[top]
000
FXUS63 KDLH 232349
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
549 PM CST MON NOV 23 2009
.UPDATE...FOR 00Z TAFS
&&
.AVIATION...UPDATE FOR 00Z TAFS
WIDESPREAD IFR OR BLO EXPECTED THRU MOST OF TAF PD IN FG/DZ. SOME
IMPVMT IN VSBY TUE AFTN...BUT IFR/MVFR CIGS STILL LIKELY. SEE AVN
DISC BELOW FOR MORE DETAILS.
&&
.PREV DISCUSSION... /ISSUED 258 PM CST MON NOV 23 2009/
SHORT TERM CONCERN IS DENSE FOG TONIGHT AND TUE MORNING...THEN
PRECIP EVENT MID-WEEK. LONG TERM CONCERN IS CURRENT SURFACE
ANALYSIS INDICATE
CURRENT SURFACE ANALYSIS INDICATES LIGHT RAIN ACROSS NORTHERN
HALF FOR FORECAST AREA MOVING NORTH AHEAD OF A WEAKENING SURFACE
TROUGH. THE RAIN WILL EVENTUALLY END LATER THIS EVENING AS IT
MOVES NORTH. THE ABUNDANT MOISTURE FROM THE PRECIP THE PAST 24
HOURS WILL CAUSE MORE DENSE FOG TO DEVELOP AGAIN AFTER SUNSET.
WILL KEEP FOG ADVISORY IN EFFECT UNTIL 16Z TUESDAY.
AN AREA OF LOW PRESSURE WILL MOVE FROM THE CENTRAL PLAINS THROUGH
IOWA TO THE SOUTHERN GREAT LAKES BY WEDNESDAY. COLDER AIR WILL
FILTER INTO THE FORECAST AREA BY WEDNESDAY ALONG WITH THE
MOISTURE. THE BEST BET FOR SNOWFALL WILL B ALONG A INL-GPZ-BRD
LINE WHERE A TOTAL OF 1-2 INCHES MAY FALL. A LOT OF IT MAY MELT
DUE TO TEMPS ABV FREEZING AND WARM GROUND. AREAS EAST OF AFFECTED
AREA WILL SEE LESS WITH A MIXTURE MORE LIKELY. THE LOW PRESSURE
AREA PULLS EAST OF AREA TAKING THE PRECIP WITH IT. HIGH PRESSURE
BUILDS INTO THE AREA ON THURSDAY.
EXTENDED...THUR NIGHT THRU SUNDAY...ALL MODELS CONSISTENT IN
FEATURING A MID LVL RIDGE PUSHING ACROSS CWA THUR NIGHT INTO FRIDAY.
TEMPS WILL REMAIN ABOVE AVERAGE AS THE 85H TEMP ANOMALIES REMAIN
ABOVE NORMAL. MDLS MID LVL FCST DIVERGES BY LATE SATURDAY INTO
SUNDAY AS NRN BRANCH AMPLIFIES JUST WEST OF REGION...AND VERY STRONG
JET MAXIMUM AMPLIFIES THE SRN BRANCH OVER THE 4 CRNS REGION.
GFS/GEM CLOSE OFF A MID LVL LOW BY 12Z SUN OVER NRN PLAINS WITH 12Z
EC SLOWER/WEAKER WITH THIS FEATURE...PLACING IT OVER NE MT.
REGARDLESS THERE IS A TREND TO DIG THIS MID LVL SYSTEM SOUTH INTO
CTRL PLAINS...ACCORDING TO BOTH GFS/EC. THIS SEEMS TO MAKE SENSE AS
MOST OF THE KINEMATICS WOULD FAVOR DEVELOPMENT OF ENERGETIC SRN
BRANCH SYSTEM. SUSPECT THAT A MID LVL TROF WILL CROSS CWA
SUNDAY/EARLY MONDAY WITH AT LEAST A CHANCE OF SOME LIGHT SNOW.
AVIATION...18Z TAF ISSUANCE...
KINL/KHIB/KDLH UNDER IFR CEILINGS AS MOIST SOUTHERLY FLOW OF AIR
CONTINUES INTO REGION AHEAD OF SLOW MOVING FRONTAL BDRY/INVERTED SFC
PRESSURE TROUGH. COND PRESS DEFICITS FCST SUGGESTS WHATEVER LIFTING
OF CEILING OCCURS THIS AFTERNOON WILL BE TEMPORARY AS STRATUS LAYER
BUILDS DOWNWARD AGAIN THIS EVENING. BR/FG EXPECTED TO REDEVELOP
TONIGHT AT MOST TERMINALS AS MOIST BDRY LYR COOLS OVERNIGHT.
ELONGATED SFC PRESS TROUGH WITH WINDSHIFT TO W/NW WILL ENTER INL/BRD
TERMINALS BY 18Z WITH SOME IMPROVEMENT
&&
.POINT TEMPS/POPS...
DLH 41 46 33 38 / 50 50 40 70
INL 38 43 31 35 / 70 50 40 60
BRD 39 46 32 36 / 70 40 40 60
HYR 41 48 35 39 / 20 50 50 70
ASX 41 47 38 41 / 20 40 50 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR MNZ012-019>021-
026-037.
WI...DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR WIZ001.
LS...NONE.
&&
$$
04
[top]
000
FXUS63 KMPX 232346
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
546 PM CST MON NOV 23 2009
.DISCUSSION...
VERY ACTIVE WEATHER PATTERN ABOUT TO DEVELOP ACROSS THE UPPER
MIDWEST AS A SERIES OF SHORT WAVES FORCE THE UPPER LEVEL PATTERN
TO BECOME MORE CONDUCIVE OF A PERIOD TO -RA/-DZ...THEN MIXING WITH
AND CHANGING TO -SN BY WED/WED NIGHT.
SHORT TERM CONCERNS DEAL WITH A STRONG UPPER WAVE ACROSS EASTERN
COLORADO THIS AFTN AND HOW THE UPPER LEVEL FORCING BECOMES
ELONGATED AND MOVES E/NE ACROSS IOWA/S MN AND WI. ALTHOUGH THERE
REMAINS SUBTLE DIFFERENCES IN THE OVERALL EVOLUTION OF THIS STRONG
UPPER WAVE...THE MAIN THEME WILL BE A LARGE AREA OF PRECIPITATION
DEVELOPING ACROSS NE/IA...THEN SPREADING E/NE ACROSS SOUTHERN MN
BY LATE THIS EVENING/OVERNIGHT. BY TUESDAY MORNING/AFTN...THE MAIN
INFLUENCE OF THIS SYSTEM WILL BE ASSOCIATED WITH THE MAIN SFC LOW
THAT WILL BE MOVING ACROSS THE IA/MO BORDER BY TUESDAY MORNING...THEN
INTO SOUTHEAST WI BY TUESDAY EVENING. THIS WILL PLACE THE HIGHEST
PERCENTAGES OF WEATHER ELEMENTS ACROSS THE FAR S CWA...BUT STILL
LIGHT QPF AMTS DUE TO THE SEPARATION OF THE MAIN FORCING TO THE SE
OF OUR REGION.
AFTER TUE EVENING...THE NEXT SHORT WAVE WILL BE MOVING INTO THE
NORTHERN PLAINS AND INDUCE A SECONDARY FORCING AREA SOMEWHERE ACROSS
THE UPPER MIDWEST BY WEDNESDAY AFTN/EVENING. BY LATE WEDNESDAY/THU
MORNING... A SECONDARY FRONTAL BOUNDARY OR TROUGH WILL MOVE THROUGH
EASTERN PORTIONS OF THE FORECAST AREA. THE MAIN CONCERNS WILL BE HOW
COOL THE LOW LEVELS WILL BE AS THE FIRST SYSTEM EXITS...AND WHERE
THE COLD CORE OF THE NEXT SYSTEM MOVES. THE LATEST GFS REMAINS TOO
WARM FOR ALL SNOW UNTIL ALL OF THE PRECIPITATION MOVES OUT OF OUR
REGION. THE NAM/WRF IS MORE OF A COMPROMISE OF THE ENSEMBLE MEANS
AND IS COOLER AND ALLOWS FOR THE TRANSITION OF RAIN TO SNOW BY
WEDNESDAY AFTN/EVENING ACROSS MOST OF THE AREA. ALTHOUGH THE GFS
DOES SHOW SOME CONTINUITY WITH THE OVERALL PLACEMENT OF THE UPPER
LEVEL SYSTEM ON WED/THU...THE NAM/WRF SEEM TO INDICATE SOME PV
FORCING (ALONG WITH THE UPPER LOW CLOSE TO OUR CWA) WHICH WILL
LIKELY INDUCE MESOSCALE COOLING PROCESSES. THEREFORE...RAIN CHANGING
TO SNOW IS LIKELY WEDNESDAY AFTN IN THE NW...THEN INTO THE SE CWA BY
LATE WED EVENING. SNOWFALL ACCUMULATIONS WILL BE HIGHLY DEPENDENT ON
WHEN THE CHANGE OVER OCCURS...AND HOW MUCH LEFT OVER FORCING AND
MOISTURE REMAINS AS THIS SYSTEM EXITS THURSDAY MORNING. AT THIS
TIME...HPC SNOWFALL GRIDS SEEM REASONABLE WITH A BROAD AREA OF 1 TO
3 INCHES ACROSS MOSTLY THE NE 2/3 OF CWA...OR BASICALLY ALONG AND
NORTH OF AN ALEXANDRIA...TO ST CLOUD TO FBL LINE. HOWEVER...THIS
HIGHLY DEPENDENT ON THE TRACK OF THE UPPER LEVEL LOW AND IF ANY TYPE
OF TROWAL SCENARIO DEVELOPS ON THE BACK SIDE OF THIS SYSTEM.
THE EXTENDED OUTLOOK REMAINS VERY PROGRESSIVE WHICH MEANS ANOTHER
WEATHER SYSTEM AFFECTING THE AREA BY SUNDAY. THICKNESS VALUES
REMAIN COLD ENOUGH FOR ALL SNOW AT THIS TIME. ..JLT..
&&
.AVIATION.../00Z TAF ISSUANCE/
INVERTED SURFACE TROUGH IS EXTENDING FROM SOUTH TO NORTH ACROSS
WRN MN AND WILL GRADUALLY MOVE EAST THROUGH TUE MORNING...ENDING
UP IN ERN MN BY 18Z TUE BEFORE WEAKENING. ALONG AND TO THE EAST
OF THIS FEATURE WILL CONTINUE SCATTERED TO NUMEROUS SHOWERS
THROUGHOUT MUCH OF THE NIGHT. THESE WILL GENERALLY BE LIGHT...WITH
VISBILITY RESTRICTIONS PRIMARILY CENTERED ON BR/FG/DZ. DEEPEST FOG
AND LOWEST STRATUS IS PRESENTLY ALONG THE BOUNDARY AND THAT WILL
CONTINUE THROUGH THE NIGHT. KMSP SHOULD SEE 1.7 KFT CIGS NOT LONG
AFTER MIDNIGHT. THERE ARE SOME RESIDUAL 1.5 KFT CIGS IN WRN WI TO
THE IMMEDIATE EAST OF KMSP...BUT THINK THEY WILL HOLD IN PLACE
THROUGH MUCH OF THIS EVE. LIFR CONDITIONS LIKELY AT ALL TAF SITES
DURING THE MORNING WITH VERY SLOW IMPROVEMENT TOMORROW DUE TO
LIGHT WIND SPEEDS IN THE LOW LEVELS AND RESIDUAL HIGH MOISTURE.
KMSP LIKELY TO REMAIN AT OR BELOW 1.7 KFT THROUGH THE ENTIRE
MORNING AND POTENTIALLY FOR A BETTER PART OF THE AFTERNOON. SOME
SCATTERING EXPECTED IN WRN MN BY AFTN. WINDS TO BE GENERALLY LIGHT
THROUGH THIS TAF PERIOD AND SHIFT FROM ESE TO NW AS THE TROUGH
PASSES MN AIRPORTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JLT/MTF
000
FXUS63 KMPX 232149 CCA
AFDMPX
AREA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
122 PM CST MON NOV 23 2009
.DISCUSSION...
VERY ACTIVE WEATHER PATTERN ABOUT TO DEVELOP ACROSS THE UPPER
MIDWEST AS A SERIES OF SHORT WAVES FORCE THE UPPER LEVEL PATTERN
TO BECOME MORE CONDUCIVE OF A PERIOD TO -RA/-DZ...THEN MIXING WITH
AND CHANGING TO -SN BY WED/WED NIGHT.
SHORT TERM CONCERNS DEAL WITH A STRONG UPPER WAVE ACROSS EASTERN
COLORADO THIS AFTN AND HOW THE UPPER LEVEL FORCING BECOMES
ELONGATED AND MOVES E/NE ACROSS IOWA/S MN AND WI. ALTHOUGH THERE
REMAINS SUBTLE DIFFERENCES IN THE OVERALL EVOLUTION OF THIS STRONG
UPPER WAVE...THE MAIN THEME WILL BE A LARGE AREA OF PRECIPITATION
DEVELOPING ACROSS NE/IA...THEN SPREADING E/NE ACROSS SOUTHERN MN
BY LATE THIS EVENING/OVERNIGHT. BY TUESDAY MORNING/AFTN...THE MAIN
INFLUENCE OF THIS SYSTEM WILL BE ASSOCIATED WITH THE MAIN SFC LOW
THAT WILL BE MOVING ACROSS THE IA/MO BORDER BY TUESDAY MORNING...THEN
INTO SOUTHEAST WI BY TUESDAY EVENING. THIS WILL PLACE THE HIGHEST
PERCENTAGES OF WEATHER ELEMENTS ACROSS THE FAR S CWA...BUT STILL
LIGHT QPF AMTS DUE TO THE SEPARATION OF THE MAIN FORCING TO THE SE
OF OUR REGION.
AFTER TUE EVENING...THE NEXT SHORT WAVE WILL BE MOVING INTO THE
NORTHERN PLAINS AND INDUCE A SECONDARY FORCING AREA SOMEWHERE ACROSS
THE UPPER MIDWEST BY WEDNESDAY AFTN/EVENING. BY LATE WEDNESDAY/THU
MORNING... A SECONDARY FRONTAL BOUNDARY OR TROUGH WILL MOVE THROUGH
EASTERN PORTIONS OF THE FORECAST AREA. THE MAIN CONCERNS WILL BE HOW
COOL THE LOW LEVELS WILL BE AS THE FIRST SYSTEM EXITS...AND WHERE
THE COLD CORE OF THE NEXT SYSTEM MOVES. THE LATEST GFS REMAINS TOO
WARM FOR ALL SNOW UNTIL ALL OF THE PRECIPITATION MOVES OUT OF OUR
REGION. THE NAM/WRF IS MORE OF A COMPROMISE OF THE ENSEMBLE MEANS
AND IS COOLER AND ALLOWS FOR THE TRANSITION OF RAIN TO SNOW BY
WEDNESDAY AFTN/EVENING ACROSS MOST OF THE AREA. ALTHOUGH THE GFS
DOES SHOW SOME CONTINUITY WITH THE OVERALL PLACEMENT OF THE UPPER
LEVEL SYSTEM ON WED/THU...THE NAM/WRF SEEM TO INDICATE SOME PV
FORCING (ALONG WITH THE UPPER LOW CLOSE TO OUR CWA) WHICH WILL
LIKELY INDUCE MESOSCALE COOLING PROCESSES. THEREFORE...RAIN CHANGING
TO SNOW IS LIKELY WEDNESDAY AFTN IN THE NW...THEN INTO THE SE CWA BY
LATE WED EVENING. SNOWFALL ACCUMULATIONS WILL BE HIGHLY DEPENDENT ON
WHEN THE CHANGE OVER OCCURS...AND HOW MUCH LEFT OVER FORCING AND
MOISTURE REMAINS AS THIS SYSTEM EXITS THURSDAY MORNING. AT THIS
TIME...HPC SNOWFALL GRIDS SEEM REASONABLE WITH A BROAD AREA OF 1 TO
3 INCHES ACROSS MOSTLY THE NE 2/3 OF CWA...OR BASICALLY ALONG AND
NORTH OF AN ALEXANDRIA...TO ST CLOUD TO FBL LINE. HOWEVER...THIS
HIGHLY DEPENDENT ON THE TRACK OF THE UPPER LEVEL LOW AND IF ANY TYPE
OF TROWAL SCENARIO DEVELOPS ON THE BACK SIDE OF THIS SYSTEM.
THE EXTENDED OUTLOOK REMAINS VERY PROGRESSIVE WHICH MEANS ANOTHER
WEATHER SYSTEM AFFECTING THE AREA BY SUNDAY. THICKNESS VALUES
REMAIN COLD ENOUGH FOR ALL SNOW AT THIS TIME. ..JLT..
&&
.AVIATION.../18Z TAF ISSUANCE/
PCPN SLOLY DMNSHG FAR E MN INTO WC WI AS SHRTWV LIFTS NE THRU AREA.
EVEN IN PCPN...CIGS HV GNRLY REMAINED VFR. VCNTY INVERTED TROF NR
MN/DKTS BRDR CONDS RMN IFR...AND WL LIKELY REMAIN SO THRU TAF
PRD...AFFECTING MAINLY AXN IN THE SHORT TERM. AS TROF MVS EWRD THIS
EVE/TNGHT IFR CONDS WILL ACCOMPANY IT...WITH IFR CONDS NOT XPCD TO
REACH MSP TIL AFT 06Z. WV IMAGERY SHWS SHRTWV ROUNDING BASE OF TROF
IN COLORADO WITH PCPN EXPANDING ACRS W INTO CNTL NEB. THIS SURGE OF
PCPN SHUD SPRED INTO RWF AREA BY 03Z AND MSP AFT 06Z. NOT XPCTG ANY
CHG TO SNW UNTIL AFT THIS TAF PRD.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JLT/BAP
000
FXUS63 KDLH 232058
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
258 PM CST MON NOV 23 2009
SHORT TERM CONCERN IS DENSE FOG TONIGHT AND TUE MORNING...THEN
PRECIP EVENT MID-WEEK. LONG TERM CONCERN IS CURRENT SURFACE
ANALYSIS INDICATE
CURRENT SURFACE ANALYSIS INDICATES LIGHT RAIN ACROSS NORTHERN
HALF FOR FORECAST AREA MOVING NORTH AHEAD OF A WEAKENING SURFACE
TROUGH. THE RAIN WILL EVENTUALLY END LATER THIS EVENING AS IT
MOVES NORTH. THE ABUNDANT MOISTURE FROM THE PRECIP THE PAST 24
HOURS WILL CAUSE MORE DENSE FOG TO DEVELOP AGAIN AFTER SUNSET.
WILL KEEP FOG ADVISORY IN EFFECT UNTIL 16Z TUESDAY.
AN AREA OF LOW PRESSURE WILL MOVE FROM THE CENTRAL PLAINS THROUGH
IOWA TO THE SOUTHERN GREAT LAKES BY WEDNESDAY. COLDER AIR WILL
FILTER INTO THE FORECAST AREA BY WEDNESDAY ALONG WITH THE
MOISTURE. THE BEST BET FOR SNOWFALL WILL B ALONG A INL-GPZ-BRD
LINE WHERE A TOTAL OF 1-2 INCHES MAY FALL. A LOT OF IT MAY MELT
DUE TO TEMPS ABV FREEZING AND WARM GROUND. AREAS EAST OF AFFECTED
AREA WILL SEE LESS WITH A MIXTURE MORE LIKELY. THE LOW PRESSURE
AREA PULLS EAST OF AREA TAKING THE PRECIP WITH IT. HIGH PRESSURE
BUILDS INTO THE AREA ON THURSDAY.
EXTENDED...THUR NIGHT THRU SUNDAY...ALL MODELS CONSISTENT IN
FEATURING A MID LVL RIDGE PUSHING ACROSS CWA THUR NIGHT INTO FRIDAY.
TEMPS WILL REMAIN ABOVE AVERAGE AS THE 85H TEMP ANOMALIES REMAIN
ABOVE NORMAL. MDLS MID LVL FCST DIVERGES BY LATE SATURDAY INTO
SUNDAY AS NRN BRANCH AMPLIFIES JUST WEST OF REGION...AND VERY STRONG
JET MAXIMUM AMPLIFIES THE SRN BRANCH OVER THE 4 CRNS REGION.
GFS/GEM CLOSE OFF A MID LVL LOW BY 12Z SUN OVER NRN PLAINS WITH 12Z
EC SLOWER/WEAKER WITH THIS FEATURE...PLACING IT OVER NE MT.
REGARDLESS THERE IS A TREND TO DIG THIS MID LVL SYSTEM SOUTH INTO
CTRL PLAINS...ACCORDING TO BOTH GFS/EC. THIS SEEMS TO MAKE SENSE AS
MOST OF THE KINEMATICS WOULD FAVOR DEVELOPMENT OF ENERGETIC SRN
BRANCH SYSTEM. SUSPECT THAT A MID LVL TROF WILL CROSS CWA
SUNDAY/EARLY MONDAY WITH AT LEAST A CHANCE OF SOME LIGHT SNOW.
AVIATION...18Z TAF ISSUANCE...
KINL/KHIB/KDLH UNDER IFR CEILINGS AS MOIST SOUTHERLY FLOW OF AIR
CONTINUES INTO REGION AHEAD OF SLOW MOVING FRONTAL BDRY/INVERTED SFC
PRESSURE TROUGH. COND PRESS DEFICITS FCST SUGGESTS WHATEVER LIFTING
OF CEILING OCCURS THIS AFTERNOON WILL BE TEMPORARY AS STRATUS LAYER
BUILDS DOWNWARD AGAIN THIS EVENING. BR/FG EXPECTED TO REDEVELOP
TONIGHT AT MOST TERMINALS AS MOIST BDRY LYR COOLS OVERNIGHT.
ELONGATED SFC PRESS TROUGH WITH WINDSHIFT TO W/NW WILL ENTER INL/BRD
TERMINALS BY 18Z WITH SOME IMPROVEMENT
.POINT TEMPS/POPS...
DLH 41 46 33 38 / 50 50 40 70
INL 38 43 31 35 / 70 50 40 60
BRD 39 46 32 36 / 70 40 40 60
HYR 41 48 35 39 / 20 50 50 70
ASX 41 47 38 41 / 20 40 50 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR MNZ012-019>021-
026-037.
WI...DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR WIZ001.
LS...NONE.
&&
$$
06/CANNON
000
FXUS63 KDLH 231928 AAB
AFDDLH
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
128 PM CST MON NOV 23 2009
.AVIATION...18Z TAF ISSUANCE...
KINL/KHIB/KDLH UNDER IFR CEILINGS AS MOIST SOUTHERLY FLOW OF AIR
CONTINUES INTO REGION AHEAD OF SLOW MOVING FRONTAL BDRY/INVERTED
SFC PRESSURE TROUGH. COND PRESS DEFICITS FCST SUGGESTS WHATEVER LIFTING
OF CEILING OCCURS THIS AFTERNOON WILL BE TEMPORARY AS STRATUS
LAYER BUILDS DOWNWARD AGAIN THIS EVENING. KDLH TRICKY AS VLIFR HAS
JUST IMPROVED TO LIFR AND MAY EVEN REACH IFR FOR A FEW HOURS THIS
AFTERNOON BEFORE CEILINGS LOWER AGAIN. BR/FG EXPECTED TO REDEVELOP
TONIGHT AT MOST TERMINALS AS MOIST BDRY LYR COOLS OVERNIGHT.
ELONGATED SFC PRESS TROUGH WITH WINDSHIFT TO W/NW WILL ENTER
INL/BRD TERMINALS BY 18Z WITH SOME IMPROVEMENT
&&
.PREV DISCUSSION... /ISSUED 1055 AM CST MON NOV 23 2009/
UPDATE...HAVE UPDATED TO EXTEND THE DURATION OF THE DENSE FOG
ADVISORY THROUGH 10 AM TUESDAY. WHILE RAIN AND DAYTIME HEATING IS
EXPECTED TO BRING AN IMPROVEMENT IN THE DENSE FOG FOR THE
AFTERNOON...WE EXPECT THE DENSE FOG TO QUICKLY RE-ESTABLISH ITSELF
DURING THE EARLY PART OF THE EVENING. CONDITIONS SHOULD THEN
IMPROVE ON TUESDAY. RATHER THAN CANCEL THE ADVISORY AND THEN
REISSUE...WE DECIDED TO NOT AN IMPROVING TREND FOR A TIME...BEFORE
CONDITIONS DETERIORATE ONCE AGAIN EARLY THIS EVENING. FEEL FAIRLY
STRONGLY THAT DENSE FOG WILL AGAIN BE A PROBLEM TONIGHT...AND THE
DENSE FOG REPORTED LAST NIGHT WAS VERY HAZARDOUS...WITH VIRTUALLY
NO DRIVING VISIBILITY. AS A RESULT...WE WILL EXTEND THE ADVISORY
THROUGH 10 AM TUESDAY. ELSEWHERE...WE SHOULD SEE A DECREASE IN
RAIN FROM SE TO NW ACROSS NW WI. MUCH OF NE MN SHOULD SEE RAIN
CONTINUING...IF NOT DECREASING IN AREAL COVERAGE TO SOME EXTENT.
PREV DISCUSSION... /ISSUED 642 AM CST MON NOV 23 2009/
AVIATION.../12Z TAF ISSUANCE/
AREAS OF LIGHT RAIN WILL AFFECT MUCH OF THE FORECAST AREA THROUGH
TONIGHT. SOME OF THE FOG THIS MORNING AND AGAIN TONIGHT MAY BE
DENSE...ALTHOUGH GUIDANCE HAS HAD A DIFFICULT TIME IN FORECASTING
THE ONSET AND END OF THE DENSE FOG. THEREFORE CONFIDENCE IS LOW
WRT TO LIFR VSBYS. CIGS WILL ALSO VARY FROM LIFR TO VFR TODAY
THROUGH TONIGHT.
PREV DISCUSSION... /ISSUED 358 AM CST MON NOV 23 2009/
DISCUSSION...
EAST-WEST BANDS OF LOW LEVEL WARM ADVECTION...ASSOCIATED WITH A
DISSIPATED SURFACE TROUGH...ARE SPREADING NORTH ACROSS OUR AREA.
AT THIS TIME...BANDS ARE ASSOCIATED WITH LIGHT RAIN AND FOG
FORMATION MORE RAPID THAN RAIN CAN RINSE OUT. BETWEEN BANDS...
COMPENSATORY LOW LEVEL DOWNWARD MOTION BRIEFLY EXPOSES A MID DECK
AND CAUSES TEMPORARY IMPROVEMENT. A BAND NOW ALONG OUR SOUTHERN
EDGE IS INCREASING IN WIDTH AND MOISTURE AS IT SPREADS NORTH.
LOW PRESSURE OVER THE CENTRAL/SOUTHERN PLAINS WILL ESTABLISH AN
INVERTED TROUGH NORTHWARD ALONG OR IMMEDIATELY EAST OF THE RED
RIVER VALLEY BY NOON TODAY. A WEAK BUT DIGGING TROUGH ALOFT WILL
ANCHOR THE INVERTED TROUGH ALONG OUR WESTERN EDGE THROUGH TONIGHT
AND TUESDAY. WE ANTICIPATE FOG AND LIGHT RAIN TO CONTINUE...WITH
THE BACK EDGE NOT APT TO REACH OUR WESTERN AREAS EITHER TONIGHT OR
TUESDAY. AGAIN...CONTINUED WARM ADVECTION ALONG AND EAST OF THE
INVERTED TROUGH WILL KEEP THE COLUMN UNSEASONABLY WARM.
EXTENDED...TUESDAY NIGHT THRU SUNDAY.
THE MEDIUM RANGE MODELS SHOW A COMPLEX SCENARIO SETTING UP FOR THE
BEGINNING OF THE EXTENDED FORECAST PERIOD...WITH TWO DISTINCT
SHORTWAVE TROUGHS AFFECTING OUR CWA. A SRN WAVE LOCATED OVER THE
CENTRAL MIDWEST WILL BRING RAIN TO OUR SRN ZONES TUESDAY NIGHT AND
WEDNESDAY...WHILE A STRONGER SYSTEM DIGS SEWD OUT OF
CANADA...BRINGING A CHANCE OF RAIN AND SNOW TO OUR NRN ZONES. THE
MODELS SHOW THAT THESE TWO WAVES WILL EVENTUALLY MERGE OVER THE
GREAT LAKES REGION ON WEDNESDAY AND WEDNESDAY NIGHT. LIFT ASSOCIATED
WITH THESE SYSTEMS WILL PROVIDE LIFT WHICH WILL TAP AMPLE
MOISTURE...CONTINUING THE CHANCE OF PRECIP ACROSS OUR ENTIRE
CWA...WITH THE BEST CHANCE FOR PRECIP ACROSS OUR ERN ZONES. DURING
THIS TIME FRAME...THE RAIN WILL MIX WITH SNOW...AND EVENTUALLY
CHANGE TO ALL SNOW WEDNESDAY NIGHT AS COLDER AIR ADVECTS SOUTH FROM
CANADA ON THE WEST SIDE OF THE NOW DEPARTING LOW. A WEAKER ELONGATED
VORTMAX WILL FOLLOW AND AFFECT THE NORTHLAND ON
THURSDAY...CONTINUING THE CHANCE OF SNOW SHOWERS ACROSS THE ERN HALF
OF OUR CWA. THE SNOW WILL END FOR MOST LOCATIONS THURSDAY
NIGHT...EXCEPT ACROSS THE SNOWBELT OF NWRN WI WHERE LAKE EFFECT SNOW
SHOWERS MAY LINGER. HIGH PRESSURE WILL MOVE OVER THE WRN GREAT LAKES
BY FRIDAY...RESULTING IN DRIER CONDITIONS. ATTM...NEXT WEEKEND
APPEARS DRY...ALTHOUGH THE ECMWF DOES SHOW ANOTHER SHORTWAVE DIGGING
SEWD OUT OF CANADA AND OVER THE UPPER MIDWEST. HOWEVER MOST OF THE
PRECIP ASSOCIATED WITH THIS DISTURBANCE SHOULDNT AFFECT THE FCST
AREA UNTIL SUNDAY AND SUNDAY NIGHT.
&&
.POINT TEMPS/POPS...
DLH 41 46 33 38 / 50 50 40 70
INL 38 43 31 35 / 70 50 40 60
BRD 39 46 32 36 / 70 40 40 60
HYR 41 48 35 39 / 20 50 50 70
ASX 41 47 38 41 / 20 40 50 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR MNZ012-019>021-
026-037.
WI...DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR WIZ001.
LS...NONE.
&&
$$
06/CANNON/CANNON
000
FXUS63 KMPX 231922
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
122 PM CST MON NOV 23 2009
.DISCUSSION...
VERY ACTIVE WEATHER PATTERN ABOUT TO DEVELOP ACROSS THE UPPER
MIDWEST AS A SERIES OF SHORT WAVES FORCE THE UPPER LEVEL PATTERN
TO BECOME MORE CONDUCIVE OF A PERIOD OF -RA/-DZ...THEN MIXING WITH
AND CHANGING TO -SN BY WED/WED NIGHT.
SHORT TERM CONCERNS DEAL WITH A STRONG UPPER WAVE ACROSS EASTERN
COLORADO THIS AFTN AND HOW THE UPPER LEVEL FORCING BECOMES
ELONGATED AND MOVES E/NE ACROSS IOWA/S MN AND WI. ALTHOUGH THERE
REMAINS SUBTLE DIFFERENCES IN THE OVERALL EVOLUTION OF THIS STRONG
UPPER WAVE...THE MAIN THEME WILL BE A LARGE AREA OF PRECIPITATION
DEVELOPING ACROSS NE/IA...THEN SPREADING E/NE ACROSS SOUTHERN MN
BY LATE THIS EVENING/OVERNIGHT. BY TUESDAY MORNING/AFTN...THE MAIN
INFLUENCE OF THIS SYSTEM WILL BE ASSOCIATED WITH THE MAIN SFC LOW
THAT WILL BE MOVING ACROSS THE IA/MO BORDER BY TUESDAY MORNING...THEN
INTO SOUTHEAST WI BY TUESDAY EVENING. THIS WILL PLACE THE HIGHEST
PERCENTAGES OF WEATHER ELEMENTS ACROSS THE FAR S CWA...BUT STILL
LIGHT QPF AMTS DUE TO THE SEPARATION OF THE MAIN FORCING SE OF
OUR REGION.
AFT TUE EVENING...THE NEXT SHORT WAVE WILL MOVING INTO THE
NORTHERN PLAINS AND INDUCE A SECONDARY FORCING AREA SOMEWHERE
ACROSS THE UPPER MIDWEST BY WEDNESDAY AFTN/EVENING. BY LATE
WEDNESDAY/THU MORNING... A SECONDARY FRONTAL BOUNDARY OR TROUGH
WILL MOVE THROUGH EASTERN PORTIONS OF THE FORECAST AREA. THE MAIN
CONCERNS WILL BE HOW COOL THE LOW LEVELS WILL BE AS THE FIRST
SYSTEM EXITS...AND WHERE THE COLD CORE OF THE NEXT SYSTEM MOVES.
THE LATEST GFS REMAINS TOO WARM FOR ALL SNOW UNTIL ALL OF THE
PRECIPITATION MOVES OUT OF OUR REGION. THE NAM/WRF IS MORE OF A
COMPROMISE OF THE ENSEMBLE MEANS AND IS COOLER AND ALLOWS FOR THE
TRANSITION OF RAIN TO SNOW BY WEDNESDAY AFTN/EVENING ACROSS MOST
OF THE AREA. ALTHOUGH THE GFS DOES SHOW SOME CONTINUITY WITH THE
OVERALL PLACEMENT OF THE UPPER LEVEL SYSTEM ON WED/THU...THE
NAM/WRF SEEM TO INDICATE SOME PV FORCING (ALONG WITH THE UPPER LOW
CLOSE TO OUR CWA) WHICH WILL LIKELY INDUCE MESOSCALE COOLING
PROCESSES. THEREFORE...RAIN CHANGING TO SNOW IS LIKELY WEDNESDAY
AFTN IN THE NW...THEN INTO THE SE CWA BY LATE WED EVENING.
SNOWFALL ACCUMULATIONS WILL BE HIGHLY DEPENDENT ON WHEN THE CHANGE
OVER OCCURS...AND HOW MUCH LEFT OVER FORCING AND MOISTURE REMAINS
AS THIS SYSTEM EXITS THURSDAY MORNING. AT THIS TIME...HPC SNOWFALL
GRIDS SEEM REASONABLE WITH A BROAD AREA OF 1 TO 3 INCHES ACROSS
MOSTLY THE NE 2/3 OF CWA...OR BASICALLY ALONG AND NORTH OF AN
ALEXANDRIA...TO ST CLOUD TO FBL LINE. HOWEVER...THIS HIGHLY
DEPENDENT ON THE TRACK OF THE UPPER LEVEL LOW AND IF ANY TYPE OF
TROWAL SCENARIO DEVELOPS ON THE BACK SIDE OF THIS SYSTEM.
THE EXTENDED OUTLOOK REMAINS VERY PROGRESSIVE WHICH MEANS ANOTHER
WEATHER SYSTEM AFFECTING THE AREA BY SUNDAY. THICKNESS VALUES
REMAIN COLD ENOUGH FOR ALL SNOW AT THIS TIME. ..JLT..
&&
.AVIATION.../18Z TAF ISSUANCE/
PCPN SLOLY DMNSHG FAR E MN INTO WC WI AS SHRTWV LIFTS NE THRU AREA.
EVEN IN PCPN...CIGS HV GNRLY REMAINED VFR. VCNTY INVERTED TROF NR
MN/DKTS BRDR CONDS RMN IFR...AND WL LIKELY REMAIN SO THRU TAF
PRD...AFFECTING MAINLY AXN IN THE SHORT TERM. AS TROF MVS EWRD THIS
EVE/TNGHT IFR CONDS WILL ACCOMPANY IT...WITH IFR CONDS NOT XPCD TO
REACH MSP TIL AFT 06Z. WV IMAGERY SHWS SHRTWV ROUNDING BASE OF TROF
IN COLORADO WITH PCPN EXPANDING ACRS W INTO CNTL NEB. THIS SURGE OF
PCPN SHUD SPRED INTO RWF AREA BY 03Z AND MSP AFT 06Z. NOT XPCTG ANY
CHG TO SNW UNTIL AFT THIS TAF PRD.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JLT/BAP
000
FXUS63 KMPX 231754 AAA
AFDMPX
AREA FORECAST DISCUSSION...UPDATED FOR 18Z TAF
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1155 AM CST MON NOV 23 2009
.DISCUSSION...ISSUED 322 AM CST
THE FORECAST CHALLENGES THIS PERIOD ARE PRECIPITATION CHANCES AND
PRECIP TRANSITION OVER TO SNOW BEFORE THANKSGIVING EVE.
IN THE NEAR TERM...A NEARLY STATIONARY FRONT OVER CENTRAL MN...WILL
MOVE LITTLE TODAY AS A WEAK SURFACE TROUGH OVER THE CENTRAL PLAINS
DRIFTS SLOWLY EAST OVER THE MIDWEST THROUGH TUESDAY.
MOIST AND WARM AIR CONTINUE TO LIFT NORTH OVER THE FRONTAL BOUNDARY
ACROSS THE UPPER MIDWEST. LIGHT RAIN SHOULD BEGIN TO PUSH OUT OF
SOUTH CENTRAL MN AND WESTERN WISCONSIN LATER THIS MORNING WITH
LINGERING LIGHT RAIN OR DRIZZLE OVER THE REST OF THE FORECAST AREA
THROUGH THE REMAINDER OF THE DAY.
THE MODELS ARE IN GENERAL AGREEMENT IN THE MEDIUM RANGE...
MODELS HAVE BEEN CONSISTENT FROM RUN TO RUN WITH UPPER LOW OVER THE
CENTRAL PLAINS...LIFTING NORTHEAST OVER THE LOWER GREAT LAKES BY
WEDNESDAY MORNING. STRONGER UPPER LEVEL TROUGH OVER THE PACIFIC
NORTHWEST...WILL BEGIN TO CARVE OUT A STRONGER TROUGH OVER THE
NORTHERN PLAINS/UPPER MIDWEST BY WEDNESDAY.
THE GEM-NHEM MODEL BLEND INDICATES THE PRECIPITATION SHOULD BE
MAINLY RAIN THROUGH TUESDAY...THEN BECOME A MIXTURE OF RAIN OR
SNOW OVER PORTIONS OF WEST CENTRAL MINNESOTA TUESDAY NIGHT THEN
SWITCH OVER TO ALL SNOW OVER THE ENTIRE FORECAST AREA ON WEDNESDAY
AS COLDER AIR SINKS OVER THE MIDWEST.
THANKSGIVING DAY AND FRIDAY...LOOKS COLD AND DRY AS A SFC RIDGE
BUILDS EAST OVER THE UPPER MIDWEST DURING THE PERIOD.
&&
.AVIATION.../18Z TAF ISSUANCE/
PCPN SLOLY DMNSHG FAR E MN INTO WC WI AS SHRTWV LIFTS NE THRU AREA.
EVEN IN PCPN...CIGS HV GNRLY REMAINED VFR. VCNTY INVERTED TROF NR
MN/DKTS BRDR CONDS RMN IFR...AND WL LIKELY REMAIN SO THRU TAF
PRD...AFFECTING MAINLY AXN IN THE SHORT TERM. AS TROF MVS EWRD THIS
EVE/TNGHT IFR CONDS WILL ACCOMPANY IT...WITH IFR CONDS NOT XPCD TO
REACH MSP TIL AFT 06Z. WV IMAGERY SHWS SHRTWV ROUNDING BASE OF TROF
IN COLORADO WITH PCPN EXPANDING ACRS W INTO CNTL NEB. THIS SURGE OF
PCPN SHUD SPRED INTO RWF AREA BY 03Z AND MSP AFT 06Z. NOT XPCTG ANY
CHG TO SNW UNTIL AFT THIS TAF PRD.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JVM/BAP
000
FXUS63 KDLH 231655
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
1055 AM CST MON NOV 23 2009
.UPDATE...HAVE UPDATED TO EXTEND THE DURATION OF THE DENSE FOG
ADVISORY THROUGH 10 AM TUESDAY. WHILE RAIN AND DAYTIME HEATING IS
EXPECTED TO BRING AN IMPROVEMENT IN THE DENSE FOG FOR THE
AFTERNOON...WE EXPECT THE DENSE FOG TO QUICKLY RE-ESTABLISH ITSELF
DURING THE EARLY PART OF THE EVENING. CONDITIONS SHOULD THEN
IMPROVE ON TUESDAY. RATHER THAN CANCEL THE ADVISORY AND THEN
REISSUE...WE DECIDED TO NOT AN IMPROVING TREND FOR A TIME...BEFORE
CONDITIONS DETERIORATE ONCE AGAIN EARLY THIS EVENING. FEEL FAIRLY
STRONGLY THAT DENSE FOG WILL AGAIN BE A PROBLEM TONIGHT...AND THE
DENSE FOG REPORTED LAST NIGHT WAS VERY HAZARDOUS...WITH VIRTUALLY
NO DRIVING VISIBILITY. AS A RESULT...WE WILL EXTEND THE ADVISORY
THROUGH 10 AM TUESDAY. ELSEWHERE...WE SHOULD SEE A DECREASE IN
RAIN FROM SE TO NW ACROSS NW WI. MUCH OF NE MN SHOULD SEE RAIN
CONTINUING...IF NOT DECREASING IN AREAL COVERAGE TO SOME EXTENT.
&&
.PREV DISCUSSION... /ISSUED 642 AM CST MON NOV 23 2009/
AVIATION.../12Z TAF ISSUANCE/
AREAS OF LIGHT RAIN WILL AFFECT MUCH OF THE FORECAST AREA THROUGH
TONIGHT. SOME OF THE FOG THIS MORNING AND AGAIN TONIGHT MAY BE
DENSE...ALTHOUGH GUIDANCE HAS HAD A DIFFICULT TIME IN FORECASTING
THE ONSET AND END OF THE DENSE FOG. THEREFORE CONFIDENCE IS LOW
WRT TO LIFR VSBYS. CIGS WILL ALSO VARY FROM LIFR TO VFR TODAY
THROUGH TONIGHT.
PREV DISCUSSION... /ISSUED 358 AM CST MON NOV 23 2009/
DISCUSSION...
EAST-WEST BANDS OF LOW LEVEL WARM ADVECTION...ASSOCIATED WITH A
DISSIPATED SURFACE TROUGH...ARE SPREADING NORTH ACROSS OUR AREA.
AT THIS TIME...BANDS ARE ASSOCIATED WITH LIGHT RAIN AND FOG
FORMATION MORE RAPID THAN RAIN CAN RINSE OUT. BETWEEN BANDS...
COMPENSATORY LOW LEVEL DOWNWARD MOTION BRIEFLY EXPOSES A MID DECK
AND CAUSES TEMPORARY IMPROVEMENT. A BAND NOW ALONG OUR SOUTHERN
EDGE IS INCREASING IN WIDTH AND MOISTURE AS IT SPREADS NORTH.
LOW PRESSURE OVER THE CENTRAL/SOUTHERN PLAINS WILL ESTABLISH AN
INVERTED TROUGH NORTHWARD ALONG OR IMMEDIATELY EAST OF THE RED
RIVER VALLEY BY NOON TODAY. A WEAK BUT DIGGING TROUGH ALOFT WILL
ANCHOR THE INVERTED TROUGH ALONG OUR WESTERN EDGE THROUGH TONIGHT
AND TUESDAY. WE ANTICIPATE FOG AND LIGHT RAIN TO CONTINUE...WITH
THE BACK EDGE NOT APT TO REACH OUR WESTERN AREAS EITHER TONIGHT OR
TUESDAY. AGAIN...CONTINUED WARM ADVECTION ALONG AND EAST OF THE
INVERTED TROUGH WILL KEEP THE COLUMN UNSEASONABLY WARM.
EXTENDED...TUESDAY NIGHT THRU SUNDAY.
THE MEDIUM RANGE MODELS SHOW A COMPLEX SCENARIO SETTING UP FOR THE
BEGINNING OF THE EXTENDED FORECAST PERIOD...WITH TWO DISTINCT
SHORTWAVE TROUGHS AFFECTING OUR CWA. A SRN WAVE LOCATED OVER THE
CENTRAL MIDWEST WILL BRING RAIN TO OUR SRN ZONES TUESDAY NIGHT AND
WEDNESDAY...WHILE A STRONGER SYSTEM DIGS SEWD OUT OF
CANADA...BRINGING A CHANCE OF RAIN AND SNOW TO OUR NRN ZONES. THE
MODELS SHOW THAT THESE TWO WAVES WILL EVENTUALLY MERGE OVER THE
GREAT LAKES REGION ON WEDNESDAY AND WEDNESDAY NIGHT. LIFT ASSOCIATED
WITH THESE SYSTEMS WILL PROVIDE LIFT WHICH WILL TAP AMPLE
MOISTURE...CONTINUING THE CHANCE OF PRECIP ACROSS OUR ENTIRE
CWA...WITH THE BEST CHANCE FOR PRECIP ACROSS OUR ERN ZONES. DURING
THIS TIME FRAME...THE RAIN WILL MIX WITH SNOW...AND EVENTUALLY
CHANGE TO ALL SNOW WEDNESDAY NIGHT AS COLDER AIR ADVECTS SOUTH FROM
CANADA ON THE WEST SIDE OF THE NOW DEPARTING LOW. A WEAKER ELONGATED
VORTMAX WILL FOLLOW AND AFFECT THE NORTHLAND ON
THURSDAY...CONTINUING THE CHANCE OF SNOW SHOWERS ACROSS THE ERN HALF
OF OUR CWA. THE SNOW WILL END FOR MOST LOCATIONS THURSDAY
NIGHT...EXCEPT ACROSS THE SNOWBELT OF NWRN WI WHERE LAKE EFFECT SNOW
SHOWERS MAY LINGER. HIGH PRESSURE WILL MOVE OVER THE WRN GREAT LAKES
BY FRIDAY...RESULTING IN DRIER CONDITIONS. ATTM...NEXT WEEKEND
APPEARS DRY...ALTHOUGH THE ECMWF DOES SHOW ANOTHER SHORTWAVE DIGGING
SEWD OUT OF CANADA AND OVER THE UPPER MIDWEST. HOWEVER MOST OF THE
PRECIP ASSOCIATED WITH THIS DISTURBANCE SHOULDNT AFFECT THE FCST
AREA UNTIL SUNDAY AND SUNDAY NIGHT.
&&
.POINT TEMPS/POPS...
DLH 49 39 46 33 / 70 50 40 40
INL 48 35 43 31 / 70 70 50 40
BRD 51 39 47 32 / 60 60 40 40
HYR 53 41 48 35 / 60 10 40 50
ASX 51 41 47 38 / 30 10 30 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR MNZ012-019>021-
026-037.
WI...DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR WIZ001.
LS...NONE.
&&
$$
06/CANNON
000
FXUS63 KDLH 231242
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
642 AM CST MON NOV 23 2009
.AVIATION.../12Z TAF ISSUANCE/
AREAS OF LIGHT RAIN WILL AFFECT MUCH OF THE FORECAST AREA THROUGH
TONIGHT. SOME OF THE FOG THIS MORNING AND AGAIN TONIGHT MAY BE
DENSE...ALTHOUGH GUIDANCE HAS HAD A DIFFICULT TIME IN FORECASTING
THE ONSET AND END OF THE DENSE FOG. THEREFORE CONFIDENCE IS LOW
WRT TO LIFR VSBYS. CIGS WILL ALSO VARY FROM LIFR TO VFR TODAY
THROUGH TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 358 AM CST MON NOV 23 2009/
DISCUSSION...
EAST-WEST BANDS OF LOW LEVEL WARM ADVECTION...ASSOCIATED WITH A
DISSIPATED SURFACE TROUGH...ARE SPREADING NORTH ACROSS OUR AREA.
AT THIS TIME...BANDS ARE ASSOCIATED WITH LIGHT RAIN AND FOG
FORMATION MORE RAPID THAN RAIN CAN RINSE OUT. BETWEEN BANDS...
COMPENSATORY LOW LEVEL DOWNWARD MOTION BRIEFLY EXPOSES A MID DECK
AND CAUSES TEMPORARY IMPROVEMENT. A BAND NOW ALONG OUR SOUTHERN
EDGE IS INCREASING IN WIDTH AND MOISTURE AS IT SPREADS NORTH.
LOW PRESSURE OVER THE CENTRAL/SOUTHERN PLAINS WILL ESTABLISH AN
INVERTED TROUGH NORTHWARD ALONG OR IMMEDIATELY EAST OF THE RED
RIVER VALLEY BY NOON TODAY. A WEAK BUT DIGGING TROUGH ALOFT WILL
ANCHOR THE INVERTED TROUGH ALONG OUR WESTERN EDGE THROUGH TONIGHT
AND TUESDAY. WE ANTICIPATE FOG AND LIGHT RAIN TO CONTINUE...WITH
THE BACK EDGE NOT APT TO REACH OUR WESTERN AREAS EITHER TONIGHT OR
TUESDAY. AGAIN...CONTINUED WARM ADVECTION ALONG AND EAST OF THE
INVERTED TROUGH WILL KEEP THE COLUMN UNSEASONABLY WARM.
EXTENDED...TUESDAY NIGHT THRU SUNDAY.
THE MEDIUM RANGE MODELS SHOW A COMPLEX SCENARIO SETTING UP FOR THE
BEGINNING OF THE EXTENDED FORECAST PERIOD...WITH TWO DISTINCT
SHORTWAVE TROUGHS AFFECTING OUR CWA. A SRN WAVE LOCATED OVER THE
CENTRAL MIDWEST WILL BRING RAIN TO OUR SRN ZONES TUESDAY NIGHT AND
WEDNESDAY...WHILE A STRONGER SYSTEM DIGS SEWD OUT OF
CANADA...BRINGING A CHANCE OF RAIN AND SNOW TO OUR NRN ZONES. THE
MODELS SHOW THAT THESE TWO WAVES WILL EVENTUALLY MERGE OVER THE
GREAT LAKES REGION ON WEDNESDAY AND WEDNESDAY NIGHT. LIFT ASSOCIATED
WITH THESE SYSTEMS WILL PROVIDE LIFT WHICH WILL TAP AMPLE
MOISTURE...CONTINUING THE CHANCE OF PRECIP ACROSS OUR ENTIRE
CWA...WITH THE BEST CHANCE FOR PRECIP ACROSS OUR ERN ZONES. DURING
THIS TIME FRAME...THE RAIN WILL MIX WITH SNOW...AND EVENTUALLY
CHANGE TO ALL SNOW WEDNESDAY NIGHT AS COLDER AIR ADVECTS SOUTH FROM
CANADA ON THE WEST SIDE OF THE NOW DEPARTING LOW. A WEAKER ELONGATED
VORTMAX WILL FOLLOW AND AFFECT THE NORTHLAND ON
THURSDAY...CONTINUING THE CHANCE OF SNOW SHOWERS ACROSS THE ERN HALF
OF OUR CWA. THE SNOW WILL END FOR MOST LOCATIONS THURSDAY
NIGHT...EXCEPT ACROSS THE SNOWBELT OF NWRN WI WHERE LAKE EFFECT SNOW
SHOWERS MAY LINGER. HIGH PRESSURE WILL MOVE OVER THE WRN GREAT LAKES
BY FRIDAY...RESULTING IN DRIER CONDITIONS. ATTM...NEXT WEEKEND
APPEARS DRY...ALTHOUGH THE ECMWF DOES SHOW ANOTHER SHORTWAVE DIGGING
SEWD OUT OF CANADA AND OVER THE UPPER MIDWEST. HOWEVER MOST OF THE
PRECIP ASSOCIATED WITH THIS DISTURBANCE SHOULDNT AFFECT THE FCST
AREA UNTIL SUNDAY AND SUNDAY NIGHT.
AVIATION...11/23/06Z ISSUANCE...
LITTLE CHANGE FROM 00Z TAF SET. VFR AT KINL AND KHYR...WHICH WILL
CONTINUE UNTIL ABOUT 07-08Z WHEN -DZ/BR/FG REDUCE VSBYS AND CIGS TO
MVFR WITH ISOLD IFR. BOTH LOCATIONS BECOME IFR/LIFR AS LOW
CLOUDS/-DZ/BR/FG PERSIST AFTER 10Z. KDLH/KHIB/KBRD WILL BE IFR/LIFR
THROUGH THE TAF PERIOD WITH INSTANCES OF VLIFR IN -DZ/BR/FG.
&&
.POINT TEMPS/POPS...
DLH 48 39 46 33 / 70 50 40 40
INL 47 35 43 31 / 70 70 50 40
BRD 49 39 47 32 / 60 60 40 40
HYR 51 41 48 35 / 60 10 40 50
ASX 50 41 47 38 / 30 10 30 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR MNZ012-
019>021-026-037.
WI...DENSE FOG ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR WIZ001.
LS...NONE.
&&
$$
BERDES
000
FXUS63 KMPX 231209
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
609 AM CST MON NOV 23 2009
.UPDATE...
12Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
THE FORECAST CHALLENGES THIS PERIOD ARE PRECIPITATION CHANCES AND
PRECIP TRANSITION OVER TO SNOW BEFORE THANKSGIVING EVE.
IN THE NEAR TERM...A NEARLY STATIONARY FRONT OVER CENTRAL MN...WILL
MOVE LITTLE TODAY AS A WEAK SURFACE TROUGH OVER THE CENTRAL PLAINS
DRIFTS SLOWLY EAST OVER THE MIDWEST THROUGH TUESDAY.
MOIST AND WARM AIR CONTINUE TO LIFT NORTH OVER THE FRONTAL BOUNDARY
ACROSS THE UPPER MIDWEST. LIGHT RAIN SHOULD BEGIN TO PUSH OUT OF
SOUTH CENTRAL MN AND WESTERN WISCONSIN LATER THIS MORNING WITH
LINGERING LIGHT RAIN OR DRIZZLE OVER THE REST OF THE FORECAST AREA
THROUGH THE REMAINDER OF THE DAY.
THE MODELS ARE IN GENERAL AGREEMENT IN THE MEDIUM RANGE...
MODELS HAVE BEEN CONSISTENT FROM RUN TO RUN WITH UPPER LOW OVER THE
CENTRAL PLAINS...LIFTING NORTHEAST OVER THE LOWER GREAT LAKES BY
WEDNESDAY MORNING. STRONGER UPPER LEVEL TROUGH OVER THE PACIFIC
NORTHWEST...WILL BEGIN TO CARVE OUT A STRONGER TROUGH OVER THE
NORTHERN PLAINS/UPPER MIDWEST BY WEDNESDAY.
THE GEM-NHEM MODEL BLEND INDICATES THE PRECIPITATION SHOULD BE
MAINLY RAIN THROUGH TUESDAY...THEN BECOME A MIXTURE OF RAIN OR
SNOW OVER PORTIONS OF WEST CENTRAL MINNESOTA TUESDAY NIGHT THEN
SWITCH OVER TO ALL SNOW OVER THE ENTIRE FORECAST AREA ON WEDNESDAY
AS COLDER AIR SINKS OVER THE MIDWEST.
THANKSGIVING DAY AND FRIDAY...LOOKS COLD AND DRY AS A SFC RIDGE
BUILDS EAST OVER THE UPPER MIDWEST DURING THE PERIOD.
&&
.AVIATION.../12Z TAF ISSUANCE/
CONDITIONS A BIT CHAOTIC THIS MORNING AS AREA SITS UNDER STRONG
WAA REGIME SE OF A WARM FRONT THAT HAS PUSHED NW OF ALL TERMINALS.
THE WAA AT LOW LEVELS HAS IMPEDED MOISTENING OF ATMO AND DEVELOPMENT
OF STRATUS ALL NIGHT. THE LOWEST STRATUS HAS STAYED ALONG THE
FRONT...WHICH PUSHED LIFR CLOUDS OUT OF AXN EARLIER. OVER
WI...RAIN ALL NIGHT...COMBINED WITH A WEAKENING IN LOW LEVEL WAA
HAS MOISTENED ATMO ENOUGH TO BRING IN SOME MVFR CLOUDS NEAR THE
MN/WI BORDER. RNH SO FAR IS THE ONLY TERMINAL TO BE IMPACTED...BUT
FOLLOWING RUC 925 MB RH...WHICH NICELY DEPICTED THE FORMATION OF
THE WI CLOUDS...EXPECT SE WINDS OVER MSP TO BRING THESE CLOUDS
OVER THE FIELD SHORTLY. ALSO EXPECT THEM TO EXPAND INTO EAU AND
EVENTUALLY MAKE UP INTO STC. THOUGH HAVE KEPT CONDITIONS MVFR AT
ALL BUT EAU THIS AFTERNOON...WARMER/DRIER LOW LEVEL AIR MAY YET
MAKE IT INTO THE AREA FROM THE SOUTH THIS AFTERNOON...WHICH COULD
LEAD TO A FEW HOURS OF VFR CONDITIONS AT MSP...BEFORE CONDITIONS
DETERIORATE AGAIN TONIGHT. FOR TONIGHT...FRONT WILL TURN INTO AN
INVERTED TROUGH ASSOCIATED WITH A DEVELOPING LOW OVER WRN
IA...THIS WILL SPREAD MORE LIGHT RAIN INTO WRN MN FIRST...THEN
WORK EAST. FEEL MORE CONFIDENT ABOUT SEEING IFR CONDITIONS
OVERNIGHT AS BEST WAA WILL BE OFF OVER THE GREAT LAKES...WHICH
SHOULD KEEP LOW LEVELS MOIST HERE AND ALLOW FOR STRATUS TO LOWER
INTO AT LEAST THE IFR CATEGORY. WITH WINDS...WILL REMAIN AT 10
KTS OR LESS OUT OF THE ESE. AXN/RWF WILL SEE WINDS TURN THE N
TOMORROW MORNING HOWEVER AS THEY GET ON BACK SIDE OF TROUGH.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JVM/MPG
000
FXUS63 KDLH 230958
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
358 AM CST MON NOV 23 2009
.DISCUSSION...
EAST-WEST BANDS OF LOW LEVEL WARM ADVECTION...ASSOCIATED WITH A
DISSIPATED SURFACE TROUGH...ARE SPREADING NORTH ACROSS OUR AREA.
AT THIS TIME...BANDS ARE ASSOCIATED WITH LIGHT RAIN AND FOG
FORMATION MORE RAPID THAN RAIN CAN RINSE OUT. BETWEEN BANDS...
COMPENSATORY LOW LEVEL DOWNWARD MOTION BRIEFLY EXPOSES A MID DECK
AND CAUSES TEMPORARY IMPROVEMENT. A BAND NOW ALONG OUR SOUTHERN
EDGE IS INCREASING IN WIDTH AND MOISTURE AS IT SPREADS NORTH.
LOW PRESSURE OVER THE CENTRAL/SOUTHERN PLAINS WILL ESTABLISH AN
INVERTED TROUGH NORTHWARD ALONG OR IMMEDIATELY EAST OF THE RED
RIVER VALLEY BY NOON TODAY. A WEAK BUT DIGGING TROUGH ALOFT WILL
ANCHOR THE INVERTED TROUGH ALONG OUR WESTERN EDGE THROUGH TONIGHT
AND TUESDAY. WE ANTICIPATE FOG AND LIGHT RAIN TO CONTINUE...WITH
THE BACK EDGE NOT APT TO REACH OUR WESTERN AREAS EITHER TONIGHT OR
TUESDAY. AGAIN...CONTINUED WARM ADVECTION ALONG AND EAST OF THE
INVERTED TROUGH WILL KEEP THE COLUMN UNSEASONABLY WARM.
.EXTENDED...TUESDAY NIGHT THRU SUNDAY.
THE MEDIUM RANGE MODELS SHOW A COMPLEX SCENARIO SETTING UP FOR THE
BEGINNING OF THE EXTENDED FORECAST PERIOD...WITH TWO DISTINCT
SHORTWAVE TROUGHS AFFECTING OUR CWA. A SRN WAVE LOCATED OVER THE
CENTRAL MIDWEST WILL BRING RAIN TO OUR SRN ZONES TUESDAY NIGHT AND
WEDNESDAY...WHILE A STRONGER SYSTEM DIGS SEWD OUT OF
CANADA...BRINGING A CHANCE OF RAIN AND SNOW TO OUR NRN ZONES. THE
MODELS SHOW THAT THESE TWO WAVES WILL EVENTUALLY MERGE OVER THE
GREAT LAKES REGION ON WEDNESDAY AND WEDNESDAY NIGHT. LIFT ASSOCIATED
WITH THESE SYSTEMS WILL PROVIDE LIFT WHICH WILL TAP AMPLE
MOISTURE...CONTINUING THE CHANCE OF PRECIP ACROSS OUR ENTIRE
CWA...WITH THE BEST CHANCE FOR PRECIP ACROSS OUR ERN ZONES. DURING
THIS TIME FRAME...THE RAIN WILL MIX WITH SNOW...AND EVENTUALLY
CHANGE TO ALL SNOW WEDNESDAY NIGHT AS COLDER AIR ADVECTS SOUTH FROM
CANADA ON THE WEST SIDE OF THE NOW DEPARTING LOW. A WEAKER ELONGATED
VORTMAX WILL FOLLOW AND AFFECT THE NORTHLAND ON
THURSDAY...CONTINUING THE CHANCE OF SNOW SHOWERS ACROSS THE ERN HALF
OF OUR CWA. THE SNOW WILL END FOR MOST LOCATIONS THURSDAY
NIGHT...EXCEPT ACROSS THE SNOWBELT OF NWRN WI WHERE LAKE EFFECT SNOW
SHOWERS MAY LINGER. HIGH PRESSURE WILL MOVE OVER THE WRN GREAT LAKES
BY FRIDAY...RESULTING IN DRIER CONDITIONS. ATTM...NEXT WEEKEND
APPEARS DRY...ALTHOUGH THE ECMWF DOES SHOW ANOTHER SHORTWAVE DIGGING
SEWD OUT OF CANADA AND OVER THE UPPER MIDWEST. HOWEVER MOST OF THE
PRECIP ASSOCIATED WITH THIS DISTURBANCE SHOULDNT AFFECT THE FCST
AREA UNTIL SUNDAY AND SUNDAY NIGHT.
&&
.AVIATION...11/23/06Z ISSUANCE...
LITTLE CHANGE FROM 00Z TAF SET. VFR AT KINL AND KHYR...WHICH WILL
CONTINUE UNTIL ABOUT 07-08Z WHEN -DZ/BR/FG REDUCE VSBYS AND CIGS TO
MVFR WITH ISOLD IFR. BOTH LOCATIONS BECOME IFR/LIFR AS LOW
CLOUDS/-DZ/BR/FG PERSIST AFTER 10Z. KDLH/KHIB/KBRD WILL BE IFR/LIFR
THROUGH THE TAF PERIOD WITH INSTANCES OF VLIFR IN -DZ/BR/FG.
&&
.POINT TEMPS/POPS...
DLH 48 39 46 33 / 70 50 40 40
INL 47 35 43 31 / 70 70 50 40
BRD 49 39 47 32 / 60 60 40 40
HYR 51 41 48 35 / 60 10 40 50
ASX 50 41 47 38 / 30 10 30 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR MNZ012-
019>021-026-037.
WI...DENSE FOG ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR WIZ001.
LS...NONE.
&&
$$
EOM/BERDES
000
FXUS63 KMPX 230923
AFDMPX
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
322 AM CST MON NOV 23 2009
.DISCUSSION...
THE FORECAST CHALLENGE THIS PERIOD ARE PRECIPITATION CHANCES AND
PRECIP TRANSITION OVER TO SNOW BEFORE THANKSGIVING EVE.
IN THE NEAR TERM...A NEARLY STATIONARY FRONT OVER CENTRAL MN...WILL
MOVE LITTLE TODAY AS A WEAK SURFACE TROUGH OVER THE CENTRAL PLAINS
DRIFTS SLOWLY EAST OVER THE MIDWEST THROUGH TUESDAY.
MOIST AND WARM AIR CONTINUE TO LIFT NORTH OVER THE FRONTAL BOUNDARY
ACROSS THE UPPER MIDWEST. LIGHT RAIN SHOULD BEGIN TO PUSH OUT OF
SOUTH CENTRAL MN AND WESTERN WISCONSIN LATER THIS MORNING WITH
LINGERING LIGHT RAIN OR DRIZZLE OVER THE REST OF THE FORECAST AREA
THROUGH THE REMAINDER OF THE DAY.
THE MODELS ARE IN GENERAL AGREEMENT IN THE MEDIUM RANGE...
MODELS HAVE BEEN CONSISTENT FROM RUN TO RUN WITH UPPER LOW OVER THE
CENTRAL PLAINS...LIFTING NORTHEAST OVER THE LOWER GREAT LAKES BY
WEDNESDAY MORNING. STRONGER UPPER LEVEL TROUGH OVER THE PACIFIC
NORTHWEST...WILL BEGIN TO CARVE OUT A STRONGER TROUGH OVER THE
NORTHERN PLAIN/UPPER MIDWEST BY WEDNESDAY.
THE GEM-NHEM MODEL BLEND INDICATES THE PRECIPITATION SHOULD BE
MAINLY RAIN THROUGH TUESDAY...THEN BECOMING A MIXTURE OF RAIN OR
SNOW OVER PORTIONS OF WEST CENTRAL MINNESOTA TUESDAY NIGHT THEN
SWITCH OVER TO ALL SNOW OVER THE ENTIRE FORECAST AREA ON WEDNESDAY
AS COLDER AIR SINKS OVER THE MIDWEST.
THANKSGIVING DAY AND FRIDAY...LOOKS COLD AND DRY AS A SFC RIDGE
BUILDS EAST OVER THE UPPER MIDWEST DURING THE PERIOD.
&&
.AVIATION.../06Z TAF ISSUANCE/
A SURFACE WARM FRONT IS EXTENDING FROM SOUTHWEST MN TO NORTHEAST
MN AND IS GRADUALLY LIFTING NORTHWEST. ALONG THIS FEATURE HAS
BEEN FOG AND LOW STRATUS. THIS WILL KEEP KAXN DOWN TONIGHT AND
INTO THE MORNING WITH LITTLE RECOVERY AFTER. OTHER TAF SITES MAY
DROP BACK INTO THE STRATUS TONIGHT AS LOW LEVEL MOISTURE IS WELL
ABOVE NORMAL FOR THIS TIME OF YEAR. SOME WIND COMPONENT SHOULD
KEEP THE FOG FROM DROPPING TO IFR AT SITES...THOUGH AT KSTC AND
KRWF THERE IS LESS CONFIDENCE IN THIS. ALL SITES WILL BE
VULNERABLE IN THE MORNING AFTER DAYBREAK THROUGH 18Z. RAIN
ACTIVITY EXPECTED TO GRADUALLY INCREASE OVER CTRL MN OVERNIGHT
WITH SHOWER ACTIVITY PERSISTING THROUGH THE MORNING. SHOWERS IN
WRN MN DURING THE AFTN SHOULD CONTINUE ALONG THE FRONT BEFORE IT
BEGINS TO SCOOT BACK EAST MON NIGHT. IFR CONDITIONS EXPECTED TO
REDEVELOP AT SITES MON NIGHT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JM/MTF
000
FXUS63 KMPX 230922
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
322 AM CST MON NOV 23 2009
.DISCUSSION...
THE FORECAST CHALLENGE THIS PERIOD ARE PRECIPITATION CHANCES AND
PRECIP TRANSITION OVER TO SNOW BEFORE THANKSGIVING EVE.
IN THE NEAR TERM...A NEARLY STATIONARY FRONT OVER CENTRAL MN...WILL
MOVE LITTLE TODAY AS A WEAK SURFACE TROUGH OVER THE CENTRAL PLAINS
DRIFTS SLOWLY EAST OVER THE MIDWEST THROUGH TUESDAY.
MOIST AND WARM AIR CONTINUE TO LIFT NORTH OVER THE FRONTAL BOUNDARY
ACROSS THE UPPER MIDWEST. LIGHT RAIN SHOULD BEGIN TO PUSH OUT OF
SOUTH CENTRAL MN AND WESTERN WISCONSIN LATER THIS MORNING WITH
LINGERING LIGHT RAIN OR DRIZZLE OVER THE REST OF THE FORECAST AREA
THROUGH THE REMAINDER OF THE DAY.
THE MODELS ARE IN GENERAL AGREEMENT IN THE MEDIUM RANGE...
MODELS HAVE BEEN CONSISTENT FROM RUN TO RUN WITH UPPER LOW OVER THE
CENTRAL PLAINS...LIFTING NORTHEAST OVER THE LOWER GREAT LAKES BY
WEDNESDAY MORNING. STRONGER UPPER LEVEL TROUGH OVER THE PACIFIC
NORTHWEST...WILL BEGIN TO CARVE OUT A STRONGER TROUGH OVER THE
NORTHERN PLAIN/UPPER MIDWEST BY WEDNESDAY.
THE GEM-NHEM MODEL BLEND INDICATES THE PRECIPITATION SHOULD BE
MAINLY RAIN THROUGH TUESDAY...THEN BECOMING A MIXTURE OF RAIN OR
SNOW OVER PORTIONS OF WEST CENTRAL MINNESOTA TUESDAY NIGHT THEN
SWITCH OVER TO ALL SNOW OVER THE ENTIRE FORECAST AREA ON WEDNESDAY
AS COLDER AIR SINKS OVER THE MIDWEST.
THANKSGIVING DAY AND FRIDAY...LOOKS COLD AND DRY AS A SFC RIDGE
BUILDS EAST OVER THE UPPER MIDWEST DURING THE PERIOD.
&&
.AVIATION.../06Z TAF ISSUANCE/
A SURFACE WARM FRONT IS EXTENDING FROM SOUTHWEST MN TO NORTHEAST
MN AND IS GRADUALLY LIFTING NORTHWEST. ALONG THIS FEATURE HAS
BEEN FOG AND LOW STRATUS. THIS WILL KEEP KAXN DOWN TONIGHT AND
INTO THE MORNING WITH LITTLE RECOVERY AFTER. OTHER TAF SITES MAY
DROP BACK INTO THE STRATUS TONIGHT AS LOW LEVEL MOISTURE IS WELL
ABOVE NORMAL FOR THIS TIME OF YEAR. SOME WIND COMPONENT SHOULD
KEEP THE FOG FROM DROPPING TO IFR AT SITES...THOUGH AT KSTC AND
KRWF THERE IS LESS CONFIDENCE IN THIS. ALL SITES WILL BE
VULNERABLE IN THE MORNING AFTER DAYBREAK THROUGH 18Z. RAIN
ACTIVITY EXPECTED TO GRADUALLY INCREASE OVER CTRL MN OVERNIGHT
WITH SHOWER ACTIVITY PERSISTING THROUGH THE MORNING. SHOWERS IN
WRN MN DURING THE AFTN SHOULD CONTINUE ALONG THE FRONT BEFORE IT
BEGINS TO SCOOT BACK EAST MON NIGHT. IFR CONDITIONS EXPECTED TO
REDEVELOP AT SITES MON NIGHT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
BAP/MTF
000
FXUS63 KDLH 230544
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
1144 PM CST SUN NOV 22 2009
.AVIATION...06Z TAFS.
LITTLE CHANGE FROM 00Z TAF SET. VFR AT KINL AND KHYR...WHICH WILL
CONTINUE UNTIL ABOUT 07-08Z WHEN -DZ/BR/FG REDUCE VSBYS AND CIGS TO
MVFR WITH ISOLD IFR. BOTH LOCATIONS BECOME IFR/LIFR AS LOW
CLOUDS/-DZ/BR/FG PERSIST AFTER 10Z. KDLH/KHIB/KBRD WILL BE IFR/LIFR
THROUGH THE TAF PERIOD WITH INSTANCES OF VLIFR IN -DZ/BR/FG.
&&
.PREV DISCUSSION... /ISSUED 900 PM CST SUN NOV 22 2009/
UPDATE...STALLED FRONTAL BOUNDARY OVER THE WESTERN PART OF THE FA
MAKING FOR A TRICKY FORECAST. DENS FOG HAS DEVELOPED FROM THE
WESTERN IRON RANGE TO THE TWIN PORTS INTO THE MN ARROWHEAD AND
HAVE ADDED TO THE DENSE FOG ADVISORY. WAA CONTINUES TO PUMP THE
MOISTURE INTO THE FA AHEAD OF THE FRONT. ISOLD -SHRA/-DZ HAVE BEEN
AFFECTING THIS AREA THIS EVENING WITH MORE -SHRA ON THE WAY AS
SEEN ON RADAR MOSAIC. MEANWHILE...THE NW PORTION OF THE FA IS
MOSTLY CLEAR WITH THIN CI ATTM. MID CLOUDS ARE DEVELOPING UPSTREAM
AS AN UPPER LEVEL SHORT WAVE APPROACHES FROM THE SW AND WILL
ARRIVE EVENTUALLY. REST OF FORECAST ON TRACK.
PREV DISCUSSION... /ISSUED 546 PM CST SUN NOV 22 2009/
AVIATION...00Z TAFS.
COMPLEX WEATHER CIGS/VSBYS ACROSS THE FA THIS EVENING. VFR AT KINL
AND KHYR...WHICH WILL CONTINUE UNTIL 04-06Z WHEN -DZ/BR REDUCE
VSBYS AND CIGS TO MVFR WITH ISOLD IFR. BOTH LOCATIONS BECOME
IFR/LIFR AS LOW CLOUDS/-DZ/BR PERSIST AFTER 06Z. KDLH/KHIB/KBRD
WILL BE IFR THROUGH THE TAF PERIOD WITH INSTANCES OF LIFR IN
-DZ/BR/FG.
PREV DISCUSSION... /ISSUED 246 PM CST SUN NOV 22 2009/
DISCUSSION...TONIGHT THROUGH WEDNESDAY
MODELS IN AGREEMENT WITH SHARPENING THE LOW LEVEL TROUGH OVER OUR
CWA TONIGHT. UPPER WAVE IS FORECAST TO MOVE FROM THE NORTHERN
ROCKIES...SOUTHEAST INTO NE/KS BY 00Z TUE...THEN EAST INTO IL BY 12Z
WED. THE MODELS HAVE MADE SOME RUN TO RUN CHANGES...BUT OVERALL
THE FORECAST IS SIMILAR TO WHAT YESTERDAYS RUNS SHOWED.
RAIN WAS MOVING OVER PINE/BURNETT COUNTIES THIS AFTERNOON...NORTHEAST
INTO THE TWIN PORTS. THIS WAS OCCURRING IN AN AREA OF LOW LEVEL
FGEN AND ISENTROPIC LIFT. WE HAVE HIGHEST POPS OVER THAT AREA
TONIGHT. WE ISSUED A DENSE FOG ADVISORY EARLIER THIS
AFTERNOON...AND VSBYS HAVE COME UP IN SPOTS...BUT KCKC WAS
REPORTING LESS THAN A QUARTER MILE. WEAK ONSHORE FLOW...AND PLENTY
OF LOW LEVEL MOISTURE WILL BE SUPPORTIVE OF FOG TONIGHT...AND
WE`LL KEEP THE ADVISORY GOING. FOG WILL BE MOST DENSE IN THE
HIGHER TERRAIN JUST INLAND FROM LAKE SUPERIOR. CLOUDS WILL REMAIN
OVER CENTRAL AND EASTERN CWA...BUT A PORTION OF THE WEST-NORTHWEST
WILL BE CLEAR TO PARTLY CLOUDY FOR A PORTION OF THE NIGHT.
TEMPERATURES WILL NOT FALL MUCH...EXCEPT IN THE W-NW.
AS THE UPPER WAVE MOVES INTO KS/NE ON MONDAY...THE INVERTED TROUGH WILL
ROTATE BACK TO THE WEST...AND WE SHIFTED HIGHER POPS OVER OUR
WESTERN ZONES. CLOUDS MAY DIMINISH OVER A PORTION OF NORTHWEST
WISCONSIN...BUT WE KEPT THEM MOSTLY CLOUDY AT THIS TIME.
AS THE UPPER LOW DEEPENS MONDAY NIGHT INTO TUESDAY...SURFACE LOW
PRESSURE WILL DEVELOP/DEEPEN IN SOUTHERN IA. THERE WILL BE A
CONTINUED CHANCE FOR RAIN...WITH RAIN LIKELY OVER OUR WEST NEAR
THE WEAKENING TROUGH.
A STRONG NORTHERN STREAM WAVE WILL DIVE INTO THE AREA TUESDAY
NIGHT/WEDNESDAY. LOW PRESSURE AT THE SURFACE WILL TRACK INTO THE
LAKE MICHIGAN AREA. WE KEPT A MENTION OF JUST RAIN TUESDAY
EVENING...THEN MIXED IN SNOW FROM WEST TO EAST LATE TUESDAY NIGHT
INTO WEDNESDAY. WE HAVE CHANCE POPS ON WEDNESDAY AT THIS
TIME...BUT THEY MAY HAVE TO BE INCREASED WITH LATER FORECASTS.
SNOW ACCUMULATIONS LOOK LIGHT TUESDAY NIGHT INTO WEDNESDAY.
EXTENDED...THURSDAY THROUGH SUNDAY
ADJUSTED POPS FURTHER WEST AND INCREASED FOR MOST AREAS WED
NIGHT/THURS AS MDLS CONTINUE TO SUPPORT A SLOWER TREND IN EJECTING
THE MID LVL LOW OVER THE ERN GRT LKS FRI. UPR LVL RIDING WILL PUSH E
OVER THE UPR MIDWEST OVER THE WEEKEND AS ANOTHER TROUGH CROSSES THE
ROCKIES AND MOVES INTO THE NORTHLAND LATE IN THE WEEKEND/EARLY NEXT
WEEK.
MAIN FCST CHALLENGE IN EXTENDED IS PTYPE AND CHANGE OVER TIMING
WED/THURS AS THE LOW TRACKS TO THE SE OF THE FA AND CANADIAN AIR
FILTERS INTO THE REGION. THE 12Z GFS/ECM IN GOOD AGREEMENT THAT CORE
OF COLDEST 850 MB TEMPS /-8C/ FUNNEL SWRD OVER THE DAKOTAS/SW MN
ALONG THE MAIN VORT/JET MAX WED WHILE 850 TEMPS IN THE NEGATIVE 2-5
C RANGE SPREAD OVER THE DLH FA BY THURS. HOWEVER...CROSS SECTIONS
FROM THE GFS/ECM AT KIWD/KHYR/KPBH DEPICT A SHALLOW LAYER SFC-900 MB
THAT REMAINS A FEW DEGREES ABV FZING THROUGH 12Z THURS. IN
ADDITION...THE GFS BUFKIT AT KIWD/HYR SHOWS RAIN FOR MOST OF THE
NIGHT AND HOLD OFF CHANGING TO SN UNTIL 08Z-12Z THURS WITH A BRIEF
PERIOD OF IP POSSIBLE. ATTM...LEFT PTYPE AS ALL SN WED NIGHT DUE TO THE
UNCERTAINTY IN TIMING THE PHASE CHANGE. HOWEVER...THERE REMAINS A
POSSIBILITY FOR THE RA/SN MIX TO CONTINUE THROUGH WED EVENING. LATER
SHIFTS MAY NEED TO CARRY THE RA/SN MIX INTO WED NIGHT FOR THE S
SHORE AND NRN WIS ZONES.
AVIATION...18Z TAF ISSUANCE
WDSPRD IFR/LIFR CONDITIONS WITH FG/DZ WILL PERSIST THROUGH TAF
PERIOD. THE EXCEPTION WILL BE ALONG AND WEST OF TROUGH SITUATED
FROM KINL TO KSAZ/KBRD. THE KINL AREA WILL REMAIN VFR THROUGH THE
NIGHT...FALLING IFR MON MORNING. THE KBRD AREA MAY HAVE A FEW HR
PERIOD THIS EVENING WITH MVFR CIGS AND SCT LOW CLOUDS...BUT IFR
RESTRICTIONS AND BR/FG WILL AGAIN PREVAIL AFT 06Z.
&&
.POINT TEMPS/POPS...
DLH 44 47 39 41 / 60 60 40 40
INL 24 43 35 42 / 10 60 60 40
BRD 40 49 40 46 / 30 50 70 40
HYR 43 50 40 46 / 60 20 10 30
ASX 44 49 40 46 / 60 20 10 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 3 PM CST MONDAY FOR MNZ012-019>021-026-
037.
WI...DENSE FOG ADVISORY UNTIL 3 PM CST MONDAY FOR WIZ001.
LS...NONE.
&&
$$
GSF/GSF/GSF
000
FXUS63 KMPX 230508
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1108 PM CST SUN NOV 22 2009
.DISCUSSION...
SATELLITE IMAGERY CURRENTLY SHOWING SOME COOLING OF CLOUD TOPS
ACROSS WESTERN AND CENTRAL IA WITH RADAR SHOWING GRADUAL INCREASE IN
LIGHT RAIN. BUMPED UP POPS FOR THE OVERNIGHT ACROSS THE EASTERN AND
SOUTHERN CWA WITH LIGHT QPF. VERY WARM MINS AHEAD FOR TONIGHT WITH
SEVERAL STATIONS LIKELY HAVING RECORD OR NEAR RECORD HIGHS
MINIMUMS...RECORD FOR MSP IS 44...41 AT EAU AND 35 AT STC. WITH
CLOUDS AND CONTINUED SOUTHERLY FLOW AHEAD OF WEAKENING FRONT IN
WESTERN MINNESOTA DON`T SEE MUCH OF A TEMPERATURE DROP OVERNIGHT.
STRENGTH OF UPPER LOW COMING ONSHORE IN PACIFIC NW EXHIBITED IN 500
MB HEIGHT FALL AROUND 150 METERS. LOW TO CONTINUE DIGGING SE NEXT 48
HOURS OR SO INTO THE KS/MO AREA...A BIT FARTHER S THAT SOME EARLIER
RUNS. SYSTEM THEN BEGINS TO LIFT OUT AS NEXT STRONG TROF COMES IN
BEHIND IT FROM CANADIAN PRAIRIES. TEMPERATURE PROFILES WARM ENOUGH
TO KEEP PRECIP AS ALL RAIN WITH THE FIRST TROUGH. BUFKIT SOUNDINGS
ON NAM/GFS PLOW IN ENUF COLD AIR TO TRANSITION PRECIP TO PRETTY MUCH
ALL SNOW BY EARLY EVENING WEDNESDAY AS SECOND LOW DROPS ACROSS MN
INTO IA. WILL PROBABLY SEE A BROAD BAND OF AN INCH OR SO OF SNOW
ACROSS AREA...WITH PERHAPS A COUPLE OF INCHES IN E MN INTO W WI WED
AFTERNOON/NIGHT WHERE QPF OUTPUT STILL SUFFICENT AS COLUMN COOLS.
TEMPERATURES MONDAY STILL QUITE MILD AS COLD AIR MAKES LITTLE
PROGRESS EASTWARD AS INVERTED TROF BECOMES ESTABLISHED ACROSS
WESTERN MINNESOTA. ONLY A SLOW COOLING MONDAY NIGHT INTO TUESDAY AS
TROUGH SLOWLY CRAWLS ACROSS STATE. TEMPERATURES BEGIN TO COOL MORE
SHARPLY ON WEDNESDAY AND REMAIN COOL UNTIL SOME MODERATION BEGINNING
FRIDAY INTO SATURDAY AHEAD OF NEXT TROUGH.
&&
.AVIATION.../06Z TAF ISSUANCE/
A SURFACE WARM FRONT IS EXTENDING FROM SOUTHWEST MN TO NORTHEAST
MN AND IS GRADUALLY LIFTING NORTHWEST. ALONG THIS FEATURE HAS
BEEN FOG AND LOW STRATUS. THIS WILL KEEP KAXN DOWN TONIGHT AND
INTO THE MORNING WITH LITTLE RECOVERY AFTER. OTHER TAF SITES MAY
DROP BACK INTO THE STRATUS TONIGHT AS LOW LEVEL MOISTURE IS WELL
ABOVE NORMAL FOR THIS TIME OF YEAR. SOME WIND COMPONENT SHOULD
KEEP THE FOG FROM DROPPING TO IFR AT SITES...THOUGH AT KSTC AND
KRWF THERE IS LESS CONFIDENCE IN THIS. ALL SITES WILL BE
VULNERABLE IN THE MORNING AFTER DAYBREAK THROUGH 18Z. RAIN
ACTIVITY EXPECTED TO GRADUALLY INCREASE OVER CTRL MN OVERNIGHT
WITH SHOWER ACTIVITY PERSISTING THROUGH THE MORNING. SHOWERS IN
WRN MN DURING THE AFTN SHOULD CONTINUE ALONG THE FRONT BEFORE IT
BEGINS TO SCOOT BACK EAST MON NIGHT. IFR CONDITIONS EXPECTED TO
REDEVELOP AT SITES MON NIGHT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
BAP/MTF
000
FXUS63 KDLH 230300
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
900 PM CST SUN NOV 22 2009
.UPDATE...STALLED FRONTAL BOUNDARY OVER THE WESTERN PART OF THE FA
MAKING FOR A TRICKY FORECAST. DENS FOG HAS DEVELOPED FROM THE
WESTERN IRON RANGE TO THE TWIN PORTS INTO THE MN ARROWHEAD AND
HAVE ADDED TO THE DENSE FOG ADVISORY. WAA CONTINUES TO PUMP THE
MOISTURE INTO THE FA AHEAD OF THE FRONT. ISOLD -SHRA/-DZ HAVE BEEN
AFFECTING THIS AREA THIS EVENING WITH MORE -SHRA ON THE WAY AS
SEEN ON RADAR MOSAIC. MEANWHILE...THE NW PORTION OF THE FA IS
MOSTLY CLEAR WITH THIN CI ATTM. MID CLOUDS ARE DEVELOPING UPSTREAM
AS AN UPPER LEVEL SHORT WAVE APPROACHES FROM THE SW AND WILL
ARRIVE EVENTUALLY. REST OF FORECAST ON TRACK.
&&
.PREV DISCUSSION... /ISSUED 546 PM CST SUN NOV 22 2009/
AVIATION...00Z TAFS.
COMPLEX WEATHER CIGS/VSBYS ACROSS THE FA THIS EVENING. VFR AT KINL
AND KHYR...WHICH WILL CONTINUE UNTIL 04-06Z WHEN -DZ/BR REDUCE
VSBYS AND CIGS TO MVFR WITH ISOLD IFR. BOTH LOCATIONS BECOME
IFR/LIFR AS LOW CLOUDS/-DZ/BR PERSIST AFTER 06Z. KDLH/KHIB/KBRD
WILL BE IFR THROUGH THE TAF PERIOD WITH INSTANCES OF LIFR IN
-DZ/BR/FG.
PREV DISCUSSION... /ISSUED 246 PM CST SUN NOV 22 2009/
DISCUSSION...TONIGHT THROUGH WEDNESDAY
MODELS IN AGREEMENT WITH SHARPENING THE LOW LEVEL TROUGH OVER OUR
CWA TONIGHT. UPPER WAVE IS FORECAST TO MOVE FROM THE NORTHERN
ROCKIES...SOUTHEAST INTO NE/KS BY 00Z TUE...THEN EAST INTO IL BY 12Z
WED. THE MODELS HAVE MADE SOME RUN TO RUN CHANGES...BUT OVERALL
THE FORECAST IS SIMILAR TO WHAT YESTERDAYS RUNS SHOWED.
RAIN WAS MOVING OVER PINE/BURNETT COUNTIES THIS AFTERNOON...NORTHEAST
INTO THE TWIN PORTS. THIS WAS OCCURRING IN AN AREA OF LOW LEVEL
FGEN AND ISENTROPIC LIFT. WE HAVE HIGHEST POPS OVER THAT AREA
TONIGHT. WE ISSUED A DENSE FOG ADVISORY EARLIER THIS
AFTERNOON...AND VSBYS HAVE COME UP IN SPOTS...BUT KCKC WAS
REPORTING LESS THAN A QUARTER MILE. WEAK ONSHORE FLOW...AND PLENTY
OF LOW LEVEL MOISTURE WILL BE SUPPORTIVE OF FOG TONIGHT...AND
WE`LL KEEP THE ADVISORY GOING. FOG WILL BE MOST DENSE IN THE
HIGHER TERRAIN JUST INLAND FROM LAKE SUPERIOR. CLOUDS WILL REMAIN
OVER CENTRAL AND EASTERN CWA...BUT A PORTION OF THE WEST-NORTHWEST
WILL BE CLEAR TO PARTLY CLOUDY FOR A PORTION OF THE NIGHT.
TEMPERATURES WILL NOT FALL MUCH...EXCEPT IN THE W-NW.
AS THE UPPER WAVE MOVES INTO KS/NE ON MONDAY...THE INVERTED TROUGH WILL
ROTATE BACK TO THE WEST...AND WE SHIFTED HIGHER POPS OVER OUR
WESTERN ZONES. CLOUDS MAY DIMINISH OVER A PORTION OF NORTHWEST
WISCONSIN...BUT WE KEPT THEM MOSTLY CLOUDY AT THIS TIME.
AS THE UPPER LOW DEEPENS MONDAY NIGHT INTO TUESDAY...SURFACE LOW
PRESSURE WILL DEVELOP/DEEPEN IN SOUTHERN IA. THERE WILL BE A
CONTINUED CHANCE FOR RAIN...WITH RAIN LIKELY OVER OUR WEST NEAR
THE WEAKENING TROUGH.
A STRONG NORTHERN STREAM WAVE WILL DIVE INTO THE AREA TUESDAY
NIGHT/WEDNESDAY. LOW PRESSURE AT THE SURFACE WILL TRACK INTO THE
LAKE MICHIGAN AREA. WE KEPT A MENTION OF JUST RAIN TUESDAY
EVENING...THEN MIXED IN SNOW FROM WEST TO EAST LATE TUESDAY NIGHT
INTO WEDNESDAY. WE HAVE CHANCE POPS ON WEDNESDAY AT THIS
TIME...BUT THEY MAY HAVE TO BE INCREASED WITH LATER FORECASTS.
SNOW ACCUMULATIONS LOOK LIGHT TUESDAY NIGHT INTO WEDNESDAY.
EXTENDED...THURSDAY THROUGH SUNDAY
ADJUSTED POPS FURTHER WEST AND INCREASED FOR MOST AREAS WED
NIGHT/THURS AS MDLS CONTINUE TO SUPPORT A SLOWER TREND IN EJECTING
THE MID LVL LOW OVER THE ERN GRT LKS FRI. UPR LVL RIDING WILL PUSH E
OVER THE UPR MIDWEST OVER THE WEEKEND AS ANOTHER TROUGH CROSSES THE
ROCKIES AND MOVES INTO THE NORTHLAND LATE IN THE WEEKEND/EARLY NEXT
WEEK.
MAIN FCST CHALLENGE IN EXTENDED IS PTYPE AND CHANGE OVER TIMING
WED/THURS AS THE LOW TRACKS TO THE SE OF THE FA AND CANADIAN AIR
FILTERS INTO THE REGION. THE 12Z GFS/ECM IN GOOD AGREEMENT THAT CORE
OF COLDEST 850 MB TEMPS /-8C/ FUNNEL SWRD OVER THE DAKOTAS/SW MN
ALONG THE MAIN VORT/JET MAX WED WHILE 850 TEMPS IN THE NEGATIVE 2-5
C RANGE SPREAD OVER THE DLH FA BY THURS. HOWEVER...CROSS SECTIONS
FROM THE GFS/ECM AT KIWD/KHYR/KPBH DEPICT A SHALLOW LAYER SFC-900 MB
THAT REMAINS A FEW DEGREES ABV FZING THROUGH 12Z THURS. IN
ADDITION...THE GFS BUFKIT AT KIWD/HYR SHOWS RAIN FOR MOST OF THE
NIGHT AND HOLD OFF CHANGING TO SN UNTIL 08Z-12Z THURS WITH A BRIEF
PERIOD OF IP POSSIBLE. ATTM...LEFT PTYPE AS ALL SN WED NIGHT DUE TO THE
UNCERTAINTY IN TIMING THE PHASE CHANGE. HOWEVER...THERE REMAINS A
POSSIBILITY FOR THE RA/SN MIX TO CONTINUE THROUGH WED EVENING. LATER
SHIFTS MAY NEED TO CARRY THE RA/SN MIX INTO WED NIGHT FOR THE S
SHORE AND NRN WIS ZONES.
AVIATION...18Z TAF ISSUANCE
WDSPRD IFR/LIFR CONDITIONS WITH FG/DZ WILL PERSIST THROUGH TAF
PERIOD. THE EXCEPTION WILL BE ALONG AND WEST OF TROUGH SITUATED
FROM KINL TO KSAZ/KBRD. THE KINL AREA WILL REMAIN VFR THROUGH THE
NIGHT...FALLING IFR MON MORNING. THE KBRD AREA MAY HAVE A FEW HR
PERIOD THIS EVENING WITH MVFR CIGS AND SCT LOW CLOUDS...BUT IFR
RESTRICTIONS AND BR/FG WILL AGAIN PREVAIL AFT 06Z.
&&
.POINT TEMPS/POPS...
DLH 44 47 39 41 / 50 60 40 40
INL 24 43 35 42 / 10 60 60 40
BRD 40 49 40 46 / 30 50 70 40
HYR 43 50 40 46 / 50 20 10 30
ASX 45 49 40 46 / 50 20 10 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 3 PM CST MONDAY FOR MNZ012-019>021-026-
037.
WI...DENSE FOG ADVISORY UNTIL 3 PM CST MONDAY FOR WIZ001.
LS...NONE.
&&
$$
GSF/GSF
000
FXUS63 KMPX 222354 AAA
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
555 PM CST SUN NOV 22 2009
.UPDATED FOR AVIATION DISCUSSION BELOW...
.DISCUSSION...
SATELLITE IMAGERY CURRENTLY SHOWING SOME COOLING OF CLOUD TOPS
ACROSS WESTERN AND CENTRAL IA WITH RADAR SHOWING GRADUAL INCREASE IN
LIGHT RAIN. BUMPED UP POPS FOR THE OVERNIGHT ACROSS THE EASTERN AND
SOUTHERN CWA WITH LIGHT QPF. VERY WARM MINS AHEAD FOR TONIGHT WITH
SEVERAL STATIONS LIKELY HAVING RECORD OR NEAR RECORD HIGHS
MINIMUMS...RECORD FOR MSP IS 44...41 AT EAU AND 35 AT STC. WITH
CLOUDS AND CONTINUED SOUTHERLY FLOW AHEAD OF WEAKENING FRONT IN
WESTERN MINNESOTA DON`T SEE MUCH OF A TEMPERATURE DROP OVERNIGHT.
STRENGTH OF UPPER LOW COMING ONSHORE IN PACIFIC NW EXHIBITED IN 500
MB HEIGHT FALL AROUND 150 METERS. LOW TO CONTINUE DIGGING SE NEXT 48
HOURS OR SO INTO THE KS/MO AREA...A BIT FARTHER S THAT SOME EARLIER
RUNS. SYSTEM THEN BEGINS TO LIFT OUT AS NEXT STRONG TROF COMES IN
BEHIND IT FROM CANADIAN PRAIRIES. TEMPERATURE PROFILES WARM ENOUGH
TO KEEP PRECIP AS ALL RAIN WITH THE FIRST TROUGH. BUFKIT SOUNDINGS
ON NAM/GFS PLOW IN ENUF COLD AIR TO TRANSITION PRECIP TO PRETTY MUCH
ALL SNOW BY EARLY EVENING WEDNESDAY AS SECOND LOW DROPS ACROSS MN
INTO IA. WILL PROBABLY SEE A BROAD BAND OF AN INCH OR SO OF SNOW
ACROSS AREA...WITH PERHAPS A COUPLE OF INCHES IN E MN INTO W WI WED
AFTERNOON/NIGHT WHERE QPF OUTPUT STILL SUFFICENT AS COLUMN COOLS.
TEMPERATURES MONDAY STILL QUITE MILD AS COLD AIR MAKES LITTLE
PROGRESS EASTWARD AS INVERTED TROF BECOMES ESTABLISHED ACROSS
WESTERN MINNESOTA. ONLY A SLOW COOLING MONDAY NIGHT INTO TUESDAY AS
TROUGH SLOWLY CRAWLS ACROSS STATE. TEMPERATURES BEGIN TO COOL MORE
SHARPLY ON WEDESDAY AND REMAIN COOL UNTIL SOME MODERATION BEGINNING
FRIDAY INTO SATURDAY AHEAD OF NEXT TROUGH.
&&
.AVIATION.../00Z TAF ISSUANCE/
MESSY AVIATION FCST AHEAD WITH CONDITIONS DETERIORATING OVER EASTERN
AND FAR NW FA THIS EVENING. SFC BDNRY NOW POSITIONED NEAR A
KRWF-KSTC LINE IS FCST TO DRIFT WESTWARD THIS EVENING AS INITIAL
SHORT WAVE TROUGH LIFTS NORTHEAST. THIS SHOULD SPREAD CURRENT LIFR
CONDS ALONG BNDRY WESTWARD TO KAXN THROUGH ABOUT 06Z. THE IFR/LIFR
CONDS SHOULD BEGIN TO EXPAND EAST OVERNIGHT AS WELL...AS LOWER
BNDRY SATURATES PER 285K/290K ISENTROPIC FCST. AREA OF -SHRA
LIFTING NORTHEAST AROUND 30KTS WILL MOVE ACROSS MAINLY WC WI DURING
THE NIGHT. FGEN INCREASES DURING THE EVENING ACROSS THE REGION AND A
STEADY RAIN IS EXPECTED TO AFFECT KEAU/KRNH AND POSSIBLY THE KMSP
REGION BEFORE MIDNIGHT...ALTHOUGH SCT AT KMSP. THEN AS WAVE LIFTS
NORTHEAST LIGHT RAIN WILL ENSUE OVER MOST OF THE FA THE REMAINDER OF
THE NIGHT/ALONG WITH THE LIFR/IFR CONDS. ONLY MARGINAL IMPROVEMENT
EXPECT THROUGH MON MORNING WITH PERHAPS BECOMING MVFR BEFORE THE
NEXT SURGE OF FORCING MOVES INTO THE REGION LATE AFTERNOON. THE FAR
WEST WILL CONTINUE THE IFR CONDITIONS ALONG WITH THE THREAT OF
-RADZ. LIGHT SOUTHEAST WINDS EAST OF THE SFC BDNRY WITH LIGHT/VRBL
WIND OVER THE WESTERN AREAS BECOMING MORE EAST/NORTHEAST.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
BAP/DWE
000
FXUS63 KDLH 222346
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
546 PM CST SUN NOV 22 2009
.AVIATION...00Z TAFS.
COMPLEX WEATHER CIGS/VSBYS ACROSS THE FA THIS EVENING. VFR AT KINL
AND KHYR...WHICH WILL CONTINUE UNTIL 04-06Z WHEN -DZ/BR REDUCE
VSBYS AND CIGS TO MVFR WITH ISOLD IFR. BOTH LOCATIONS BECOME
IFR/LIFR AS LOW CLOUDS/-DZ/BR PERSIST AFTER 06Z. KDLH/KHIB/KBRD
WILL BE IFR THROUGH THE TAF PERIOD WITH INSTANCES OF LIFR IN
-DZ/BR/FG.
&&
.PREV DISCUSSION... /ISSUED 246 PM CST SUN NOV 22 2009/
DISCUSSION...TONIGHT THROUGH WEDNESDAY
MODELS IN AGREEMENT WITH SHARPENING THE LOW LEVEL TROUGH OVER OUR
CWA TONIGHT. UPPER WAVE IS FORECAST TO MOVE FROM THE NORTHERN
ROCKIES...SOUTHEAST INTO NE/KS BY 00Z TUE...THEN EAST INTO IL BY 12Z
WED. THE MODELS HAVE MADE SOME RUN TO RUN CHANGES...BUT OVERALL
THE FORECAST IS SIMILAR TO WHAT YESTERDAYS RUNS SHOWED.
RAIN WAS MOVING OVER PINE/BURNETT COUNTIES THIS AFTERNOON...NORTHEAST
INTO THE TWIN PORTS. THIS WAS OCCURRING IN AN AREA OF LOW LEVEL
FGEN AND ISENTROPIC LIFT. WE HAVE HIGHEST POPS OVER THAT AREA
TONIGHT. WE ISSUED A DENSE FOG ADVISORY EARLIER THIS
AFTERNOON...AND VSBYS HAVE COME UP IN SPOTS...BUT KCKC WAS
REPORTING LESS THAN A QUARTER MILE. WEAK ONSHORE FLOW...AND PLENTY
OF LOW LEVEL MOISTURE WILL BE SUPPORTIVE OF FOG TONIGHT...AND
WE`LL KEEP THE ADVISORY GOING. FOG WILL BE MOST DENSE IN THE
HIGHER TERRAIN JUST INLAND FROM LAKE SUPERIOR. CLOUDS WILL REMAIN
OVER CENTRAL AND EASTERN CWA...BUT A PORTION OF THE WEST-NORTHWEST
WILL BE CLEAR TO PARTLY CLOUDY FOR A PORTION OF THE NIGHT.
TEMPERATURES WILL NOT FALL MUCH...EXCEPT IN THE W-NW.
AS THE UPPER WAVE MOVES INTO KS/NE ON MONDAY...THE INVERTED TROUGH WILL
ROTATE BACK TO THE WEST...AND WE SHIFTED HIGHER POPS OVER OUR
WESTERN ZONES. CLOUDS MAY DIMINISH OVER A PORTION OF NORTHWEST
WISCONSIN...BUT WE KEPT THEM MOSTLY CLOUDY AT THIS TIME.
AS THE UPPER LOW DEEPENS MONDAY NIGHT INTO TUESDAY...SURFACE LOW
PRESSURE WILL DEVELOP/DEEPEN IN SOUTHERN IA. THERE WILL BE A
CONTINUED CHANCE FOR RAIN...WITH RAIN LIKELY OVER OUR WEST NEAR
THE WEAKENING TROUGH.
A STRONG NORTHERN STREAM WAVE WILL DIVE INTO THE AREA TUESDAY
NIGHT/WEDNESDAY. LOW PRESSURE AT THE SURFACE WILL TRACK INTO THE
LAKE MICHIGAN AREA. WE KEPT A MENTION OF JUST RAIN TUESDAY
EVENING...THEN MIXED IN SNOW FROM WEST TO EAST LATE TUESDAY NIGHT
INTO WEDNESDAY. WE HAVE CHANCE POPS ON WEDNESDAY AT THIS
TIME...BUT THEY MAY HAVE TO BE INCREASED WITH LATER FORECASTS.
SNOW ACCUMULATIONS LOOK LIGHT TUESDAY NIGHT INTO WEDNESDAY.
EXTENDED...THURSDAY THROUGH SUNDAY
ADJUSTED POPS FURTHER WEST AND INCREASED FOR MOST AREAS WED
NIGHT/THURS AS MDLS CONTINUE TO SUPPORT A SLOWER TREND IN EJECTING
THE MID LVL LOW OVER THE ERN GRT LKS FRI. UPR LVL RIDING WILL PUSH E
OVER THE UPR MIDWEST OVER THE WEEKEND AS ANOTHER TROUGH CROSSES THE
ROCKIES AND MOVES INTO THE NORTHLAND LATE IN THE WEEKEND/EARLY NEXT
WEEK.
MAIN FCST CHALLENGE IN EXTENDED IS PTYPE AND CHANGE OVER TIMING
WED/THURS AS THE LOW TRACKS TO THE SE OF THE FA AND CANADIAN AIR
FILTERS INTO THE REGION. THE 12Z GFS/ECM IN GOOD AGREEMENT THAT CORE
OF COLDEST 850 MB TEMPS /-8C/ FUNNEL SWRD OVER THE DAKOTAS/SW MN
ALONG THE MAIN VORT/JET MAX WED WHILE 850 TEMPS IN THE NEGATIVE 2-5
C RANGE SPREAD OVER THE DLH FA BY THURS. HOWEVER...CROSS SECTIONS
FROM THE GFS/ECM AT KIWD/KHYR/KPBH DEPICT A SHALLOW LAYER SFC-900 MB
THAT REMAINS A FEW DEGREES ABV FZING THROUGH 12Z THURS. IN
ADDITION...THE GFS BUFKIT AT KIWD/HYR SHOWS RAIN FOR MOST OF THE
NIGHT AND HOLD OFF CHANGING TO SN UNTIL 08Z-12Z THURS WITH A BRIEF
PERIOD OF IP POSSIBLE. ATTM...LEFT PTYPE AS ALL SN WED NIGHT DUE TO THE
UNCERTAINTY IN TIMING THE PHASE CHANGE. HOWEVER...THERE REMAINS A
POSSIBILITY FOR THE RA/SN MIX TO CONTINUE THROUGH WED EVENING. LATER
SHIFTS MAY NEED TO CARRY THE RA/SN MIX INTO WED NIGHT FOR THE S
SHORE AND NRN WIS ZONES.
AVIATION...18Z TAF ISSUANCE
WDSPRD IFR/LIFR CONDITIONS WITH FG/DZ WILL PERSIST THROUGH TAF
PERIOD. THE EXCEPTION WILL BE ALONG AND WEST OF TROUGH SITUATED
FROM KINL TO KSAZ/KBRD. THE KINL AREA WILL REMAIN VFR THROUGH THE
NIGHT...FALLING IFR MON MORNING. THE KBRD AREA MAY HAVE A FEW HR
PERIOD THIS EVENING WITH MVFR CIGS AND SCT LOW CLOUDS...BUT IFR
RESTRICTIONS AND BR/FG WILL AGAIN PREVAIL AFT 06Z.
&&
.POINT TEMPS/POPS...
DLH 44 47 39 41 / 60 60 40 40
INL 24 43 35 42 / 10 60 60 40
BRD 40 49 40 46 / 30 50 70 40
HYR 43 50 40 46 / 50 20 10 30
ASX 45 49 40 46 / 50 20 10 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 3 PM CST MONDAY FOR MNZ012-020-021-037.
WI...DENSE FOG ADVISORY UNTIL 3 PM CST MONDAY FOR WIZ001.
LS...NONE.
&&
$$
GSF/GSF/GSF
000
FXUS63 KDLH 222046
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
246 PM CST SUN NOV 22 2009
.DISCUSSION...TONIGHT THROUGH WEDNESDAY
MODELS IN AGREEMENT WITH SHARPENING THE LOW LEVEL TROUGH OVER OUR
CWA TONIGHT. UPPER WAVE IS FORECAST TO MOVE FROM THE NORTHERN
ROCKIES...SOUTHEAST INTO NE/KS BY 00Z TUE...THEN EAST INTO IL BY 12Z
WED. THE MODELS HAVE MADE SOME RUN TO RUN CHANGES...BUT OVERALL
THE FORECAST IS SIMILAR TO WHAT YESTERDAYS RUNS SHOWED.
RAIN WAS MOVING OVER PINE/BURNETT COUNTIES THIS AFTERNOON...NORTHEAST
INTO THE TWIN PORTS. THIS WAS OCCURRING IN AN AREA OF LOW LEVEL
FGEN AND ISENTROPIC LIFT. WE HAVE HIGHEST POPS OVER THAT AREA
TONIGHT. WE ISSUED A DENSE FOG ADVISORY EARLIER THIS
AFTERNOON...AND VSBYS HAVE COME UP IN SPOTS...BUT KCKC WAS
REPORTING LESS THAN A QUARTER MILE. WEAK ONSHORE FLOW...AND PLENTY
OF LOW LEVEL MOISTURE WILL BE SUPPORTIVE OF FOG TONIGHT...AND
WE`LL KEEP THE ADVISORY GOING. FOG WILL BE MOST DENSE IN THE
HIGHER TERRAIN JUST INLAND FROM LAKE SUPERIOR. CLOUDS WILL REMAIN
OVER CENTRAL AND EASTERN CWA...BUT A PORTION OF THE WEST-NORTHWEST
WILL BE CLEAR TO PARTLY CLOUDY FOR A PORTION OF THE NIGHT.
TEMPERATURES WILL NOT FALL MUCH...EXCEPT IN THE W-NW.
AS THE UPPER WAVE MOVES INTO KS/NE ON MONDAY...THE INVERTED TROUGH WILL
ROTATE BACK TO THE WEST...AND WE SHIFTED HIGHER POPS OVER OUR
WESTERN ZONES. CLOUDS MAY DIMINISH OVER A PORTION OF NORTHWEST
WISCONSIN...BUT WE KEPT THEM MOSTLY CLOUDY AT THIS TIME.
AS THE UPPER LOW DEEPENS MONDAY NIGHT INTO TUESDAY...SURFACE LOW
PRESSURE WILL DEVELOP/DEEPEN IN SOUTHERN IA. THERE WILL BE A
CONTINUED CHANCE FOR RAIN...WITH RAIN LIKELY OVER OUR WEST NEAR
THE WEAKENING TROUGH.
A STRONG NORTHERN STREAM WAVE WILL DIVE INTO THE AREA TUESDAY
NIGHT/WEDNESDAY. LOW PRESSURE AT THE SURFACE WILL TRACK INTO THE
LAKE MICHIGAN AREA. WE KEPT A MENTION OF JUST RAIN TUESDAY
EVENING...THEN MIXED IN SNOW FROM WEST TO EAST LATE TUESDAY NIGHT
INTO WEDNESDAY. WE HAVE CHANCE POPS ON WEDNESDAY AT THIS
TIME...BUT THEY MAY HAVE TO BE INCREASED WITH LATER FORECASTS.
SNOW ACCUMULATIONS LOOK LIGHT TUESDAY NIGHT INTO WEDNESDAY.
.EXTENDED...THURSDAY THROUGH SUNDAY
ADJUSTED POPS FURTHER WEST AND INCREASED FOR MOST AREAS WED
NIGHT/THURS AS MDLS CONTINUE TO SUPPORT A SLOWER TREND IN EJECTING
THE MID LVL LOW OVER THE ERN GRT LKS FRI. UPR LVL RIDING WILL PUSH E
OVER THE UPR MIDWEST OVER THE WEEKEND AS ANOTHER TROUGH CROSSES THE
ROCKIES AND MOVES INTO THE NORTHLAND LATE IN THE WEEKEND/EARLY NEXT
WEEK.
MAIN FCST CHALLENGE IN EXTENDED IS PTYPE AND CHANGE OVER TIMING
WED/THURS AS THE LOW TRACKS TO THE SE OF THE FA AND CANADIAN AIR
FILTERS INTO THE REGION. THE 12Z GFS/ECM IN GOOD AGREEMENT THAT CORE
OF COLDEST 850 MB TEMPS /-8C/ FUNNEL SWRD OVER THE DAKOTAS/SW MN
ALONG THE MAIN VORT/JET MAX WED WHILE 850 TEMPS IN THE NEGATIVE 2-5
C RANGE SPREAD OVER THE DLH FA BY THURS. HOWEVER...CROSS SECTIONS
FROM THE GFS/ECM AT KIWD/KHYR/KPBH DEPICT A SHALLOW LAYER SFC-900 MB
THAT REMAINS A FEW DEGREES ABV FZING THROUGH 12Z THURS. IN
ADDITION...THE GFS BUFKIT AT KIWD/HYR SHOWS RAIN FOR MOST OF THE
NIGHT AND HOLD OFF CHANGING TO SN UNTIL 08Z-12Z THURS WITH A BRIEF
PERIOD OF IP POSSIBLE. ATTM...LEFT PTYPE AS ALL SN WED NIGHT DUE TO THE
UNCERTAINTY IN TIMING THE PHASE CHANGE. HOWEVER...THERE REMAINS A
POSSIBILITY FOR THE RA/SN MIX TO CONTINUE THROUGH WED EVENING. LATER
SHIFTS MAY NEED TO CARRY THE RA/SN MIX INTO WED NIGHT FOR THE S
SHORE AND NRN WIS ZONES.
&&
.AVIATION...18Z TAF ISSUANCE
WDSPRD IFR/LIFR CONDITIONS WITH FG/DL WILL PERSIST THROUGH TAF
PERIOD. THE EXCEPTION WILL BE ALONG AND WEST OF TROUGH SITUATED
FROM KINL TO KSAZ/KBRD. THE KINL AREA WILL REMAIN VFR THROUGH THE
NIGHT...FALLING IFR MON MORNING. THE KBRD AREA MAY HAVE A FEW HR
PERIOD THIS EVENING WITH MVFR CIGS AND SCT LOW CLOUDS...BUT IFR
RESTRICTIONS AND BR/FG WILL AGAIN PREVAIL AFT 06Z.
&&
.POINT TEMPS/POPS...
DLH 44 47 39 41 / 60 60 40 40
INL 24 43 35 42 / 10 60 60 40
BRD 40 49 40 46 / 30 50 70 40
HYR 43 50 40 46 / 50 20 10 30
ASX 45 49 40 46 / 50 20 10 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 3 PM CST MONDAY FOR MNZ012-020-021-037.
WI...DENSE FOG ADVISORY UNTIL 3 PM CST MONDAY FOR WIZ001.
LS...NONE.
&&
$$
MELDE/GRANING
000
FXUS63 KMPX 222040
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
245 PM CST SUN NOV 22 2009
.DISCUSSION...
SATELLITE IMAGERY CURRENTLY SHOWING SOME COOLING OF CLOUD TOPS
ACROSS WESTERN AND CENTRAL IA WITH RADAR SHOWING GRADUAL INCREASE IN
LIGHT RAIN. BUMPED UP POPS FOR THE OVERNIGHT ACROSS THE EASTERN AND
SOUTHERN CWA WITH LIGHT QPF. VERY WARM MINS AHEAD FOR TONIGHT WITH
SEVERAL STATIONS LIKELY HAVING RECORD OR NEAR RECORD HIGHS
MINIMUMS...RECORD FOR MSP IS 44...41 AT EAU AND 35 AT STC. WITH
CLOUDS AND CONTINUED SOUTHERLY FLOW AHEAD OF WEAKENING FRONT IN
WESTERN MINNESOTA DON`T SEE MUCH OF A TEMPERATURE DROP OVERNIGHT.
STRENGTH OF UPPER LOW COMING ONSHORE IN PACIFIC NW EXHIBITED IN 500
MB HEIGHT FALL AROUND 150 METERS. LOW TO CONTINUE DIGGING SE NEXT 48
HOURS OR SO INTO THE KS/MO AREA...A BIT FARTHER S THAT SOME EARLIER
RUNS. SYSTEM THEN BEGINS TO LIFT OUT AS NEXT STRONG TROF COMES IN
BEHIND IT FROM CANADIAN PRAIRIES. TEMPERATURE PROFILES WARM ENOUGH
TO KEEP PRECIP AS ALL RAIN WITH THE FIRST TROUGH. BUFKIT SOUNDINGS
ON NAM/GFS PLOW IN ENUF COLD AIR TO TRANSITION PRECIP TO PRETTY MUCH
ALL SNOW BY EARLY EVENING WEDNESDAY AS SECOND LOW DROPS ACROSS MN
INTO IA. WILL PROBABLY SEE A BROAD BAND OF AN INCH OR SO OF SNOW
ACROSS AREA...WITH PERHAPS A COUPLE OF INCHES IN E MN INTO W WI WED
AFTERNOON/NIGHT WHERE QPF OUTPUT STILL SUFFICENT AS COLUMN COOLS.
TEMPERATURES MONDAY STILL QUITE MILD AS COLD AIR MAKES LITTLE
PROGRESS EASTWARD AS INVERTED TROF BECOMES ESTABLISHED ACROSS
WESTERN MINNESOTA. ONLY A SLOW COOLING MONDAY NIGHT INTO TUESDAY AS
TROUGH SLOWLY CRAWLS ACROSS STATE. TEMPERATURES BEGIN TO COOL MORE
SHARPLY ON WEDESDAY AND REMAIN COOL UNTIL SOME MODERATION BEGINNING
FRIDAY INTO SATURDAY AHEAD OF NEXT TROUGH.
&&
.AVIATION.../18Z TAF ISSUANCE/
VISIBLE SATELLITE IMAGE INDICATED A LARGE BREAK IN THE CLD CVR
S/SE OF MSP/RNH/EAU WITH AXN NEARLY VFR WITH SOME FG/BR EARLY THIS
AFTN. VFR CONDITIONS WITH A SMALL MVFR CEILING WINDOW IS LIKELY
FOR MSP/RNH/EAU. AXN WILL LIKELY HOLD ONTO THE BR WITH VSBY AROUND
3 OR 4SM. RWF WILL LIKELY HOLD IN THE MVFR RANGE WITH
WEAK/MODERATE ISENTROPIC LIFT DEVELOP JUST AHEAD OF THE SHALLED
FRONTAL BOUNDARY IN FAR WESTERN MN. A LARGE AREA OF SHRA IS
DEVELOPING IN AN INCREASE STRONG OMEGA REGION IN N MO/S IA WHICH
IS PROGGED TO MOVE N/NE ACROSS SE MN/EC MN AND WC WISCONSIN DURING
THE EVENING. IN ADDITION...INSENTROPIC LIFT AHEAD OF FRONTAL
BOUNDARY OUT WEST WILL LIKELY DEVELOP AN AREA OF -RA/-DZ FOR RWF
DURING THE LATE AFTN/EVENING PERIOD. AXN WILL LIKELY HOLD OFF ON
ANY PRECIPITATION UNTIL WINDS BACK TO THE E/SE TOWARD MORNING AND
INCREASING THE INSENTROPIC LIFT IN THIS REGION. MSP/RNH/EAU WILL
LIKELY SEE LOWER CEILINGS DEVELOPING OVERNIGHT WITH SHRA/-RA/-DA
SPREADING NORTHWARD. AFT 06/09Z...CONDITIONS WILL BE VARIABLE DUE
TO MIXING IN THE BOUNDARY LAYER WITH -RA/-SHRA AROUND THE AREA.
LATER SHIFTS WILL NEED TO UPDATE TRENDS AS THE FORECAST TIME
PERIOD GETS CLOSER. ..JLT..
.CWSU DISCUSSION...
VFR CIGS CURRENTLY. ALL MODELS SUPPORT MAINTAINING VFR CIGS THROUGH
THE AFTERNOON. RUC & HRRR SUGGEST LOW CIGS (~015) RETURNING SHORTLY
AFTER 00Z. OCCASIONAL BREAK IN THIS LOW DECK POSSIBLE, BUT BY
MORNING, EXPECTED THE CIG TO LOWER TO IFR HEIGHTS. THE BEST CHANCE
FOR RAIN APPEARS TO BE MONDAY MORNING... NOT MUCH REDUCTION IN
VISIBILITY, OUTSIDE OF THIN FOG EXPECTED. LOOKING FOR IMPROVEMENT
AGAIN DURING THE DAYLIGHT HOURS... UP TO AROUND 030 CIGS FOR MONDAY
AFTERNOON.
FRONT WILL STALL OUT, BUT WILL BECOME MORE SW/NE ORIENTED. SO WINDS
WILL GRADUALLY BECOME MORE EASTERLY DURING THE FORECAST PERIOD. NOT
MUCH STRONGER...UP TO 10 KTS DURING THE AFTERNOONS. - KFM
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
BAP/JLT
000
FXUS63 KDLH 221844 AAC
AFDDLH
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
1244 PM CST SUN NOV 22 2009
AVIATION...18Z TAF ISSUANCE
WDSPRD IFR/LIFR CONDITIONS WITH FG/DL WILL PERSIST THROUGH TAF
PERIOD. THE EXCEPTION WILL BE ALONG AND WEST OF TROUGH SITUATED
FROM KINL TO KSAZ/KBRD. THE KINL AREA WILL REMAIN VFR THROUGH THE
NIGHT...FALLING IFR MON MORNING. THE KBRD AREA MAY HAVE A FEW HR
PERIOD THIS EVENING WITH MVFR CIGS AND SCT LOW CLOUDS...BUT IFR
RESTRICTIONS AND BR/FG WILL AGAIN PREVAIL AFT 06Z.
&&
.PREV DISCUSSION... /ISSUED 1241 PM CST SUN NOV 22 2009/
DISCUSSION...
HAVE UPDATED GRIDS AND ISSUED A DENSE FOG ADVISORY. WEBCAMS AND
OBSERVATIONS SHOWS VSBYS HAVE BEEN DROPPING. KDLH DROPPED TO A
QUARTER MILE FOR A TIME. THERE WILL BE LITTLE CHANGE IN CONDITIONS
THIS AFTERNOON INTO TONIGHT...AND WITH ONSHORE WINDS...WE FELT
DENSE WILL BECOME MORE LIKELY. THE FOG MAY CONTINUE ALL DAY
MONDAY...AND THE ADVISORY MAY HAVE TO BE EXTENDED INTO MONDAY NIGHT.
PREV DISCUSSION... /ISSUED 923 AM CST SUN NOV 22 2009/
DISCUSSION...
CLOUDS COVERED MUCH OF THE CWA THIS MORNING...AND THAT IS FORECAST
TO CONTINUE THIS AFTERNOON. THE EXCEPTION WILL BE OVER FAR WEST-
NORTHWEST AREAS...WHICH WILL SEE SOME SUN.
WE INCREASED POPS THIS AFTERNOON...ESPECIALLY FOR THE AREA FROM
PINE/BURNETT COUNTY...NORTHEAST THROUGH THE NORTH SHORE. MODELS
HAVE BEEN FORECASTING SOME LOW LEVEL FGEN IN THIS AREA FOR SEVERAL
RUNS...AND ALL MODELS HAVE THEIR HIGHEST QPF IN THIS AREA.
WE ALSO ADDED FOG TO THE FORECAST...AS MANY AREAS ARE SEEING VSBYS
DOWN TO 1 TO 3 MILES.
PREV DISCUSSION... /ISSUED 643 AM CST SUN NOV 22 2009/
UPDATE...
AREAS OF DRIZZLE AND A SLIGHT CHANCE OF RAIN HAS BEEN INCLUDED FOR
NORTHWESTERN WISCONSIN FOR THIS MORNING.
DISCUSSION...
LOW LEVEL MOISTURE HAS MOVED INTO THE AREA...RESULTING IN A LOW
STRATUS DECK. THE MOISTURE WILL DEEPEN...REACHING THE 750 MB OR
800 MB LEVEL FOR AREAS AROUND...EAST AND SOUTH OF BAYFIELD
PENINSULA BY NOON TODAY...THIS DEPTH IS SUFFICIENT FOR AREAS OF
DRIZZLE AND EVEN A SLIGHT CHANCE A LIGHT WETTING RAIN.
PREV DISCUSSION... /ISSUED 602 AM CST SUN NOV 22 2009/
UPDATE...FOR 12Z TAF ISSUANCE...SEE DISCUSSION BELOW
AVIATION...12Z TAF ISSUANCE...LOW MVFR/HIGH IFR CIGS WITH VSBYS
IN THE 4-6SM RANGE WILL PERSIST THROUGH THE MORNING AND INTO THE
EARLY AFTERNOON. KINL WILL SEE MVFR CIGS IN THE 1800-2800 FT RANGE
BEFORE GOING SCATTERED THIS MORNING...AND KBRD WILL SCATTER OUT
SOONER AS A COLD FRONT AND DRIER AIR APPROACH. THIS FRONT WILL
ATTEMPT TO PUSH EAST BUT STALLS...SO SOME UNCERTAINLY LIES IN
WHETHER KHIB/KDLH LOSE THE MVFR CIGS. IF SO...THERE MAY STILL BE MVFR
VSBYS.
BEST CHANCE FOR -RA/-DZ TODAY WILL BE IN NW WISC WHERE THE BEST
ISENTROPIC LIFT EXISTS...EXTENDING UP THE NORTH SHORE.
COLD/OCCLUDED FRONT WILL THEN STALL AND LIFT NORTHWARD OVERNIGHT.
PRECIP CHANCES WILL INCREASE FROM SOUTH TO NORTH WITH IFR
CONDITIONS LIKELY FROM KDLH SOUTH...WITH THESE CONDITIONS PUSHING
FURTHER NORTH AFTER THIS TAF SET.
PREV DISCUSSION... /ISSUED 323 AM CST SUN NOV 22 2009/
DISCUSSION...
TODAY...SOUTH WINDS BEHIND HIGH PRESSURE WILL BE MITIGATED BY THE
APPROACH OF A WEAKENING TROUGH...NOW OVER THE RED RIVER VALLEY. A
STRATOCUMULUS DECK HAS OVERSPREAD THE AREA...MODELS INCLUDING THE
LAV...SUGGEST THE SUDDEN APPEARANCE OF A LOW DECK AND EVEN SOME
FOG. WE SEE NO EVIDENCE OF THAT. ANY RAIN IS DOUBTFUL TODAY...THE
MODELS CONCUR WITH THAT. WE LEFT A SLIGHT CHANCE OF LIGHT RAIN OR
DRIZZLE AROUND SHORELINE AREAS THIS AFTERNOON. AN INVERTED TROUGH
DEVELOPS OVER THE AREA...WITH MORE OF A POSSIBILITY OF RAIN
TONIGHT. A WEAKENING SHORT WAVE...ALOFT...OVER THE NORTHWEST WILL
BECOME SEPARATED FROM THE NORTHERN BRANCH...STALL OVER IOWA ON
MONDAY...AND ANCHOR THE INVERTED TROUGH OVER OUR AREA MONDAY AND
TUESDAY...RESULTING IN MORE CLOUDS AND PERHAPS LIGHT RAIN OVER OUR
AREA THROUGH TUESDAY. THE COLUMN WILL REMAIN TOO WARM FOR ANY SNOW
OR WINTRY MIX.
EXTENDED...TUESDAY NIGHT THROUGH FRIDAY...
THE MODELS ARE COMING INTO BETTER AGREEMENT REGARDING THE
EVOLUTION OF CLIPPER SYSTEM ON THE HEELS OF A DEPARTING CLOSED
UPPER LEVEL CIRCULATION TO THE SOUTH AND ASSOCIATED INVERTED
TROUGH...BUT STILL SOME NOTICEABLE DIFFERENCES.
ALL THE MODELS DIG A 130+ KNOT UPPER LEVEL JET INTO THE NORTHERN AND
CENTRAL PLAINS ON WEDNESDAY. THE GFS PUSHES THE UPPER LOW INTO NW
MINNESOTA BEFORE PUSHING IT SOUTH. BOTH MODELS SUGGEST PRECIP WILL
BREAK OUT IN OUR NW ZONES BY 12Z...BUT FOR DIFFERENT REASONS. THE
GFS BRINGS THE MID LEVEL VORT INTO NW MN...WITH THE ASSOCIATED
SURFACE COLD FRONT THROUGH NE MN. THE NAM...AT THE END OF ITS 84HR
RUN...SUPPORTS THIS IDEA. IT HAS SOME QG FORCING FURTHER NORTH INTO
OUR NW ZONES. THE EURO AND ITS ASSOCIATED QG FORCING IS FURTHER WEST
AND SOUTH...AND IT DRAGS THE COLD FRONT SOUTHWEST. BUT...IT HAS THE
INVERTED TROUGH AXIS POINTED TO THIS SAME AREA FROM THE PREVIOUS
SYSTEM. EITHER WAY...WE HAVE INCREASED POPS ACCORDINGLY IN THE
NW...AND KEPT HIGHER CHC POPS IN OUR SE ZONES WITH DEPARTING
INVERTED TROUGH AXIS. ALL RAIN IN NW WISC BEFORE 12Z WITH 925 TEMPS
1-3 C EVEN WITH THE COLDER GFS. WITH UNCERTAINTY ON LONG RANGE TEMP
FCSTS...HAVE NOT CHANGED TEMPS TOO MUCH...AND HAVE CONTINUED TO LEAN
MORE TOWARDS THE EURO/GEM AT THIS TIME. THOUGH GIVE SOME CREDIT TO
THE GFS THAT THE EURO/GEM HAVE BEEN COMING MORE IN LINE WITH THE
PROGRESSIVE GFS FOR THE SYSTEM EARLIER IN THE WEEK. THE GFS IS
COLDER WITH ITS INITIAL MORE PROGRESSIVE NATURE...AND SUPPORTS ALL
SNOW IN THE NW. THE 12Z/0Z EURO ARE WARMER AND SOUNDINGS WOULD
SUGGEST A RAIN/SNOW MIX. WE HAVE KEPT THE RAIN/SNOW MIX MENTION FOR
WEDNESDAY MORNING EVERYWHERE...WITH SNOW BECOMING MORE DOMINANT IN
THE NORTH AND WEST WEDNESDAY AFTERNOON...RAIN/SNOW MORE SO EAST...THOUGH
IF THE GFS PANS OUT...SNOW WILL BE THE DOMINANT P TYPE
EVERYWHERE...ESPECIALLY IN THE AFTERNOON.
THINGS WILL BEGIN TO WIND DOWN ELSEWHERE WEDNESDAY NIGHT AS MODELS
AGREE ON DROPPING UPPER LOW AND ASSOCIATED FORCING SOUTH. DEPENDING
ON HOW THINGS PAN OUT WILL DETERMINE THE LAKE EFFECT SNOW POTENTIAL
FOR WEDS NIGHT/THURSDAY. GFS FAVORS A GOOD NNW TRAJECTORY...DELTA
T`S NEAR 13-14 C AT 850...AND SUFFICIENT LOW LEVEL AND 850-700 RH
THROUGH THURSDAY. THE EURO HAS MORE OF A NE FLOW BUT SIMILIAR
CONDITIONS OTHERWISE...ALBEIT SLIGHTLY WARMER. THIS WOULD FAVOR
SIMILIAR AREA THOUGH FROM A DIFFERENT TRAJECTORY AND LONGER FETCH.
RIDGING WILL BUILD IN THURSDAY NIGHT INTO FRIDAY WHICH WILL MEAN A
CHILLY NIGHT THURSDAY NIGHT AND THEN A QUICK REBOUND TO WARMER AND
DRIER WEATHER FOR THE HOLIDAY WEEKEND. IN A LONGER OUTLOOK...COLDER
WEATHER APPEARS TO BE ON THE HORIZON FOR THE START OF
DECEMBER...WITH THE GFS BRINGING DOWN SOME POLAR/ARCTIC AIR. THE
EUROPEAN IS NOT SO BOLD BUT HINTING AT THIS IDEA. SEE THE DAY 8-14
CPC OUTLOOK FOR ADDITIONAL INFO.
AVIATION...11/22/06Z ISSUANCE...
VFR CIGS EXPECTED THROUGH THE TAF PERIOD. THE EXCEPTION WILL BE
WITH THE FORMATION OF PATCHES OF FOG WHEN CIGS/VSBYS MAY BRIEFLY
DROP INTO THE MVFR RANGE...ESPECIALLY AT KHIB AND KHYR UNTIL 14Z.
&&
.POINT TEMPS/POPS...
DLH 41 47 38 45 / 60 60 30 40
INL 26 43 35 40 / 10 50 60 40
BRD 40 49 37 44 / 30 50 60 40
HYR 45 50 38 47 / 50 20 10 40
ASX 44 49 38 47 / 50 20 10 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 3 PM CST MONDAY FOR MNZ012-020-021-037.
WI...DENSE FOG ADVISORY UNTIL 3 PM CST MONDAY FOR WIZ001.
LS...NONE.
&&
$$
MELDE/GRANING/GRANING
000
FXUS63 KDLH 221841
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
1241 PM CST SUN NOV 22 2009
.DISCUSSION...
HAVE UPDATED GRIDS AND ISSUED A DENSE FOG ADVISORY. WEBCAMS AND
OBSERVATIONS SHOWS VSBYS HAVE BEEN DROPPING. KDLH DROPPED TO A
QUARTER MILE FOR A TIME. THERE WILL BE LITTLE CHANGE IN CONDITIONS
THIS AFTERNOON INTO TONIGHT...AND WITH ONSHORE WINDS...WE FELT
DENSE WILL BECOME MORE LIKELY. THE FOG MAY CONTINUE ALL DAY
MONDAY...AND THE ADVISORY MAY HAVE TO BE EXTENDED INTO MONDAY NIGHT.
&&
.PREV DISCUSSION... /ISSUED 923 AM CST SUN NOV 22 2009/
DISCUSSION...
CLOUDS COVERED MUCH OF THE CWA THIS MORNING...AND THAT IS FORECAST
TO CONTINUE THIS AFTERNOON. THE EXCEPTION WILL BE OVER FAR WEST-
NORTHWEST AREAS...WHICH WILL SEE SOME SUN.
WE INCREASED POPS THIS AFTERNOON...ESPECIALLY FOR THE AREA FROM
PINE/BURNETT COUNTY...NORTHEAST THROUGH THE NORTH SHORE. MODELS
HAVE BEEN FORECASTING SOME LOW LEVEL FGEN IN THIS AREA FOR SEVERAL
RUNS...AND ALL MODELS HAVE THEIR HIGHEST QPF IN THIS AREA.
WE ALSO ADDED FOG TO THE FORECAST...AS MANY AREAS ARE SEEING VSBYS
DOWN TO 1 TO 3 MILES.
PREV DISCUSSION... /ISSUED 643 AM CST SUN NOV 22 2009/
UPDATE...
AREAS OF DRIZZLE AND A SLIGHT CHANCE OF RAIN HAS BEEN INCLUDED FOR
NORTHWESTERN WISCONSIN FOR THIS MORNING.
DISCUSSION...
LOW LEVEL MOISTURE HAS MOVED INTO THE AREA...RESULTING IN A LOW
STRATUS DECK. THE MOISTURE WILL DEEPEN...REACHING THE 750 MB OR
800 MB LEVEL FOR AREAS AROUND...EAST AND SOUTH OF BAYFIELD
PENINSULA BY NOON TODAY...THIS DEPTH IS SUFFICIENT FOR AREAS OF
DRIZZLE AND EVEN A SLIGHT CHANCE A LIGHT WETTING RAIN.
PREV DISCUSSION... /ISSUED 602 AM CST SUN NOV 22 2009/
UPDATE...FOR 12Z TAF ISSUANCE...SEE DISCUSSION BELOW
AVIATION...12Z TAF ISSUANCE...LOW MVFR/HIGH IFR CIGS WITH VSBYS
IN THE 4-6SM RANGE WILL PERSIST THROUGH THE MORNING AND INTO THE
EARLY AFTERNOON. KINL WILL SEE MVFR CIGS IN THE 1800-2800 FT RANGE
BEFORE GOING SCATTERED THIS MORNING...AND KBRD WILL SCATTER OUT
SOONER AS A COLD FRONT AND DRIER AIR APPROACH. THIS FRONT WILL
ATTEMPT TO PUSH EAST BUT STALLS...SO SOME UNCERTAINLY LIES IN
WHETHER KHIB/KDLH LOSE THE MVFR CIGS. IF SO...THERE MAY STILL BE MVFR
VSBYS.
BEST CHANCE FOR -RA/-DZ TODAY WILL BE IN NW WISC WHERE THE BEST
ISENTROPIC LIFT EXISTS...EXTENDING UP THE NORTH SHORE.
COLD/OCCLUDED FRONT WILL THEN STALL AND LIFT NORTHWARD OVERNIGHT.
PRECIP CHANCES WILL INCREASE FROM SOUTH TO NORTH WITH IFR
CONDITIONS LIKELY FROM KDLH SOUTH...WITH THESE CONDITIONS PUSHING
FURTHER NORTH AFTER THIS TAF SET.
PREV DISCUSSION... /ISSUED 323 AM CST SUN NOV 22 2009/
DISCUSSION...
TODAY...SOUTH WINDS BEHIND HIGH PRESSURE WILL BE MITIGATED BY THE
APPROACH OF A WEAKENING TROUGH...NOW OVER THE RED RIVER VALLEY. A
STRATOCUMULUS DECK HAS OVERSPREAD THE AREA...MODELS INCLUDING THE
LAV...SUGGEST THE SUDDEN APPEARANCE OF A LOW DECK AND EVEN SOME
FOG. WE SEE NO EVIDENCE OF THAT. ANY RAIN IS DOUBTFUL TODAY...THE
MODELS CONCUR WITH THAT. WE LEFT A SLIGHT CHANCE OF LIGHT RAIN OR
DRIZZLE AROUND SHORELINE AREAS THIS AFTERNOON. AN INVERTED TROUGH
DEVELOPS OVER THE AREA...WITH MORE OF A POSSIBILITY OF RAIN
TONIGHT. A WEAKENING SHORT WAVE...ALOFT...OVER THE NORTHWEST WILL
BECOME SEPARATED FROM THE NORTHERN BRANCH...STALL OVER IOWA ON
MONDAY...AND ANCHOR THE INVERTED TROUGH OVER OUR AREA MONDAY AND
TUESDAY...RESULTING IN MORE CLOUDS AND PERHAPS LIGHT RAIN OVER OUR
AREA THROUGH TUESDAY. THE COLUMN WILL REMAIN TOO WARM FOR ANY SNOW
OR WINTRY MIX.
EXTENDED...TUESDAY NIGHT THROUGH FRIDAY...
THE MODELS ARE COMING INTO BETTER AGREEMENT REGARDING THE
EVOLUTION OF CLIPPER SYSTEM ON THE HEELS OF A DEPARTING CLOSED
UPPER LEVEL CIRCULATION TO THE SOUTH AND ASSOCIATED INVERTED
TROUGH...BUT STILL SOME NOTICEABLE DIFFERENCES.
ALL THE MODELS DIG A 130+ KNOT UPPER LEVEL JET INTO THE NORTHERN AND
CENTRAL PLAINS ON WEDNESDAY. THE GFS PUSHES THE UPPER LOW INTO NW
MINNESOTA BEFORE PUSHING IT SOUTH. BOTH MODELS SUGGEST PRECIP WILL
BREAK OUT IN OUR NW ZONES BY 12Z...BUT FOR DIFFERENT REASONS. THE
GFS BRINGS THE MID LEVEL VORT INTO NW MN...WITH THE ASSOCIATED
SURFACE COLD FRONT THROUGH NE MN. THE NAM...AT THE END OF ITS 84HR
RUN...SUPPORTS THIS IDEA. IT HAS SOME QG FORCING FURTHER NORTH INTO
OUR NW ZONES. THE EURO AND ITS ASSOCIATED QG FORCING IS FURTHER WEST
AND SOUTH...AND IT DRAGS THE COLD FRONT SOUTHWEST. BUT...IT HAS THE
INVERTED TROUGH AXIS POINTED TO THIS SAME AREA FROM THE PREVIOUS
SYSTEM. EITHER WAY...WE HAVE INCREASED POPS ACCORDINGLY IN THE
NW...AND KEPT HIGHER CHC POPS IN OUR SE ZONES WITH DEPARTING
INVERTED TROUGH AXIS. ALL RAIN IN NW WISC BEFORE 12Z WITH 925 TEMPS
1-3 C EVEN WITH THE COLDER GFS. WITH UNCERTAINTY ON LONG RANGE TEMP
FCSTS...HAVE NOT CHANGED TEMPS TOO MUCH...AND HAVE CONTINUED TO LEAN
MORE TOWARDS THE EURO/GEM AT THIS TIME. THOUGH GIVE SOME CREDIT TO
THE GFS THAT THE EURO/GEM HAVE BEEN COMING MORE IN LINE WITH THE
PROGRESSIVE GFS FOR THE SYSTEM EARLIER IN THE WEEK. THE GFS IS
COLDER WITH ITS INITIAL MORE PROGRESSIVE NATURE...AND SUPPORTS ALL
SNOW IN THE NW. THE 12Z/0Z EURO ARE WARMER AND SOUNDINGS WOULD
SUGGEST A RAIN/SNOW MIX. WE HAVE KEPT THE RAIN/SNOW MIX MENTION FOR
WEDNESDAY MORNING EVERYWHERE...WITH SNOW BECOMING MORE DOMINANT IN
THE NORTH AND WEST WEDNESDAY AFTERNOON...RAIN/SNOW MORE SO EAST...THOUGH
IF THE GFS PANS OUT...SNOW WILL BE THE DOMINANT P TYPE
EVERYWHERE...ESPECIALLY IN THE AFTERNOON.
THINGS WILL BEGIN TO WIND DOWN ELSEWHERE WEDNESDAY NIGHT AS MODELS
AGREE ON DROPPING UPPER LOW AND ASSOCIATED FORCING SOUTH. DEPENDING
ON HOW THINGS PAN OUT WILL DETERMINE THE LAKE EFFECT SNOW POTENTIAL
FOR WEDS NIGHT/THURSDAY. GFS FAVORS A GOOD NNW TRAJECTORY...DELTA
T`S NEAR 13-14 C AT 850...AND SUFFICIENT LOW LEVEL AND 850-700 RH
THROUGH THURSDAY. THE EURO HAS MORE OF A NE FLOW BUT SIMILIAR
CONDITIONS OTHERWISE...ALBEIT SLIGHTLY WARMER. THIS WOULD FAVOR
SIMILIAR AREA THOUGH FROM A DIFFERENT TRAJECTORY AND LONGER FETCH.
RIDGING WILL BUILD IN THURSDAY NIGHT INTO FRIDAY WHICH WILL MEAN A
CHILLY NIGHT THURSDAY NIGHT AND THEN A QUICK REBOUND TO WARMER AND
DRIER WEATHER FOR THE HOLIDAY WEEKEND. IN A LONGER OUTLOOK...COLDER
WEATHER APPEARS TO BE ON THE HORIZON FOR THE START OF
DECEMBER...WITH THE GFS BRINGING DOWN SOME POLAR/ARCTIC AIR. THE
EUROPEAN IS NOT SO BOLD BUT HINTING AT THIS IDEA. SEE THE DAY 8-14
CPC OUTLOOK FOR ADDITIONAL INFO.
AVIATION...11/22/06Z ISSUANCE...
VFR CIGS EXPECTED THROUGH THE TAF PERIOD. THE EXCEPTION WILL BE
WITH THE FORMATION OF PATCHES OF FOG WHEN CIGS/VSBYS MAY BRIEFLY
DROP INTO THE MVFR RANGE...ESPECIALLY AT KHIB AND KHYR UNTIL 14Z.
&&
.POINT TEMPS/POPS...
DLH 41 47 38 45 / 60 60 30 40
INL 26 43 35 40 / 10 50 60 40
BRD 40 49 37 44 / 30 50 60 40
HYR 45 50 38 47 / 50 20 10 40
ASX 44 49 38 47 / 50 20 10 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 3 PM CST MONDAY FOR MNZ012-020-021-037.
WI...DENSE FOG ADVISORY UNTIL 3 PM CST MONDAY FOR WIZ001.
LS...NONE.
&&
$$
MELDE/GRANING
000
FXUS63 KMPX 221714
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1114 AM CST SUN NOV 22 2009
.DISCUSSION...
CWA SITS UNDER AREA OF STRONG WAA ADVECTION THIS MORNING...AS
EVIDENCED BY TEMPS AT 4 AM ALREADY CLIMBING THROUGH THE 40S. THIS
IS ALL IN RESPONSE TO RATHER BROAD...BUT WEAKENING H5 TROUGH
ENTERING THE HIGH PLAINS THIS MORNING. ISENTROPIC ASCENT
OVERSPREADING AREA OVERNIGHT HAS RESULTED IN BLANKET OF STRATUS
THIS MORNING. THERE ARE ALSO SOME LIGHT RETURNS ON RADAR OVER
W CENTRAL WI. NAM 290K SFC HAS DONE WELL WITH DEPICTING THIS AREA
OF SPRINKLES/DRIZZLE THIS MORNING AND EXPECT IT TO IMPACT WI
PORTION OF CWA EARLY ON BEFORE LIFTING NE TOWARD LK SUPERIOR.
AFTER THAT...HAVE TO WAIT UNTIL AFTER 00Z TONIGHT BEFORE ATMO
COLUMN BEGINS TO MOISTEN ENOUGH TO START SEEING RAIN...SO EXPECT A
MAINLY DRY...BUT MOSTLY CLOUDY AFTERNOON. DESPITE CLOUDS...STRONG
WAA THROUGHOUT THE DAY WILL STILL ALLOW HIGHS TO SNEAK INTO THE
LOW 50S ONCE AGAIN...WHICH IS A NICE BLEND BETWEEN THE GENERALLY
WARMER MAV AND COOLER MET.
FOR TONIGHT...EXPECT RAIN CHANCES TO SLOWLY INCREASE THROUGH THE
NIGHT...ESPECIALLY AFTER 06Z AS THE SHORTWAVE AND RIGHT ENTRANCE
REGION OF UPPER JET MOVE ACROSS AREA. TO GO ALONG WITH
THIS...NAM/GFS BOTH RAPIDLY DECREASING COND PRESSURE DEFICITS ON
THETA SFCS...WHICH WILL FINALLY ALLOW FOR ATMO TO MOISTEN. EXPECT
FRONT CURRENTLY OVER THE ERN DAKOTAS TO STALL OUT ABOUT HALF WAY
ACROSS CWA. THIS WILL HELP FOCUS LOW RAIN CHANCES ALONG AND EAST
OF IT TONIGHT. WITH CLOUD COVER AND CONTINUED WAA PROGGED FOR
TONIGHT...ALSO INCREASED MIN TEMPS A FEW DEGREES.
MORE ACTIVE PATTERN THEN SETS IN FROM MONDAY ALL THE WAY TO THE
THANKSGIVING HOLIDAY. FOR THIS PERIOD...STAYED CLOSE TO THE
ECMWF/NAM SOLUTIONS DUE TO THEIR BETTER RUN TO RUN CONSISTENCY...
THOUGH THE GEM/GFS WITH THE 22.00Z RUNS WERE COMING MORE IN LINE
WITH THE ECMWF AND WERE ONLY A LITTLE FASTER WITH PULLING PRECIP
CHANCES OUT OF THE AREA WEDNESDAY NIGHT. FOR THIS PERIOD...FIRST
WAVE CURRENTLY COMING ONSHORE IN THE PAC NW WILL MOVE INTO THE
NRN HIGH PLAINS MONDAY...AND IS PROGGED TO DEEPEN....WITH A CLOSED
H5 LOW FORMING OVER NE/KS MONDAY NIGHT. SFC CYCLONE WILL DEVELOP
OVER SE NE IN RESPONSE TO THIS...TAKING WHAT IS LEFT OF THE FRONT
OVER WRN MN AND TURNING IT INTO AN INVERTED TROUGH. WILL SEE RAIN
CHANCES INCREASE MONDAY NIGHT ACROSS WRN MN ALONG AND EAST OF THIS
TROUGH. THESE FEATURES WILL SLOWLY SLIDE EAST TUESDAY...REACHING
LK MICHIGAN BY 00Z WEDNESDAY. THIS HAS RESULTED IN BEST POPS
OCCURRING TUESDAY AS THE SFC LOW PASSES ACROSS IA. INVERTED TROUGH
WILL WEAKEN SOME DURING THE DAY TUESDAY...WITH QG FORCING BECOMING
FOCUSED CLOSE TO THE IA LOW. WILL LIKELY RESULT IN BEST RAIN
CHANCES TRANSITIONING FROM WRN MN TUESDAY MORNING TO ACROSS THE
SOUTH DURING THE DAY.
THE COMPLICATING FACTOR WITH ALL OF THIS WILL THEN BE THE NEXT
WAVE COMING DOWN IN NW FLOW BEHIND TUESDAYS SYSTEM. BLEND OF
ECMWF/GFS/GEM SHOWS STRONG/DEEPENING WAVE COMING DOWN FROM ALBERTA
WEDNESDAY...MERGING WITH AND INTENSIFYING THE FIRST WAVE OVER THE
GREAT LAKES WEDNESDAY NIGHT. THIS WAVE WILL BRING A STRONG PUSH
OF COLD AIR WITH IT...ENOUGH TO START TURNING PRECIP OVER TO SNOW
OR A MIX TUESDAY NIGHT/WEDNESDAY. WITH THIS SECOND WAVE MERGING
INTO BACK SIDE OF THE FIRST...PATTERN MOMENTARILY STALLS
OUT...KEEPING DEFORMATION AND CYCLONIC FLOW GOING ACROSS ERN CWA
WEDNESDAY/NIGHT. ECMWF/GEM/GFS ALL HINTING AT POSSIBILITY OF SNOW
ACROSS ERN MN WI FOR THE BUSY TRAVEL DAY/NIGHT BEFORE
THANKSGIVING. WITH AS WARM AS NOVEMBER HAS BEEN...GROUND
TEMPERATURES ARE STILL VERY WARM FOR THE TIME OF YEAR...BUT GIVEN
THE AMOUNT OF TRAVELERS OUT AND ABOUT THIS TIME PERIOD THIS WILL
BE SOMETHING TO WATCH WITH FUTURE MODEL RUNS.
LAST PROBLEM WITH ALL OF THIS WILL BE TEMPERATURES. DID NOT MAKE
MANY CHANGES TO HIGHS THROUGH THE PERIOD...BUT GIVEN AMOUNT OF
CLOUD COVER AND WARM AIR EXPECTED TO BE AROUND...ALONG WITH
SLIGHTLY SLOWER PROGRESSION OF FEATURES...DID INCREASE LOWS
MONDAY/TUESDAY NIGHT ACROSS ENTIRE AREA AND WEDNESDAY NIGHT ACROSS
MAINLY WIS. OVER THE NEXT WEEK...THURSDAY STILL LOOKS TO BE THE
COLDEST DAY...WITH GFS/ECMWF PROGGING H85 TEMPS TO BE AROUND
-6C...BUT BY FRIDAY WAA IS EXPECTED TO SET BACK IN AND
WILL START SEEING A SLIGHT MODERATION IN TEMPS BEGIN BY THE
WEEKEND.
&&
.AVIATION.../18Z TAF ISSUANCE/
VISIBLE SATELLITE IMAGE INDICATED A LARGE BREAK IN THE CLD CVR
S/SE OF MSP/RNH/EAU WITH AXN NEARLY VFR WITH SOME FG/BR EARLY THIS
AFTN. VFR CONDITIONS WITH A SMALL MVFR CEILING WINDOW IS LIKELY
FOR MSP/RNH/EAU. AXN WILL LIKELY HOLD ONTO THE BR WITH VSBY AROUND
3 OR 4SM. RWF WILL LIKELY HOLD IN THE MVFR RANGE WITH
WEAK/MODERATE ISENTROPIC LIFT DEVELOP JUST AHEAD OF THE SHALLED
FRONTAL BOUNDARY IN FAR WESTERN MN. A LARGE AREA OF SHRA IS
DEVELOPING IN AN INCREASE STRONG OMEGA REGION IN N MO/S IA WHICH
IS PROGGED TO MOVE N/NE ACROSS SE MN/EC MN AND WC WISCONSIN DURING
THE EVENING. IN ADDITION...INSENTROPIC LIFT AHEAD OF FRONTAL
BOUNDARY OUT WEST WILL LIKELY DEVELOP AN AREA OF -RA/-DZ FOR RWF
DURING THE LATE AFTN/EVENING PERIOD. AXN WILL LIKELY HOLD OFF ON
ANY PRECIPITATION UNTIL WINDS BACK TO THE E/SE TOWARD MORNING AND
INCREASING THE INSENTROPIC LIFT IN THIS REGION. MSP/RNH/EAU WILL
LIKELY SEE LOWER CEILINGS DEVELOPING OVERNIGHT WITH SHRA/-RA/-DA
SPREADING NORTHWARD. AFT 06/09Z...CONDITIONS WILL BE VARIABLE DUE
TO MIXING IN THE BOUNDARY LAYER WITH -RA/-SHRA AROUND THE AREA.
LATER SHIFTS WILL NEED TO UPDATE TRENDS AS THE FORECAST TIME
PERIOD GETS CLOSER. ..JLT..
.CWSU DISCUSSION...
VFR CIGS CURRENTLY. ALL MODELS SUPPORT MAINTAINING VFR CIGS THROUGH
THE AFTERNOON. RUC & HRRR SUGGEST LOW CIGS (~015) RETURNING SHORTLY
AFTER 00Z. OCCASIONAL BREAK IN THIS LOW DECK POSSIBLE, BUT BY
MORNING, EXPECTED THE CIG TO LOWER TO IFR HEIGHTS. THE BEST CHANCE
FOR RAIN APPEARS TO BE MONDAY MORNING... NOT MUCH REDUCTION IN
VISIBILITY, OUTSIDE OF THIN FOG EXPECTED. LOOKING FOR IMPROVEMENT
AGAIN DURING THE DAYLIGHT HOURS... UP TO AROUND 030 CIGS FOR MONDAY
AFTERNOON.
FRONT WILL STALL OUT, BUT WILL BECOME MORE SW/NE ORIENTED. SO WINDS
WILL GRADUALLY BECOME MORE EASTERLY DURING THE FORECAST PERIOD. NOT
MUCH STRONGER...UP TO 10 KTS DURING THE AFTERNOONS. - KFM
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
MPG/JLT
000
FXUS63 KDLH 221523 AAA
AFDDLH
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
923 AM CST SUN NOV 22 2009
.DISCUSSION...
CLOUDS COVERED MUCH OF THE CWA THIS MORNING...AND THAT IS FORECAST
TO CONTINUE THIS AFTERNOON. THE EXCEPTION WILL BE OVER FAR WEST-
NORTHWEST AREAS...WHICH WILL SEE SOME SUN.
WE INCREASED POPS THIS AFTERNOON...ESPCIALLY FOR THE AREA FROM
PINE/BURNETT COUNTY...NORTHEAST THROUGH THE NORTH SHORE. MODELS
HAVE BEEN FORECASTING SOME LOW LEVEL FGEN IN THIS AREA FOR SEVERAL
RUNS...AND ALL MODELS HAVE THEIR HIGHEST QPF IN THIS AREA.
WE ALSO ADDED FOG TO THE FORECAST...AS MANY AREAS ARE SEEING VSBYS
DOWN TO 1 TO 3 MILES.
&&
.PREV DISCUSSION... /ISSUED 643 AM CST SUN NOV 22 2009/
UPDATE...
AREAS OF DRIZZLE AND A SLIGHT CHANCE OF RAIN HAS BEEN INCLUDED FOR
NORTHWESTERN WISCONSIN FOR THIS MORNING.
DISCUSSION...
LOW LEVEL MOISTURE HAS MOVED INTO THE AREA...RESULTING IN A LOW
STRATUS DECK. THE MOISTURE WILL DEEPEN...REACHING THE 750 MB OR
800 MB LEVEL FOR AREAS AROUND...EAST AND SOUTH OF BAYFIELD
PENINSULA BY NOON TODAY...THIS DEPTH IS SUFFICIENT FOR AREAS OF
DRIZZLE AND EVEN A SLIGHT CHANCE A LIGHT WETTING RAIN.
PREV DISCUSSION... /ISSUED 602 AM CST SUN NOV 22 2009/
UPDATE...FOR 12Z TAF ISSUANCE...SEE DISCUSSION BELOW
AVIATION...12Z TAF ISSUANCE...LOW MVFR/HIGH IFR CIGS WITH VSBYS
IN THE 4-6SM RANGE WILL PERSIST THROUGH THE MORNING AND INTO THE
EARLY AFTERNOON. KINL WILL SEE MVFR CIGS IN THE 1800-2800 FT RANGE
BEFORE GOING SCATTERED THIS MORNING...AND KBRD WILL SCATTER OUT
SOONER AS A COLD FRONT AND DRIER AIR APPROACH. THIS FRONT WILL
ATTEMPT TO PUSH EAST BUT STALLS...SO SOME UNCERTAINLY LIES IN
WHETHER KHIB/KDLH LOSE THE MVFR CIGS. IF SO...THERE MAY STILL BE MVFR
VSBYS.
BEST CHANCE FOR -RA/-DZ TODAY WILL BE IN NW WISC WHERE THE BEST
ISENTROPIC LIFT EXISTS...EXTENDING UP THE NORTH SHORE.
COLD/OCCLUDED FRONT WILL THEN STALL AND LIFT NORTHWARD OVERNIGHT.
PRECIP CHANCES WILL INCREASE FROM SOUTH TO NORTH WITH IFR
CONDITIONS LIKELY FROM KDLH SOUTH...WITH THESE CONDITIONS PUSHING
FURTHER NORTH AFTER THIS TAF SET.
PREV DISCUSSION... /ISSUED 323 AM CST SUN NOV 22 2009/
DISCUSSION...
TODAY...SOUTH WINDS BEHIND HIGH PRESSURE WILL BE MITIGATED BY THE
APPROACH OF A WEAKENING TROUGH...NOW OVER THE RED RIVER VALLEY. A
STRATOCUMULUS DECK HAS OVERSPREAD THE AREA...MODELS INCLUDING THE
LAV...SUGGEST THE SUDDEN APPEARANCE OF A LOW DECK AND EVEN SOME
FOG. WE SEE NO EVIDENCE OF THAT. ANY RAIN IS DOUBTFUL TODAY...THE
MODELS CONCUR WITH THAT. WE LEFT A SLIGHT CHANCE OF LIGHT RAIN OR
DRIZZLE AROUND SHORELINE AREAS THIS AFTERNOON. AN INVERTED TROUGH
DEVELOPS OVER THE AREA...WITH MORE OF A POSSIBILITY OF RAIN
TONIGHT. A WEAKENING SHORT WAVE...ALOFT...OVER THE NORTHWEST WILL
BECOME SEPARATED FROM THE NORTHERN BRANCH...STALL OVER IOWA ON
MONDAY...AND ANCHOR THE INVERTED TROUGH OVER OUR AREA MONDAY AND
TUESDAY...RESULTING IN MORE CLOUDS AND PERHAPS LIGHT RAIN OVER OUR
AREA THROUGH TUESDAY. THE COLUMN WILL REMAIN TOO WARM FOR ANY SNOW
OR WINTRY MIX.
EXTENDED...TUESDAY NIGHT THROUGH FRIDAY...
THE MODELS ARE COMING INTO BETTER AGREEMENT REGARDING THE
EVOLUTION OF CLIPPER SYSTEM ON THE HEELS OF A DEPARTING CLOSED
UPPER LEVEL CIRCULATION TO THE SOUTH AND ASSOCIATED INVERTED
TROUGH...BUT STILL SOME NOTICEABLE DIFFERENCES.
ALL THE MODELS DIG A 130+ KNOT UPPER LEVEL JET INTO THE NORTHERN AND
CENTRAL PLAINS ON WEDNESDAY. THE GFS PUSHES THE UPPER LOW INTO NW
MINNESOTA BEFORE PUSHING IT SOUTH. BOTH MODELS SUGGEST PRECIP WILL
BREAK OUT IN OUR NW ZONES BY 12Z...BUT FOR DIFFERENT REASONS. THE
GFS BRINGS THE MID LEVEL VORT INTO NW MN...WITH THE ASSOCIATED
SURFACE COLD FRONT THROUGH NE MN. THE NAM...AT THE END OF ITS 84HR
RUN...SUPPORTS THIS IDEA. IT HAS SOME QG FORCING FURTHER NORTH INTO
OUR NW ZONES. THE EURO AND ITS ASSOCIATED QG FORCING IS FURTHER WEST
AND SOUTH...AND IT DRAGS THE COLD FRONT SOUTHWEST. BUT...IT HAS THE
INVERTED TROUGH AXIS POINTED TO THIS SAME AREA FROM THE PREVIOUS
SYSTEM. EITHER WAY...WE HAVE INCREASED POPS ACCORDINGLY IN THE
NW...AND KEPT HIGHER CHC POPS IN OUR SE ZONES WITH DEPARTING
INVERTED TROUGH AXIS. ALL RAIN IN NW WISC BEFORE 12Z WITH 925 TEMPS
1-3 C EVEN WITH THE COLDER GFS. WITH UNCERTAINTY ON LONG RANGE TEMP
FCSTS...HAVE NOT CHANGED TEMPS TOO MUCH...AND HAVE CONTINUED TO LEAN
MORE TOWARDS THE EURO/GEM AT THIS TIME. THOUGH GIVE SOME CREDIT TO
THE GFS THAT THE EURO/GEM HAVE BEEN COMING MORE IN LINE WITH THE
PROGRESSIVE GFS FOR THE SYSTEM EARLIER IN THE WEEK. THE GFS IS
COLDER WITH ITS INITIAL MORE PROGRESSIVE NATURE...AND SUPPORTS ALL
SNOW IN THE NW. THE 12Z/0Z EURO ARE WARMER AND SOUNDINGS WOULD
SUGGEST A RAIN/SNOW MIX. WE HAVE KEPT THE RAIN/SNOW MIX MENTION FOR
WEDNESDAY MORNING EVERYWHERE...WITH SNOW BECOMING MORE DOMINANT IN
THE NORTH AND WEST WEDNESDAY AFTERNOON...RAIN/SNOW MORE SO EAST...THOUGH
IF THE GFS PANS OUT...SNOW WILL BE THE DOMINANT P TYPE
EVERYWHERE...ESPECIALLY IN THE AFTERNOON.
THINGS WILL BEGIN TO WIND DOWN ELSEWHERE WEDNESDAY NIGHT AS MODELS
AGREE ON DROPPING UPPER LOW AND ASSOCIATED FORCING SOUTH. DEPENDING
ON HOW THINGS PAN OUT WILL DETERMINE THE LAKE EFFECT SNOW POTENTIAL
FOR WEDS NIGHT/THURSDAY. GFS FAVORS A GOOD NNW TRAJECTORY...DELTA
T`S NEAR 13-14 C AT 850...AND SUFFICIENT LOW LEVEL AND 850-700 RH
THROUGH THURSDAY. THE EURO HAS MORE OF A NE FLOW BUT SIMILIAR
CONDITIONS OTHERWISE...ALBEIT SLIGHTLY WARMER. THIS WOULD FAVOR
SIMILIAR AREA THOUGH FROM A DIFFERENT TRAJECTORY AND LONGER FETCH.
RIDGING WILL BUILD IN THURSDAY NIGHT INTO FRIDAY WHICH WILL MEAN A
CHILLY NIGHT THURSDAY NIGHT AND THEN A QUICK REBOUND TO WARMER AND
DRIER WEATHER FOR THE HOLIDAY WEEKEND. IN A LONGER OUTLOOK...COLDER
WEATHER APPEARS TO BE ON THE HORIZON FOR THE START OF
DECEMBER...WITH THE GFS BRINGING DOWN SOME POLAR/ARCTIC AIR. THE
EUROPEAN IS NOT SO BOLD BUT HINTING AT THIS IDEA. SEE THE DAY 8-14
CPC OUTLOOK FOR ADDITIONAL INFO.
AVIATION...11/22/06Z ISSUANCE...
VFR CIGS EXPECTED THROUGH THE TAF PERIOD. THE EXCEPTION WILL BE
WITH THE FORMATION OF PATCHES OF FOG WHEN CIGS/VSBYS MAY BRIEFLY
DROP INTO THE MVFR RANGE...ESPECIALLY AT KHIB AND KHYR UNTIL 14Z.
&&
.POINT TEMPS/POPS...
DLH 48 40 48 38 / 40 60 30 30
INL 49 33 46 35 / 10 10 40 60
BRD 49 39 48 37 / 20 30 50 60
HYR 50 42 52 38 / 30 40 20 10
ASX 50 42 51 38 / 30 40 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
MELDE/GRANING
000
FXUS63 KDLH 221243 AAA
AFDDLH
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
643 AM CST SUN NOV 22 2009
.UPDATE...
AREAS OF DRIZZLE AND A SLIGHT CHANCE OF RAIN HAS BEEN INCLUDED FOR
NORTHWESTERN WISCONSIN FOR THIS MORNING.
.DISCUSSION...
LOW LEVEL MOISTURE HAS MOVED INTO THE AREA...RESULTING IN A LOW
STRATUS DECK. THE MOISTURE WILL DEEPEN...REACHING THE 750 MB OR
800 MB LEVEL FOR AREAS AROUND...EAST AND SOUTH OF BAYFIELD
PENINSULA BY NOON TODAY...THIS DEPTH IS SUFFICIENT FOR AREAS OF
DRIZZLE AND EVEN A SLIGHT CHANCE A LIGHT WETTING RAIN.
&&
.PREV DISCUSSION... /ISSUED 602 AM CST SUN NOV 22 2009/
UPDATE...FOR 12Z TAF ISSUANCE...SEE DISCUSSION BELOW
AVIATION...12Z TAF ISSUANCE...LOW MVFR/HIGH IFR CIGS WITH VSBYS
IN THE 4-6SM RANGE WILL PERSIST THROUGH THE MORNING AND INTO THE
EARLY AFTERNOON. KINL WILL SEE MVFR CIGS IN THE 1800-2800 FT RANGE
BEFORE GOING SCATTERED THIS MORNING...AND KBRD WILL SCATTER OUT
SOONER AS A COLD FRONT AND DRIER AIR APPROACH. THIS FRONT WILL
ATTEMPT TO PUSH EAST BUT STALLS...SO SOME UNCERTAINLY LIES IN
WHETHER KHIB/KDLH LOSE THE MVFR CIGS. IF SO...THERE MAY STILL BE MVFR
VSBYS.
BEST CHANCE FOR -RA/-DZ TODAY WILL BE IN NW WISC WHERE THE BEST
ISENTROPIC LIFT EXISTS...EXTENDING UP THE NORTH SHORE.
COLD/OCCLUDED FRONT WILL THEN STALL AND LIFT NORTHWARD OVERNIGHT.
PRECIP CHANCES WILL INCREASE FROM SOUTH TO NORTH WITH IFR
CONDITIONS LIKELY FROM KDLH SOUTH...WITH THESE CONDITIONS PUSHING
FURTHER NORTH AFTER THIS TAF SET.
PREV DISCUSSION... /ISSUED 323 AM CST SUN NOV 22 2009/
DISCUSSION...
TODAY...SOUTH WINDS BEHIND HIGH PRESSURE WILL BE MITIGATED BY THE
APPROACH OF A WEAKENING TROUGH...NOW OVER THE RED RIVER VALLEY. A
STRATOCUMULUS DECK HAS OVERSPREAD THE AREA...MODELS INCLUDING THE
LAV...SUGGEST THE SUDDEN APPEARANCE OF A LOW DECK AND EVEN SOME
FOG. WE SEE NO EVIDENCE OF THAT. ANY RAIN IS DOUBTFUL TODAY...THE
MODELS CONCUR WITH THAT. WE LEFT A SLIGHT CHANCE OF LIGHT RAIN OR
DRIZZLE AROUND SHORELINE AREAS THIS AFTERNOON. AN INVERTED TROUGH
DEVELOPS OVER THE AREA...WITH MORE OF A POSSIBILITY OF RAIN
TONIGHT. A WEAKENING SHORT WAVE...ALOFT...OVER THE NORTHWEST WILL
BECOME SEPARATED FROM THE NORTHERN BRANCH...STALL OVER IOWA ON
MONDAY...AND ANCHOR THE INVERTED TROUGH OVER OUR AREA MONDAY AND
TUESDAY...RESULTING IN MORE CLOUDS AND PERHAPS LIGHT RAIN OVER OUR
AREA THROUGH TUESDAY. THE COLUMN WILL REMAIN TOO WARM FOR ANY SNOW
OR WINTRY MIX.
EXTENDED...TUESDAY NIGHT THROUGH FRIDAY...
THE MODELS ARE COMING INTO BETTER AGREEMENT REGARDING THE
EVOLUTION OF CLIPPER SYSTEM ON THE HEELS OF A DEPARTING CLOSED
UPPER LEVEL CIRCULATION TO THE SOUTH AND ASSOCIATED INVERTED
TROUGH...BUT STILL SOME NOTICEABLE DIFFERENCES.
ALL THE MODELS DIG A 130+ KNOT UPPER LEVEL JET INTO THE NORTHERN AND
CENTRAL PLAINS ON WEDNESDAY. THE GFS PUSHES THE UPPER LOW INTO NW
MINNESOTA BEFORE PUSHING IT SOUTH. BOTH MODELS SUGGEST PRECIP WILL
BREAK OUT IN OUR NW ZONES BY 12Z...BUT FOR DIFFERENT REASONS. THE
GFS BRINGS THE MID LEVEL VORT INTO NW MN...WITH THE ASSOCIATED
SURFACE COLD FRONT THROUGH NE MN. THE NAM...AT THE END OF ITS 84HR
RUN...SUPPORTS THIS IDEA. IT HAS SOME QG FORCING FURTHER NORTH INTO
OUR NW ZONES. THE EURO AND ITS ASSOCIATED QG FORCING IS FURTHER WEST
AND SOUTH...AND IT DRAGS THE COLD FRONT SOUTHWEST. BUT...IT HAS THE
INVERTED TROUGH AXIS POINTED TO THIS SAME AREA FROM THE PREVIOUS
SYSTEM. EITHER WAY...WE HAVE INCREASED POPS ACCORDINGLY IN THE
NW...AND KEPT HIGHER CHC POPS IN OUR SE ZONES WITH DEPARTING
INVERTED TROUGH AXIS. ALL RAIN IN NW WISC BEFORE 12Z WITH 925 TEMPS
1-3 C EVEN WITH THE COLDER GFS. WITH UNCERTAINTY ON LONG RANGE TEMP
FCSTS...HAVE NOT CHANGED TEMPS TOO MUCH...AND HAVE CONTINUED TO LEAN
MORE TOWARDS THE EURO/GEM AT THIS TIME. THOUGH GIVE SOME CREDIT TO
THE GFS THAT THE EURO/GEM HAVE BEEN COMING MORE IN LINE WITH THE
PROGRESSIVE GFS FOR THE SYSTEM EARLIER IN THE WEEK. THE GFS IS
COLDER WITH ITS INITIAL MORE PROGRESSIVE NATURE...AND SUPPORTS ALL
SNOW IN THE NW. THE 12Z/0Z EURO ARE WARMER AND SOUNDINGS WOULD
SUGGEST A RAIN/SNOW MIX. WE HAVE KEPT THE RAIN/SNOW MIX MENTION FOR
WEDNESDAY MORNING EVERYWHERE...WITH SNOW BECOMING MORE DOMINANT IN
THE NORTH AND WEST WEDNESDAY AFTERNOON...RAIN/SNOW MORE SO EAST...THOUGH
IF THE GFS PANS OUT...SNOW WILL BE THE DOMINANT P TYPE
EVERYWHERE...ESPECIALLY IN THE AFTERNOON.
THINGS WILL BEGIN TO WIND DOWN ELSEWHERE WEDNESDAY NIGHT AS MODELS
AGREE ON DROPPING UPPER LOW AND ASSOCIATED FORCING SOUTH. DEPENDING
ON HOW THINGS PAN OUT WILL DETERMINE THE LAKE EFFECT SNOW POTENTIAL
FOR WEDS NIGHT/THURSDAY. GFS FAVORS A GOOD NNW TRAJECTORY...DELTA
T`S NEAR 13-14 C AT 850...AND SUFFICIENT LOW LEVEL AND 850-700 RH
THROUGH THURSDAY. THE EURO HAS MORE OF A NE FLOW BUT SIMILIAR
CONDITIONS OTHERWISE...ALBEIT SLIGHTLY WARMER. THIS WOULD FAVOR
SIMILIAR AREA THOUGH FROM A DIFFERENT TRAJECTORY AND LONGER FETCH.
RIDGING WILL BUILD IN THURSDAY NIGHT INTO FRIDAY WHICH WILL MEAN A
CHILLY NIGHT THURSDAY NIGHT AND THEN A QUICK REBOUND TO WARMER AND
DRIER WEATHER FOR THE HOLIDAY WEEKEND. IN A LONGER OUTLOOK...COLDER
WEATHER APPEARS TO BE ON THE HORIZON FOR THE START OF
DECEMBER...WITH THE GFS BRINGING DOWN SOME POLAR/ARCTIC AIR. THE
EUROPEAN IS NOT SO BOLD BUT HINTING AT THIS IDEA. SEE THE DAY 8-14
CPC OUTLOOK FOR ADDITIONAL INFO.
AVIATION...11/22/06Z ISSUANCE...
VFR CIGS EXPECTED THROUGH THE TAF PERIOD. THE EXCEPTION WILL BE
WITH THE FORMATION OF PATCHES OF FOG WHEN CIGS/VSBYS MAY BRIEFLY
DROP INTO THE MVFR RANGE...ESPECIALLY AT KHIB AND KHYR UNTIL 14Z.
&&
.POINT TEMPS/POPS...
DLH 50 40 48 38 / 20 50 30 30
INL 49 33 46 35 / 10 10 40 60
BRD 51 39 48 37 / 10 30 50 60
HYR 54 42 52 38 / 20 30 20 10
ASX 53 42 51 38 / 20 30 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
EOM/DONOFRIO
000
FXUS63 KDLH 221202 AAA
AFDDLH
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
602 AM CST SUN NOV 22 2009
.UPDATE...FOR 12Z TAF ISSUANCE...SEE DISCUSSION BELOW
&&
.AVIATION...12Z TAF ISSUANCE...LOW MVFR/HIGH IFR CIGS WITH VSBYS
IN THE 4-6SM RANGE WILL PERSIST THROUGH THE MORNING AND INTO THE
EARLY AFTERNOON. KINL WILL SEE MVFR CIGS IN THE 1800-2800 FT RANGE
BEFORE GOING SCATTERED THIS MORNING...AND KBRD WILL SCATTER OUT
SOONER AS A COLD FRONT AND DRIER AIR APPROACH. THIS FRONT WILL
ATTEMPT TO PUSH EAST BUT STALLS...SO SOME UNCERTAINLY LIES IN
WHETHER KHIB/KDLH LOSE THE MVFR CIGS. IF SO...THERE MAY STILL BE MVFR
VSBYS.
BEST CHANCE FOR -RA/-DZ TODAY WILL BE IN NW WISC WHERE THE BEST
ISENTROPIC LIFT EXISTS...EXTENDING UP THE NORTH SHORE.
COLD/OCCLUDED FRONT WILL THEN STALL AND LIFT NORTHWARD OVERNIGHT.
PRECIP CHANCES WILL INCREASE FROM SOUTH TO NORTH WITH IFR
CONDITIONS LIKELY FROM KDLH SOUTH...WITH THESE CONDITIONS PUSHING
FURTHER NORTH AFTER THIS TAF SET.
&&
.PREV DISCUSSION... /ISSUED 323 AM CST SUN NOV 22 2009/
DISCUSSION...
TODAY...SOUTH WINDS BEHIND HIGH PRESSURE WILL BE MITIGATED BY THE
APPROACH OF A WEAKENING TROUGH...NOW OVER THE RED RIVER VALLEY. A
STRATOCUMULUS DECK HAS OVERSPREAD THE AREA...MODELS INCLUDING THE
LAV...SUGGEST THE SUDDEN APPEARANCE OF A LOW DECK AND EVEN SOME
FOG. WE SEE NO EVIDENCE OF THAT. ANY RAIN IS DOUBTFUL TODAY...THE
MODELS CONCUR WITH THAT. WE LEFT A SLIGHT CHANCE OF LIGHT RAIN OR
DRIZZLE AROUND SHORELINE AREAS THIS AFTERNOON. AN INVERTED TROUGH
DEVELOPS OVER THE AREA...WITH MORE OF A POSSIBILITY OF RAIN
TONIGHT. A WEAKENING SHORT WAVE...ALOFT...OVER THE NORTHWEST WILL
BECOME SEPARATED FROM THE NORTHERN BRANCH...STALL OVER IOWA ON
MONDAY...AND ANCHOR THE INVERTED TROUGH OVER OUR AREA MONDAY AND
TUESDAY...RESULTING IN MORE CLOUDS AND PERHAPS LIGHT RAIN OVER OUR
AREA THROUGH TUESDAY. THE COLUMN WILL REMAIN TOO WARM FOR ANY SNOW
OR WINTRY MIX.
EXTENDED...TUESDAY NIGHT THROUGH FRIDAY...
THE MODELS ARE COMING INTO BETTER AGREEMENT REGARDING THE
EVOLUTION OF CLIPPER SYSTEM ON THE HEELS OF A DEPARTING CLOSED
UPPER LEVEL CIRCULATION TO THE SOUTH AND ASSOCIATED INVERTED
TROUGH...BUT STILL SOME NOTICEABLE DIFFERENCES.
ALL THE MODELS DIG A 130+ KNOT UPPER LEVEL JET INTO THE NORTHERN AND
CENTRAL PLAINS ON WEDNESDAY. THE GFS PUSHES THE UPPER LOW INTO NW
MINNESOTA BEFORE PUSHING IT SOUTH. BOTH MODELS SUGGEST PRECIP WILL
BREAK OUT IN OUR NW ZONES BY 12Z...BUT FOR DIFFERENT REASONS. THE
GFS BRINGS THE MID LEVEL VORT INTO NW MN...WITH THE ASSOCIATED
SURFACE COLD FRONT THROUGH NE MN. THE NAM...AT THE END OF ITS 84HR
RUN...SUPPORTS THIS IDEA. IT HAS SOME QG FORCING FURTHER NORTH INTO
OUR NW ZONES. THE EURO AND ITS ASSOCIATED QG FORCING IS FURTHER WEST
AND SOUTH...AND IT DRAGS THE COLD FRONT SOUTHWEST. BUT...IT HAS THE
INVERTED TROUGH AXIS POINTED TO THIS SAME AREA FROM THE PREVIOUS
SYSTEM. EITHER WAY...WE HAVE INCREASED POPS ACCORDINGLY IN THE
NW...AND KEPT HIGHER CHC POPS IN OUR SE ZONES WITH DEPARTING
INVERTED TROUGH AXIS. ALL RAIN IN NW WISC BEFORE 12Z WITH 925 TEMPS
1-3 C EVEN WITH THE COLDER GFS. WITH UNCERTAINTY ON LONG RANGE TEMP
FCSTS...HAVE NOT CHANGED TEMPS TOO MUCH...AND HAVE CONTINUED TO LEAN
MORE TOWARDS THE EURO/GEM AT THIS TIME. THOUGH GIVE SOME CREDIT TO
THE GFS THAT THE EURO/GEM HAVE BEEN COMING MORE IN LINE WITH THE
PROGRESSIVE GFS FOR THE SYSTEM EARLIER IN THE WEEK. THE GFS IS
COLDER WITH ITS INITIAL MORE PROGRESSIVE NATURE...AND SUPPORTS ALL
SNOW IN THE NW. THE 12Z/0Z EURO ARE WARMER AND SOUNDINGS WOULD
SUGGEST A RAIN/SNOW MIX. WE HAVE KEPT THE RAIN/SNOW MIX MENTION FOR
WEDNESDAY MORNING EVERYWHERE...WITH SNOW BECOMING MORE DOMINANT IN
THE NORTH AND WEST WEDNESDAY AFTERNOON...RAIN/SNOW MORE SO EAST...THOUGH
IF THE GFS PANS OUT...SNOW WILL BE THE DOMINANT P TYPE
EVERYWHERE...ESPECIALLY IN THE AFTERNOON.
THINGS WILL BEGIN TO WIND DOWN ELSEWHERE WEDNESDAY NIGHT AS MODELS
AGREE ON DROPPING UPPER LOW AND ASSOCIATED FORCING SOUTH. DEPENDING
ON HOW THINGS PAN OUT WILL DETERMINE THE LAKE EFFECT SNOW POTENTIAL
FOR WEDS NIGHT/THURSDAY. GFS FAVORS A GOOD NNW TRAJECTORY...DELTA
T`S NEAR 13-14 C AT 850...AND SUFFICIENT LOW LEVEL AND 850-700 RH
THROUGH THURSDAY. THE EURO HAS MORE OF A NE FLOW BUT SIMILIAR
CONDITIONS OTHERWISE...ALBEIT SLIGHTLY WARMER. THIS WOULD FAVOR
SIMILIAR AREA THOUGH FROM A DIFFERENT TRAJECTORY AND LONGER FETCH.
RIDGING WILL BUILD IN THURSDAY NIGHT INTO FRIDAY WHICH WILL MEAN A
CHILLY NIGHT THURSDAY NIGHT AND THEN A QUICK REBOUND TO WARMER AND
DRIER WEATHER FOR THE HOLIDAY WEEKEND. IN A LONGER OUTLOOK...COLDER
WEATHER APPEARS TO BE ON THE HORIZON FOR THE START OF
DECEMBER...WITH THE GFS BRINGING DOWN SOME POLAR/ARCTIC AIR. THE
EUROPEAN IS NOT SO BOLD BUT HINTING AT THIS IDEA. SEE THE DAY 8-14
CPC OUTLOOK FOR ADDITIONAL INFO.
AVIATION...11/22/06Z ISSUANCE...
VFR CIGS EXPECTED THROUGH THE TAF PERIOD. THE EXCEPTION WILL BE
WITH THE FORMATION OF PATCHES OF FOG WHEN CIGS/VSBYS MAY BRIEFLY
DROP INTO THE MVFR RANGE...ESPECIALLY AT KHIB AND KHYR UNTIL 14Z.
&&
.POINT TEMPS/POPS...
DLH 50 40 48 38 / 20 50 30 30
INL 49 33 46 35 / 10 10 40 60
BRD 51 39 48 37 / 10 30 50 60
HYR 54 42 52 38 / 10 30 20 10
ASX 53 42 51 38 / 20 30 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM: EOM
LONG TERM/AVIATION: DONOFRIO
000
FXUS63 KMPX 221159
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
559 AM CST SUN NOV 22 2009
.UPDATE...
ADDED 12Z TAF DISCUSSION BELOW.
&&
.DISCUSSION...
CWA SITS UNDER AREA OF STRONG WAA ADVECTION THIS MORNING...AS
EVIDENCED BY TEMPS AT 4 AM ALREADY CLIMBING THROUGH THE 40S. THIS
IS ALL IN RESPONSE TO RATHER BROAD...BUT WEAKENING H5 TROUGH
ENTERING THE HIGH PLAINS THIS MORNING. ISENTROPIC ASCENT
OVERSPREADING AREA OVERNIGHT HAS RESULTED IN BLANKET OF STRATUS
THIS MORNING. THERE ARE ALSO SOME LIGHT RETURNS ON RADAR OVER
W CENTRAL WI. NAM 290K SFC HAS DONE WELL WITH DEPICTING THIS AREA
OF SPRINKLES/DRIZZLE THIS MORNING AND EXPECT IT TO IMPACT WI
PORTION OF CWA EARLY ON BEFORE LIFTING NE TOWARD LK SUPERIOR.
AFTER THAT...HAVE TO WAIT UNTIL AFTER 00Z TONIGHT BEFORE ATMO
COLUMN BEGINS TO MOISTEN ENOUGH TO START SEEING RAIN...SO EXPECT A
MAINLY DRY...BUT MOSTLY CLOUDY AFTERNOON. DESPITE CLOUDS...STRONG
WAA THROUGHOUT THE DAY WILL STILL ALLOW HIGHS TO SNEAK INTO THE
LOW 50S ONCE AGAIN...WHICH IS A NICE BLEND BETWEEN THE GENERALLY
WARMER MAV AND COOLER MET.
FOR TONIGHT...EXPECT RAIN CHANCES TO SLOWLY INCREASE THROUGH THE
NIGHT...ESPECIALLY AFTER 06Z AS THE SHORTWAVE AND RIGHT ENTRANCE
REGION OF UPPER JET MOVE ACROSS AREA. TO GO ALONG WITH
THIS...NAM/GFS BOTH RAPIDLY DECREASING COND PRESSURE DEFICITS ON
THETA SFCS...WHICH WILL FINALLY ALLOW FOR ATMO TO MOISTEN. EXPECT
FRONT CURRENTLY OVER THE ERN DAKOTAS TO STALL OUT ABOUT HALF WAY
ACROSS CWA. THIS WILL HELP FOCUS LOW RAIN CHANCES ALONG AND EAST
OF IT TONIGHT. WITH CLOUD COVER AND CONTINUED WAA PROGGED FOR
TONIGHT...ALSO INCREASED MIN TEMPS A FEW DEGREES.
MORE ACTIVE PATTERN THEN SETS IN FROM MONDAY ALL THE WAY TO THE
THANKSGIVING HOLIDAY. FOR THIS PERIOD...STAYED CLOSE TO THE
ECMWF/NAM SOLUTIONS DUE TO THEIR BETTER RUN TO RUN CONSISTENCY...
THOUGH THE GEM/GFS WITH THE 22.00Z RUNS WERE COMING MORE IN LINE
WITH THE ECMWF AND WERE ONLY A LITTLE FASTER WITH PULLING PRECIP
CHANCES OUT OF THE AREA WEDNESDAY NIGHT. FOR THIS PERIOD...FIRST
WAVE CURRENTLY COMING ONSHORE IN THE PAC NW WILL MOVE INTO THE
NRN HIGH PLAINS MONDAY...AND IS PROGGED TO DEEPEN....WITH A CLOSED
H5 LOW FORMING OVER NE/KS MONDAY NIGHT. SFC CYCLONE WILL DEVELOP
OVER SE NE IN RESPONSE TO THIS...TAKING WHAT IS LEFT OF THE FRONT
OVER WRN MN AND TURNING IT INTO AN INVERTED TROUGH. WILL SEE RAIN
CHANCES INCREASE MONDAY NIGHT ACROSS WRN MN ALONG AND EAST OF THIS
TROUGH. THESE FEATURES WILL SLOWLY SLIDE EAST TUESDAY...REACHING
LK MICHIGAN BY 00Z WEDNESDAY. THIS HAS RESULTED IN BEST POPS
OCCURRING TUESDAY AS THE SFC LOW PASSES ACROSS IA. INVERTED TROUGH
WILL WEAKEN SOME DURING THE DAY TUESDAY...WITH QG FORCING BECOMING
FOCUSED CLOSE TO THE IA LOW. WILL LIKELY RESULT IN BEST RAIN
CHANCES TRANSITIONING FROM WRN MN TUESDAY MORNING TO ACROSS THE
SOUTH DURING THE DAY.
THE COMPLICATING FACTOR WITH ALL OF THIS WILL THEN BE THE NEXT
WAVE COMING DOWN IN NW FLOW BEHIND TUESDAYS SYSTEM. BLEND OF
ECMWF/GFS/GEM SHOWS STRONG/DEEPENING WAVE COMING DOWN FROM ALBERTA
WEDNESDAY...MERGING WITH AND INTENSIFYING THE FIRST WAVE OVER THE
GREAT LAKES WEDNESDAY NIGHT. THIS WAVE WILL BRING A STRONG PUSH
OF COLD AIR WITH IT...ENOUGH TO START TURNING PRECIP OVER TO SNOW
OR A MIX TUESDAY NIGHT/WEDNESDAY. WITH THIS SECOND WAVE MERGING
INTO BACK SIDE OF THE FIRST...PATTERN MOMENTARILY STALLS
OUT...KEEPING DEFORMATION AND CYCLONIC FLOW GOING ACROSS ERN CWA
WEDNESDAY/NIGHT. ECMWF/GEM/GFS ALL HINTING AT POSSIBILITY OF SNOW
ACROSS ERN MN WI FOR THE BUSY TRAVEL DAY/NIGHT BEFORE
THANKSGIVING. WITH AS WARM AS NOVEMBER HAS BEEN...GROUND
TEMPERATURES ARE STILL VERY WARM FOR THE TIME OF YEAR...BUT GIVEN
THE AMOUNT OF TRAVELERS OUT AND ABOUT THIS TIME PERIOD THIS WILL
BE SOMETHING TO WATCH WITH FUTURE MODEL RUNS.
LAST PROBLEM WITH ALL OF THIS WILL BE TEMPERATURES. DID NOT MAKE
MANY CHANGES TO HIGHS THROUGH THE PERIOD...BUT GIVEN AMOUNT OF
CLOUD COVER AND WARM AIR EXPECTED TO BE AROUND...ALONG WITH
SLIGHTLY SLOWER PROGRESSION OF FEATURES...DID INCREASE LOWS
MONDAY/TUESDAY NIGHT ACROSS ENTIRE AREA AND WEDNESDAY NIGHT ACROSS
MAINLY WIS. OVER THE NEXT WEEK...THURSDAY STILL LOOKS TO BE THE
COLDEST DAY...WITH GFS/ECMWF PROGGING H85 TEMPS TO BE AROUND
-6C...BUT BY FRIDAY WAA IS EXPECTED TO SET BACK IN AND
WILL START SEEING A SLIGHT MODERATION IN TEMPS BEGIN BY THE
WEEKEND.
&&
.AVIATION.../12Z TAF ISSUANCE/
A SOMEWHAT COMPLICATED PATTERN THIS PERIOD. MILD AND MOIST SOUTHERLY
FLOW STILL DOMINATES MOST OF THE AREA THIS MORNING WITH MAINLY
MVFR CIGS AFFECTING TAF SITES. ALTHOUGH VFR CONDITIONS HAVE BEEN
MIXED IN. A SFC TROUGH WILL APPROACH THE FORECAST AREA TODAY BUT
STALL OUT..STILL LEAVING A WEAKER SSE FLOW. AREAS OF EAST
CENTRAL MN AND WEST CENTRAL WISCONSIN AND WILL LIKELY IMPROVE TO
VFR WITH WEAKER LOW LEVEL CONV AND LOW LEVEL MOISTURE TRANSPORT
WINDING DOWN AND SHIFTING OFF TO THE NE. MVFR CIGS AND PATCHY IFR
CIGS MAY PERSIST FROM KRWF TO KSTC...WHILE DRIER AIR MOVES INTO
THE KAXN AREA NEAR THE SFC TROF. LOWER CONDITIONS DEVELOP AGAIN
LATE TONIGHT AS LOW PRESSURE STRENGTHENS OVER THE DAKOTAS INTO THE
HIGH PLAINS. AN UPPER LEVEL WAVE AND RENEWED LOW LEVEL MOISTURE
TRANSPORT WILL ALSO APPROACH THE AREA WITH THE CHANCE OF LIGHT
RAIN AND DRIZZLE. EXPECT MVFR CIGS AND VSBYS TO DEVELOP OVER MOST
OF THE AREA WITH IFR POSSIBLE FROM KSTC TO KRWF.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
MPG/JPR
000
FXUS63 KMPX 221023
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
423 AM CST SUN NOV 22 2009
.DISCUSSION...
CWA SITS UNDER AREA OF STRONG WAA ADVECTION THIS MORNING...AS
EVIDENCED BY TEMPS AT 4 AM ALREADY CLIMBING THROUGH THE 40S. THIS
IS ALL IN RESPONSE TO RATHER BROAD...BUT WEAKENING H5 TROUGH
ENTERING THE HIGH PLAINS THIS MORNING. ISENTROPIC ASCENT
OVERSPREADING AREA OVERNIGHT HAS RESULTED IN BLANKET OF STRATUS
THIS MORNING. THERE ARE ALSO SOME LIGHT RETURNS ON RADAR OVER
W CENTRAL WI. NAM 290K SFC HAS DONE WELL WITH DEPICTING THIS AREA
OF SPRINKLES/DRIZZLE THIS MORNING AND EXPECT IT TO IMPACT WI
PORTION OF CWA EARLY ON BEFORE LIFTING NE TOWARD LK SUPERIOR.
AFTER THAT...HAVE TO WAIT UNTIL AFTER 00Z TONIGHT BEFORE ATMO
COLUMN BEGINS TO MOISTEN ENOUGH TO START SEEING RAIN...SO EXPECT A
MAINLY DRY...BUT MOSTLY CLOUDY AFTERNOON. DESPITE CLOUDS...STRONG
WAA THROUGHOUT THE DAY WILL STILL ALLOW HIGHS TO SNEAK INTO THE
LOW 50S ONCE AGAIN...WHICH IS A NICE BLEND BETWEEN THE GENERALLY
WARMER MAV AND COOLER MET.
FOR TONIGHT...EXPECT RAIN CHANCES TO SLOWLY INCREASE THROUGH THE
NIGHT...ESPECIALLY AFTER 06Z AS THE SHORTWAVE AND RIGHT ENTRANCE
REGION OF UPPER JET MOVE ACROSS AREA. TO GO ALONG WITH
THIS...NAM/GFS BOTH RAPIDLY DECREASING COND PRESSURE DEFICITS ON
THETA SFCS...WHICH WILL FINALLY ALLOW FOR ATMO TO MOISTEN. EXPECT
FRONT CURRENTLY OVER THE ERN DAKOTAS TO STALL OUT ABOUT HALF WAY
ACROSS CWA. THIS WILL HELP FOCUS LOW RAIN CHANCES ALONG AND EAST
OF IT TONIGHT. WITH CLOUD COVER AND CONTINUED WAA PROGGED FOR
TONIGHT...ALSO INCREASED MIN TEMPS A FEW DEGREES.
MORE ACTIVE PATTERN THEN SETS IN FROM MONDAY ALL THE WAY TO THE
THANKSGIVING HOLIDAY. FOR THIS PERIOD...STAYED CLOSE TO THE
ECMWF/NAM SOLUTIONS DUE TO THEIR BETTER RUN TO RUN CONSISTENCY...
THOUGH THE GEM/GFS WITH THE 22.00Z RUNS WERE COMING MORE IN LINE
WITH THE ECMWF AND WERE ONLY A LITTLE FASTER WITH PULLING PRECIP
CHANCES OUT OF THE AREA WEDNESDAY NIGHT. FOR THIS PERIOD...FIRST
WAVE CURRENTLY COMING ONSHORE IN THE PAC NW WILL MOVE INTO THE
NRN HIGH PLAINS MONDAY...AND IS PROGGED TO DEEPEN....WITH A CLOSED
H5 LOW FORMING OVER NE/KS MONDAY NIGHT. SFC CYCLONE WILL DEVELOP
OVER SE NE IN RESPONSE TO THIS...TAKING WHAT IS LEFT OF THE FRONT
OVER WRN MN AND TURNING IT INTO AN INVERTED TROUGH. WILL SEE RAIN
CHANCES INCREASE MONDAY NIGHT ACROSS WRN MN ALONG AND EAST OF THIS
TROUGH. THESE FEATURES WILL SLOWLY SLIDE EAST TUESDAY...REACHING
LK MICHIGAN BY 00Z WEDNESDAY. THIS HAS RESULTED IN BEST POPS
OCCURRING TUESDAY AS THE SFC LOW PASSES ACROSS IA. INVERTED TROUGH
WILL WEAKEN SOME DURING THE DAY TUESDAY...WITH QG FORCING BECOMING
FOCUSED CLOSE TO THE IA LOW. WILL LIKELY RESULT IN BEST RAIN
CHANCES TRANSITIONING FROM WRN MN TUESDAY MORNING TO ACROSS THE
SOUTH DURING THE DAY.
THE COMPLICATING FACTOR WITH ALL OF THIS WILL THEN BE THE NEXT
WAVE COMING DOWN IN NW FLOW BEHIND TUESDAYS SYSTEM. BLEND OF
ECMWF/GFS/GEM SHOWS STRONG/DEEPENING WAVE COMING DOWN FROM ALBERTA
WEDNESDAY...MERGING WITH AND INTENSIFYING THE FIRST WAVE OVER THE
GREAT LAKES WEDNESDAY NIGHT. THIS WAVE WILL BRING A STRONG PUSH
OF COLD AIR WITH IT...ENOUGH TO START TURNING PRECIP OVER TO SNOW
OR A MIX TUESDAY NIGHT/WEDNESDAY. WITH THIS SECOND WAVE MERGING
INTO BACK SIDE OF THE FIRST...PATTERN MOMENTARILY STALLS
OUT...KEEPING DEFORMATION AND CYCLONIC FLOW GOING ACROSS ERN CWA
WEDNESDAY/NIGHT. ECMWF/GEM/GFS ALL HINTING AT POSSIBILITY OF SNOW
ACROSS ERN MN WI FOR THE BUSY TRAVEL DAY/NIGHT BEFORE
THANKSGIVING. WITH AS WARM AS NOVEMBER HAS BEEN...GROUND
TEMPERATURES ARE STILL VERY WARM FOR THE TIME OF YEAR...BUT GIVEN
THE AMOUNT OF TRAVELERS OUT AND ABOUT THIS TIME PERIOD THIS WILL
BE SOMETHING TO WATCH WITH FUTURE MODEL RUNS.
LAST PROBLEM WITH ALL OF THIS WILL BE TEMPERATURES. DID NOT MAKE
MANY CHANGES TO HIGHS THROUGH THE PERIOD...BUT GIVEN AMOUNT OF
CLOUD COVER AND WARM AIR EXPECTED TO BE AROUND...ALONG WITH
SLIGHTLY SLOWER PROGRESSION OF FEATURES...DID INCREASE LOWS
MONDAY/TUESDAY NIGHT ACROSS ENTIRE AREA AND WEDNESDAY NIGHT ACROSS
MAINLY WIS. OVER THE NEXT WEEK...THURSDAY STILL LOOKS TO BE THE
COLDEST DAY...WITH GFS/ECMWF PROGGING H85 TEMPS TO BE AROUND
-6C...BUT BY FRIDAY WAA IS EXPECTED TO SET BACK IN AND
WILL START SEEING A SLIGHT MODERATION IN TEMPS BEGIN BY THE
WEEKEND.
&&
.AVIATION.../06Z TAF ISSUANCE/
TREND OF PREVIOUS FCST IS FAIRLY GOOD SHAPE. STILL EXPECT IFR CONDS
TO DEVELOP OVER MUCH OF THE FA AFTER 10Z SUN. LOWER LEVEL RH DOES
SHOW UP ON LOWER ISENTROPIC SURFACES...ESPECIALLY ACROSS THE EAST
AND CENTRAL. SOME -DZ AND BR ASSOCIATED WITH LOWEST CEILINGS
THROUGH 16Z. THEN MODEL DIVERGE SOME ON HOW SIGNIFICANT STRATUS
WILL BE DURING TH DAY. DO EXPECT WEAK SFC TROUGH OVER THE CENTRAL
CWA AND WILL FOCUS LOWER FLYING CONDITIONS THERE. THERE MAY BE SOME
DRYING OVER THE FAR WEST-KAXN AND OVER THE EAST (KRNH AND KEAU)
DURING THE AFTERNOON AS TROUGH BEGINS TO DIG/DEVELOP FARTHER SOUTH.
GFS TRIES AND BREAK IT OUT OVER THESE AREAS DURING THE
AFTERNOON/EVENING. LOW CLOUDS EXPECTED TO DEVELOP AGAIN SUNDAY
NIGHT OVER THE AREA WITH PERHAPS SOME -RA/BR AGAIN. SOUTHEAST TO
SOUTH WINDS AHEAD OF TROUGH PERHAPS BECOMING MORE WEST AT KAXN LATE
IN THE AFTERNOON. WINDS WILL BE LIGHT HOWEVER AS THIS BNDRY STALL
OVER THE FA.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
MPG/DWE
000
FXUS63 KDLH 220923
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
323 AM CST SUN NOV 22 2009
.DISCUSSION...
TODAY...SOUTH WINDS BEHIND HIGH PRESSURE WILL BE MITIGATED BY THE
APPROACH OF A WEAKENING TROUGH...NOW OVER THE RED RIVER VALLEY. A
STRATOCUMULUS DECK HAS OVERSPREAD THE AREA...MODELS INCLUDING THE
LAV...SUGGEST THE SUDDEN APPEARANCE OF A LOW DECK AND EVEN SOME
FOG. WE SEE NO EVIDENCE OF THAT. ANY RAIN IS DOUBTFUL TODAY...THE
MODELS CONCUR WITH THAT. WE LEFT A SLIGHT CHANCE OF LIGHT RAIN OR
DRIZZLE AROUND SHORELINE AREAS THIS AFTERNOON. AN INVERTED TROUGH
DEVELOPS OVER THE AREA...WITH MORE OF A POSSIBILITY OF RAIN
TONIGHT. A WEAKENING SHORT WAVE...ALOFT...OVER THE NORTHWEST WILL
BECOME SEPARATED FROM THE NORTHERN BRANCH...STALL OVER IOWA ON
MONDAY...AND ANCHOR THE INVERTED TROUGH OVER OUR AREA MONDAY AND
TUESDAY...RESULTING IN MORE CLOUDS AND PERHAPS LIGHT RAIN OVER OUR
AREA THROUGH TUESDAY. THE COLUMN WILL REMAIN TOO WARM FOR ANY SNOW
OR WINTRY MIX.
.EXTENDED...TUESDAY NIGHT THROUGH FRIDAY...
THE MODELS ARE COMING INTO BETTER AGREEMENT REGARDING THE
EVOLUTION OF CLIPPER SYSTEM ON THE HEELS OF A DEPARTING CLOSED
UPPER LEVEL CIRCULATION TO THE SOUTH AND ASSOCIATED INVERTED
TROUGH...BUT STILL SOME NOTICEABLE DIFFERENCES.
ALL THE MODELS DIG A 130+ KNOT UPPER LEVEL JET INTO THE NORTHERN AND
CENTRAL PLAINS ON WEDNESDAY. THE GFS PUSHES THE UPPER LOW INTO NW
MINNESOTA BEFORE PUSHING IT SOUTH. BOTH MODELS SUGGEST PRECIP WILL
BREAK OUT IN OUR NW ZONES BY 12Z...BUT FOR DIFFERENT REASONS. THE
GFS BRINGS THE MID LEVEL VORT INTO NW MN...WITH THE ASSOCIATED
SURFACE COLD FRONT THROUGH NE MN. THE NAM...AT THE END OF ITS 84HR
RUN...SUPPORTS THIS IDEA. IT HAS SOME QG FORCING FURTHER NORTH INTO
OUR NW ZONES. THE EURO AND ITS ASSOCIATED QG FORCING IS FURTHER WEST
AND SOUTH...AND IT DRAGS THE COLD FRONT SOUTHWEST. BUT...IT HAS THE
INVERTED TROUGH AXIS POINTED TO THIS SAME AREA FROM THE PREVIOUS
SYSTEM. EITHER WAY...WE HAVE INCREASED POPS ACCORDINGLY IN THE
NW...AND KEPT HIGHER CHC POPS IN OUR SE ZONES WITH DEPARTING
INVERTED TROUGH AXIS. ALL RAIN IN NW WISC BEFORE 12Z WITH 925 TEMPS
1-3 C EVEN WITH THE COLDER GFS. WITH UNCERTAINTY ON LONG RANGE TEMP
FCSTS...HAVE NOT CHANGED TEMPS TOO MUCH...AND HAVE CONTINUED TO LEAN
MORE TOWARDS THE EURO/GEM AT THIS TIME. THOUGH GIVE SOME CREDIT TO
THE GFS THAT THE EURO/GEM HAVE BEEN COMING MORE IN LINE WITH THE
PROGRESSIVE GFS FOR THE SYSTEM EARLIER IN THE WEEK. THE GFS IS
COLDER WITH ITS INITIAL MORE PROGRESSIVE NATURE...AND SUPPORTS ALL
SNOW IN THE NW. THE 12Z/0Z EURO ARE WARMER AND SOUNDINGS WOULD
SUGGEST A RAIN/SNOW MIX. WE HAVE KEPT THE RAIN/SNOW MIX MENTION FOR
WEDNESDAY MORNING EVERYWHERE...WITH SNOW BECOMING MORE DOMINANT IN
THE NORTH AND WEST WEDNESDAY AFTERNOON...RAIN/SNOW MORE SO EAST...THOUGH
IF THE GFS PANS OUT...SNOW WILL BE THE DOMINANT P TYPE
EVERYWHERE...ESPECIALLY IN THE AFTERNOON.
THINGS WILL BEGIN TO WIND DOWN ELSEWHERE WEDNESDAY NIGHT AS MODELS
AGREE ON DROPPING UPPER LOW AND ASSOCIATED FORCING SOUTH. DEPENDING
ON HOW THINGS PAN OUT WILL DETERMINE THE LAKE EFFECT SNOW POTENTIAL
FOR WEDS NIGHT/THURSDAY. GFS FAVORS A GOOD NNW TRAJECTORY...DELTA
T`S NEAR 13-14 C AT 850...AND SUFFICIENT LOW LEVEL AND 850-700 RH
THROUGH THURSDAY. THE EURO HAS MORE OF A NE FLOW BUT SIMILIAR
CONDITIONS OTHERWISE...ALBEIT SLIGHTLY WARMER. THIS WOULD FAVOR
SIMILIAR AREA THOUGH FROM A DIFFERENT TRAJECTORY AND LONGER FETCH.
RIDGING WILL BUILD IN THURSDAY NIGHT INTO FRIDAY WHICH WILL MEAN A
CHILLY NIGHT THURSDAY NIGHT AND THEN A QUICK REBOUND TO WARMER AND
DRIER WEATHER FOR THE HOLIDAY WEEKEND. IN A LONGER OUTLOOK...COLDER
WEATHER APPEARS TO BE ON THE HORIZON FOR THE START OF
DECEMBER...WITH THE GFS BRINGING DOWN SOME POLAR/ARCTIC AIR. THE
EUROPEAN IS NOT SO BOLD BUT HINTING AT THIS IDEA. SEE THE DAY 8-14
CPC OUTLOOK FOR ADDITIONAL INFO.
&&
.AVIATION...11/22/06Z ISSUANCE...
VFR CIGS EXPECTED THROUGH THE TAF PERIOD. THE EXCEPTION WILL BE
WITH THE FORMATION OF PATCHES OF FOG WHEN CIGS/VSBYS MAY BRIEFLY
DROP INTO THE MVFR RANGE...ESPECIALLY AT KHIB AND KHYR UNTIL 14Z.
&&
.POINT TEMPS/POPS...
DLH 50 40 48 38 / 20 50 30 30
INL 49 33 46 35 / 10 10 40 60
BRD 51 39 48 37 / 10 30 50 60
HYR 54 42 52 38 / 10 30 20 10
ASX 53 42 51 38 / 20 30 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
EOM/DONOFRIO
000
FXUS63 KMPX 220540 AAA
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1140 PM CST SAT NOV 21 2009
.UPDATED FOR AVIATION DISCUSSION BELOW...
.DISCUSSION...
LOW LEVEL MOISTURE HAS BEEN ADVANCING NORTH WITH DWPTS ACROSS W IA
INTO E NEB NOW INTO THE LOWER 40S. STRONG SOUTHERLY FLOW WILL
CONTINUE THEIR NWRD EXPANSION. POCKETS OF STRATUS TO OUR SOUTH WILL
EXPAND UNDER COVER OF DARKNESS AS LOW LEVELS MOISTEN. CLOUDS WILL
LIKELY THICKEN ENUF LATE TONIGHT FOR SOME DRIZZLE. SHUD BE ENUF WIND
TO KEEP VISIBILITY FROM BEING SIGNIFICANT IMPACT...BUT DID INTRODUCE
PATCHY FOG INTO FORECAST FOR LATE TONIGHT AND SUNDAY MORNING.
COMBINATION OF CLOUDS...WIND..AND INCREASING DEWPOINTS WILL YIELD
MIN TEMPS ABOUT 10 DEGREES WARMER THAN THIS MORNING.
SOME CONCERN WITH TOMORROWS TEMPERATURES WITH EXPECTED CLOUDS AND
POSSIBLE LIGHT PRECIPITATION. TRIMMMED THEM A BIT..BUT MID SHIFT
WILL HAVE TO TAKE ANOTHER LOOK AT THIS.
UPSTREAM TROF NO MOVING ACROSS W MT INTO THE SW U.S. WILL BECOME A
BIT LESS DEFINED AS IT MOVES EAST AND STRONGER TROF BARRELS OFF
PACIFIC BEHIND IT. TROFFINESS...INCREASING MOISTURE AND WEAK SURFACE
FRONT MOVING INTO AREA WILL BRING SCATTERED LIGHT PRECIPITATION INTO
AREA SUNDAY AND MONDAY.
UPPED POPS FOR MONDAY NIGHT AND TUESDAY MAINLY ACROSS SOUTHERN CWA
AS THIS NEXT SYSTEM DROPS OUT OF THE NORTHERN ROCKIES THEN RATHER
SLOWLY MOVES ACROSS E SODAK AND IOWA. TEMPERATURE PROFILES WOULD
KEEP PRECIP AS ALL RAIN UNTIL A TRANSITION BEGINNING TUESDAY NIGHT.
POSITION OF UPPER JET COMING AROUND BASE OF TROF WOULD PLACE S MN IN
LEFT EXIT REGION OF UPPER JET LATE MONDAY INTO EARLY TUESDAY.
ECMWF NOW LEANING MORE TOWARD GFS SOLUTION OF SECOND TROF DIVING OUT
OF CANADA AND ACROSS SW MN LATE WEDNESDAY...AND BECOMING QUITE
AGGRESSIVE ON QPF OUTPUT. FEEL QPF IS PROBABLY OVERDONE IN THAT
UPPER TROF WILL BE FIGHTING COLD ADVECTION...BUT UPPED POPS SOMEWHAT
FOR THAT PERIOD.
&&
.AVIATION.../06Z TAF ISSUANCE/
TREND OF PREVIOUS FCST IS FAIRLY GOOD SHAPE. STILL EXPECT IFR CONDS
TO DEVELOP OVER MUCH OF THE FA AFTER 10Z SUN. LOWER LEVEL RH DOES
SHOW UP ON LOWER ISENTROPIC SURFACES...ESPECIALLY ACROSS THE EAST
AND CENTRAL. SOME -DZ AND BR ASSOCIATED WITH LOWEST CEILINGS
THROUGH 16Z. THEN MODEL DIVERGE SOME ON HOW SIGNIFICANT STRATUS
WILL BE DURING TH DAY. DO EXPECT WEAK SFC TROUGH OVER THE CENTRAL
CWA AND WILL FOCUS LOWER FLYING CONDITIONS THERE. THERE MAY BE SOME
DRYING OVER THE FAR WEST-KAXN AND OVER THE EAST (KRNH AND KEAU)
DURING THE AFTERNOON AS TROUGH BEGINS TO DIG/DEVELOP FARTHER SOUTH.
GFS TRIES AND BREAK IT OUT OVER THESE AREAS DURING THE
AFTERNOON/EVENING. LOW CLOUDS EXPECTED TO DEVELOP AGAIN SUNDAY
NIGHT OVER THE AREA WITH PERHAPS SOME -RA/BR AGAIN. SOUTHEAST TO
SOUTH WINDS AHEAD OF TROUGH PERHAPS BECOMING MORE WEST AT KAXN LATE
IN THE AFTERNOON. WINDS WILL BE LIGHT HOWEVER AS THIS BNDRY STALL
OVER THE FA.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
BAP/DWE
000
FXUS63 KDLH 220536
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
1136 PM CST SAT NOV 21 2009
.AVIATION...06Z TAFS.
VFR CIGS EXPECTED THROUGH THE TAF PERIOD. THE EXCEPTION WILL BE
WITH THE FORMATION OF PATCHES OF FOG WHEN CIGS/VSBYS MAY BRIEFLY
DROP INTO THE MVFR RANGE...ESPECIALLY AT KHIB AND KHYR UNTIL 14Z.
&&
.PREV DISCUSSION... /ISSUED 855 PM CST SAT NOV 21 2009/
UPDATE...40 KT LLJ IS SURGING MOISTURE/CLOUDS INTO THE FA ATTM.
SOME FOG HAS FORMED IN THE MN ARROWHEAD TO NEAR THE TWIN PORTS
THANKS TO OROGRAPHIC LIFT ALONG THE NORTH SHORE ON SOUTHERLY WIND.
HAVE ADDED A MENTION OF FOG TO ACCOUNT FOR THIS. REMOVED THE
MENTION OF FOG IN THE WESTERN FA AS INL 00Z SOUNDING INDICATES
LACK OF LOW LEVEL MOISTURE FOR FOG FORMATION. ALSO MADE
ADJUSTMENTS TO TEMPS/WIND AND REMOVED DRIZZLE IN SOUTHERN FA AS
00Z NAM INDICATES NO SOURCE OF LIFT AVAILABLE OVERNIGHT.
PREV DISCUSSION... /ISSUED 701 PM CST SAT NOV 21 2009/
AVIATION...00Z TAFS.
VFR CONDITIONS UNTIL 03-04Z WHEN FOG FORMATION IS ONCE AGAIN
POSSIBLE AT KHYR WITH MVFR CIGS/VSBYS. MVFR CIGS MAY ALSO AFFECT
KDLH AND KHIB AS INCREASING LOW LEVEL MOISTURE FROM A
STRENGTHENING LLJ SHOULD BRING THE CLOUDS IN. AN ASSIST MAY ALSO
COME FROM OROGRAPHIC LIFT ALONG THE NORTH SHORE FROM A SOUTHERLY
WIND WHICH MAY SPREAD IFR CONDITIONS TO NEAR KDLH/KHIB THROUGH THE
EVENING.
PREV DISCUSSION... /ISSUED 319 PM CST SAT NOV 21 2009/
DISCUSSION...
THE MODELS ARE IN DECENT AGREEMENT...EACH SHOWING SOME RUN TO RUN
DIFFERENCES. A DT/DPROG OF THE ECMWF AT 84 HOURS SHOWS THE LOW
MOVING A BIT QUICKER...INTO SOUTHEAST IA. A BLEND OF THE MODELS WAS
USED THROUGH TUESDAY.
FOG HAS DISSIPATED THIS AFTERNOON...WITH A FEW STATIONS STILL
REPORTING 4-5SM IN HAZE. OVERALL...SKIES WERE MOSTLY SUNNY...WITH
MORE CLOUDS OVER PORTIONS OF SAWYER/PRICE/ASHLAND/IRON COUNTIES THIS
AFTERNOON.
LOW LEVEL MOISTURE IS FORECAST TO INCREASE RAPIDLY TONIGHT...AS LOW
LEVEL WINDS INCREASE. NAM FORECASTS SOUTHERLY 925MB WINDS OF
40-45KT. CLOUDS HAVE BEEN SURGING NORTH THROUGH MO/EASTERN
NE/EASTERN KS INTO IA THIS AFTERNOON. WE INCREASED CLOUD COVER
TONIGHT FOR ALL AREAS...ESPECIALLY LATE TONIGHT. THERE COULD BE SOME
DRIZZLE OR SPRINKLES LATER TONIGHT OVER A PORTION OF NORTHWEST
WISCONSIN WEST TOWARD PINE COUNTY WITH BETTER MOISTURE AND
ISENTROPIC LIFT IN THIS AREA. WE ADDED PATCHY FOG FOR TONIGHT...AS
LOW LEVEL MOISTURE INCREASES.
MODELS ALSO IN DECENT AGREEMENT WITH PLACING THEIR HIGHEST QPF OVER
THE NORTH SHORE...SOUTHWEST THROUGH THE TWIN PORTS AND PINE COUNTY.
THIS AREA UNDER DEEPER MOISTURE AND SOME LOW LEVEL FGEN. WE HAVE
HIGHEST POPS THERE FOR TOMORROW.
WE INCREASED POPS FOR SUNDAY NIGHT...INTO LIKELY FOR A PORTION OF
OUR EASTERN MINNESOTA ZONES. THE LOW LEVEL INVERTED SHARP SHARPENS
SUNDAY NIGHT...WITH FGEN PRESENT...ESPECIALLY IN THE LOW LEVELS.
PRECIP SHOULD BE RAIN...AS CLOUD COVER WILL KEEP BOUNDARY LAYER
TEMPS ABOVE FREEZING AND 925MB TEMPS OF 3-7C ARE FORECAST OVER OUR
AREA.
AS THE UPPER TROUGH SWINGS IN FROM THE WEST ON MONDAY...THE INVERTED
TROUGH IS FORECAST TO ROTATE TO THE WEST. WE KEYED OUR HIGHER POPS
ON THE INVERTED TROUGH...AND HAVE THEM LIKELY OVER A GOOD PORTION OF
NORTHEAST MINNESOTA.
THE UPPER LOW WILL CLOSE OFF AS IT DIVES ESE TOWARD SOUTHWEST IA BY
12Z TUESDAY...THEN EAST DURING THE DAY TUESDAY. THE INVERTED TROUGH
WEAKENS MONDAY NIGHT INTO TUESDAY...AND WE JUST HAVE CHANCE POPS AT
THIS TIME. THERE IS WEAK ISENTROPIC LIFT PRESENT
TUESDAY...ESPECIALLY OVER SOUTHERN AREAS. WE COULD BE IN FOR A
PERIOD OF DRIZZLE...BUT LEFT JUST A CHANCE FOR LIGHT RAIN ATTM.
EXTENDED...WEDNESDAY THROUGH SATURDAY
BRUSHED SMALL POPS FURTHER INTO WRN ZONES AND INCREASED TO MID/HIGH
CHC FOR ERN ZONES TUES NIGHT THROUGH WED NIGHT. ALSO INCREASED TEMPS
A FEW DEGREES TO ACCOUNT FOR STRONG WAA AND MDLS TRENDING WARMER.
THE GFS/EC STRUGGLING WITH THE STORM TRACK THROUGH LONG TERM AS A
DOUBLE BARREL LOW PATTERN DEVELOPS. THE INITIAL LOW WILL EXITS TO
THE NE WHILE AN ELONGATED MID LVL VORT/100 KT UPR LVL JET DIVES S
OVER THE DAKOTAS DEVELOPING A SECONDARY LOW. THE 12Z GFS SUGGESTS
THE ERN CUT LOW TRACKS NE OVER TORONTO/QUEBEC THROUGH 12Z THURS AS
THE SECONDARY WAVE DIGS OVER THE NRN PLAINS AND DEEPENS INTO A CUT
OFF LOW AT THE BASE OF LK MICHIGAN DURING THIS TIME. MEANWHILE...THE
00Z ECMWF MERGES THE TWO VORTS INTO A BROAD SYSTEM OVER THE ERN GRT
LKS. ALTHOUGH TIMING AND SPECIFIC DETAILS WILL STILL BE WORKED
OUT...BOTH MDLS SHOW SUFFICIENT MOISTURE AND PERSISTENT CYCLONIC
FLOW OVER THE FA THROUGH MID WEEK WITH DEFORMATION ZONE SETTING UP
TUES NIGHT OVER NRN MN THAT COULD POTENTIALLY BRING GREATER QPF OR A
BAND OF SN ACCUMULATION.
AVIATION...
SOUTH WINDS WILL GUST 15-20 KT WITH VFR CIGS THROUGH 00-03Z. BY
06Z...A 40 KT LLJ AROUND 2 KFT WILL SPREAD LOW CLOUDS NWRD OVER
THE FA AHEAD OF AN APPROACHING TROUGH. MVFR CEILINGS AND VSBYS
WILL BECOME WDSPRD AFT 09Z...PERSISTING THROUGH END OF PERIOD. A
FEW -SHRA WILL ALSO BE POSSIBLE SUN...MAINLY ALONG A LINE FROM
KBRD TO KHIB. INTRODUCED LLWS INTO KDLH/KHIB TERMINALS...WHILE
EXPECTING SFC WINDS TO REMAIN HIGHER IN WRN LOCATIONS WHERE
GRADIENT IS BEST.
&&
.POINT TEMPS/POPS...
DLH 37 47 41 44 / 10 40 60 50
INL 33 46 28 41 / 10 10 10 50
BRD 36 49 37 47 / 10 30 50 60
HYR 39 50 42 51 / 10 40 30 30
ASX 39 50 43 49 / 10 40 40 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
GSF/GSF/GSF
000
FXUS63 KDLH 220255
AFDDLH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
855 PM CST SAT NOV 21 2009
.UPDATE...40 KT LLJ IS SURGING MOISTURE/CLOUDS INTO THE FA ATTM.
SOME FOG HAS FORMED IN THE MN ARROWHEAD TO NEAR THE TWIN PORTS
THANKS TO OROGRAPHIC LIFT ALONG THE NORTH SHORE ON SOUTHERLY WIND.
HAVE ADDED A MENTION OF FOG TO ACCOUNT FOR THIS. REMOVED THE
MENTION OF FOG IN THE WESTERN FA AS INL 00Z SOUNDING INDICATES
LACK OF LOW LEVEL MOISTURE FOR FOG FORMATION. ALSO MADE
ADJUSTMENTS TO TEMPS/WIND AND REMOVED DRIZZLE IN SOUTHERN FA AS
00Z NAM INDICATES NO SOURCE OF LIFT AVAILABLE OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 701 PM CST SAT NOV 21 2009/
AVIATION...00Z TAFS.
VFR CONDITIONS UNTIL 03-04Z WHEN FOG FORMATION IS ONCE AGAIN
POSSIBLE AT KHYR WITH MVFR CIGS/VSBYS. MVFR CIGS MAY ALSO AFFECT
KDLH AND KHIB AS INCREASING LOW LEVEL MOISTURE FROM A
STRENGTHENING LLJ SHOULD BRING THE CLOUDS IN. AN ASSIST MAY ALSO
COME FROM OROGRAPHIC LIFT ALONG THE NORTH SHORE FROM A SOUTHERLY
WIND WHICH MAY SPREAD IFR CONDITIONS TO NEAR KDLH/KHIB THROUGH THE
EVENING.
PREV DISCUSSION... /ISSUED 319 PM CST SAT NOV 21 2009/
DISCUSSION...
THE MODELS ARE IN DECENT AGREEMENT...EACH SHOWING SOME RUN TO RUN
DIFFERENCES. A DT/DPROG OF THE ECMWF AT 84 HOURS SHOWS THE LOW
MOVING A BIT QUICKER...INTO SOUTHEAST IA. A BLEND OF THE MODELS WAS
USED THROUGH TUESDAY.
FOG HAS DISSIPATED THIS AFTERNOON...WITH A FEW STATIONS STILL
REPORTING 4-5SM IN HAZE. OVERALL...SKIES WERE MOSTLY SUNNY...WITH
MORE CLOUDS OVER PORTIONS OF SAWYER/PRICE/ASHLAND/IRON COUNTIES THIS
AFTERNOON.
LOW LEVEL MOISTURE IS FORECAST TO INCREASE RAPIDLY TONIGHT...AS LOW
LEVEL WINDS INCREASE. NAM FORECASTS SOUTHERLY 925MB WINDS OF
40-45KT. CLOUDS HAVE BEEN SURGING NORTH THROUGH MO/EASTERN
NE/EASTERN KS INTO IA THIS AFTERNOON. WE INCREASED CLOUD COVER
TONIGHT FOR ALL AREAS...ESPECIALLY LATE TONIGHT. THERE COULD BE SOME
DRIZZLE OR SPRINKLES LATER TONIGHT OVER A PORTION OF NORTHWEST
WISCONSIN WEST TOWARD PINE COUNTY WITH BETTER MOISTURE AND
ISENTROPIC LIFT IN THIS AREA. WE ADDED PATCHY FOG FOR TONIGHT...AS
LOW LEVEL MOISTURE INCREASES.
MODELS ALSO IN DECENT AGREEMENT WITH PLACING THEIR HIGHEST QPF OVER
THE NORTH SHORE...SOUTHWEST THROUGH THE TWIN PORTS AND PINE COUNTY.
THIS AREA UNDER DEEPER MOISTURE AND SOME LOW LEVEL FGEN. WE HAVE
HIGHEST POPS THERE FOR TOMORROW.
WE INCREASED POPS FOR SUNDAY NIGHT...INTO LIKELY FOR A PORTION OF
OUR EASTERN MINNESOTA ZONES. THE LOW LEVEL INVERTED SHARP SHARPENS
SUNDAY NIGHT...WITH FGEN PRESENT...ESPECIALLY IN THE LOW LEVELS.
PRECIP SHOULD BE RAIN...AS CLOUD COVER WILL KEEP BOUNDARY LAYER
TEMPS ABOVE FREEZING AND 925MB TEMPS OF 3-7C ARE FORECAST OVER OUR
AREA.
AS THE UPPER TROUGH SWINGS IN FROM THE WEST ON MONDAY...THE INVERTED
TROUGH IS FORECAST TO ROTATE TO THE WEST. WE KEYED OUR HIGHER POPS
ON THE INVERTED TROUGH...AND HAVE THEM LIKELY OVER A GOOD PORTION OF
NORTHEAST MINNESOTA.
THE UPPER LOW WILL CLOSE OFF AS IT DIVES ESE TOWARD SOUTHWEST IA BY
12Z TUESDAY...THEN EAST DURING THE DAY TUESDAY. THE INVERTED TROUGH
WEAKENS MONDAY NIGHT INTO TUESDAY...AND WE JUST HAVE CHANCE POPS AT
THIS TIME. THERE IS WEAK ISENTROPIC LIFT PRESENT
TUESDAY...ESPECIALLY OVER SOUTHERN AREAS. WE COULD BE IN FOR A
PERIOD OF DRIZZLE...BUT LEFT JUST A CHANCE FOR LIGHT RAIN ATTM.
EXTENDED...WEDNESDAY THROUGH SATURDAY
BRUSHED SMALL POPS FURTHER INTO WRN ZONES AND INCREASED TO MID/HIGH
CHC FOR ERN ZONES TUES NIGHT THROUGH WED NIGHT. ALSO INCREASED TEMPS
A FEW DEGREES TO ACCOUNT FOR STRONG WAA AND MDLS TRENDING WARMER.
THE GFS/EC STRUGGLING WITH THE STORM TRACK THROUGH LONG TERM AS A
DOUBLE BARREL LOW PATTERN DEVELOPS. THE INITIAL LOW WILL EXITS TO
THE NE WHILE AN ELONGATED MID LVL VORT/100 KT UPR LVL JET DIVES S
OVER THE DAKOTAS DEVELOPING A SECONDARY LOW. THE 12Z GFS SUGGESTS
THE ERN CUT LOW TRACKS NE OVER TORONTO/QUEBEC THROUGH 12Z THURS AS
THE SECONDARY WAVE DIGS OVER THE NRN PLAINS AND DEEPENS INTO A CUT
OFF LOW AT THE BASE OF LK MICHIGAN DURING THIS TIME. MEANWHILE...THE
00Z ECMWF MERGES THE TWO VORTS INTO A BROAD SYSTEM OVER THE ERN GRT
LKS. ALTHOUGH TIMING AND SPECIFIC DETAILS WILL STILL BE WORKED
OUT...BOTH MDLS SHOW SUFFICIENT MOISTURE AND PERSISTENT CYCLONIC
FLOW OVER THE FA THROUGH MID WEEK WITH DEFORMATION ZONE SETTING UP
TUES NIGHT OVER NRN MN THAT COULD POTENTIALLY BRING GREATER QPF OR A
BAND OF SN ACCUMULATION.
AVIATION...
SOUTH WINDS WILL GUST 15-20 KT WITH VFR CIGS THROUGH 00-03Z. BY
06Z...A 40 KT LLJ AROUND 2 KFT WILL SPREAD LOW CLOUDS NWRD OVER
THE FA AHEAD OF AN APPROACHING TROUGH. MVFR CEILINGS AND VSBYS
WILL BECOME WDSPRD AFT 09Z...PERSISTING THROUGH END OF PERIOD. A
FEW -SHRA WILL ALSO BE POSSIBLE SUN...MAINLY ALONG A LINE FROM
KBRD TO KHIB. INTRODUCED LLWS INTO KDLH/KHIB TERMINALS...WHILE
EXPECTING SFC WINDS TO REMAIN HIGHER IN WRN LOCATIONS WHERE
GRADIENT IS BEST.
&&
.POINT TEMPS/POPS...
DLH 37 47 41 44 / 10 40 60 50
INL 33 46 28 41 / 10 10 10 50
BRD 36 49 37 47 / 10 30 50 60
HYR 39 50 42 51 / 10 40 30 30
ASX 39 50 43 49 / 10 40 40 30
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
GSF
| 
