES THE AXIS OF HIER MSTR FARTHER W OVER WRN LK SUP.
CONSIDERING THE FAIRLY HI AMPLITUDE WRN TROF/ERN RDG PATTERN THAT
WOULD FAVOR A SLOWER W-E PROGRESSION...TENDED TOWARD THE NAM AND
GOING FCST. ALTHOUGH THE EXPLICIT GFS FCST SHOWS PCPN...THE GFS MOS
FCST FOR IWD SHOWS ONLY A 10 POP FOR 18Z-24Z SUN...SUPPORTING THE
DRIER NAM AND UKMET. OVER THE E...THERE WL LIKELY BE SOME SUNSHINE
AFT MRNG FOG/ST BURNS OFF WITH MID LVL DRY AIR THRU THE DAY. MORE
PERSISTENT CLD COVER OVER THE W WL LIMIT THE DIURNAL TEMP REBOUND...
BUT BUMPED UP FCST HI TEMPS FARTHER E AWAY FM THE MODERATING
INFLUENCE OF LK MI WITH EXPECTATION FOR MORE AFTN SUNSHINE.
TENDED TO FOLLOW THE LESS PROGRESSIVE NAM/UKMET/12Z ECMWF AGAIN ON
SUN NGT AND CUT BACK ON EWD PROGRESSION OF POPS IN PREVIOUS FCST
GIVEN STRENGTH OF RDG TO THE E AND LINGERING MID LVL DRY AIR. WENT
WITH HIEST POPS OVER WRN LK SUP WHERE NAM SHOWS AXIS OF HIER H85-7
SPECIFIC HUMIDITY AND SOME WEAK UPR DVGC FOR A TIME IN RRQ OF H3 JET
MAX LIFTING NEWD THRU NW ONTARIO. OVER THE E...LOWERED GOING FCST
MIN TEMPS BLO MOS GUIDANCE GIVEN PERSISTENCE OF DRY AIR ALF AND
WHERE NAM SHOWS RISING MSLP/WEAKER GRADIENT FLOW. ALSO ADDED SOME
FOG IN THESE AREAS WHERE DRIER AIR/LIGHTER WINDS WOULD FAVOR THE
SHARPER DIURNAL TEMP FALL. RAISED FCST MIN TEMPS OVER THE W WITH
MORE CLDS/STRONGER WINDS/DOWNSLOPING SLY FLOW.
WITH RDG/ACYC FLOW TENDING TO STRENGTHEN ON MON DOWNSTREAM OF
DEEPENING TROF IN THE PLAINS...TRIMMED GOING POPS TO FCST SCHC POPS
ONLY OVER THE FAR W CLOSER TO LO PRES TROF IN NE MN ON MON AND MON
NGT. WITH TENDENCY FOR DRIER AIR...INCRSD MAX TEMPS ON MON AND
LOWERED FCST FOR MON NGT MINS. ADDED FOG AGAIN OVER THE INTERIOR
ECNTRL WHERE LOWEST TEMPS ARE FAVORED UNDER HIER MSLP. TENDED TO CUT
POPS OVER ESPECIALLY THE NE FA ON TUE AS WELL WITH FAVORED 00Z ECMWF
STILL SHOWING TENACIOUS DRY AIR THERE THRU 00Z WED CLOSER TO SFC HI
IN QUEBEC.
COORDINATED WITH GRB.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
SINCE BOUNDARY LAYER MOISTURE WAS NOT ABLE TO MIX OUT DURING THE
AFTN...RADIATIONAL FOG HAS DEVELOPED UNDER CLEAR SKIES AT KCMX/KSAW.
KSAW SHOULD CONTINUE TO HAVE LOWER VIS AND CIGS (VLIFR/LIFR) THAN
KCMX AS DRIER AIR AT THE LOW LEVELS IS SLOWLY MAKING PROGRESS ACROSS
LAKE SUPERIOR. HOWEVER...IT APPEARS ON SATELLITE IMAGERY THAT
STRATUS OR DENSER FOG HAS DEVELOPED RECENTLY OVER PARTS OF THE
KEWEENAW PENINSULA. HAVE THUS INCLUDED A MENTION OF LIFR CONDITIONS
AT TIMES OVERNIGHT AT KCMX. AFTER ANY MORNING FOG...VFR CONDITIONS
WILL BE THE RULE AT KCMX/KSAW THRU THE REMAINDER OF THE FCST PERIOD
AS DEEP DRY AIRMASS SETTLES OVER THE AREA.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
WINDS WILL REMAIN BELOW 25 KNOTS THROUGH THIS FORECAST PERIOD AS
HIGH PRESSURE REMAINS OVER THE UPPER GREAT LAKES AND KEEPS SYSTEMS
OUT OF THE AREA. WINDS WILL START TO INCREASE WED...POSSIBLY TO GALE
FORCE...AS A STORM SYSTEM COMES UP FROM THE SOUTH.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS/DISCUSSION...KC
AVIATION...ROLFSON
MARINE...PEARSON
000
FXUS63 KDTX 210840
AFDDTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
340 AM EST SAT NOV 21 2009
.SHORT TERM...TODAY
VERY LITTLE CHANGE TODAY AS CLOUDY SKIES PERSIST MOST IF NOT ALL OF
THE DAY. THE AIRMASS HAS BEEN ABLE TO MODIFY...SO TEMPERATURES WILL
TOP OUT IN THE LOW/MID 50S -VS- FRIDAY/S AROUND 50. THERE WILL BE A
BETTER CHANCE AT A FEW BREAKS IN THE CLOUDS DURING THE AFTERNOON BUT
WITH SUNSET JUST AFTER 5 PM...THE WINDOW WILL CLOSE PRETTY QUICKLY.
NO SIGNIFICANT CHANGES WERE NEEDED TO THE GOING FORECAST.
&&
.LONG TERM...TONIGHT THROUGH NEXT FRIDAY
THE CONCERNS IN THE EXTENDED FORECAST REVOLVE AROUND THE POTENTIAL
FOR FOG DEVELOPMENT SUNDAY AND MONDAY MORNINGS AND THEN THE
DEVELOPMENT OF THE LOW PRESSURE SYSTEM THAT WILL HEAD FOR THE AREA
AROUND THANKSGIVING.
A WEAK AREA OF HIGH PRESSURE WILL SLIDE EAST OF THE REGION TONIGHT
GIVING OUR WIND FIELD A SLIGHT EASTERLY COMPONENT. THIS MOIST FLOW
OFF LAKE ERIE WILL ACT TO REINFORCE THE ALREADY MOIST LOW LEVELS.
FAIRLY HIGH SURFACE DEWPOINTS IN THE UPPER 30S TO LOW 40S WILL BE IN
PLACE DURING SUNDAY AND MONDAY MORNINGS. NAMBUFR SOUNDINGS SHOW A
VERY STRONG INVERSION FORMING BETWEEN 925 AND 950MB WHICH WILL TRAP
THIS MOISTURE AT THE SURFACE. SEE NO REASON NOT TO CONTINUE
INHERITED FORECAST MENTION OF FOG FOR BOTH THESE MORNINGS.
TEMPERATURES LOOK TO REMAIN SLIGHTLY ABOVE NORMAL THIS WEEKEND
THROUGH THE EARLY PART OF THE WEEK...44/29 FNT AND 46/32
DTW...THOUGH THERE WILL BE A GRADUAL DECREASE EACH DAY ALONG THE
WAY. TEMPS WILL THEN FALL TO AT OR BELOW NORMAL VALUES AS WE FEEL
THE EFFECTS OF THE NEXT LOW PRESSURE SYSTEM AROUND THANKSGIVING.
THE 00Z MODEL SUITE CONTINUE TO SHOW DISAGREEMENT WITH THE
DEVELOPMENT OF THE MID WEEK LOW AS THEIR PRIOR RUNS HAVE DONE ALL
ALONG AS WELL. THE GFS DEVELOPS A LOW OVER THE NORTHERN PLAINS EARLY
IN THE WEEK AND SHOWS HINTS OF CUTTING OFF THE LOW BUT A FAST MOVING
SHORTWAVE BEHIND THE INITIAL LOW ACTS TO REINFORCE THE LONGWAVE
TROUGH AND NEVER LET IT GET FULLY CUTOFF. THIS SOLUTION KEEPS THINGS
QUITE PROGRESSIVE MEANING PRECIP MOVES IN FASTER ALONG WITH A COLD
CANADIAN AIRMASS. ON THE OTHER HAND YOU HAVE THE ECMWF/NGM/DGEX ALL
HAVE THE LOW BECOMING MORE CUTOFF AND LOCATED FURTHER SOUTH. THIS
LEADS TO A SLOWER PROGRESSION AND HOLDS OFF PRECIP AN EXTRA DAY FOR
THE REGION. ONE THINGS THE MODELS HAVE IN COMMON IS THE COLD AIR
THIS SYSTEM WILL BRING DOWN TO MICHIGAN. 850MB TEMPS WILL FALL FROM
THEIR CURRENT VALUE OF AROUND +4C DOWN TO -5C...AND IF THE GFS PANS
OUT POSSIBLY -10C. THIS EQUATES TO MAX TEMPS ONLY IN THE LOW 40S AND
LOWS IN THE MID 20S. THIS COLD AIRMASS WILL LEAD TO A RAIN/SNOW MIX
THURSDAY AND POSSIBLY ALL SNOW ON FRIDAY ON THE BACKSIDE OF THE
PASSING LOW.
&&
.MARINE...
WINDS WILL BE LIGHT TODAY AS HIGH PRESSURE BUILDS OVER THE AREA.
THIS HIGH WILL REMAIN IN PLACE INTO SUNDAY AND THEN ONLY SLOWLY
PROGRESS TO THE EAST EARLY NEXT WEEK...ALLOWING A VERY GRADUAL
INCREASE IN SOUTHEAST FLOW FROM MONDAY INTO TUESDAY. 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 LOW OVER/NEAR THE REGION. THIS TIME
FRAME WILL BRING THE NEXT PERIOD OF HEADLINE WORTHY WINDS/WAVES.
&&
.PREV DISCUSSION...ISSUED 1145 PM EST FRI NOV 20 2009
AVIATION...
SUSTAINED AREA OF LOW LEVEL MOISTURE TRAPPED BENEATH A STRONG
INVERSION WILL MAINTAIN A PERSISTENT STRATUS DECK THROUGH SATURDAY
AFTERNOON. CEILING HEIGHTS WILL CONTINUE TO DISPLAY SOME
VARIABILITY FOR THE NEXT SEVERAL HOURS AS CONDITIONS BOUNCE IN AND
OUT OF MVFR. LOWERING INVERSION HEIGHTS WILL FAVOR CONDITIONS
BECOMING PREDOMINATELY MVFR AGAIN THROUGH THE EARLY MORNING
HOURS...WITH AREAS FROM PTK NORTHWARD MORE VULNERABLE TO A PERIOD OF
IFR CIGS TOWARD SUNRISE. IN ADDITION...ALL TERMINALS WILL CONTINUE
TO SEE SOME RESTRICTION OF VISIBILITY IN FOG...BUT THE BKN/OVC
CANOPY OF STRATUS SHOULD LIMIT THE VISIBILITY RESTRICTIONS TO MAINLY
MVFR/BRIEF IFR. CEILINGS WILL SLOWLY RISE IN RESPONSE TO WEAK
DAYTIME MIXING ON SATURDAY...BUT PLENTY OF LOW LEVEL MOISTURE WILL
ENSURE MVFR STRATUS HOLDS THROUGH THE AFTERNOON. A WEAK WIND FIELD
WITH HIGH PRESSURE IN PLACE WILL FAVOR BETTER FOG FORMATION SATURDAY
NIGHT ASSUMING MORE BREAKS DEVELOP IN THE STRATUS.
&&
.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 KAPX 210539
AFDAPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1240 AM EST SAT NOV 21 2009
.SYNOPSIS.../ISSUED AT 329 PM/
A LARGE AREA OF HIGH PRESSURE WILL SLOWLY PIVOT ACROSS THE NORTHERN
LAKES OVER THE COURSE OF THE NEXT SEVERAL DAYS...RESULTING IN THE
REEMERGENCE OF PRECIPITATION-FREE CONDITIONS AND A RETURN TO
SEASONABLY MILD TEMPERATURES THROUGH THE BEGINNING OF NEXT WORK
WEEK. RAIN CHANCES ARE EXPECTED TO INCREASE TUESDAY THROUGH
WEDNESDAY AS THE NEXT STORM SYSTEM APPROACHES. LOOKING FARTHER
AHEAD...CURRENT INDICATIONS ARE...THE THANKSGIVING HOLIDAY COULD BE
RATHER INCLEMENT AND COOL...WITH SNOW SHOWERS AND HIGH TEMPERATURES
STRUGGLING TO REACH THE 40 DEGREE MARK.
MSB
&&
.SHORT TERM.../ISSUED AT 915 PM/...OVERNIGHT
UPPER LEVEL TROUGH LINGERS ACROSS THE WRN GREAT LAKES REGION LATE
THIS EVENING. SURFACE RIDGE IS TRYING TO BUILD INTO MICHIGAN...
CONNECTED TO A LARGE AREA OF HIGH PRESSURE STRETCHED ACROSS THE MID
MISSISSIPPI VALLEY AND THE OHIO VALLEY. HOWEVER...LAKES ARE
PRODUCING SOME WEAKNESS IN THE SURFACE PATTERN AS IS TYPICAL THIS
TIME OF YEAR. THIS WEAKNESS COMBINED WITH PERSISTENT/AMPLE LOW LEVEL
MOISTURE HANGING OVER THE REGION IS RESULTING IN THE REDEVELOPMENT
OF LOW STRATUS AND FOG AS ANTICIPATED. IN ADDITIONAL...SCATTERED
SPRINKLES HAVE DEVELOPED IN ERN UPR MICHIGAN AND THE STRAITS AREA
ASSOCIATED WITH A WEAK VORT LOBE ROTATING THRU THE UPPER TROUGH.
HAVE ALREADY ADJUSTED GRIDS TO ACCOUNT FOR THIS LIGHT PRECIP. ALL
PRECIP SHOULD EXIT THE REGION BEFORE MIDNIGHT. THE OVERNIGHT HOURS
WILL BRING AN INCREASE IN LOW STATUS AND FOG...WITH LOWERING CIGS
AND VSBYS. AT THIS POINT...DO NOT EXPECT WIDESPREAD DENSE FOG...BUT
A FEW AREAS MAY SEE HALF MILE VSBYS AT TIMES.
&&
.LONG TERM.../ISSUED AT 329 PM/...SATURDAY AND BEYOND
SATURDAY AND SUNDAY...STRONG HIGH PRESSURE REGAINS CONTROL OF THE
GREAT LAKES AND MUCH OF THE EASTERN CONUS WITH LONGER WAVE RIDGING
REGAINING A FOOT HOLD OVER THE EAST. THUS MILD CONDITIONS EXPECTED
TO PERSIST WITH DAYTIME TEMPS AGAIN MAKING A RUN INTO THE UPPER
40S/LOWER 50S...ESPECIALLY ON SUNDAY. UPSTREAM 500 MB WAVE AND AREA
OF ENHANCED CLOUDINESS NOTED OVER WISCONSIN TODAY...WILL SLOWLY
PROGRESS ACROSS THE STATE THROUGH SATURDAY. COMBINED WITH LINGERING
LOW LEVEL MOISTURE/CLOUDS/FOG SATURDAY MORNING WILL RESULT IN A LESS
THAN PERFECT DAY SATURDAY (CLOUD WISE)...BUT NOT BAD OVERALL. SUNDAY
STILL LOOKING FINE UNDER AT LEAST PARTLY SUNNY SKIES AND INCREASING
S/SE WARM ADVECTION FLOW WITH TEMPS PUSHING INTO THE 50S FOR MOST.
MONDAY AND TUESDAY...06Z AND 12Z GFS SOLUTIONS TRENDED TOWARD THE
SLOWER ECMWF IDEA...WITH NRN STREAM ENERGY AND LOWERING HEIGHTS NOT
REALLY ARRIVING IN THE GREAT LAKES UNTIL AT LEAST TUESDAY. THIS
SUPPORTS THE IDEA STARTED BY MIDNIGHT FORECASTER OF DELAYING POPS
INTO THE STATE UNTIL AT LEAST TUESDAY. RECENT ECMWF SOLUTIONS ARGUE
EVEN LATER...POSSIBLY WEDNESDAY...BEFORE ANY SIGNIFICANT WEATHER
ARRIVES AND STARTING TO HINT TOWARD A WARMER/CUTOFF LOW SCENARIO
OVER THE MIDWEST SIMILAR TO THIS LAST SYSTEM. WILL STAY WITH A DRY
MONDAY AND MONDAY NIGHT FORECAST WITH MILD DAYTIME TEMPS HOLDING
ON...RANGING FROM THE UPPER 40S TO LOWER 50S. BUT AM RELUCTANT TO GO
TO FAR WITH POP TRIMMING AND AT THIS POINT WILL LEAVE PRECIP CHANCES
IN TUESDAY.
WEDNESDAY ONWARD...SIMILAR IDEA/TRENDS AMONG THE MEDIUM RANGE
GUIDANCE TODAY...SUPPORTING A BRIEF BOUT OF COLDER WEATHER NEXT
WEEK...AS LONG WAVE TROUGHING IN THE WEST PROGRESSES INTO THE
EASTERN CONUS. POSSIBILITIES FOR ACCUMULATING SNOW AROUND
THANKSGIVING STILL HIGHLIGHT THE FORECAST...ALTHOUGH QUITE A BIT OF
UNCERTAINTY REGARDING HOW COLD IT GETS AS TROUGHING DEEPENS OVER THE
REGION. GFS REMAINS THE COLDEST (TYPICAL) DRAGGING A CORE OF -10C
OR BETTER THROUGH THE STATE ON THANKSGIVING...ON THE HEELS OF A
RATHER STRONG LOW PRESSURE SYSTEM THAT MOVES THROUGH LATE TUESDAY
INTO WEDNESDAY. EUROPEAN SOLUTION IS SLOWER/MORE CUTOFF AND WARMER
BUT STILL UNSETTLED...AND JUST BARELY SUPPORTS A RAIN/SNOW MIX. AT
THIS POINT...NO MAJOR TRAVEL PROBLEMS ANTICIPATED ACROSS THE STATE
FOR THE HOLIDAY TRAVEL DAY (WEDNESDAY). WILL MAINTAIN A WETTER
FORECAST FROM WEDNESDAY ONWARD WITH PRECIP TYPE TRANSITIONING TO
MAINLY SNOW FOR THANKSGIVING AND FRIDAY. WITH THAT SAID...IF RECENT
EUROPEAN TRENDS HOLD WILL NEED TO TONE BACK ON SNOW WORDING FOR THE
HOLIDAY.
ADAM
&&
.MARINE.../ISSUED AT 329 PM/
STRONG HIGH PRESSURE WILL BUILD ACROSS THE REGION AND REMAIN IN
CONTROL THROUGH THE UPCOMING WEEKEND. THIS WILL RESULT IN RATHER
LIGHT WINDS ON THE WATERS AND MINIMAL WAVES. NO MARINE HEADLINES
ANTICIPATED THROUGH THE ENTIRE WEEKEND.
ADAM
&&
.AVIATION.../ISSUED AT 1240 AM/...VALID FOR 06Z TAFS
AMPLE LOW LEVEL MOISTURE HANGING OVER NRN LWR MICHIGAN WILL MAINTAIN
LOW STRATUS AND AREAS OF FOG OVERNIGHT AND SATURDAY MORNING. MAINLY MVFR
CONDITIONS WILL GRADUALLY DETERIORATE TO IFR AND EVEN LIFR AT TIMES
OVERNIGHT. CONDITIONS WILL RETURN TO VFR BY MIDDAY SATURDAY AS DRIER
AIR ADVECTS IN FROM THE WEST.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
LH...NONE.
LS...NONE.
&&
$$
000
FXUS63 KMQT 210528 AAB
AFDMQT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MARQUETTE MI
1230 AM EST SAT NOV 21 2009
UPDATED FOR AVIATION DISCUSSION FOR 06Z TAF ISSUANCE
.SHORT TERM (THROUGH 00Z SUN)... /ISSUED AT 343 PM EST/
UPPER AIR PATTERN CONSISTS OF A CLOSED 500 MB LOW OVER THE LOWER
GREAT LAKES AND RIDGING OVER THE CENTRAL AND NORTHERN ROCKIES AND
TROUGHING INTO THE GREAT BEND REGION OF TEXAS AND THE SOUTHERN
ROCKIES AND A TROUGH OFF THE WEST COAST. IT CONTINUES TO LOOK PRETTY
QUIET AND WARM FOR A WHILE LONGER. THE TROUGH OFF THE WEST COAST
WILL MOVE EAST INTO THE ROCKIES AND THIS WILL PUSH UP A RIDGE INTO
THE UPPER GREAT LAKES THIS PERIOD.
MAIN FORECAST PROBLEM TONIGHT WILL BE FOG AND HOW MUCH OF IT AND
WHEN IT FORMS. LOOKS GOOD FOR FOG TONIGHT WITH LIGHT WINDS. ONLY
PROBLEM IS NAM WHICH IS MODEL I FOLLOWED IS SHOWING SOME LIGHT
WESTERLY WINDS. LOW LEVEL MOISTURE REMAINS AROUND HERE AS IT DOES
NOT GET SCOURED OUT...SO FOG LOOKS GOOD. WILL GO WITH PATCHY TO
AREAS OF FOG TONIGHT AND FORM A LITTLE EARLIER AS CLOUDS WILL
CONTINUE TO DECREASE AND WILL HAVE LIGHT WINDS. THINK FOG WILL FORM
IN THE EVENING AND WILL CONTINUE THROUGH MID MORNING ANYWAY. DID NOT
MAKE TOO MANY CHANGES TO GOING TEMPERATURES OR TO WEATHER OTHERWISE.
.LONG TERM (SAT NIGHT THROUGH NEXT FRI)... /ISSUED AT 343 PM EST/
HIGHER HEIGHTS ASSOCIATED WITH RIDGE OVR THE GREAT LAKES ONLY SLOWLY
FALL INTO SUNDAY AS TROUGH MOVES INTO NORTHERN PLAINS AND CNTRL
CANADA. GFS/NAM/ECMWF TRENDED SLOWER WITH ARRIVAL OF LOW-LEVEL MOIST
ADVECTION...KEEPING MAJORITY OF ANY WARM AIR ADVECTION QPF TO THE
WEST OF UPR MI THROUGH SUN AFTN. PREV FCST WAS IN GOOD SHAPE AND
MADE FEW CHANGES. TRIMMED EAST EXTENT OF POPS SUN NIGHT AS RIBBON OF
HIER H85 DWPNTS AND CONVERGENCE PERSISTS OVR WRN UPR MI INTO WRN LK
SUPERIOR. DUE TO THE MOISTURE ADVECTION...SOUNDINGS ACROSS UPR MI
INDICATE ABUNDANT CLOUD COVER IN THE H9-H8 LAYER...SO TEMPS SHOULD
REMAIN IN THE MID-UPR 30S. PCPN CHANCES ON MONDAY LOOK PRETTY MEAGER
AS UPR LAKES ARE BTWN TROUGH EXITING TOWARD HUDSON BAY AND ANOTHER
TROUGH FORMING OVR THE CENTRAL CONUS. KEPT SKIES MAINLY CLOUDY AS
MOISTURE COULD BECOME TRAPPED BENEATH INVERSION.
OVERALL...UPPER LEVEL PATTERN EARLY NEXT WEEK BEGINS WITH A RIDGE
OVR THE EASTERN CONUS AND A DEVELOPING TROUGH IN THE NW CONUS. TO
START OFF...GFS REMAINS IN OPPOSITION TO UKMET/CANADIAN/ECMWF...AS
WELL AS THE ENSEMBLES FM THE CANADIAN/GEFS/ECMWF. SO...DESPITE THE
GFS CONSISTENTLY SHOWING LEAD SHORTWAVE SWEEPING ACROSS UPR LAKES
TUE AND HEADING INTO NORTHERN NEW ENGLAND AND EASTERN CANADA BY
WED...HAVE DISCOUNTED ITS OUTLIER SOLUTION AS RIDGE OVR THE EASTERN
CONUS SHOULD HOLD FIRM. INSTEAD PREFER SOLUTION SHOWN BY MAJORITY
OF GUIDANCE WITH A CLOSED OFF TROUGH MOVING INTO THE CNTRL PLAINS BY
TUE MORNING...THEN SLOWLY GRINDING INTO THE UPR LAKES WED INTO
THANKSGIVING DAY. IT IS INTERESTING THAT ALTHOUGH THE GFS IS VERY
DIFFERENT FM OTHER GUIDANCE FOR EARLY IN THE WEEK...IT ACTUALLY DOES
COME BACK INTO SOME AGREEMENT BY LATE WEEK AS IT SHOWS GENERAL
TROUGHING/COLDER AIR OVR THE UPR LAKES.
DETAILS...INCLUDING TIMING OF WHEN MORE WIDESPREAD PCPN OCCURS
AND THE ALL IMPORTANT PTYPE QUESTION...REMAIN FAR FROM CERTAIN.
GOING WITH THE PREFERRED ECMWF/CANADIAN IDEA...THE MAJORITY OF
SIGNIFICANT PCPN OCCURS WED INTO WED NIGHT AND PERHAPS EVEN
LINGERING INTO THANKSGIVING. AGAIN...GFS SOLN WOULD BE 18-24 HR
EARLIER THAN THIS. INITIAL PCPN INTO WED WOULD BE MAINLY RAIN
AS THE UPR LOW/SFC LOWS AND SLUG OF WARMER AIR LIFT TOWARD UPR
MICHIGAN. CANADIAN IS EVEN A BIT FARTHER WEST...SUGGESTING MORE
RAIN THAN SNOW. BY WED NIGHT INTO THU...MAJORITY OF PCPN WOULD
TRANSITION TO SNOW AS SFC LOW AND LOW-LEVEL WARM AIR HEADS TO THE
EAST...ALLOWING FOR COLDEST AIRMASS SEEN SO FAR THIS FALL (H85
TEMPS FALLING BLO -10C)...TO SURGE INTO THE UPR LAKES. WILL CONTINUE
TO MENTION THE POTENTIAL OF A MODERATE STRENGTH SYSTEM IN THE
HAZARDOUS WEATHER OUTLOOK AS IT COULD AFFECT THE HOLIDAY TRAVEL
BEFORE THANKSGIVING.
MAIN RESULT FOR THANKSGIVING INTO FRI IS COOLER TEMPERATURES THAN
HAVE BEEN SEEN MOST OF NOVEMBER AND THE CHANCE OF SYNOPTIC SNOW ON
THU TRANSITIONING TO LK EFFECT SNOW SHOWERS LATER THU INTO FRI...
MAINLY IN AREAS FAVORED BY NW FLOW CLOSE TO LK SUPERIOR. BOUT OF
COLDER TEMPS LOOKS BRIEF THOUGH WITH TEMPS BEGINNING TO REBOUND NEXT
WEEKEND AS UPPER LEVEL RIDGING ARRIVES.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
SINCE BOUNDARY LAYER MOISTURE WAS NOT ABLE TO MIX OUT DURING THE
AFTN...RADIATIONAL FOG HAS DEVELOPED UNDER CLEAR SKIES AT KCMX/KSAW.
KSAW SHOULD CONTINUE TO HAVE LOWER VIS AND CIGS (VLIFR/LIFR) THAN
KCMX AS DRIER AIR AT THE LOW LEVELS IS SLOWLY MAKING PROGRESS ACROSS
LAKE SUPERIOR. HOWEVER...IT APPEARS ON SATELLITE IMAGERY THAT
STRATUS OR DENSER FOG HAS DEVELOPED RECENTLY OVER PARTS OF THE
KEWEENAW PENINSULA. HAVE THUS INCLUDED A MENTION OF LIFR CONDITIONS
AT TIMES OVERNIGHT AT KCMX. AFTER ANY MORNING FOG...VFR CONDITIONS
WILL BE THE RULE AT KCMX/KSAW THRU THE REMAINDER OF THE FCST PERIOD
AS DEEP DRY AIRMASS SETTLES OVER THE AREA.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
WINDS WILL REMAIN BELOW 25 KNOTS THROUGH THIS FORECAST PERIOD AS
HIGH PRESSURE MOVES IN AND KEEPS SYSTEMS OUT OF THE AREA. WINDS WILL
START TO INCREASE WED AS A STORM SYSTEM COMES UP FROM THE SOUTH.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...07
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...07
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