000
FXUS63 KARX 240403
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
1001 PM CST MON NOV 24 2009

.UPDATE...

COMPLEX BUT NON-SIGNIFICANT WEATHER FOR THE OVERNIGHT IS
CHALLENGING. GOES WATER VAPOR SHOWING THE FIRST PIECE OF
SHORTWAVE TROUGH ENERGY AND POTENTIAL VORTICITY /PV/ LOBE EJECTING
INTO IOWA /NEAR KOMA/ AROUND LARGER LOW OVER NEB/KS. RADAR IS ACTIVE
ON A FRONTOGENETIC REGION FROM KOMA TO KMSP THIS EVENING WITH PV
ADVECTION HELPING ALOFT. OVER THE PAST HOUR SOME -SHRA AND -DZ AROUND
WEST OF MISS RIVER AS WELL. LATEST 24.00 NCEP RUC DOES DEPICT THIS
AREA STRONGEST OVER NW IOWA AND WEAKER FURTHER NE. BUT IT IS THROUGH
A DEEPER LAYER FROM THE SURFACE TO NEAR 600 MB. WITHIN THIS FRONTAL
ZONE AND JUST ABOVE THE SURFACE THERE IS SOME VERY WEAK INSTABILITY
WITH SATURATION. THE PARCELS ARE ALSO ON A SLOW ISENTROPIC ASCENT
THROUGH THE VERY LOW-LEVELS. THIS HAS ASSISTED IN THE PATCHY -DZ/-
SHRA GENERATION. WHILE MOST OF THE ASCENT IS IN FURTHER WEST
FORECAST AREA OVERNIGHT...THERE IS A SLIGHT SHIFT EASTWARD SEEN ON
THE 290K SURFACE WHICH WOULD INDICATE RAIN CHANCES OR COVERAGE
INCREASING TOWARD SUNRISE PER 24.00 RUC. 24.00 NAM DOES HAVE SOME
SUGGESTION OF THIS SLIGHT SAG EASTWARD TOWARD THE RIVER TOO. THE
24.01Z RUC SOUNDING FOR KRST IS NOW SATURATED FROM THE SURFACE TO
600MB...QUITE A MOISTENING TREND OVER THE LAST RUNS.

OVERALL HAVE UPDATED THE FORECAST AND WENT TO A COVERAGE OF
WEATHER WEST OF THE RIVER. HAVE INCREASED THE RAIN CHANCES CLOSEST
TO I-35 IN THE FORECAST AREA AND KEPT WI DRY STILL. HOWEVER...THE
CHANCES AND COVERAGE OF RAIN MAY NEED TO BE INCREASED FURTHER BASED
ON DISCUSSION ABOVE...WILL MONITOR TRENDS.

&&

.AVIATION...HAVE UPDATE TAFS WITH A LARGE CHANGE TO IFR CONDITIONS
FOR MOST OF THE NIGHT. EARLIER THINKING WAS THAT THE NEAR IFR
CLOUDS THAT WERE OVER MOST OF WISCONSIN WOULD INITIALLY SHIFT WEST
THIS EVENING...THEN MOVE NORTHEAST AND PROVIDE VFR CIGS. HOWEVER...
THIS APPEARS TO NOT BE THE CASE WITH PREVALENT SE FLOW FROM A
MOISTURE RICH SOURCE AND GENTLE ISENTROPIC LIFT. THUS...EXPECT
CONDITIONS TO SLOWLY DETERIORATE OVERNIGHT AT TAF SITES. SOME
SPOTTY DRIZZLE COULD ALSO OCCUR. GOOD CONFIDENCE THAT IFR WILL
OCCUR AT KRST AND POSSIBLY KLSE...BUT LOW CONFIDENCE IN THE TIMING OF
THE LOWERING CIGS/VSBYS OVERNIGHT.
&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

BAUMGARDT

000
FXUS63 KGRB 240401 CCA
AFDGRB

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE GREEN BAY WI
1001 PM CST MON NOV 23 2009

.UPDATE...SAME OLD STORY AGAIN TNGT. VSBYS GRADUALLY COMING DOWN.
AM SURE WE WL GET SOME DENSE FOG LATER TNGT...BUT ONCE AGAIN IT/S
TOUGH TO PICK OUT WHERE IT WL GET WIDESPREAD ENOUGH TO WARRANT AN
ADVISORY. WL HANDLE AS IN THE PAST COUPLE NGTS...BY ISSUING AN SPS
TO HIGHLIGHT THE TRAVEL HAZARD.

MOISTURE ADVECTING IN ON SELY FLOW GENERATING SOME DZ ACRS THE
AREA. RUNNING WSR-88D IN LONG-PULSE /VCP-31/ DOES A NICE JOB OF
PICKING OUT THE AREAS WHERE DZ PROBABLY OCCURRING. BEST SIGNATURE
CURRENTLY JUST NW OF GRB...AND PCPN NOW BEING REPORTED ON THE EZS
AND CLI METARS. RETURNS INCRG AGAIN SE OF GRB...SO COULD SEE
ANOTHER ROUND MOVE THROUGH THE FOX VALLEY LATE IN THE EVENING. AT
THIS POINT JUST GOING TO HAVE OCNL DZ IN THE GRIDS/ZONES FOR THE
REST OF THE NGT. TWEAKED MINS UP A DEG DUE TO THE LOW CLOUDS AND
MOIST AIR MASS ACRS THE AREA.

SYSTEM FOR WED NGT/THU BECOMING MORE PROBLEMATIC. A COUPLE NGTS
AGO...IT SEEMED LIKE A GOOD BET THAT BOUNDARY LAYER TEMPS WOULD
HOLD UP ENOUGH TO KEEP AT LEAST THE BULK OF THE PCPN RAIN. MODELS
HAVE TRENDED A LITTLE COLDER...AND HAVE PRIMARY SFC LOW ON MORE
SLY TRACK. LATEST ECMWF/GFS/NAM ALL SUGGEST UPR DEFORMATION ZONE
ON NRN FLANK OF SECONDARY SHRTWV DIGGING SE FM THE PLAINS WL SET-
UP FM SW/W-C TO E-C/NE WI LATE WED NGT AND THANKSGIVING MORNING.
WARMEST BL TEMPS CONT TO LINGER IN THE NE CORNER OF THE
STATE...BUT IT/S REALLY STARTING TO GET TO BE A CLOSE CALL IF IT
WL BE WARM ENOUGH TO KEEP THE PCPN LIQUID. AND MODELS HAVE ALSO
TRENDED UP WITH THE AMNT OF PCPN FALLING WITH THE COMMA HEAD
PIVOTING ACRS THE AREA. ALREADY HAVE SPS ON THE SITN...AND THAT
SHOULD BE SUFFICIENT FOR NOW.

FROM A LOGISTICS PERSPECTIVE...WL MERGE THE SPS ON THE FOG INTO
THE ONE WE HAVE GOING ON THE SNOW POTENTIAL IN ORDER TO KEEP ONE
FROM OVERWRITING THE OTHER.

UPDATED PRODUCT SUITE WL BE OUT ASAP.

SKOWRONSKI
&&

.PREV DISCUSSION...ISSUED AT 321 PM CST MON NOV 23 2009...

SHORT TERM...TONIGHT AND TUESDAY.

LATEST RUC ANALYSIS AND VIS/IR/WV/RADAR IMAGERY SHOW A LARGE AREA OF
STRATUS STRETCHING FROM THE UPPER PENINSULA...ACROSS THE EASTERN
HALF OF WISCONSIN...AND INTO NORTHERN ILLINOIS THIS AFTERNOON.
BREAKS IN THIS STRATUS ARE FAR AND FEW BETWEEN AND CIGS REMAIN IFR
TO LIFR AT THIS HOUR.  HAVE SEEN SOME EROSION OVER NORTHERN ILLINOIS
INTO SW WISCONSIN...BUT WITH ONLY A COUPLE HOURS LEFT OF
HEATING...HAVE A HARD TIME IMAGINING THIS STRATUS DECK SCATTERING
OUT.  MEANWHILE...WEAK SHORTWAVE ENERGY IS LIFTING TO THE NORTHEAST
OVER THE GREAT LAKES WITHOUT ANY PRECIP AS MID-LEVELS ARE DRY.  MORE
POTENT ENERGY IS EXITING THE ROCKIES INTO THE PLAINS...WHICH WILL
POSE PROBLEMS FOR HOLIDAY TRAVEL LATER THIS WEEK.  OVER THE NEXT 24
HOURS...MAIN FORECAST CONCERNS REVOLVE AROUND DENSE FOG CHANCES
TONIGHT AND PRECIP CHANCES TOMORROW AFTERNOON.

TONIGHT...ASSUMING THE WIDESPREAD STRATUS DOESNT MIX OUT LATE THIS
AFTERNOON...CANNOT FIND A COMPELLING REASON WHY IT WOULD DO SO
TONIGHT.  SHORTWAVE OVERHEAD INITIALLY WILL SHIFT TO THE NORTHEAST
OF THE REGION TONIGHT...WHILE WEAK LOW LEVEL TROUGHING OVER ILLINOIS
WILL SHIFT NORTHWARD ACROSS WISCONSIN.  COMBINED WITH MOIST ONSHORE
FLOW OFF LAKE MICHIGAN (AND UPSLOPE FLOW OVER CENTRAL
WISCONSIN)...BELIEVE NOCTURNAL COOLING WILL CAUSE THE STUBBORN
STRATUS SHIELD TO LOWER OVERNIGHT...POSSIBLY REACHING THE SURFACE
OVER THE HIGHER TERRAIN CAUSING ANOTHER EPISODE OF DENSE FOG.  IN
ADDITION...BOUNDARY LAYER WINDS ARE LESS THAN 10 KTS WITH A DRY
LAYER DIRECTLY ABOVE THE STRATUS DECK THAT WOULD BE FAVORABLE FOR
STRATUS BUILD DOWN.  AS RESULT...HAVE TRENDED MORE PESSIMISTIC WITH
CLOUD COVER AND INCLUDED WIDESPREAD FOG AFTER MIDNIGHT...REDUCING
VISIBILITIES TO QUARTER MILE OR LESS OVER CENTRAL WISCONSIN.  LOWS
IN THE MIDDLE 30S TO NEAR 40.

TOMORROW...LOW PRESSURE OVER NW KANSAS WILL TRACK NE TO THE
IOWA/MISSOURI/ILLINOIS BORDER...WHICH IS A SLOWER SOLUTION THAN OVER
THE PAST FEW RUNS.  ISENTROPIC LIFT ON THE 285-290K SURFACES AND QG
FORCING LOOKS TO REMAIN SOUTH OF THE AREA FOR MOST OF THE DAY AS A
RESULT.  BUT IF TODAY IS ANY INDICATION...THE MOIST EASTERLY FLOW
WILL CAUSE ANY FOG AND/OR STRATUS DECK TO SLOWLY ERODE...AND
PROBABLY NOT ENOUGH TO DESCRIBE THE DAY AS ANYTHING LESS THE MOSTLY
CLOUDY.  WILL LEAVE A SLIVER OF SMALL CHANCY POPS ACROSS CENTRAL
WISCONSIN TO ACCOUNT FOR THE UNCERTAINTY FACTOR BUT THINK WILL SEE
DRY CONDITIONS TOMORROW.  WITH THE CLOUD COVER...HIGHS IN THE MIDDLE
40S NORTH TO LOW 50S SOUTH SEEMS ABOUT RIGHT.

LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY. COMPLEX DEVELOPING
UPPER LOW SYSTEM TO IMPACT THE REGION TUESDAY NIGHT INTO THURSDAY
WITH POTENTIAL PROBLEMS FOR HOLIDAY TRAVELERS WITH MIXED PRECIPITATION.

FROM TUESDAY NIGHT INTO WEDNESDAY...AND PERHAPS EVEN INTO EARLY WED
EVENING...FORECAST SOUNDINGS INDICATE PCPN TYPE WILL BE MAINLY
RAIN WITH ANY MIX THAT DOES FALL WILL BE OVER AN ABOVE FREEZING
SURFACE. STRONGEST CAA WRAPPING TOWARD SRN WI LATE AFTERNOON AND
EARLY WED EVENING AS H8 TROF DEVELOPS OVER ERN WI...WITH NEUTRAL
ADVECTION OVER MUCH OF NE AND NRN WISCONSIN. AS A RESULT RAIN WILL
STRUGGLE TO CHANGE OVER TO A MIX INITIALLY.  MODELS ARE ALSO IN
GOOD AGREEMENT WITH DELAYING THE ARRIVAL OF THIS PCPN WITH INITIAL
UPPER LOW TUESDAY NIGHT SO WILL DELAY LIKELY WORDING TO NRN WI
LATE TUESDAY NIGHT.

UPPER LOW SYSTEM THEN PROGGED TO DEEPEN TOWARD WEDNESDAY NIGHT
WITH COOLING TEMPERATURES ALOFT AS SECONDARY SHORT WAVE TROF
PHASES WITH THE INITIAL UPPER LOW.  WHILE BOUNDARY LEVEL TEMPS
REMAIN ABOVE FREEZING WED NIGHT FOR MOST OF THE NIGHT...ECMWF AND GFS
PROG H7 TEMPS COOL TO -10 C WHICH COULD TURN THE MIX TO MOSTLY
SNOW FOR A WHILE WHICH MAY ALSO CONTINUE INTO THURSDAY MORNING.
NEVERTHELESS THE COOLING ALOFT WILL BE OFFSET SOMEWHAT WITH
INITIALLY AND RELATIVELY MILD BOUNDARY LAYER TEMPS...BUT IF THE
ECMWF QPF PROGS ARE CORRECT WITH ONE HALF INCH TOTALS WED NIGHT
AND THURSDAY...THE MOD PCPN COULD MIX DOWN THE COLDER AIR TO TURN
PCPN TYPE INTO A PERIOD OF MOD SNOW FOR LATE WED NIGHT. MIX PCPN
OTHERWISE WILL HOLD THROUGH THURSDAY OVER EC WI UNTIL CAA ON THE
BACKSIDE OF TROF WORKS IN ON NW WINDS. THE PROGS SUGGEST THE
BETTER PCPN/SNOW POTENTIAL SHIFTS INTO ERN WI THURSDAY AS THE
UPPER SYSTEM WITH SURFACE LOW SHIFTS EASTWARD. WITH THE POTENTIAL
OF ACCUMULATING SNOW FOR THE WEDNESDAY NIGHT AND THURSDAY TRAVEL
PERIOD...WILL ISSUE A SPS ALONG WITH HIGHLIGHTING THE HWO.

MODELS ARE FAIRLY GOOD AGREEMENT WITH THE SYSTEM DEPARTING
THURSDAY NIGHT TO DECREASE OR END THE PCPN CHCS WITH THE EXCEPTION
OF LES ACTIVITY OVER FAR NC WI.

QUIET WEATHER RETURNS FRIDAY INTO SATURDAY AS THE UPPER RIDGE
DRIFTS OVER THE AREA.

MDM RANGE MODELS PASS ANOTHER SHORT WAVE TROF OVER THE AREA SUNDAY
INTO MONDAY. WILL ADD A SMALL POP MENTION FOR THIS FEATURE FOR
NOW BUT WILL TAKE A LOOK AT LATER RUNS FOR CONSISTENCY.

AVIATION...STUBBORN STRATUS AND MVFR/IFR VSBYS ARE HOLDING TOUGH
THIS AFTERNOON...WITH LITTLE OPPORTUNITY FOR DISSIPATION BEFORE
NOCTURNAL COOLING SETS IN.  MODELS INDICATE THAT MOIST EASTERLY FLOW
WILL CONTINUE TONIGHT...WHICH SHOULD ALLOW FOR THE STRATUS TO LOWER
AGAIN TO PRODUCE WIDESPREAD FOG UNDER LIGHT WINDS.  THE FOG WILL BE
SLOW TO LIFT INTO A STRATUS DECK TOMORROW MORNING. BY
AFTERNOON...LOW PRESSURE WILL BE MOVING INTO THE MID-MISSISSIPPI
VALLEY WITH RAIN MOVING INTO SW HALF OF WISCONSIN.  AT THIS
POINT...MODELS INDICATE THAT PRECIP WILL HOLD OFF UNTIL TOMORROW
NIGHT AT THE TAF SITES.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

000
FXUS63 KGRB 240333 AAA
AFDGRB

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GREEN BAY WI
933 PM CST MON NOV 23 2009

.UPDATE...SAME OLD STORY AGAIN TNGT. VSBYS GRADUALLY COMING DOWN.
AM SURE WE WL GET SOME DENSE FOG LATER TNGT...BUT ONCE AGAIN IT/S
TOUGH TO PICK OUT WHERE IT WL GET WIDESPREAD ENOUGH TO WARRANT AN
ADVISORY. WL HANDLE AS IN THE PAST COUPLE NGTS...BY ISSUING AN SPS
TO HIGHLIGHT THE TRAVEL HAZARD.

MOISTURE ADVECTING IN ON SELY FLOW GENERATING SOME DZ ACRS THE
AREA. RUNNING WSR-88D IN LONG-PULSE /VCP-31/ DOES A NICE JOB OF
PICKING OUT THE AREAS WHERE DZ PROBABLY OCCURRING. BEST SIGNATURE
CURRENTLY JUST NW OF GRB...AND PCPN NOW BEING REPORTED ON THE EZS
AND CLI METARS. RETURNS INCRG AGAIN SE OF GRB...SO COULD SEE
ANOTHER ROUND MOVE THROUGH THE FOX VALLEY LATE IN THE EVENING. AT
THIS POINT JUST GOING TO HAVE OCNL DZ IN THE GRIDS/ZONES FOR THE
REST OF THE NGT. TWEAKED MINS UP A DEG DUE TO THE LOW CLOUDS AND
MOIST AIR MASS ACRS THE AREA.

SYSTEM FOR WED NGT/THU BECOMING MORE PROBLEMATIC. A COUPLE NGTS
AGO...IT SEEMED LIKE A GOOD BET THAT BOUNDARY LAYER TEMPS WOULD
HOLD UP ENOUGH TO KEEP AT LEAST THE BULK OF THE PCPN RAIN. MODELS
HAVE TRENDED A LITTLE COLDER...AND HAVE PRIMARY SFC LOW ON MORE
SLY TRACK. LATEST ECMWF/GFS/NAM ALL SUGGEST UPR DEFORMATION ZONE
ON NRN FLANK OF SECONDARY SHRTWV DIGGING SE FM THE PLAINS WL SET-
UP FM SW/W-C TO E-C/NE WI LATE WED NGT AND THANKSGIVING MORNING.
WARMEST BL TEMPS CONT TO LINGER IN THE NE CORNER OF THE
STATE...BUT IT/S REALLY STARTING TO GET TO BE A CLOSE CALL IF IT
WL BE WARM ENOUGH TO KEEP THE PCPN LIQUID. AND MODELS HAVE ALSO
TRENDED UP WITH THE AMNT OF PCPN FALLING WITH THE COMMA HEAD
PIVOTING ACRS THE AREA. ALREADY HAVE SPS ON THE SITN...AND THAT
SHOULD BE SUFFICIENT FOR NOW.

FROM A LOGISTICS PROSPECTIVE...WL MERGE THE SPS ON THE FOG INTO
THE ONE WE HAVE GOING ON THE SNOW POTENTIAL IN ORDER TO KEEP ONE
FROM OVERWRITING THE OTHER.

UPDATED PRODUCT SUITE WL BE OUT ASAP.

SKOWRONSKI
&&

.PREV DISCUSSION...ISSUED AT 321 PM CST MON NOV 23 2009...

SHORT TERM...TONIGHT AND TUESDAY.

LATEST RUC ANALYSIS AND VIS/IR/WV/RADAR IMAGERY SHOW A LARGE AREA OF
STRATUS STRETCHING FROM THE UPPER PENINSULA...ACROSS THE EASTERN
HALF OF WISCONSIN...AND INTO NORTHERN ILLINOIS THIS AFTERNOON.
BREAKS IN THIS STRATUS ARE FAR AND FEW BETWEEN AND CIGS REMAIN IFR
TO LIFR AT THIS HOUR.  HAVE SEEN SOME EROSION OVER NORTHERN ILLINOIS
INTO SW WISCONSIN...BUT WITH ONLY A COUPLE HOURS LEFT OF
HEATING...HAVE A HARD TIME IMAGINING THIS STRATUS DECK SCATTERING
OUT.  MEANWHILE...WEAK SHORTWAVE ENERGY IS LIFTING TO THE NORTHEAST
OVER THE GREAT LAKES WITHOUT ANY PRECIP AS MID-LEVELS ARE DRY.  MORE
POTENT ENERGY IS EXITING THE ROCKIES INTO THE PLAINS...WHICH WILL
POSE PROBLEMS FOR HOLIDAY TRAVEL LATER THIS WEEK.  OVER THE NEXT 24
HOURS...MAIN FORECAST CONCERNS REVOLVE AROUND DENSE FOG CHANCES
TONIGHT AND PRECIP CHANCES TOMORROW AFTERNOON.

TONIGHT...ASSUMING THE WIDESPREAD STRATUS DOESNT MIX OUT LATE THIS
AFTERNOON...CANNOT FIND A COMPELLING REASON WHY IT WOULD DO SO
TONIGHT.  SHORTWAVE OVERHEAD INITIALLY WILL SHIFT TO THE NORTHEAST
OF THE REGION TONIGHT...WHILE WEAK LOW LEVEL TROUGHING OVER ILLINOIS
WILL SHIFT NORTHWARD ACROSS WISCONSIN.  COMBINED WITH MOIST ONSHORE
FLOW OFF LAKE MICHIGAN (AND UPSLOPE FLOW OVER CENTRAL
WISCONSIN)...BELIEVE NOCTURNAL COOLING WILL CAUSE THE STUBBORN
STRATUS SHIELD TO LOWER OVERNIGHT...POSSIBLY REACHING THE SURFACE
OVER THE HIGHER TERRAIN CAUSING ANOTHER EPISODE OF DENSE FOG.  IN
ADDITION...BOUNDARY LAYER WINDS ARE LESS THAN 10 KTS WITH A DRY
LAYER DIRECTLY ABOVE THE STRATUS DECK THAT WOULD BE FAVORABLE FOR
STRATUS BUILD DOWN.  AS RESULT...HAVE TRENDED MORE PESSIMISTIC WITH
CLOUD COVER AND INCLUDED WIDESPREAD FOG AFTER MIDNIGHT...REDUCING
VISIBILITIES TO QUARTER MILE OR LESS OVER CENTRAL WISCONSIN.  LOWS
IN THE MIDDLE 30S TO NEAR 40.

TOMORROW...LOW PRESSURE OVER NW KANSAS WILL TRACK NE TO THE
IOWA/MISSOURI/ILLINOIS BORDER...WHICH IS A SLOWER SOLUTION THAN OVER
THE PAST FEW RUNS.  ISENTROPIC LIFT ON THE 285-290K SURFACES AND QG
FORCING LOOKS TO REMAIN SOUTH OF THE AREA FOR MOST OF THE DAY AS A
RESULT.  BUT IF TODAY IS ANY INDICATION...THE MOIST EASTERLY FLOW
WILL CAUSE ANY FOG AND/OR STRATUS DECK TO SLOWLY ERODE...AND
PROBABLY NOT ENOUGH TO DESCRIBE THE DAY AS ANYTHING LESS THE MOSTLY
CLOUDY.  WILL LEAVE A SLIVER OF SMALL CHANCY POPS ACROSS CENTRAL
WISCONSIN TO ACCOUNT FOR THE UNCERTAINTY FACTOR BUT THINK WILL SEE
DRY CONDITIONS TOMORROW.  WITH THE CLOUD COVER...HIGHS IN THE MIDDLE
40S NORTH TO LOW 50S SOUTH SEEMS ABOUT RIGHT.

LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY. COMPLEX DEVELOPING
UPPER LOW SYSTEM TO IMPACT THE REGION TUESDAY NIGHT INTO THURSDAY
WITH POTENTIAL PROBLEMS FOR HOLIDAY TRAVELERS WITH MIXED PRECIPITATION.

FROM TUESDAY NIGHT INTO WEDNESDAY...AND PERHAPS EVEN INTO EARLY WED
EVENING...FORECAST SOUNDINGS INDICATE PCPN TYPE WILL BE MAINLY
RAIN WITH ANY MIX THAT DOES FALL WILL BE OVER AN ABOVE FREEZING
SURFACE. STRONGEST CAA WRAPPING TOWARD SRN WI LATE AFTERNOON AND
EARLY WED EVENING AS H8 TROF DEVELOPS OVER ERN WI...WITH NEUTRAL
ADVECTION OVER MUCH OF NE AND NRN WISCONSIN. AS A RESULT RAIN WILL
STRUGGLE TO CHANGE OVER TO A MIX INITIALLY.  MODELS ARE ALSO IN
GOOD AGREEMENT WITH DELAYING THE ARRIVAL OF THIS PCPN WITH INITIAL
UPPER LOW TUESDAY NIGHT SO WILL DELAY LIKELY WORDING TO NRN WI
LATE TUESDAY NIGHT.

UPPER LOW SYSTEM THEN PROGGED TO DEEPEN TOWARD WEDNESDAY NIGHT
WITH COOLING TEMPERATURES ALOFT AS SECONDARY SHORT WAVE TROF
PHASES WITH THE INITIAL UPPER LOW.  WHILE BOUNDARY LEVEL TEMPS
REMAIN ABOVE FREEZING WED NIGHT FOR MOST OF THE NIGHT...ECMWF AND GFS
PROG H7 TEMPS COOL TO -10 C WHICH COULD TURN THE MIX TO MOSTLY
SNOW FOR A WHILE WHICH MAY ALSO CONTINUE INTO THURSDAY MORNING.
NEVERTHELESS THE COOLING ALOFT WILL BE OFFSET SOMEWHAT WITH
INITIALLY AND RELATIVELY MILD BOUNDARY LAYER TEMPS...BUT IF THE
ECMWF QPF PROGS ARE CORRECT WITH ONE HALF INCH TOTALS WED NIGHT
AND THURSDAY...THE MOD PCPN COULD MIX DOWN THE COLDER AIR TO TURN
PCPN TYPE INTO A PERIOD OF MOD SNOW FOR LATE WED NIGHT. MIX PCPN
OTHERWISE WILL HOLD THROUGH THURSDAY OVER EC WI UNTIL CAA ON THE
BACKSIDE OF TROF WORKS IN ON NW WINDS. THE PROGS SUGGEST THE
BETTER PCPN/SNOW POTENTIAL SHIFTS INTO ERN WI THURSDAY AS THE
UPPER SYSTEM WITH SURFACE LOW SHIFTS EASTWARD. WITH THE POTENTIAL
OF ACCUMULATING SNOW FOR THE WEDNESDAY NIGHT AND THURSDAY TRAVEL
PERIOD...WILL ISSUE A SPS ALONG WITH HIGHLIGHTING THE HWO.

MODELS ARE FAIRLY GOOD AGREEMENT WITH THE SYSTEM DEPARTING
THURSDAY NIGHT TO DECREASE OR END THE PCPN CHCS WITH THE EXCEPTION
OF LES ACTIVITY OVER FAR NC WI.

QUIET WEATHER RETURNS FRIDAY INTO SATURDAY AS THE UPPER RIDGE
DRIFTS OVER THE AREA.

MDM RANGE MODELS PASS ANOTHER SHORT WAVE TROF OVER THE AREA SUNDAY
INTO MONDAY. WILL ADD A SMALL POP MENTION FOR THIS FEATURE FOR
NOW BUT WILL TAKE A LOOK AT LATER RUNS FOR CONSISTENCY.

AVIATION...STUBBORN STRATUS AND MVFR/IFR VSBYS ARE HOLDING TOUGH
THIS AFTERNOON...WITH LITTLE OPPORTUNITY FOR DISSIPATION BEFORE
NOCTURNAL COOLING SETS IN.  MODELS INDICATE THAT MOIST EASTERLY FLOW
WILL CONTINUE TONIGHT...WHICH SHOULD ALLOW FOR THE STRATUS TO LOWER
AGAIN TO PRODUCE WIDESPREAD FOG UNDER LIGHT WINDS.  THE FOG WILL BE
SLOW TO LIFT INTO A STRATUS DECK TOMORROW MORNING. BY
AFTERNOON...LOW PRESSURE WILL BE MOVING INTO THE MID-MISSISSIPPI
VALLEY WITH RAIN MOVING INTO SW HALF OF WISCONSIN.  AT THIS
POINT...MODELS INDICATE THAT PRECIP WILL HOLD OFF UNTIL TOMORROW
NIGHT AT THE TAF SITES.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

000
FXUS63 KMKX 232140
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
340 PM CST MON NOV 23 2009

.SHORT TERM...
TONIGHT...AN UPPER LEVEL LOW PRESSURE TROUGH EXTENDING FROM EASTERN
SASKATCHEWAN DOWN TO KANSAS IS HELPING A SFC LOW TO DEVELOP OVER
KANSAS THIS EVENING. THE SFC LOW WILL TRACK INTO WESTERN MO
OVERNIGHT AS THE UPPER LOW BEGINS TO CLOSE OFF AND DRIFT TOWARD THE
MIDWEST.

STAGNANT AIR AND ABUNDANT LOW LEVEL MOISTURE CREATING LOW STRATUS
OVER THE CWA IS EXPECTED TO CONTINUE OVERNIGHT. AREAS OF FOG SHOULD
DEVELOP ONCE AGAIN WITH DENSE FOG POSSIBLE IN SOME LOCATIONS. MID
CLOUDS ARE EXPECTED TO MOVE INTO THE SOUTHWEST TOWARD
MORNING...WHICH SHOULD HELP TO THIN THE FOG A BIT. CAN/T RULE OUT A
DENSE FOG ADVISORY ONCE AGAIN...BUT NO CONFIDENCE IN WHERE THE DENSE
FOG WOULD OCCUR.

TUESDAY...UPPER LEVEL JET NOSING INTO THE WESTERN GREAT LAKES WILL
CREATE AN AREA OF UPPER LEVEL DIVERGENCE OVER NORTHERN
IL...ENHANCING THE RAIN ON THE NORTH SIDE OF THE SFC LOW. HIGHEST
QPF LOOKS LIKE IT WILL BE ACROSS NORTHERN IL TUE AFTERNOON...AND
THEN SPREAD NORTHWARD INTO SOUTHERN WI TUE NIGHT.

WEDENSDAY...AS THE UPPER LOW SHIFTS NORTHEAST TO THE EASTERN GREAT
LAKES...ANOTHER UPPER LOW DIPS DOWN ACROSS THE UPPER MIDWEST. THIS
WILL GIVE THE OCCLUDED AND WEAKENING SFC LOW A LITTLE EXTRA PUNCH TO
PRODUCE MORE RAIN SHOWERS ACROSS WI.

WEDNESDAY NIGHT...COLD AIR WILL BEGIN TO WRAP INTO THE CLOSED SFC
LOW AND CLOSED UPPER LEVEL LOW THAT IS STATIONARY OVER THE GREAT
LAKES REGION. MODELS HINT AT SOUTHERN WI DRYING OUT FOR A SHORT TIME
WED NIGHT UNTIL ANOTHER WAVE ROUNDS THE BASE OF THE LOW ON THU.

THURSDAY...THE SHORTWAVE CROSSING SOUTHERN WI COULD BE COLD ENOUGH
AT UPPER LEVELS TO DROP SOME SNOW EARLY THU MORNING AND POSSIBLY
INTO THE AFTERNOON. A QUICK QUARTER TO HALF INCH OF SNOW COULD CAUSE
SOME TRAVEL HEADACHES. HOWEVER...GROUND AND SFC AIR TEMPS SHOULD BE
MODERATE ENOUGH TO MELT THE SNOW QUICKLY.

.LONG TERM...RIDGING AND DRY AIR WILL WORK INTO SOUTHERN WI QUICKLY
THU NIGHT AND FRIDAY AND LOOKS TO KEEP US DRY AND SEASONABLE THROUGH
NEXT WEEKEND.

&&

.AVIATION...STUBBORN IFR STRATUS DECK CONTINUES TO SIT OVER SOUTHERN
WISCONSIN...WITH IFR TO MVFR VISBYS. MODELS NOT HANDLING THE CURRENT
SITUATION VERY WELL...SO NOT GIVING MUCH ATTENTION TO MORE
OPTIMISTIC CIGS IN MOS GUIDANCE FOR THIS EVENING AND TONIGHT.
CURRENTLY SEEING NO REASON FOR THIS STRATUS DECK TO BUDGE THROUGH
MUCH OF THE NIGHT. DO THINK THAT VISBYS WILL GO BACK DOWN
TONIGHT...WITH FOG POSSIBLY REDUCING CONDITIONS TO LIFR AFTER
MIDNIGHT.

EXPECT CONDITIONS TO IMPROVE IFR...THEN MVFR THROUGH TOMORROW
MORNING...WITH INCREASING CLOUDINESS THROUGH THE DAY AS LOW PRESSURE
APPROACHES THE STATE. RAIN IS POSSIBLE LATER TOMORROW
AFTERNOON...BUT LIKELY JUST SOUTHWEST OF MADISON.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&

$$

SHORT/LONG TERM...13/MRC
AVIATION/MARINE...07/DDV

000
FXUS63 KGRB 232121
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
321 PM CST MON NOV 23 2009

.SHORT TERM...TONIGHT AND TUESDAY.

LATEST RUC ANALYSIS AND VIS/IR/WV/RADAR IMAGERY SHOW A LARGE AREA OF
STRATUS STRETCHING FROM THE UPPER PENINSULA...ACROSS THE EASTERN
HALF OF WISCONSIN...AND INTO NORTHERN ILLINOIS THIS AFTERNOON.
BREAKS IN THIS STRATUS ARE FAR AND FEW BETWEEN AND CIGS REMAIN IFR
TO LIFR AT THIS HOUR.  HAVE SEEN SOME EROSION OVER NORTHERN ILLINOIS
INTO SW WISCONSIN...BUT WITH ONLY A COUPLE HOURS LEFT OF
HEATING...HAVE A HARD TIME IMAGINING THIS STRATUS DECK SCATTERING
OUT.  MEANWHILE...WEAK SHORTWAVE ENERGY IS LIFTING TO THE NORTHEAST
OVER THE GREAT LAKES WITHOUT ANY PRECIP AS MID-LEVELS ARE DRY.  MORE
POTENT ENERGY IS EXITING THE ROCKIES INTO THE PLAINS...WHICH WILL
POSE PROBLEMS FOR HOLIDAY TRAVEL LATER THIS WEEK.  OVER THE NEXT 24
HOURS...MAIN FORECAST CONCERNS REVOLVE AROUND DENSE FOG CHANCES
TONIGHT AND PRECIP CHANCES TOMORROW AFTERNOON.

TONIGHT...ASSUMING THE WIDESPREAD STRATUS DOESNT MIX OUT LATE THIS
AFTERNOON...CANNOT FIND A COMPELLING REASON WHY IT WOULD DO SO
TONIGHT.  SHORTWAVE OVERHEAD INITIALLY WILL SHIFT TO THE NORTHEAST
OF THE REGION TONIGHT...WHILE WEAK LOW LEVEL TROUGHING OVER ILLINOIS
WILL SHIFT NORTHWARD ACROSS WISCONSIN.  COMBINED WITH MOIST ONSHORE
FLOW OFF LAKE MICHIGAN (AND UPSLOPE FLOW OVER CENTRAL
WISCONSIN)...BELIEVE NOCTURNAL COOLING WILL CAUSE THE STUBBORN
STRATUS SHIELD TO LOWER OVERNIGHT...POSSIBLY REACHING THE SURFACE
OVER THE HIGHER TERRAIN CAUSING ANOTHER EPISODE OF DENSE FOG.  IN
ADDITION...BOUNDARY LAYER WINDS ARE LESS THAN 10 KTS WITH A DRY
LAYER DIRECTLY ABOVE THE STRATUS DECK THAT WOULD BE FAVORABLE FOR
STRATUS BUILD DOWN.  AS RESULT...HAVE TRENDED MORE PESSIMISTIC WITH
CLOUD COVER AND INCLUDED WIDESPREAD FOG AFTER MIDNIGHT...REDUCING
VISIBILITIES TO QUARTER MILE OR LESS OVER CENTRAL WISCONSIN.  LOWS
IN THE MIDDLE 30S TO NEAR 40.

TOMORROW...LOW PRESSURE OVER NW KANSAS WILL TRACK NE TO THE
IOWA/MISSOURI/ILLINOIS BORDER...WHICH IS A SLOWER SOLUTION THAN OVER
THE PAST FEW RUNS.  ISENTROPIC LIFT ON THE 285-290K SURFACES AND QG
FORCING LOOKS TO REMAIN SOUTH OF THE AREA FOR MOST OF THE DAY AS A
RESULT.  BUT IF TODAY IS ANY INDICATION...THE MOIST EASTERLY FLOW
WILL CAUSE ANY FOG AND/OR STRATUS DECK TO SLOWLY ERODE...AND
PROBABLY NOT ENOUGH TO DESCRIBE THE DAY AS ANYTHING LESS THE MOSTLY
CLOUDY.  WILL LEAVE A SLIVER OF SMALL CHANCY POPS ACROSS CENTRAL
WISCONSIN TO ACCOUNT FOR THE UNCERTAINTY FACTOR BUT THINK WILL SEE
DRY CONDITIONS TOMORROW.  WITH THE CLOUD COVER...HIGHS IN THE MIDDLE
40S NORTH TO LOW 50S SOUTH SEEMS ABOUT RIGHT.

.LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY. COMPLEX DEVELOPING
UPPER LOW SYSTEM TO IMPACT THE REGION TUESDAY NIGHT INTO THURSDAY
WITH POTENTIAL PROBLEMS FOR HOLIDAY TRAVELERS WITH MIXED PRECIPITATION.

FROM TUESDAY NIGHT INTO WEDNESDAY...AND PERHAPS EVEN INTO EARLY WED
EVENING...FORECAST SOUNDINGS INDICATE PCPN TYPE WILL BE MAINLY
RAIN WITH ANY MIX THAT DOES FALL WILL BE OVER AN ABOVE FREEZING
SURFACE. STRONGEST CAA WRAPPING TOWARD SRN WI LATE AFTERNOON AND
EARLY WED EVENING AS H8 TROF DEVELOPS OVER ERN WI...WITH NEUTRAL
ADVECTION OVER MUCH OF NE AND NRN WISCONSIN. AS A RESULT RAIN WILL
STRUGGLE TO CHANGE OVER TO A MIX INITIALLY.  MODELS ARE ALSO IN
GOOD AGREEMENT WITH DELAYING THE ARRIVAL OF THIS PCPN WITH INITIAL
UPPER LOW TUESDAY NIGHT SO WILL DELAY LIKELY WORDING TO NRN WI
LATE TUESDAY NIGHT.

UPPER LOW SYSTEM THEN PROGGED TO DEEPEN TOWARD WEDNESDAY NIGHT
WITH COOLING TEMPERATURES ALOFT AS SECONDARY SHORT WAVE TROF
PHASES WITH THE INITIAL UPPER LOW.  WHILE BOUNDARY LEVEL TEMPS
REMAIN ABOVE FREEZING WED NIGHT FOR MOST OF THE NIGHT...ECMWF AND GFS
PROG H7 TEMPS COOL TO -10 C WHICH COULD TURN THE MIX TO MOSTLY
SNOW FOR A WHILE WHICH MAY ALSO CONTINUE INTO THURSDAY MORNING.
NEVERTHELESS THE COOLING ALOFT WILL BE OFFSET SOMEWHAT WITH
INITIALLY AND RELATIVELY MILD BOUNDARY LAYER TEMPS...BUT IF THE
ECMWF QPF PROGS ARE CORRECT WITH ONE HALF INCH TOTALS WED NIGHT
AND THURSDAY...THE MOD PCPN COULD MIX DOWN THE COLDER AIR TO TURN
PCPN TYPE INTO A PERIOD OF MOD SNOW FOR LATE WED NIGHT. MIX PCPN
OTHERWISE WILL HOLD THROUGH THURSDAY OVER EC WI UNTIL CAA ON THE
BACKSIDE OF TROF WORKS IN ON NW WINDS. THE PROGS SUGGEST THE
BETTER PCPN/SNOW POTENTIAL SHIFTS INTO ERN WI THURSDAY AS THE
UPPER SYSTEM WITH SURFACE LOW SHIFTS EASTWARD. WITH THE POTENTIAL
OF ACCUMULATING SNOW FOR THE WEDNESDAY NIGHT AND THURSDAY TRAVEL
PERIOD...WILL ISSUE A SPS ALONG WITH HIGHLIGHTING THE HWO.

MODELS ARE FAIRLY GOOD AGREEMENT WITH THE SYSTEM DEPARTING
THURSDAY NIGHT TO DECREASE OR END THE PCPN CHCS WITH THE EXCEPTION
OF LES ACTIVITY OVER FAR NC WI.

QUIET WEATHER RETURNS FRIDAY INTO SATURDAY AS THE UPPER RIDGE
DRIFTS OVER THE AREA.

MDM RANGE MODELS PASS ANOTHER SHORT WAVE TROF OVER THE AREA SUNDAY
INTO MONDAY. WILL ADD A SMALL POP MENTION FOR THIS FEATURE FOR
NOW BUT WILL TAKE A LOOK AT LATER RUNS FOR CONSISTENCY.
&&

.AVIATION...STUBBORN STRATUS AND MVFR/IFR VSBYS ARE HOLDING TOUGH
THIS AFTERNOON...WITH LITTLE OPPORTUNITY FOR DISSIPATION BEFORE
NOCTURNAL COOLING SETS IN.  MODELS INDICATE THAT MOIST EASTERLY FLOW
WILL CONTINUE TONIGHT...WHICH SHOULD ALLOW FOR THE STRATUS TO LOWER
AGAIN TO PRODUCE WIDESPREAD FOG UNDER LIGHT WINDS.  THE FOG WILL BE
SLOW TO LIFT INTO A STRATUS DECK TOMORROW MORNING. BY
AFTERNOON...LOW PRESSURE WILL BE MOVING INTO THE MID-MISSISSIPPI
VALLEY WITH RAIN MOVING INTO SW HALF OF WISCONSIN.  AT THIS
POINT...MODELS INDICATE THAT PRECIP WILL HOLD OFF UNTIL TOMORROW
NIGHT AT THE TAF SITES.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$
MPC/TDH

000
FXUS63 KARX 232108
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
308 PM CST MON NOV 23 2009

.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT
MAIN FORECAST CONCERN IS ON SYSTEM TO AFFECT THE AREA TUESDAY INTO
THANKSGIVING.

CURRENTLY AS OF 21Z...WATER VAPOR AND RUC 500MB HEIGHT ANALYSIS
SHOWED TROUGHING ALONG THE LEE OF THE U.S. ROCKIES...RIDGING AHEAD
OF IT OVER THE GREAT LAKES AND RIDGING BEHIND IT OVER THE PACIFIC
NORTHWEST...AND A POTENT TROUGH MOVING INTO BRITISH COLUMBIA. ALSO
OF NOTE IS A VERY WEAK SHORTWAVE TROUGH OVER THE FORECAST AREA...
WHICH WHEN COMBINED WITH LOW LEVEL ISENTROPIC LIFT HELPED PRODUCE
THE RAIN OBSERVED LAST NIGHT INTO THIS MORNING. SUBSIDENCE FOLLOWING
IN THE WAKE OF THE TROUGH AND LACK OF ISENTROPIC LIFT HAS DIMINISHED
THE RAIN...AS WELL AS CLEARED OUT SOME OF THE CLOUDS WEST OF A LINE
FROM EAU CLAIRE TO DUBUQUE. ALONG AND EAST OF THIS LINE...A LARGE
AMOUNT OF VERY LOW STRATUS EXISTS. A LOT OF THIS RESULTED FROM FOG
WHICH MIXED OUT...BUT THE MOISTURE GOT TRAPPED UNDER A SUBSIDENCE
INVERSION...SIMILAR TO SATURDAY. 12Z GRB SOUNDING REFLECTS THIS
WELL. FARTHER TO THE WEST...DESPITE THE TROUGH PRESENT OVER THE
WESTERN PLAINS...VERY LITTLE PRECIPITATION ACTIVITY IS OCCURRING.
HOWEVER...LOW PRESSURE HAS FORMED AHEAD OF THE TROUGH FROM EASTERN
SOUTH DAKOTA INTO THE OKLAHOMA PANHANDLE...WITH THE MAIN LOW IN THE
OKLAHOMA PANHANDLE.

TONIGHT...UPPER TROUGH OVER THE WESTERN PLAINS IS EXPECTED TO DIG
DOWN INTO KANSAS AND OKLAHOMA...WITH A CLOSED LOW FORMING WITHIN IT
NEAR KANSAS CITY BY 12Z TUESDAY. AHEAD OF THE UPPER TROUGH...RIDGING
WILL CONTINUE TO BUILD OVER THE FORECAST AREA...MAINTAINING
SUBSIDENCE. HOWEVER...AFTER 06Z...23.12Z GFS/NAM BOTH DEPICT
ISENTROPIC LIFT INCREASING ON THE 290K AND 295K SURFACES OVER
SOUTHEAST MINNESOTA AND NORTHEAST IOWA. THIS LIFT IS AHEAD OF THE
LOW PRESSURE TROUGH IN THE EASTERN DAKOTAS...WHICH MODELS PROG
REACHING I-35 BY 12Z TUESDAY. IN ADDITION...AN UPPER LEVEL JET
STREAK CURRENTLY OVER THE OKLAHOMA PANHANDLE IS INDICATED TO MOVE
NORTHEAST INTO EASTERN IOWA BY 12Z...IN RESPONSE TO THE DIGGING
UPPER TROUGH. THEREFORE AT LEAST NORTHEAST IOWA COULD GET INTO SOME
UPPER LEVEL DIVERGENCE IN THE LEFT EXIT REGION OF THE GET. NET
RESULT OF ALL THIS IS TO MAINTAIN AT LEAST THE GOING 20-40 PERCENT
CHANCES OF RAIN AFTER 06Z. DO BELIEVE THAT THE BULK OF RAIN WILL END
UP WEST OF THE FORECAST AREA...THOUGH...CLOSER TO THE LOW PRESSURE
TROUGH WHERE MORE LOW TO MID-LEVEL FRONTOGENESIS EXISTS. OTHER
CONCERN TONIGHT IS THE LOW STRATUS DECK HANGING AROUND OVER THE
EASTERN TWO THIRDS OF WISCONSIN. WITH LOW LEVEL SOUTHEAST FLOW...
NIGHT TIME COOLING AND HIGH DEWPOINTS...THE STRATUS MAY JUST ADVECT
WESTWARD THIS EVENING. THEREFORE...FORECAST TONIGHT IS MOSTLY CLOUDY
TO CLOUDY. HAVE ALSO INCLUDED PATCHY FOG UNDERNEATH THE LOW STRATUS
DECK...GIVEN THAT MOST SITES UNDERNEATH IT RIGHT NOW HAVE 1 TO 3
MILE VISIBILITIES. IF STRATUS DOES INDEED SPREAD WESTWARD THIS
EVENING...THE PATCHY FOG MAY NEED EXPANSION WESTWARD. THE CLOUDS AND
HIGH DEWPOINTS SHOULD HELP HOLD TEMPERATURES UP...WITH LOWS IN MOST
LOCATIONS IN THE LOW TO MID 40S.

TUESDAY...UPPER LOW NEAR KANSAS CITY...AS WELL AS ITS ASSOCIATED LOW
PRESSURE AREA WHICH SHOULD BE JUST NORTH OF THE LOW...IS PROGGED TO
HEAD NORTHEAST TO A POSITION NEAR KIRKSVILLE MISSOURI BY 00Z. THE
PUSH NORTHEASTWARD IS CAUSED BY THE CURRENT POTENT TROUGH ENTERING
BRITISH COLUMBIA TRYING TO DIG DOWN INTO NORTHEAST MONTANA AND
WESTERN NORTH DAKOTA. AS THE UPPER AND SURFACE LOWS MOVE
NORTHEASTWARD...ISENTROPIC LIFT AND FRONTOGENESIS FORCING INCREASES
IN A ZONE ABOUT 100 MILES NORTH OF THE UPPER LOW...I.E. WHERE THE
WARM CONVEYOR BELT IS PROGGED. MANY QUESTIONS EXIST NOW IF THIS ZONE
WILL MAKE IT UP INTO THE FORECAST AREA WITH THE 23.12Z MODEL CYCLE.
MOST MODELS SHOW THE ZONE EITHER MOVING INTO THE NORTHEAST IOWA AND
FAR SOUTHWEST WISCONSIN COUNTIES...OR JUST STAYING TO THE SOUTH. AS
FOR THE LOW PRESSURE TROUGH NEAR I-35 IN THE MORNING AND ITS
ASSOCIATED LOW TO MID LEVEL FRONTOGENESIS...MODELS BASICALLY SHOW
THIS STAYING STATIONARY. WITH ALL OF THIS INFORMATION...DECIDED TO
REDUCE CHANCES OF PRECIPITATION FROM CENTRAL WISCONSIN INTO THE
SOUTHEAST MINNESOTA COUNTIES BORDERING THE MISSISSIPPI RIVER...AS
WELL AS THE FIRST TIER OF NORTHEAST IOWA COUNTIES BORDERING
MINNESOTA. FURTHER LOWERING OF PRECIPITATION CHANCES MAY BE
NECESSARY...AS THE NEW 23.18Z NAM INDICATES. ALTHOUGH PRECIPITATION
MAY NOT BE WIDESPREAD...CLOUD COVER DOES...LIMITING DAYTIME HEATING.
IN FACT...THERE MAY NOT BE MUCH RISE OFF TONIGHTS LOWS...ESPECIALLY
WHERE IT PRECIPITATES.

TUESDAY NIGHT AND WEDNESDAY...POTENT UPPER TROUGH DROPPING DOWN INTO
THE FAR NORTHERN PLAINS AT 00Z WEDNESDAY IS FORECAST BY MODELS TO
DIVE SOUTH THROUGH THE DAKOTAS TUESDAY NIGHT...THEN MOVE INTO IOWA
BY 00Z THURSDAY. THE DIGGING NATURE OF THIS TROUGH WILL HELP KICK
THE UPPER LOW NEAR KIRKSVILLE AT 00Z NORTHEASTWARD QUICKLY...AND
MODELS SHOW IT REACHING THE EASTERN GREAT LAKES WEDNESDAY AFTERNOON.
HOWEVER...ITS SURFACE LOW IS GOING TO HANG UP OVER UPPER MICHIGAN IN
RESPONSE TO THE DIGGING TROUGH. AS FOR THE IMPACTS OF THE UPPER LOW
ON THE FORECAST AREA...SHOULD SEE THE DEFORMATION ZONE OF RAIN ON
THE NORTH SIDE OF THE LOW MOVE ACROSS NORTHEAST IOWA...WESTERN
WISCONSIN AND POSSIBLY SOUTHEAST MINNESOTA TUESDAY NIGHT. SOUTHEAST
MINNESOTA AND NORTHEAST IOWA COULD ALSO BE AFFECTED BY THE
DIMINISHING FRONTOGENESIS ZONE NEAR I-35...WHICH SHOULD SLIDE SLOWLY
EAST. OVERALL THE PREVIOUS FORECAST HANDLED THIS WELL...HAVING 60-70
PRECIPITATION PROBABILITIES. MAJORITY OF THE RAIN MAY TEND
TO DIMINISH FOR A TIME WEDNESDAY MORNING...UNTIL THE POTENT UPPER
TROUGH NEARS THE AREA...CAUSING MID LEVEL HEIGHTS TO FALL AND THE
DEVELOPMENT OF A NEW BAND OF FRONTOGENETICAL PRECIPITATION. THIS
AREA OF PRECIPITATION LOOKS TO MOVE INTO MOST OF THE FORECAST AREA
LATE IN THE MORNING AND THEN REMAIN THROUGH THE REST OF THE DAY.
AGAIN...THE PREVIOUS FORECAST HAD A GOOD HANDLE WITH THE
PRECIPITATION PROBABILITIES...GENERALLY AROUND 60 PERCENT. MOST OF
THE PRECIPITATION LOOKS TO BE LIGHT...UNLESS THE 23.12Z ECMWF IS
CORRECT...AND THEREFORE WAS NOT CONFIDENT ENOUGH TO ADJUST THE
PROBABILITIES. PRECIPITATION TYPE DOES BECOME A CONCERN AS THE
TROUGH MOVES CLOSER...RESULTING FROM 850MB TEMPS FALLING TO -2C IN
CENTRAL WISCONSIN TO -6C IN NORTHEAST IOWA. THIS COLD AIR ADVECTION
SHOULD ALLOW RAIN TO SLOWLY CHANGE TO SNOW...ESPECIALLY IN NORTHEAST
IOWA AND SOUTHWEST MINNESOTA...CLOSER TO THE CORE OF THE UPPER
TROUGH. THE COLD AIR ADVECTION MAY NOT BE STRONG ENOUGH TO IMPACT
THE DIURNAL CURVE...AS NOTED IN THE NAM/GFS. NONETHELESS...BOTH LOWS
ON TUESDAY NIGHT AND HIGHS ON WEDNESDAY ARE EXPECTED TO BE COOLER
THAN AS OF LATE.

WEDNESDAY NIGHT...BEST SHOT OF ACCUMULATING SNOW EXISTS DURING THIS
PERIOD...THOUGH THERE IS TOO MUCH UNCERTAINTY AS INDICATED BY QPF
FIELDS TO SPECULATE ON HOW MUCH SNOW. MODELS SHOW THE UPPER TROUGH
OVER IOWA HEADING EAST INTO ILLINOIS...WITH A MID-LEVEL
FRONTOGENESIS ZONE ON ITS NORTH AND NORTHWEST SIDE MOVING THROUGH
THE FORECAST AREA. NIGHT-TIME AND DYNAMIC COOLING SHOULD HELP MANY
AREAS SWITCH OVER TO SNOW...ESPECIALLY WEST OF THE MISSISSIPPI
RIVER. RAIN OR A RAIN/SNOW MIX COULD LINGER EAST OF THE RIVER...
THOUGH...DUE TO WARMER AIR WRAPPING AROUND THE LOW IN UPPER MICHIGAN
INTO THE FORECAST AREA. STAY TUNED TO LATER FORECASTS FOR AMOUNTS...
BUT RIGHT NOW IT SEEMS LIKE THEY SHOULD BE NO HIGHER THAN ADVISORY
CRITERIA. IN THE CASE OF THE 23.12Z NAM/GFS...THERE MAY NOT BE MUCH
SNOW AT ALL. ONLY THE 23.12Z ECMWF WOULD SUGGEST A POSSIBLE NEED FOR
AN ADVISORY.

.LONG TERM...THANKSGIVING THROUGH MONDAY

MODELS AND ENSEMBLES ARE IN FAIRLY GOOD AGREEMENT AT THE BEGINNING
OF THE PERIOD...SAY THROUGH FRIDAY...THEN THE DETERMINISTIC MODELS
(23.00Z ECMWF...23.06Z GFS AND 23.00Z CANADIAN) BEGIN TO DIVERGE.
THEREFORE CONFIDENCE DECREASES FOR THE WEEKEND INTO EARLY NEXT
WEEK...THOUGH THE 22.12Z ECMWF ENSEMBLES AND 23.00Z CANADIAN
ENSEMBLES PROVIDE QUITE A BIT OF HELP. THE PATTERN STARTS OFF WITH
TROUGHING OVER MOST OF THE MISSISSIPPI VALLEY THANKSGIVING
MORNING...WHICH PROGRESSES TO THE EAST COAST BY LATE FRIDAY IN
RESPONSE TO RIDGING MOVING INTO THE NORTHERN PLAINS. ALSO LATE ON
FRIDAY...THERE SHOULD BE SOME TROUGH IN THE WESTERN U.S....BUT ITS
DEPTH AT THAT TIME HAS A LOT OF SPREAD. THE 23.00Z CANADIAN SEEMS
TOO DEEP AND FAST AT THAT TIME COMPARED TO ENSEMBLES...AND THEREFORE
HAS BEEN DISCOUNTED. HOWEVER...ECMWF...GFS AND CANADIAN ENSEMBLES DO
SHOW THAT THE TROUGH IN THE WEST WILL LIKELY DEEPEN OVER THE
WEEKEND...AND COULD SPLIT INTO TWO. THIS APPEARS TO BE THE FAVORED
SCENARIO...WHICH ALSO THE 23.00Z ECMWF (AS WELL AS IT PREVIOUS RUNS)
INDICATES. THEREFORE FOR OUR AREA...INTEREST IS ON THE NORTHERN
PORTION OF THE TROUGH...WHICH LOOKS TO CROSS THE UPPER MISSISSIPPI
VALLEY SUNDAY NIGHT. RIDGING IS THEN EXPECTED TO BUILD ACROSS THE
NORTHERN ROCKIES ON MONDAY.

REGARDING THE DETAILS...SOME LINGERING DEFORMATION PRECIPITATION IS
EXPECTED ON THANKSGIVING...ESPECIALLY EAST OF THE RIVER. WET-BULB
ZERO HEIGHTS SUGGESTS MOST OF THE PRECIPITATION IN THE FORM OF
SNOW...THOUGH COULD NOT COMPLETELY RULE OUT SOME RAIN MIXING IN EAST
OF THE RIVER. CONFIDENCE IS TOO LOW TO INCLUDE RAIN...THOUGH.
CONDITIONS SHOULD DRY OUT FOR THURSDAY NIGHT...BUT CONCERN STILL
REMAINS THAT THE DEFORMATION PRECIPITATION COULD BE AROUND. FOR NOW
HAVE FOLLOWED THE DRIER 23.00Z/23.12Z ECMWF AND 23.12Z NAM/GFS. DRY
CONDITIONS THEN LOOK TO FOLLOW FOR FRIDAY THROUGH SATURDAY AS UPPER
LEVEL RIDGING BUILDS OVER THE FORECAST AREA. THE SATURDAY NIGHT
THROUGH SUNDAY NIGHT FORECAST REVOLVES AROUND THE NORTHERN PORTION
OF THE WESTERN TROUGH IMPACTING THE AREA. AT LEAST FOR SATURDAY
NIGHT AND SUNDAY...THE 23.00Z ECMWF DOES NOT SHOW ANY
PRECIPITATION...DESPITE A COLD FRONTAL PASSAGE AHEAD OF THE TROUGH.
THE 22.12Z ECMWF WAS SIMILAR AS WELL. THEREFORE HAVE KEPT THE PERIOD
DRY. SOME PRECIPITATION IS INDICATED SUNDAY NIGHT AS THE TROUGH
CROSSES THE AREA...WHICH THERMAL PROFILES WOULD SUGGEST AS SNOW
(850MB TEMPS DOWN TO -6C). THEREFORE HAVE INCLUDED SOME LOW
PROBABILITIES. WILL KEEP THESE LOW PROBABILITIES GOING INTO MONDAY
GIVEN TIMING ISSUES WITH THE TROUGH. IT SHOULD BE NOTED AGAIN THAT
THE PERIOD FROM SATURDAY NIGHT AND BEYOND IS VERY UNCERTAIN...SO THE
PERIOD IS SUBJECT TO CHANGE.

&&

.AVIATION...TONIGHT AND TUESDAY

LITTLE OVERALL CHANGE IN THE PATTERN IS EXPECTED FOR MUCH OF THE
PERIOD. A WEAK SURFACE BOUNDARY WILL REMAIN WEST OF THE REGION
MAINTAINING THE SOUTH FLOW OVER THE AREA...WITH GENERAL VFR
CONDITIONS EMBEDDED IN THIS FLOW. THE CONCERN COMES FOR LATE TONIGHT
INTO TUESDAY MORNING. A DEVELOPING CUT OFF UPPER LEVEL LOW OVER
WESTERN NEBRASKA THIS MORNING WILL SHIFT EAST INTO NORTHERN MISSOURI
BY 18Z TUESDAY. WITH THIS TRACK...BOTH THE 23.12Z NAM AND GFS
INDICATE THE BEST PV ADVECTION IN THE 500-300 MB LAYER WILL STAY TO
THE SOUTH OF THE TAF SITES WITH ONLY SOME WEAK OMEGA DEVELOPING
TUESDAY MORNING DUE TO SOME UPPER LEVEL DIFLUENCE IN THE NORTHEAST
QUADRANT OF THE UPPER LEVEL LOW. THE SURFACE LOW IS ANTICIPATED TO
MOVE INTO CENTRAL IOWA BY 18Z TUESDAY ALLOWING THE WEAK BOUNDARY TO
PROGRESS EAST INTO CENTRAL MINNESOTA. THIS WILL MAINTAIN THE SOUTH
TO SOUTHEAST FLOW AND THE LOW LEVEL WARM AIR ADVECTION. THE WARM AIR
ADVECTION WILL MAINTAIN 1-2 UBARS/S OF UP GLIDE ON THE 290K
ISENTROPIC SURFACE...SO THE QUESTION BECOME WHETHER THIS COMBINED
FROM THE WEAK LIFT FROM THE UPPER LEVEL LOW WILL BE ENOUGH TO
PRODUCE LOW CEILINGS AND SOME RAIN. THE 12Z GFS LOOKS TO SUFFER FROM
CONVECTIVE FEEDBACK PRODUCING A SPURIOUS SHORT WAVE TROUGH AND
PRECIPITATION BULLS EYE OVER THE AREA LATE TONIGHT AND TUESDAY
MORNING. THE NAM SUGGEST THE POSSIBILITY OF SOME LIGHT RAIN AND
MVFR/IFR CEILINGS FOR KRST WHILE THE LOCAL WRF KEEPS ALL THE
PRECIPITATION SOUTH OF THE TAF SITES. FOR NOW HAVE BLENDED THE NAM
AND WRF SOLUTIONS BY BRINGING IN VICINITY SHOWERS WITH MVFR CEILINGS
AT KRST AFTER 14Z TUESDAY. HAVE CONTINUED THE IFR VISIBILITY FROM
THE PREVIOUS FORECAST ALTHOUGH CONFIDENCE IS NOT HIGH GIVEN LACK OF
IFR CONDITIONS THAT DEVELOPED THIS MORNING IN SIMILAR CONDITIONS.
THINK THE RAIN WILL NOT GET TO KLSE SO KEPT THE CEILINGS VFR WHILE
MAINTAINING MVFR VISIBILITY IN SOME FOG.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

SHORT/LONG TERM...AJ
AVIATION...04

000
FXUS63 KARX 231001
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
401 AM CST MON NOV 23 2009

.SHORT TERM...TODAY THROUGH WEDNESDAY

AT 3 AM...A BAND OF RAIN WAS MOVING NORTH ACROSS PARTS OF
NORTHEAST IOWA...SOUTHEAST MINNESOTA...AND WEST CENTRAL WISCONSIN.
THIS RAIN WAS ASSOCIATED WITH MOISTURE TRANSPORT AND FRONTOGENESIS
AHEAD OF A SHORT WAVE TROUGH MOVING NORTHEAST ACROSS EASTERN SOUTH
DAKOTA...SOUTHERN MINNESOTA...IOWA...AND NORTHERN ILLINOIS. WHILE
THE COURSER 23.00Z MODELS ARE SHOWING THAT THIS RAIN WILL CONTINUE
THROUGH 23.12Z...THE 4 KM SPC NAM WRF INDICATES THAT THIS
RAIN WILL CONTINUE THROUGH AT LEAST 23.15Z AND THEN IT MOVES
QUICKLY NORTH THROUGH SOUTHEAST MINNESOTA AND WEST CENTRAL
WISCONSIN BETWEEN BETWEEN 23.15Z AND 23.18Z. SINCE THIS MODEL IS
DOING SO WELL THIS MORNING...THE FORECAST FOR TODAY WAS TRENDED
TOWARD IT.

LIKE THE PAST COUPLE OF DAYS...IT CONTINUES TO LOOK LIKE THE BEST
FORCING AND MOISTURE TRANSPORT WILL REMAIN WEST OF THE FORECAST
AREA THIS AFTERNOON AND EVENING. AS A RESULT...THESE FORECAST
PERIODS WERE LEFT DRY.

FROM LATE TONIGHT THROUGH TUESDAY NIGHT...THE MODELS HAVE
CONTINUED TO TREND A BIT FURTHER SOUTH WITH THE LOW PRESSURE AREA.
THE NAM/WRF IS BY FAR THE FARTHEST SOUTH WITH THIS SYSTEM. IT IS
ACTUALLY AN OUTLIER WHEN COMPARED WITH THE GFS...GEM...AND ECMWF.
DUE TO THIS...THE NAM/WRF WAS NOT USED FOR THESE TIME PERIODS.
THERE WAS AN ATTEMPT TO LOWER THE PRECIPITATION CHANCES ALONG AND
NORTH OF INTERSTATE 94 ON TUESDAY...BUT THERE WAS STILL ENOUGH CONCERN
THAT THIS PRECIPITATION MAY BE A BIT FURTHER NORTH THAT THERE WAS
LITTLE CHANGE TO THE PRECIPITATION CHANCES IN THESE AREAS. WHILE
THERE WAS NO CHANGE TO THIS...THERE WAS SOME TIMING FOR THE RAIN
ADDED TO THE GRIDS ON TUESDAY.

ON WEDNESDAY...IT CONTINUES TO LOOK LIKE COLD AIR ADVECTION WILL
MOVE INTO THE FORECAST AREA DURING THE AFTERNOON. DUE TO THIS A
NON DIURNAL TEMPERATURE CURVE WAS USED. IN ADDITION...THE SNOW
CHANCES WERE REMOVED ACROSS WESTERN WISCONSIN...AND DELAYED UNTIL
THE MID TO LATE AFTERNOON IN NORTHWEST IOWA AND SOUTHEAST MINNESOTA.

.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY

THE 23.00Z GFS...GEM...AND ECMWF CONTINUES TO SHOW THAT A
SECONDARY SHORT WAVE TROUGH WILL DROP INTO THE LONG WAVE TROUGH
LOCATED ACROSS NORTHERN AND CENTRAL PLAINS...MID AND UPPER
MISSISSIPPI RIVER VALLEYS...GREAT LAKES AND OHIO VALLEY ON
WEDNESDAY NIGHT. THIS GREATLY ENHANCES THE FRONTOGENESIS ACROSS
WISCONSIN...EASTERN MINNESOTA...AND NORTHERN IOWA. IN ADDITION...
THE SURFACE LOW SLOWLY DEEPENS AS IT MOVES NORTHEAST ACROSS
SOUTHERN AND EASTERN WISCONSIN. AS THIS OCCURS...THE GFS INDICATES
THAT WARM AIR ALOFT /POSSIBLY RELATED TO A TROWAL/ IS BROUGHT BACK
WESTWARD INTO THE FORECAST AREA. MEANWHILE THE ECMWF KEEPS THIS
WARM AIR FURTHER EAST AND THE PRECIPITATION TYPE REMAINS IN THE
FORM OF SNOW. WITH SOME UNCERTAINTY IN THE PRECIPITATION TYPE
ACROSS WISCONSIN...A MIX OF RAIN AND SNOW WAS INTRODUCED INTO THE
WEATHER GRIDS FOR OUR WISCONSIN COUNTIES FOR WEDNESDAY NIGHT AND
THANKSGIVING. MEANWHILE FURTHER WEST ACROSS SOUTHEAST MINNESOTA
AND NORTHEAST IOWA...IT LOOKS LIKE THE PRECIPITATION TYPE WILL BE
MAINLY SNOW.

A MAJORITY OF THE GFS MREF PLUMES SHOW LESS THAN 2 INCHES OF SNOW
WITH THIS SYSTEM. HOWEVER THERE ARE TWO OF THEM WHICH HAVE
SNOWFALL TOTALS AROUND 6 INCHES. WHILE THERE WILL LIKELY BE A MIX
OF RAIN AND SNOW IN LA CROSSE...THE PRECIPITATION TYPE PLUMES
STILL SHOW SOME LIGHT SNOW ACCUMULATIONS /LESS THAN AN INCH/.
MEANWHILE WITH THE PRECIPITATION STAYING IN THE FORM OF SNOW IN
THE EMF...THE SNOWFALL AMOUNTS ACROSS THE FORECAST AREA RANGE
FROM 4 TO 9 INCHES. NEEDLESS TO SAY...THIS SYSTEM STILL BEARS
SOME WATCHING.

&&

.AVIATION...TODAY AND TONIGHT

BAND OF -RA CONTINUED TO EXTEND FROM NEAR DLH SOUTH ACROSS RST AND
INTO SOUTHERN IA. RAIN WAS ASSOCIATED WITH SOME FRONTOGENETIC
FORCING...ISENTROPIC UPGLIDE...AND IN AN AREA OF 850MB MOISTURE
TRANSPORT. LATEST RUC13 AND NAM12 SHIFTS THIS FORCING WEST/NORTHWEST
LATE THIS MORNING...AND SO SHOULD THE LIGHT RAIN. OTHER MESO MODELS
//SPCWRF...ETC// ALSO SUPPORT THIS. LATEST FOG/STRATUS SATELLITE
IMAGERY...COUPLED WITH SFC OBS...PLACED CEILINGS ACROSS THE LOCAL
AREA FROM 6 TO 10 KFT. SATELLITE TRENDS WERE SHIFTING THIS AC DECK TO
THE NORTH/NORTHWEST WITH WIND PROFILERS AND VAD WINDS SHOWING
BACKING TO THE SOUTHEAST IN THE 925-700 MB LAYER OVER THE PAST FEW
HOURS. JUST TO THE EAST OF THIS CLOUD MASS THE SKIES WERE
CLEAR...WHICH WAS RESULTING IN SOME FOG AND STRATUS FORMATION OVER
NORTHERN ILL/SOUTHEAST WI. WILL HAVE TO MONITOR TRENDS BEFORE 12Z
ISSUANCE TO SEE IF SOME OF THESE LOWER CEILINGS/FOG COULD IMPACT THE
KLSE. BELIEVE KRST WILL BE TOO FAR WEST. REGARDLESS....3-5SM MVFR BR
SHOULD PERSIST THROUGH THE MORNING.

UPPER LEVEL TROUGH WILL BE MOVING OVER THE SOUTHERN PLAINS BY 12Z
TUES...AND THERE LOOKS TO BE A DECENT SURGE OF MOISTURE NORTHWARD
AHEAD OF THIS SYSTEM. CEILINGS WILL GRADUALLY LOWER...POTENTIALLY
IFR CONDITIONS BY TUES NIGHT. HOWEVER...IF THE CURRENT MID CLOUDS
STAY MOSTLY WEST/NORTH OF KRST/KLSE TONIGHT...SOME FG AND STRATUS
DEVELOPMENT COULD OCCUR BY 12Z TUES. NUMERICAL GUIDANCE POINTS TO THIS
POSSIBILITY. CONFIDENCE NOT PARTICULARLY HIGH AT THE MOMENT...BUT
TRENDS WILL HAVE TO BE MONITORED. WILL HINT AT THIS POSSIBILITY...
WITH LATER UPDATES REFINING THE POTENTIAL.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

SHORT/LONG TERM...BOYNE
AVIATION...RIECK

000
FXUS63 KMKX 230943
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
343 AM CST MON NOV 23 2009

FORECAST FOCUS ON FOG AND CLOUDS TODAY...SYSTEM FOR TUESDAY
THROUGH THANKSGIVING DAY.

LATEST WATER VAPOR IMAGERY INDICATED AN UPPER LOW OVER
MONTANA...WITH A DOWNSTREAM SHORTWAVE TROUGH FROM SOUTHEAST SOUTH
DAKOTA TO SOUTHERN MISSOURI. AT THE SURFACE...HIGH PRESSURE WAS
FOUND EAST OF MAINE...WITH ITS AXIS EXTENDING WEST INTO SOUTHERN
WISCONSIN. AREA OF LIGHT RAIN AND DRIZZLE ASSOCIATED WITH LOW
LEVEL FRONTOGENESIS WAS FOUND FROM WESTERN WISCONSIN TO CENTRAL
IOWA.

.TODAY AND TONIGHT...HIGH CLOUDS STREAMING INTO THE AREA FROM THE
SOUTH. IN ADDITION...AREA OF LOW CLOUDS HAS FORMED ACROSS THE
EASTERN COUNTIES...WHICH HAS BROUGHT VISIBILITIES WITH THE FOG OUT
OF DENSE FOG CRITERIA. THIS AREA OF CLOUDS SHOULD PERSIST THROUGH
THE MORNING WITH THE EXPECTED LIGHT WINDS AND TEMPERATURE
INVERSION. SO...NOT EXPECTING WIDESPREAD DENSE FOG...AND HAVE
CANCELLED THE DENSE FOG ADVISORY FOR THE EASTERN COUNTIES. STILL
MAY BE PATCHY DENSE FOG DURING THE EARLY MORNING HOURS.

SHOULD SEE SOME BREAKS IN THE HIGH CLOUDS TODAY ACROSS THE WESTERN
COUNTIES...AND IN THE AFTERNOON IN THE EAST. HIGHS SHOULD REMAIN
MILD...AND REACH THE LOWER TO MID 50S ACROSS THE AREA. FOG
EXPECTED ONCE AGAIN TONIGHT WITH LIGHT WINDS AND LINGERING LOW
LEVEL MOISTURE UNDER THE TEMPERATURE INVERSION. THE EXPECTED LOW
STRATUS SHOULD LIMIT ANY DENSE FOG TO ISOLATED AREAS.

.TUESDAY THROUGH THANKSGIVING DAY...CONTINUED TO FOLLOW THE
CONSISTENT ECMWF MODEL WITH THE SYSTEM EXPECTED TO AFFECT THE AREA
DURING THIS PERIOD. SURFACE LOW WILL MOVE FROM NEAR KANSAS CITY TO
SOUTHEAST IOWA ON TUESDAY...THEN INTO SOUTHERN WISCONSIN TUESDAY
NIGHT. LOW TO MID LEVEL FRONTOGENESIS WITH THIS SYSTEM MOVES
NORTHEAST THROUGH THE AREA TUESDAY THROUGH TUESDAY NIGHT. EXPECT
AREA OF RAIN TO MOVE INTO THE AREA MAINLY TUESDAY AFTERNOON AND
TUESDAY NIGHT. UPPER LOW MOVING THROUGH THE AREA TUESDAY NIGHT
ALSO HELPING WITH THE UPWARD VERTICAL MOTION FIELDS. KEPT LIKELY
POPS FOR TUESDAY AFTERNOON AND TUESDAY NIGHT.

THE LOW THEN MOVES NORTHEAST TO NORTHERN LAKE MICHIGAN
WEDNESDAY...WITH A TROUGH AXIS SHIFTING SOUTHEAST THROUGH THE AREA
WEDNESDAY NIGHT INTO THANKSGIVING DAY. ANOTHER UPPER LOW SHIFTS
EASTWARD FROM IOWA TO NORTHERN ILLINOIS WEDNESDAY NIGHT...THEN
EAST ON THANKSGIVING DAY. LOW TO MID LEVEL FRONTOGENESIS BAND DOES
SHIFT ACROSS THE AREA DURING THIS TIME.

COLDER AIR MOVES SOUTHEAST THROUGH THE AREA LATER WEDNESDAY AND
WEDNESDAY NIGHT. HOWEVER...925MB TEMPERATURES AND FORECAST
SOUNDINGS SHOW PRECIPITATION TYPE SHOULD REMAIN ALL RAIN
WEDNESDAY...PERHAPS CHANGING TO A MIX WEDNESDAY NIGHT AND
THANKSGIVING DAY. CURRENT THINKING IS TO HAVE LIKELY POPS THROUGH
THANKSGIVING DAY...BUT LEAVE A RAIN TO A MIX TRANSITION DURING
THIS TIME. IT DOES NOT LOOK LIKE ACCUMULATING SNOW IS POSSIBLE
GIVEN THE WARM LOW LEVEL TEMPERATURE PROFILES. STAY TUNED...

.THURSDAY NIGHT THROUGH SUNDAY...UPPER LOW SHIFTS OUT OF THE
REGION THURSDAY NIGHT AND FRIDAY...WITH LINGERING LOW POPS. QUIET
WEATHER THEN EXPECTED INTO NEXT WEEKEND WITH A HIGH PRESSURE RIDGE
CROSSING THE AREA.

&&

.AVIATION...AN IFR TO LIFR STRATUS DECK HAS DEVELOPED OVER SERN
WI AND WILL DEVELOP WWD INTO PORTIONS OF SOUTH CENTRAL WI THIS AM.
IFR TO MVFR VSBYS WILL PREVAIL AS WELL WITH LOCAL LIFR VSBYS. THE
STRATUS AND FOG WILL PERSIST THIS AM AND BEGIN TO IMPROVE BY MID
MORNING. LOCALIZED MVFR STRATUS AND VSBYS MAY LINGER INTO THE
AFTERNOON WITH ONLY LGT ELY WINDS AND LITTLE MIXING TO IMPROVE
CONDITIONS FURTHER.

A LGT SELY FLOW AND GOOD RADIATIONAL COOLING WILL PERSIST AGAIN
TNT WITH STRATUS AND FOG FORMATION ONCE AGAIN. IFR VSBYS WILL
PREVAIL WITH LIFR TO VLIFR IN LOW LYING AREAS. SCT-BKN STRATUS
WILL LIKELY DEVELOP WITH BKN STRATUS IN THE IFR TO VLIFR RANGE.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&

$$

SHORT/LONG TERM...08/WOOD
AVIATION/MARINE...20/GEHRING

000
FXUS63 KGRB 230936
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
336 AM CST MON NOV 23 2009

.SHORT TERM...TODAY THROUGH TUESDAY...THE POTENTIAL FOR DENSE FOG
THIS MORNING AND PCPN TRENDS ON TUESDAY ARE THE MAIN FCST CONCERNS.

ASIDE FROM A FEW SPRINKLES OVER OUR FAR NW COUNTIES...THE PCPN HAS
SHIFTED WEST OF GRB CWA EARLY THIS MORNING. WITH THE MAIN MOISTURE
BAND EXPECTED TO STAY TO OUR WEST NEAR A DEVELOPING FRONTAL BOUNDARY
TODAY INTO TONIGHT...AND WEAK SFC RIDGING IN PLACE OVER NE WI...
EXPECT MAINLY DRY CONDITIONS TO PREVAIL. AS THE UPPER LOW LIFTS INTO
THE UPPER MIDWEST AND THE LFQ OF A JET STREAK PUNCHES INTO THE RGN
ON TUESDAY...EXPECT SOME PATCHY LIGHT RAIN TO DEVELOP DURING THE
AFTERNOON. THE PREVIOUS FCST HAD THIS SCENARIO WELL COVERED...SO
ONLY MINOR CHANGES WERE MADE.

CLOSELY MONITORING FOG POTENTIAL EARLY THIS MORNING. IN AREAS WHERE
SKIES HAD CLEARED (NE/C/EC WI)...FOG AND LOW STRATUS HAD DEVELOPED.
A FEW SITES HAD ALREADY DROPPED TO 1/4SM...BUT WIDESPREAD DENSE
FOG HAD NOT YET DEVELOPED. BOUNDARY LAYER WINDS ARE EXPECTED TO
DIMINISH TO AROUND 10 KTS BY 12Z...WHICH MAY ALLOW THE STRATUS
DECK TO LOWER TO THE SFC. IF THIS HAPPENS...WILL NEED TO ISSUE A
DENSE FOG ADVISORY. WILL WATCH TRENDS OVER THE NEXT HOUR OR
TWO...AND IF NEEDED...ISSUE A DENSE FOG ADVISORY WELL BEFORE RUSH
HOUR BEGINS.

FOG MAY ALSO BE A CONCERN TONIGHT...ESP IN NE/EC WI...WHERE CLOUD
COVER NOT NOT BE AS THICK...AND BOUNDARY LAYER WINDS WILL BE LIGHT.

MIXING THROUGH 925-900 MB SUPPORTS HIGH TEMPERATURES IN THE LOWER TO
MIDDLE 50S TODAY...CLOSE TO MET GUIDANCE. USED A BLEND OF MET/MAV
GUIDANCE FOR TONIGHT AND TUESDAY.

.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
AFTER LOOKING AT THE MODELS OVER THE LAST FOUR NIGHTS...CONFIDENCE
IS HIGH TO ADD SOME BEEF TO THE FORECAST FOR TUESDAY NIGHT INTO
THANKSGIVING DAY. MODELS CONTINUE TO SHOW UPPER LOW ACROSS THE
MIDDLE MISSISSIPPI RIVER VALLEY TUESDAY AFTERNOON MOVING INTO THE
WESTERN GREAT LAKES REGION BY 12Z WEDNESDAY. MEANWHILE...MORE ENERGY
IS DIVING SOUTHEAST OUT OF CANADA ON 110 TO 120 KNOT JET STREAK.
BY 12Z WEDNESDAY...MODELS CONTINUE TO SHOW A 500MB CLOSED LOW OVER
THE WESTERN GREAT LAKES AND ANOTHER TROUGH 500MB TROUGH DROPPING
INTO THE THE EASTERN DAKOTAS. THIS ENERGY WILL CONTINUE TO DIVE
SOUTHEAST AND THESE TWO 500MB FEATURES WILL THEN COMBINED INTO ONE
CLOSED 500MB LOW OVER NORTHERN ILLINOIS WEDNESDAY NIGHT. THIS
SYSTEM WILL THEN GRADUALLY PULL AWAY FROM THE AREA ON THANKSGIVING
DAY. THIS WILL MEAN A PROLONG PERIOD OF PRECIPITATION THAT WILL
BEGIN TUESDAY NIGHT AND CONTINUE THROUGH MUCH OF THANKSGIVING DAY.

FOR TUESDAY NIGHT...LOW PRESSURE WILL MOVE FROM IOWA INTO SOUTHEAST
WISCONSIN. RAIN WILL SPREAD NORTHWARD INTO THE AREA. THE FAR NORTH
WILL BE HOVERING AROUND 0C AT 850MB...BUT 925MB TEMPERATURES WAY TOO
WARM TO SUPPORT SNOW. HAVE INCREASED TO HIGH CHANCE POPS OVER THE
FAR NORTH AND WENT WITH LIKELY OVER THE SOUTHERN TWO THIRDS OF THE
FORECAST AREA. DID RAISE MINIMUM TEMPERATURES A FEW DEGREES BASED ON
MODEL SURFACE FORECAST TEMPERATURES AND NUMERICAL GUIDANCE.

ON WEDNESDAY...SURFACE LOW IS EXPECTED TO MOVE FROM SOUTHEAST WISCONSIN
INTO CENTRAL UPPER MICHIGAN. INVERTED TROUGH EXPECTED TO LINGER ACROSS
NORTHEAST INTO CENTRAL WISCONSIN DURING THE DAY. THIS WILL BE ONE OF
THE MORE UNUSUAL METEOROLOGICAL SET UPS AS THE MODELS ARE INDICATING
THE WARMEST 925MB TEMPERATURES NORTH OF THE INVERTED TROUGH. NORMALLY
DO NOT SEE THAT TOO OFTEN. THE COLDEST 850MB/925MB TEMPERATURES WILL
WRAP AROUND TO THE SOUTH OF THE FORECAST AREA. ANOTHER PROBLEM IS
THAT AIR MASS AHEAD OF THE SYSTEM AND NEAR THE INVERTED TROUGH IS
TOO MILD FOR SNOW...SO DO NOT EXPECT ANY SNOW ACROSS THE AREA ON
WEDNESDAY.

FOR WEDNESDAY NIGHT...THE UPPER LEVEL FEATURES WILL CONSOLIDATE
INTO ONE CLOSED UPPER LOW. THE SURFACE LOW WILL THEN REMAIN NEARLY
STATIONARY THROUGH MUCH OF WEDNESDAY NIGHT WITH A SLOW MOVEMENT
OF THE INVERTED TROUGH. PRECIPITATION TYPE FORECASTING FOR THIS
PERIOD IS DIFFICULT AS THE WARMEST 925MB TEMPERATURES WILL DROP
SOUTHEAST INTO NORTHEAST WISCONSIN. THE SLOW PROGRESSION OF THE
INVERTED TROUGH IMPEDES THE COLDER AIR TO WORK INTO THE FORECAST
AREA. BASED ON THE 1000/850MB THICKNESS PATTERN AND BOUNDARY
LAYER TEMPERATURES...WILL HAVE RAIN ACROSS THE EAST AND A RAIN
SNOW MIX OVER THE WEST.

FOR THURSDAY...INVERTED TROUGH SWINGS SLOWLY SOUTHEAST INTO
SOUTHEAST WISCONSIN. AGAIN BOUNDARY LAYER TEMPERATURES WILL BE
CRITICAL FOR ANY ACCUMULATING SNOWFALL. THICKNESS PATTERNS
WOULD SUGGEST MORE SNOW IN THE WEST AND MAINLY RAIN/SNOW MIX
IN THE EAST. BOUNDARY LAYER TEMPERATURES OFF THE MODELS WOULD
SUGGEST MORE OF A RAIN SNOW MIX IN THE WEST WITH THE EXCEPTION
OVER THE HIGHER TERRAIN OF THE FAR NORTHWEST PORTION OF THE
FORECAST AREA. OVER THE EAST...BOUNDARY LAYER TEMPERATURES WOULD
SUGGEST MAINLY RAIN. AS A COMPROMISE...DID ADD A CHANCE OF SNOW
OVER THE EAST EXCEPT IN DOOR COUNTY DURING THE LATE AFTERNOON.

AS YOU CAN SEE...A VERY UNIQUE AND COMPLEX SITUATION SETTING UP
FOR THE BUSY TRAVEL DAY BEFORE THANKSGIVING AND THANKSGIVING DAY
ITSELF. LATER SHIFTS CAN FINE TUNE THE DETAILS. WILL HIGHLIGHT
ANY SNOW POTENTIAL TO WEDNESDAY NIGHT INTO THURSDAY AND CONFINE
TO LOCATIONS NORTHWEST OF GREEN BAY AND THE FOX CITIES.

THE REMAINDER OF THE FORECAST LOOKS TO BE IN GOOD SHAPE WITH
LITTLE CHANGES MADE.
&&

.AVIATION...WIDESPREAD LIFR/VLIFR VSBYS/CIGS IN FOG ARE
ANTICIPATED ACROSS MUCH OF NE/EC/C WI THIS MORNING...DUE TO
FAVORABLE RADIATIONAL COOLING CONDITIONS AND MOIST FLOW OFF LAKE
MICHIGAN. LINGERING CLOUD COVER OVER NC WI MAY KEEP CIGS AND
VSBYS FROM DROPPING AS LOW THERE. THE FOGGY CONDITIONS SHOULD
IMPROVE BY AROUND 15Z TODAY. MORE FOG IS PSBL TONIGHT...ESP IN
NE/EC WI...WHERE PARTLY CLOUDY SKIES AND LGT EAST WINDS OFF LK
MICHIGAN WILL ONCE AGAIN PRODUCE FAVORABLE CONDITIONS FOR FOG
DEVELOPMENT. GENERALLY DRY CONDITIONS ARE ANTICIPATED UNTIL
TUES AFTERNOON...WHEN SOME PATCHY LGT RAIN MAY ARRIVE.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$
KIECKBUSCH/ECKBERG

000
FXUS63 KMKX 230532
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
1132 PM CST SUN NOV 22 2009

.UPDATE...

PATCHY DENSE FOG MAY BECOME MORE WIDESPREAD OVER PORTIONS OF
SOUTHEAST WISCONSIN.  HAVE ISSUED DENSE FOG ADVISORY.

&&

.PREV DISCUSSION... /ISSUED 251 PM CST SUN NOV 22 2009/

TONIGHT...RIDGING TO THE EAST WILL CONTINUE TO FEED DRY AIR BACK
INTO THE AREA. CLOUD EDGE OVER THE WESTERN CWA HAS BEEN SLOWLY
RETREATING WEST THIS AFTERNOON AND THIS SHOULD CONTINUE A BIT MORE
OVERNIGHT. OTHERWISE GENERALLY CLEAR ELSEWHERE OVER THE CWA WITH
FOG AGAIN A PROBLEM WITH HIGH DWPNTS GOING INTO THE EVENING AND
GOOD RADIATIONAL COOLING. CLOUDS/CLEAR SKIES/FOG/VALLEYS/HILLS/WATER
MAKE A DIFFICULT MIN TEMP FORECAST.

MONDAY/MONDAY NIGHT...THE FIRST OF MANY SHORT WAVES DIGGING A
LARGE MID LEVEL TROF OVER THE CENTER OF THE COUNTRY WILL TRACK
TOWARD AND THROUGH OUR AREA. THE COLUMN WILL LIKELY REMAIN TOO DRY
FOR ANY PRECIP...BUT CLOUDS SHOULD INCREASE. TEMPS WILL REMAIN
MILD IN THE DEEP SOUTHERLY FLOW.

TUESDAY/TUESDAY NIGHT...A SECOND...MUCH STRONGER SHORT WAVE
BEGINS TO EJECT OUT OF THE CENTRAL/SOUTHERN PLAINS ON TUESDAY.
THE ASSOCIATED SFC LOW SHOULD TRACK INTO IA DURING THE DAY. HERE
THE GFS AND THE ECMWF ARE IN GOOD AGREEMENT WHILE THE NAM IS
SLOWER. GOING WITH GFS/ECMWF. RAIN TO SPREAD INTO THE AREA MAINLY
DURING THE AFTERNOON...THEN CONTINUE THROUGH TUESDAY NIGHT. THE
SFC LOW SHOULD TRACK RIGHT ACROSS SOUTHERN WISCONSIN TUESDAY
NIGHT. HIGH POPS THROUGH THIS PERIOD. TEMPERATURES REMAIN WARM
ENOUGH TO KEEP IT ALL RAIN.

WEDNESDAY/WEDNESDAY NIGHT...THIS IS THE MOST INTERESTING PERIOD
OF THE FORECAST. A THIRD MORE ENERGETIC SHORTWAVE WILL DIVE INTO
THE NORTHERN PLAINS AND INTO THE BACKSIDE OF THE SECOND SHORTWAVE
MOVING THROUGH THE WESTERN/CENTRAL GREAT LAKES AT THIS TIME. THIS
PULLS BACK ON THE SECOND SHORTWAVE AND THEY DO THE CLASSIC
FUJIWARA INTERACTION AS THE ENTIRE MID LEVEL TROF AMPLIFIES
STRONGLY FROM THE GREAT LAKES TO THE LOWER MISSISSIPPI VALLEY.
PRECIP ON WEDNESDAY SHOULD LET UP...BUT STILL LIKELY EVERYONE WILL
MEASURE. COLD AIR WILL BE POURING INTO THE AREA AS THE THIRD
SHORTWAVE DIGS IN. AS THE SHORTWAVE ARRIVES LATE IN THE DAY OR
EARLY EVENING...THE PRECIP WILL INCREASE AGAIN. THE RAIN IN THE
SOUTHWEST CWA SHOULD BECOME MIXED WITH SNOW DURING THE AFTERNOON.
WEDNESDAY NIGHT THE COLD AIR CONTINUES TO OVERSPREAD THE AREA.
THE WRN CWA MOSTLY LIKELY WILL SEE THE LONGEST PERIOD OF ALL
SNOW...WHILE THE EAST WILL BE SLOWER TO TRANSITION. THE NEW ECMWF
HAS COME IN AND IT LOOKS INTERESTING. THE AMOUNT OF QPF AND ITS
COLD TEMPS WOULD SUGGEST HIGH POTENTIAL OF ACCUMULATING SNOWS
WEDNESDAY NIGHT INTO THURSDAY...POTENTIALLY A HEADLINE MAKER. OF
COURSE THIS IS THE HOLIDAY AND LOTS OF FOLKS WILL BE TRAVELING.
CAUTION IS ADVISED AS IT SHOULD BE NOTED AGAIN HOW COMPLICATED
THIS STORM SYSTEM WILL BE. LOTS OF RUN TO RUN VARIABILTY IN
SOLUTIONS IS EXPECTED OVER THE NEXT COUPLE OF CYCLES.

THE SNOW SHOULD CONTINUE THROUGH THURSDAY...THANKSGIVING...AND
HAVE TOTAL ACCUMULATIONS RANGING FROM 1 TO 3 INCHES FOR NOW. THIS
IS SUBJECT TO CHANGE.

BEYOND THURSDAY...RIDGING ARRIVES AND LOOKS TO KEEP US DRY AND
SEASONABLE THROUGH NEXT WEEKEND.

AVIATION...SKIES WILL REMAIN MOSTLY CLEAR IN THE EAST
TONIGHT...WITH DECREASING CLOUDS IN THE WEST. WINDS WILL BE LIGHT
AGAIN...LIKELY ALLOWING THE FORMATION OF FOG LATER TONIGHT. WITH
VISBYS ALREADY NEAR OR AT MVFR DUE TO HZ...EXPECT PREVAILING MVFR
CONDITIONS THROUGH THE EVENING...WITH IFR VISBYS POSSIBLE AFTER
MIDNIGHT. COULD EVEN SEE A FEW LIFR OBS TOWARD DAYBREAK IF WINDS GET
LIGHT ENOUGH. EXPECT QUIET CONDITIONS AGAIN TOMORROW...WITH MID AND
HIGH LEVEL CLOUDS IN THE AFTERNOON.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 9 AM CST MONDAY FOR WIZ052-059-060-065-
     066-070>072.

LM...NONE.
&&

$$

SHORT/LONG TERM...06
AVIATION/MARINE...06

000
FXUS63 KGRB 230317 AAA
AFDGRB

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GREEN BAY WI
917 PM CST SUN NOV 22 2009

.UPDATE...STLT AND RADAR TRENDS SUGGEST MODELS HAVE THE RIGHT IDEA
IN SHOVING PCPN BACK NWWD AND OUT OF THE FCST AREA WITH TIME. PREV
FCST HAD THAT HANDLED PRETTY WELL...SO ONLY NEED TO MAKE SOME
MINOR ADJUSTMENTS TO LINE THINGS UP WITH CURRENT RADAR.

TEMPS HOLDING UP...ESP ACRS THE W WHERE THERE ARE THICKER CLOUDS.
WL TWEAK MINS UP A LITTLE BASED ON CURRENT READINGS.

FOG AGAIN A CONCERN IN THE E WHERE WINDS ARE LGT...DWPTS HIGH FOR
THIS TIME OF YEAR...AND NOT MUCH CLOUDINESS EXISTS. VSYBS HOLDING
UP A LITTLE BETTER THAN THE PAST COUPLE NGTS...AND PEHAPS SOME CI
ARRIVING LATER TNGT WL HELP ALSO. BUT THINK WE WL AT LEAST SOME
DENSE FOG TO FORM IN LOW-LYING AREAS AGAIN. CURRENT FCST ALREADY
HAS AREAS OF DENSE FOG AFTER MIDNIGHT AND THAT LOOKS ON TRACK. WL
HIT A LITTLE HARDER BY REPLACING CURRENT NOW WITH AN SPS...BUT
DON/T PLAN ON ISSUING ANY ADVISORIES AT THIS POINT.

MODELS SEEM TO BE CONVERGING ON IDEA OF SLOW MOVG STORM SYSTEM
GRADUALLY STRENGTHENING ACRS THE AREA THROUGH MID-WEEK. TEMPS
ALOFT COOL WITH TIME...BUT BOUNDARY LAYER TEMPS WL PROBABLY BE
THE DETERMINING FACTOR GOVERNING THE TIMING OF THE CHANGEOVER TO
SNOW. CURRENT PROGS SUGGEST CHANGE SOMETIME WED NGT OVER THE W/SW
PART OF THE AREA...AND POSSIBLY MUCH LATER IN THE N/E. A SECONDARY
SHRTWV DIGGING ARND BASE OF COMPLEX UPR TROF MAY ALLOW FOR MORE
THAN JUST THE SCT LGT PCPN TYPICALLY FOUND ON THE W/SW SIDE OF SFC
SYSTEMS. AND IT WL BE FALLING DURING VERY HEAVY HOLIDAY TRAVEL
PERIOD. SITN ALREADY WELL DETAILED IN HWO...SO WORD SHOULD BE
STARTING TO GET OUT.

SKOWRONSKI
&&

.PREV DISCUSSION...ISSUED AT 311 PM CST SUN NOV 22 2009...

SHORT TERM...TONIGHT AND MONDAY.

LATEST RUC ANALYSIS AND VIS/IR/WV/RADAR IMAGERY SHOW THE STATE OF
WISCONSIN LOCATED BETWEEN LOW PRESSURE OVER THE NORTHERN PLAINS AND
HIGH PRESSURE OVER THE EASTERN GREAT LAKES.  DEEP LAYER SOUTHWEST
FLOW CONTINUES TO PUMP SEASONABLE WARM CONDITIONS AND AMPLE MOISTURE
INTO THE REGION.  LIGHT 295K ISENTROPIC ASCENT AND 700MB CONVERGENCE
SHOWERS AND SPRINKLES HAVE REMAINED MOSTLY WEST OF THE FOX VALLEY SO
FAR TODAY WITH ONLY A HUNDREDTH OR TWO REPORTED.  MORE WIDESPREAD
SHOWER ACTIVITY IS OCCURRING ACROSS IOWA AHEAD OF A RESPECTABLE
SHORTWAVE TROUGH.  FORECAST CONCERNS ARE TWO FOLD...THE FIRST BEING
PRECIP CHANCES...AND THE SECOND BEING DENSE FOG POTENTIAL TONIGHT
INTO TOMORROW.

TONIGHT...THE 850-700MB THETAE AXIS WILL STILL BE POSITIONED ACROSS
THE NORTHWEST HALF OF THE FORECAST AREA.  ALTHOUGH BEST 295K
ISENTROPIC ASCENT WILL SHIFT NORTH OF THE REGION...THE PRESENCE OF
THIS THETAE AXIS WILL KEEP THE SMALL CHANCE OF LIGHT
SHOWERS/SPRINKLES ACROSS THIS PORTION OF THE FORECAST AREA.
ADDITIONAL BUT STILL WEAK LIFT WILL ARRIVE AFTER MIDNIGHT WHEN THE
RIGHT ENTRANCE REGION OF A JET STREAK SHIFTS EAST INTO NORTH-CENTRAL
WISCONSIN.  UPSTREAM TRENDS SUGGEST AN INCREASE IN POPS IS WARRANTED
...WHICH BLENDS BETTER WITH NEIGHBORING OFFICES.  MEANWHILE...WINDS
WILL BACK AHEAD OF THE NEXT SHORTWAVE MOVING ACROSS THE CENTRAL
PLAINS...AND WILL DRAW DRIER AIR FROM THE SE INTO MUCH OF NORTHEAST
WISCONSIN.  SHOULD SEE CLEARING SKIES TONIGHT WITH MORE OF AN
ONSHORE FLOW DEVELOPING.  AS A RESULT...LOW LEVEL MOISTURE SHOULD
REMAIN PLENTIFUL FOR FOG FORMATION.  BL WINDS APPEAR TO BE THE
LIMITING FACTOR TONIGHT...BUT ARE PROJECTED TO FALL OFF FROM 15 TO
10 KTS AFTER MIDNIGHT.  UPS FOG FORECASTING TECHNIQUE SUGGESTS THIS
IS MARGINAL FOR FOG FORMATION...BUT THINK POTENTIAL IS THERE FOR
DENSE FOG ONCE AGAIN...AND WILL BOOST FOG WORDING TO INCLUDE PATCHY
DENSE FOG ACROSS THE FOX VALLEY AND POINTS EAST.  IF ENOUGH
DECOUPLING OCCURS BY MORNING...WOULD NOT BE SURPRISED TO SEE A DENSE
FOG ADVISORY ISSUED.

TOMORROW...FOG WILL STILL BE AN ISSUE TOMORROW MORNING AND WILL
PROBABLY NOT SEE THE FOG LIFT UNTIL 15-16ZISH WITH THE LOW NOVEMBER
SUN ANGLE.  PERHAPS WILL STILL SEE A LINGERING SPRINKLE ACROSS VILAS
COUNTY ALSO DURING THE MORNING BEFORE THE JET STREAK SHIFTS NORTH BY
MIDDAY.  THE SHORTWAVE ACROSS THE CENTRAL PLAINS WEAKENS AS IT
ARRIVES DURING THE AFTERNOON...BUT THE SE FLOW WILL KEEP THE
MID-LEVELS DRY. WONT EXACTLY SEE ALOT OF SUNSHINE DUE TO AN AMPLE
CIRRUS SHIELD OVERHEAD...BUT THAT SHOULD NOT STOP HIGHS FROM
REACHING INTO THE UPPER 40S NORTH TO MID 50S SOUTH.

LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY. FOCUS OF THIS
FORECAST CONTINUES TO BE WITH RESPECT TO THE MESSY EVOLVING UPPER
LOW SYSTEM TO AFFECT THE GREAT LAKES AND UPPER MIDWEST REGION LATE
TUESDAY INTO THURSDAY. MANY ISSUES REMAIN WITH TODAYS MODEL RUNS
INCLUDING PCPN TYPE...TIMING AND LOCATION OF PIECES OF ENERGY
WITHIN THE DEEPENING UPPER LOW SYSTEM. FORECAST SOUNDINGS INDICATE
SYSTEM TYPE WILL MAINLY BE RAIN TUESDAY INTO WEDNESDAY. SOME
EVAP POTENTIAL WITH THIS SYSTEM AS DRY NE FEED WRAPS INTO THE
SYSTEM THROUGH WEDNESDAY.  BUT MAIN CAA ON UPPER JET AND SECONDARY
MAIN SHORTWAVE TO DRIVE TOWARD SW WI INTO IA LATER WEDNESDAY AND
WEDNESDAY NIGHT. EVENTUALLY THE AIR COLUMN IS PROGGED TO BECOME
COLD ENOUGH WEDNESDAY NIGHT AS THE UPPER LOW DEEPENS TO CHANGE THE
PCPN TYPE OVER TO SNOW.

THE MAIN MDM RANGE SOLUTION DIVERT THURSDAY...GFS A BIT MORE
PROGRESSIVE WITH THE UPPER SYSTEM SHIFTING EASTWARD WHILE THE
ECMWF IS TRENDING SOUTHWARD AND TRACKS THE SECONDARY PIECE OF
ENERGY OVER SE WI. ECMWF INDICATES AN ADVISORY TYPE SNOW OVER
PARTS OF EC WI AND AREAS TO THE SOUTH WHILE WITH THE GFS INDICATES
BELOW ADVISORY ACCUM. LES SNOW SHOWER POTENTIAL INCREASES
WEDNESDAY NIGHT INTO THURSDAY FOR LAKE SUPERIOR AREA AND ALSO FOR
LAKE MICHIGAN IF THE ECMWF VERIFIES.

RIDGE SLIDES OVER FRIDAY INTO SATURDAY...THEN RETURN WAA FLOW
AHEAD OF NEXT SYSTEM PROGGED TO WORK OVER LATER SATURDAY INTO
SUNDAY. WILL CONTINUE A DRY FORECAST FOR SUNDAY AS THE MAIN
DYNAMICS PASSING WELL NORTH.

AVIATION...CLEARING SKIES AT GRB TONIGHT WILL LEAD TO FOG FORMATION
...WITH LIFR/VLIFR VSBYS POSSIBLE BY EARLY TOMORROW MORNING.
ANY DENSE FOG WILL LIFT BY 15-16Z TOMORROW...BUT STAGNANT AIRMASS
WILL KEEP VSBYS AT MVFR IN HAZE.  NOT AS CLEAR CUT FOR THE CENTRAL
WISCONSIN AIRPORTS.  DEEP MOISTURE CHANNEL WILL SHIFT SLOWLY TO THE
NORTHWEST TONIGHT...WHICH SHOULD KEEP CIGS VFR AT AUW/CWA IN MVFR/IFR
VSBYS.  A SMALL CHANCE OF SHOWERS WILL EXIST THROUGH THE NIGHT AT
RHI...WITH POSSIBLE VFR CIGS/VSBYS FALLING TO IFR LEVELS.
CIGS/VSBYS WILL IMPROVE TOMORROW MORNING AT RHI.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

000
FXUS63 KGRB 222111
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
311 PM CST SUN NOV 22 2009

.SHORT TERM...TONIGHT AND MONDAY.

LATEST RUC ANALYSIS AND VIS/IR/WV/RADAR IMAGERY SHOW THE STATE OF
WISCONSIN LOCATED BETWEEN LOW PRESSURE OVER THE NORTHERN PLAINS AND
HIGH PRESSURE OVER THE EASTERN GREAT LAKES.  DEEP LAYER SOUTHWEST
FLOW CONTINUES TO PUMP SEASONABLE WARM CONDITIONS AND AMPLE MOISTURE
INTO THE REGION.  LIGHT 295K ISENTROPIC ASCENT AND 700MB CONVERGENCE
SHOWERS AND SPRINKLES HAVE REMAINED MOSTLY WEST OF THE FOX VALLEY SO
FAR TODAY WITH ONLY A HUNDREDTH OR TWO REPORTED.  MORE WIDESPREAD
SHOWER ACTIVITY IS OCCURRING ACROSS IOWA AHEAD OF A RESPECTABLE
SHORTWAVE TROUGH.  FORECAST CONCERNS ARE TWO FOLD...THE FIRST BEING
PRECIP CHANCES...AND THE SECOND BEING DENSE FOG POTENTIAL TONIGHT
INTO TOMORROW.

TONIGHT...THE 850-700MB THETAE AXIS WILL STILL BE POSITIONED ACROSS
THE NORTHWEST HALF OF THE FORECAST AREA.  ALTHOUGH BEST 295K
ISENTROPIC ASCENT WILL SHIFT NORTH OF THE REGION...THE PRESENCE OF
THIS THETAE AXIS WILL KEEP THE SMALL CHANCE OF LIGHT
SHOWERS/SPRINKLES ACROSS THIS PORTION OF THE FORECAST AREA.
ADDITIONAL BUT STILL WEAK LIFT WILL ARRIVE AFTER MIDNIGHT WHEN THE
RIGHT ENTRANCE REGION OF A JET STREAK SHIFTS EAST INTO NORTH-CENTRAL
WISCONSIN.  UPSTREAM TRENDS SUGGEST AN INCREASE IN POPS IS WARRANTED
...WHICH BLENDS BETTER WITH NEIGHBORING OFFICES.  MEANWHILE...WINDS
WILL BACK AHEAD OF THE NEXT SHORTWAVE MOVING ACROSS THE CENTRAL
PLAINS...AND WILL DRAW DRIER AIR FROM THE SE INTO MUCH OF NORTHEAST
WISCONSIN.  SHOULD SEE CLEARING SKIES TONIGHT WITH MORE OF AN
ONSHORE FLOW DEVELOPING.  AS A RESULT...LOW LEVEL MOISTURE SHOULD
REMAIN PLENTIFUL FOR FOG FORMATION.  BL WINDS APPEAR TO BE THE
LIMITING FACTOR TONIGHT...BUT ARE PROJECTED TO FALL OFF FROM 15 TO
10 KTS AFTER MIDNIGHT.  UPS FOG FORECASTING TECHNIQUE SUGGESTS THIS
IS MARGINAL FOR FOG FORMATION...BUT THINK POTENTIAL IS THERE FOR
DENSE FOG ONCE AGAIN...AND WILL BOOST FOG WORDING TO INCLUDE PATCHY
DENSE FOG ACROSS THE FOX VALLEY AND POINTS EAST.  IF ENOUGH
DECOUPLING OCCURS BY MORNING...WOULD NOT BE SURPRISED TO SEE A DENSE
FOG ADVISORY ISSUED.

TOMORROW...FOG WILL STILL BE AN ISSUE TOMORROW MORNING AND WILL
PROBABLY NOT SEE THE FOG LIFT UNTIL 15-16ZISH WITH THE LOW NOVEMBER
SUN ANGLE.  PERHAPS WILL STILL SEE A LINGERING SPRINKLE ACROSS VILAS
COUNTY ALSO DURING THE MORNING BEFORE THE JET STREAK SHIFTS NORTH BY
MIDDAY.  THE SHORTWAVE ACROSS THE CENTRAL PLAINS WEAKENS AS IT
ARRIVES DURING THE AFTERNOON...BUT THE SE FLOW WILL KEEP THE
MID-LEVELS DRY. WONT EXACTLY SEE ALOT OF SUNSHINE DUE TO AN AMPLE
CIRRUS SHIELD OVERHEAD...BUT THAT SHOULD NOT STOP HIGHS FROM
REACHING INTO THE UPPER 40S NORTH TO MID 50S SOUTH.

.LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY. FOCUS OF THIS
FORECAST CONTINUES TO BE WITH RESPECT TO THE MESSY EVOLVING UPPER
LOW SYSTEM TO AFFECT THE GREAT LAKES AND UPPER MIDWEST REGION LATE
TUESDAY INTO THURSDAY. MANY ISSUES REMAIN WITH TODAYS MODEL RUNS
INCLUDING PCPN TYPE...TIMING AND LOCATION OF PIECES OF ENERGY
WITHIN THE DEEPENING UPPER LOW SYSTEM. FORECAST SOUNDINGS INDICATE
SYSTEM TYPE WILL MAINLY BE RAIN TUESDAY INTO WEDNESDAY. SOME
EVAP POTENTIAL WITH THIS SYSTEM AS DRY NE FEED WRAPS INTO THE
SYSTEM THROUGH WEDNESDAY.  BUT MAIN CAA ON UPPER JET AND SECONDARY
MAIN SHORTWAVE TO DRIVE TOWARD SW WI INTO IA LATER WEDNESDAY AND
WEDNESDAY NIGHT. EVENTUALLY THE AIR COLUMN IS PROGGED TO BECOME
COLD ENOUGH WEDNESDAY NIGHT AS THE UPPER LOW DEEPENS TO CHANGE THE
PCPN TYPE OVER TO SNOW.

THE MAIN MDM RANGE SOLUTION DIVERT THURSDAY...GFS A BIT MORE
PROGRESSIVE WITH THE UPPER SYSTEM SHIFTING EASTWARD WHILE THE
ECMWF IS TRENDING SOUTHWARD AND TRACKS THE SECONDARY PIECE OF
ENERGY OVER SE WI. ECMWF INDICATES AN ADVISORY TYPE SNOW OVER
PARTS OF EC WI AND AREAS TO THE SOUTH WHILE WITH THE GFS INDICATES
BELOW ADVISORY ACCUM. LES SNOW SHOWER POTENTIAL INCREASES
WEDNESDAY NIGHT INTO THURSDAY FOR LAKE SUPERIOR AREA AND ALSO FOR
LAKE MICHIGAN IF THE ECMWF VERIFIES.

RIDGE SLIDES OVER FRIDAY INTO SATURDAY...THEN RETURN WAA FLOW
AHEAD OF NEXT SYSTEM PROGGED TO WORK OVER LATER SATURDAY INTO
SUNDAY. WILL CONTINUE A DRY FORECAST FOR SUNDAY AS THE MAIN
DYNAMICS PASSING WELL NORTH.
&&

.AVIATION...CLEARING SKIES AT GRB TONIGHT WILL LEAD TO FOG FORMATION
...WITH LIFR/VLIFR VSBYS POSSIBLE BY EARLY TOMORROW MORNING.
ANY DENSE FOG WILL LIFT BY 15-16Z TOMORROW...BUT STAGNANT AIRMASS
WILL KEEP VSBYS AT MVFR IN HAZE.  NOT AS CLEAR CUT FOR THE CENTRAL
WISCONSIN AIRPORTS.  DEEP MOISTURE CHANNEL WILL SHIFT SLOWLY TO THE
NORTHWEST TONIGHT...WHICH SHOULD KEEP CIGS VFR AT AUW/CWA IN MVFR/IFR
VSBYS.  A SMALL CHANCE OF SHOWERS WILL EXIST THROUGH THE NIGHT AT
RHI...WITH POSSIBLE VFR CIGS/VSBYS FALLING TO IFR LEVELS.
CIGS/VSBYS WILL IMPROVE TOMORROW MORNING AT RHI.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$
MPC/TDH

000
FXUS63 KARX 222102
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
302 PM CST SUN NOV 22 2009

.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
MAIN FORECAST CONCERNS ARE ON LOW PRECIPITATION CHANCES THROUGH
MONDAY NIGHT...THEN FOR HIGHER CHANCES TUESDAY INTO TUESDAY NIGHT.

CURRENTLY AS OF 21Z...WATER VAPOR AND RUC 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE GREAT LAKES...WEAK TROUGHING OVER THE
PLAINS...WEAK RIDGING OVER THE LEE OF THE ROCKIES...AND A POTENT
TROUGH OVER THE PACIFIC NORTHWEST. FORECAST AREA IS NEARING THE
SOUTHWEST FLOW AHEAD OF THE PLAINS TROUGH...BUT WATER VAPOR AND
VISIBLE SATELLITE IMAGERY ONLY SHOW SOME MID AND HIGH CLOUDS
ASSOCIATED WITH IT. WHAT IS OF MORE INTEREST IS THE LOW LEVELS...
WHERE SATELLITE IMAGERY SHOWS A STRATUS DECK FROM WESTERN MISSOURI
INTO MOST OF THE UPPER MISSISSIPPI VALLEY REGION. CEILING HEIGHTS
ARE ALL ABOVE 4000 FT...BUT RADAR AND SURFACE OBSERVATIONS SHOW SOME
ISOLATED -SHRA WITHIN THE STRATUS. DESPITE THE CLOUD COVER...THERE
HAVE BEEN OCCASIONAL BREAKS IN IT...ALLOWING TEMPERATURES TO CLIMB
INTO THE 50S AT MOST LOCATIONS. 295-300K ISENTROPIC LIFT SURFACES
MATCH UP PRETTY WELL WITH THE AREA OF STRATUS AND SHOWERS. A LITTLE
FURTHER TO THE WEST...FROM WESTERN KANSAS INTO CENTRAL MINNESOTA...A
LINE OF 2000 FT CEILING STRATUS EXISTS. NO PRECIPITATION WITH IT...
BUT DOES LINE UP ALONG A WEAKENING COLD FRONT AND WITHIN A ZONE OF
290K ISENTROPIC LIFT.

TONIGHT...FOCUS OF CONCERN IS ON THE TWO AREAS OF ISENTROPIC LIFT.
THE FIRST AREA ASSOCIATED WITH THE STRATUS AND ISOLATED SHOWERS ON
THE 295-300K SURFACES LOOKS TO PERSIST THROUGH THE EVENING...THEN
MOVES WESTWARD OVERNIGHT AS LOW LEVEL WINDS TURN SOUTHEAST. THE
SOUTHEAST WIND IS A RESULT OF THE PLAINS TROUGH LIFTING NORTHEAST.
ALSO OVERNIGHT...THE SECOND AREA OF ISENTROPIC LIFT ON THE 290K
SURFACE IS PROGGED TO COME INTO SOUTHEAST MINNESOTA...NORTHEAST IOWA
AND INTO TAYLOR/CLARK COUNTIES. HOWEVER...THIS ZONE OF LIFT DOES NOT
APPEAR TO BE RELATED TO THAT ALONG THE WEAKENING FRONT...WHICH
ACTUALLY GETS PUSHED WESTWARD BY THE LOW LEVEL SOUTHEAST WINDS.
GIVEN BOTH WARM ADVECTION ZONES...FIGURE AT LEAST SOME CHANCE
PROBABILITIES ARE WARRANTED...ESPECIALLY OVER THE AREA OF 290K LIFT
SINCE IT INTERSECTS THAT OF THE 295-300K LIFTS. WENT BELOW MET
GUIDANCE PROBABILITIES...THOUGH...GIVEN THAT ALL OF THE LIFT IS WEAK
AT BEST. GIVEN THE CLOUD COVER...RELATIVELY HIGH DEWPOINTS AND SOME
WIND...TEMPERATURES SHOULD STAY MILD FOR LATE NOVEMBER. IN
FACT...LOWS MAY END UP 5 OR MORE DEGREES ABOVE NORMAL HIGHS.

MONDAY...PLAINS TROUGH WILL LIFT NORTHEAST ACROSS THE FORECAST AREA
AROUND NOON...WHILE THE POTENT TROUGH DIGS DOWN INTO COLORADO. NET
RESULT IS THAT BY THE AFTERNOON...WE SHOULD START SEEING HEIGHT
RISES ALOFT AND THEREFORE SUBSIDENCE. LOOKS LIKE THERE MAY BE SOME
LINGERING LIGHT PRECIPITATION IN THE MORNING IN SOUTHEAST
MINNESOTA...NORTHEAST IOWA AND INTO TAYLOR/CLARK COUNTIES...BUT THAT
IS ABOUT IT FOR THE DAY. COULD SEE SOME PARTIAL CLEARING TOO DURING
THE AFTERNOON OVER SOUTHERN WISCONSIN AND NORTHEAST IOWA...DEPENDING
IF ANY CIRRUS MOVES ACROSS. 850MB TEMPS ARE A BIT COOLER COMPARED TO
TODAY...BUT GIVEN THAT WE ARE STARTING OFF FAIRLY MILD IN THE
MORNING...SHOULD BE ANOTHER ABOVE NORMAL DAY WITH HIGHS AGAIN IN THE
50S.

MONDAY NIGHT AND TUESDAY...THE TRACK OF THE POTENT TROUGH OVER
EASTERN COLORADO AT 00Z TUESDAY IS IN MUCH BETTER AGREEMENT WITH
LATEST MODEL RUNS. 12Z CYCLE SHOWS THE TROUGH HEADING EAST TOWARDS
KANSAS CITY BY 12Z TUE...THEN LIFTS VERY SLOWLY NORTHEAST DURING THE
DAY TUESDAY IN RESPONSE TO ANOTHER POTENT TROUGH DROPPING DOWN FROM
WESTERN CANADA. FOR MONDAY NIGHT...RIDGING SHOULD BE THE RULE MOST
OF THE NIGHT AHEAD OF THE TROUGH CROSSING THE CENTRAL PLAINS. THIS
RIDGING SHOULD KEEP MOST OF THE AREA DRY. HOWEVER...A WARM CONVEYOR
BELT WILL LIKELY DEVELOP OVER KANSAS...MISSOURI AND IOWA...PART OF
WHICH MAY MOVE INTO SOUTHEAST MINNESOTA AND NORTHEAST IOWA.
THEREFORE HAVE MAINTAINED THE GOING 20-40 PERCENT CHANCES OF
PRECIPITATION FOR THE POSSIBLE AREA THE BELT WILL MOVE INTO. THIS
BELT WILL CONTINUE LIFTING NORTHEAST ON TUESDAY AS THE TROUGH NEAR
KANSAS CITY AT 12Z TUE MOVES NORTHEAST. THEREFORE...LOOK FOR THE
AREA SOUTH OF I-90 TO LIKELY BE AFFECTED. NORTH OF I-90...IT IS A
BIT QUESTIONABLE IF THE BAND CAN MAKE IT UP THAT FAR BY 00Z. 22.12Z
ECMWF AND GFS BOTH REFLECT THAT BY HAVING A LOT LESS QPF. AS A
RESULT...LOWERED PRECIPITATION PROBABILITIES AND QPF VALUES.
REGARDING TEMPERATURES...READINGS AGAIN EXPECTED TO BE MILD...WITH
PLENTY OF CLOUDS. WENT ABOVE GUIDANCE WITH LOWS FOR MONDAY NIGHT.
HOWEVER...PRECIPITATION ON TUESDAY AND AN EASTERLY FLOW WILL LIKELY
RESULT IN COOLER HIGHS COMPARED TO MONDAY.

TUESDAY NIGHT...UPPER TROUGH NEAR KANSAS CITY WILL GET A BETTER
SHOVE TO THE EAST NORTHEAST AS THE NEXT POTENT TROUGH DROPS DOWN
INTO THE DAKOTAS. WARM CONVEYOR BELT RAIN ON THE NORTH SIDE
OF THE UPPER...AND ASSOCIATED SURFACE LOWS...SHOULD MOVE ACROSS MUCH
OF THE FORECAST AREA. THE ONLY AREA THAT IT MIGHT NOT GET TO IS
TAYLOR COUNTY...AND HAVE LEFT PROBABILITIES OF PRECIPITATION THERE
AROUND 50. ELSEWHERE...PROBABILITIES WERE RAISED TO 60-70. LOW
TEMPERATURES WILL END UP COOLER THAN THE PAST FEW NIGHT...MOSTLY DUE
TO PRECIPITATION. NONETHELESS...READINGS SHOULD STILL END UP AROUND
40...CLOSE TO NORMAL HIGHS.

.LONG TERM...WEDNESDAY THROUGH SUNDAY

UNCERTAINTY IN THE LONG TERM FORECAST HAS DECREASED COMPARED TO
YESTERDAY...BUT STILL ISSUES EXIST. TODAYS MAIN ISSUE IS HOW QUICK
THE GENERAL TROUGH OVER THE CENTRAL PORTION OF THE COUNTRY...
COMPOSED AT 12Z WEDNESDAY OF THE UPPER LOW NEAR CHICAGO AND AN UPPER
LOW DROPPING DOWN THROUGH THE DAKOTAS...PUSHES EAST. THIS SPEED
ISSUE WILL HAVE GREAT INFLUENCE BOTH ON HOW LONG PRECIPITATION
LINGERS OVER THE FORECAST AREA...AS WELL AS HOW MUCH SNOW CAN FALL.
THE 22.00Z ECMWF IS THE SLOWEST OF ALL DETERMINISTIC MODELS AND
ENSEMBLES...HANGING TROUGHING OVER THE EASTERN HALF OF THE COUNTRY
THROUGH 12Z FRI. AS SUCH...ITS DERIVED SNOW ACCUMULATION OUTPUT IS
THE HIGHEST. THE 22.06Z GFS...22.00Z CANADIAN AS WELL AS THEIR
RESPECTIVE ENSEMBLES (AS WELL AS THE 21.12Z ECMWF ENSEMBLES) SHOW A
FASTER EASTWARD MOVEMENT...WITH TROUGHING EITHER OVER THE EASTERN
THIRD OF THE U.S. OR RIGHT ALONG THE EAST COAST. HPC PREFERENCE IS A
BLEND OF THE SLOWER...MORE AMPLIFIED 22.00Z ECMWF AND THE FASTER
ECMWF ENSEMBLES...WHICH SEEMS REASONABLE AT THE MOMENT. THIS BLEND
KEEPS A BIT BETTER CONTINUITY TOO WITH THE PREVIOUS FORECAST. 22.12Z
RUNS ARE FAIRLY SIMILAR TO THEIR PREDECESSORS...SO THE BLEND
PREFERENCE STILL REMAINS.

DETAILS: THE UPPER LOW OVER THE DAKOTAS SHOULD CONTINUE TO DIG
SOUTHEASTWARD ON WEDNESDAY...REACHING NORTHERN MISSOURI BY 00Z
THURSDAY...BRINGING WITH IT COLDER AIR FROM CANADA. AS THIS COLDER
AIR INTERACTS WITH LINGERING DEFORMATION PRECIPITATION OVER THE
FORECAST AREA...WHICH ACTUALLY COULD GET ENHANCED BY DPVA AHEAD OF
THE UPPER LOW...LOOK FOR THE PRECIPITATION TO CHANGE FROM RAIN TO
SNOW. FRONTOGENETICAL SNOW LOOKS TO OCCUR WEDNESDAY NIGHT AS THE
UPPER LOW SHIFTS EAST INTO ILLINOIS. GIVEN GOOD AGREEMENT ON THE
PRECIPITATION FOR WEDNESDAY AND WEDNESDAY NIGHT...DECIDED TO RAISE
PROBABILITIES UP SOMEWHAT. FOR THANKSGIVING...THE UPPER LOW IS
PROGGED TO CONTINUE SHIFTING EAST...WHICH SHOULD MEAN A DIMINISHING
TO THE SNOWFALL WEST TO EAST. HOWEVER...ENOUGH CONFIDENCE EXISTS TO
RAISE PRECIPITATION PROBABILITIES UP MORE FOR THANKSGIVING. IMAGINE
THAT OVER TIME FURTHER INCREASES IN PROBABILITIES WILL BE REQUIRED
FOR THE WEDNESDAY TO THANKSGIVING TIME FRAME. THE GENERAL UPPER
TROUGH THEN STARTS IT MARCH EAST TOWARDS THE EAST COAST THURSDAY
NIGHT AND FRIDAY...ALLOWING FOR RISING HEIGHTS AND HIGH PRESSURE TO
BUILD IN AT THE SURFACE. FOR NOW HAVE KEPT THIS PERIOD DRY...BUT
LATER FORECASTS MAY NEED TO INCLUDE CHANCES OF PRECIPITATION IN FOR
THURSDAY IF THE TROUGH IS AS SLOW AS THE 22.00Z ECMWF INDICATES.

BEYOND FRIDAY...MODEL AND ENSEMBLE AGREEMENT IS FAIRLY HIGH...WITH
THE IDEA OF UPPER RIDGING OVER THE WESTERN U.S. BUILDING OVER THE
UPPER MISSISSIPPI VALLEY ON SATURDAY. THIS IS DUE TO NEW TROUGHING
COMING INTO THE WESTERN U.S.. INDICATIONS ARE THAT THIS TROUGH WILL
SPLIT INTO TWO...WITH THE SOUTHERN PORTION BEING LEFT BEHIND IN
ARIZONA AND THE NORTHERN PORTION HEADING EAST TOWARDS OUR AREA.
HOWEVER...THE NORTHERN STREAM PORTION OF THE TROUGH DOES NOT LOOK TO
HAVE A LOT OF MOISTURE TO WORK WITH...REFLECTED BY BOTH THE 22.00Z
ECMWF AND 22.06Z GFS NOT PRODUCING QPF. THEREFORE...THE FORECAST FOR
FRIDAY NIGHT THROUGH SUNDAY WILL REMAIN DRY AT THIS TIME. IT SHOULD
BE NOTED THAT A FRONTAL PASSAGE IS EXPECTED WITH THIS NORTHERN
STREAM WAVE AROUND SUNDAY MORNING...SO LOOK FOR A COOLER SUNDAY
COMPARED TO SATURDAY. THIS FRONTAL PASSAGE IS THE SAME ONE MODELS
SHOWED YESTERDAY...JUST SLOWER BECAUSE OF THE SLOWER EASTERN TROUGH
WEDNESDAY THROUGH FRIDAY.

&&

.AVIATION...TONIGHT AND MONDAY

WEAK SURFACE BOUNDARY OVER WESTERN MINNESOTA AND EASTERN SOUTH
DAKOTA IS NOT EXPECTED TO MOVE MUCH TONIGHT AND MONDAY. THIS WILL
MAINTAIN A MOIST SOUTH FLOW OVER THE AREA. WITH WEAK LOW LEVEL WARM
AIR ADVECTION IN THIS SOUTH FLOW...BOTH THE 22.12Z NAM AND GFS
PRODUCE AROUND 2 UBAR/S OF UP GLIDE ON THE 290K ISENTROPIC SURFACE
THROUGH TONIGHT. WEAK MOISTURE TRANSPORT WILL ALSO CONTINUE IN THIS
SOUTH FLOW. MOST OF THIS MOISTURE TRANSPORT SHOULD BE TO THE WEST OF
THE AREA...BUT BY THIS EVENING INTO THE OVERNIGHT...THE AREA GETS ON
THE CONVERGENT EASTERN EDGE OF THE TRANSPORT. THIS COMBINED WITH THE
WEAK ISENTROPIC UPGLIDE COULD BE ENOUGH TO GENERATE SOME SCATTERED
SHOWERS AND ADDED VICINITY SHOWERS TO BOTH TAF SITES. THE OTHER
CONCERN WITH THE HIGH MOISTURE LEVELS IS THE POSSIBILITY OF SOME
MVFR/IFR CEILINGS AND VISIBILITIES TONIGHT DURING THE MAX COOLING
PERIOD. THE NAM BUFKIT SOUNDINGS WOULD SUGGEST THIS WILL NOT HAPPEN
AS IT HAS BRINGS IN SOME DRY AIR LATE TONIGHT INTO MONDAY MORNING.
THE GFS KEEPS THE SOUNDING SATURATED AND SUPPORTS THE DEVELOPMENT OF
THE LOW CLOUDS AND FOG. LOW CLOUDS AND FOG DID DEVELOP THIS MORNING
AHEAD OF THE SURFACE BOUNDARY OVER WESTERN MINNESOTA AND IOWA AND
WILL CONTINUE THE TRENDS OF THE PREVIOUS FORECASTS WITH MVFR/IFR
CONDITIONS FOR LATE TONIGHT INTO MONDAY MORNING.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

SHORT/LONG TERM...AJ
AVIATION...04

000
FXUS63 KMKX 222051
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
251 PM CST SUN NOV 22 2009

BIG FORECAST CHALLENGES FOR THE WEEK AHEAD. INTERESTING PHASING OF
TWO SHORT WAVES BY MID WEEK THAT COMBINE INTO ONE BIG ROTATING
UPPER LOW. THIS HAS POTENTIAL TO BRING OUR FIRST ACCUMULATING
SNOWFALL. THE COMPLEX EVOLUTION...COMBINED WITH TEMPERATURES NEAR
CRITICAL THRESHOLDS FOR SNOW CHALLENGE CONFIDENCE IN THE FINAL
DETAILS.

.TONIGHT...RIDGING TO THE EAST WILL CONTINUE TO FEED DRY AIR BACK
INTO THE AREA. CLOUD EDGE OVER THE WESTERN CWA HAS BEEN SLOWLY
RETREATING WEST THIS AFTERNOON AND THIS SHOULD CONTINUE A BIT MORE
OVERNIGHT. OTHERWISE GENERALLY CLEAR ELSEWHERE OVER THE CWA WITH
FOG AGAIN A PROBLEM WITH HIGH DWPNTS GOING INTO THE EVENING AND
GOOD RADIATIONAL COOLING. CLOUDS/CLEAR SKIES/FOG/VALLEYS/HILLS/WATER
MAKE A DIFFICULT MIN TEMP FORECAST.

.MONDAY/MONDAY NIGHT...THE FIRST OF MANY SHORT WAVES DIGGING A
LARGE MID LEVEL TROF OVER THE CENTER OF THE COUNTRY WILL TRACK
TOWARD AND THROUGH OUR AREA. THE COLUMN WILL LIKELY REMAIN TOO DRY
FOR ANY PRECIP...BUT CLOUDS SHOULD INCREASE. TEMPS WILL REMAIN
MILD IN THE DEEP SOUTHERLY FLOW.

.TUESDAY/TUESDAY NIGHT...A SECOND...MUCH STRONGER SHORT WAVE
BEGINS TO EJECT OUT OF THE CENTRAL/SOUTHERN PLAINS ON TUESDAY.
THE ASSOCIATED SFC LOW SHOULD TRACK INTO IA DURING THE DAY. HERE
THE GFS AND THE ECMWF ARE IN GOOD AGREEMENT WHILE THE NAM IS
SLOWER. GOING WITH GFS/ECMWF. RAIN TO SPREAD INTO THE AREA MAINLY
DURING THE AFTERNOON...THEN CONTINUE THROUGH TUESDAY NIGHT. THE
SFC LOW SHOULD TRACK RIGHT ACROSS SOUTHERN WISCONSIN TUESDAY
NIGHT. HIGH POPS THROUGH THIS PERIOD. TEMPERATURES REMAIN WARM
ENOUGH TO KEEP IT ALL RAIN.

.WEDNESDAY/WEDNESDAY NIGHT...THIS IS THE MOST INTERESTING PERIOD
OF THE FORECAST. A THIRD MORE ENERGETIC SHORTWAVE WILL DIVE INTO
THE NORTHERN PLAINS AND INTO THE BACKSIDE OF THE SECOND SHORTWAVE
MOVING THROUGH THE WESTERN/CENTRAL GREAT LAKES AT THIS TIME. THIS
PULLS BACK ON THE SECOND SHORTWAVE AND THEY DO THE CLASSIC
FUJIWARA INTERACTION AS THE ENTIRE MID LEVEL TROF AMPLIFIES
STRONGLY FROM THE GREAT LAKES TO THE LOWER MISSISSIPPI VALLEY.
PRECIP ON WEDNESDAY SHOULD LET UP...BUT STILL LIKELY EVERYONE WILL
MEASURE. COLD AIR WILL BE POURING INTO THE AREA AS THE THIRD
SHORTWAVE DIGS IN. AS THE SHORTWAVE ARRIVES LATE IN THE DAY OR
EARLY EVENING...THE PRECIP WILL INCREASE AGAIN. THE RAIN IN THE
SOUTHWEST CWA SHOULD BECOME MIXED WITH SNOW DURING THE AFTERNOON.
WEDNESDAY NIGHT THE COLD AIR CONTINUES TO OVERSPREAD THE AREA.
THE WRN CWA MOSTLY LIKELY WILL SEE THE LONGEST PERIOD OF ALL
SNOW...WHILE THE EAST WILL BE SLOWER TO TRANSITION. THE NEW ECMWF
HAS COME IN AND IT LOOKS INTERESTING. THE AMOUNT OF QPF AND ITS
COLD TEMPS WOULD SUGGEST HIGH POTENTIAL OF ACCUMULATING SNOWS
WEDNESDAY NIGHT INTO THURSDAY...POTENTIALLY A HEADLINE MAKER. OF
COURSE THIS IS THE HOLIDAY AND LOTS OF FOLKS WILL BE TRAVELING.
CAUTION IS ADVISED AS IT SHOULD BE NOTED AGAIN HOW COMPLICATED
THIS STORM SYSTEM WILL BE. LOTS OF RUN TO RUN VARIABILTY IN
SOLUTIONS IS EXPECTED OVER THE NEXT COUPLE OF CYCLES.

THE SNOW SHOULD CONTINUE THROUGH THURSDAY...THANKSGIVING...AND
HAVE TOTAL ACCUMULATIONS RANGING FROM 1 TO 3 INCHES FOR NOW. THIS
IS SUBJECT TO CHANGE.

.BEYOND THURSDAY...RIDGING ARRIVES AND LOOKS TO KEEP US DRY AND
SEASONABLE THROUGH NEXT WEEKEND.

&&

.AVIATION...SKIES WILL REMAIN MOSTLY CLEAR IN THE EAST
TONIGHT...WITH DECREASING CLOUDS IN THE WEST. WINDS WILL BE LIGHT
AGAIN...LIKELY ALLOWING THE FORMATION OF FOG LATER TONIGHT. WITH
VISBYS ALREADY NEAR OR AT MVFR DUE TO HZ...EXPECT PREVAILING MVFR
CONDITIONS THROUGH THE EVENING...WITH IFR VISBYS POSSIBLE AFTER
MIDNIGHT. COULD EVEN SEE A FEW LIFR OBS TOWARD DAYBREAK IF WINDS GET
LIGHT ENOUGH. EXPECT QUIET CONDITIONS AGAIN TOMORROW...WITH MID AND
HIGH LEVEL CLOUDS IN THE AFTERNOON.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&

$$

SHORT/LONG TERM...DAVIS
AVIATION/MARINE...VANCLEVE

000
FXUS63 KARX 220949
AFDARX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
349 AM CST SUN NOV 22 2009

.SHORT TERM...TODAY THROUGH TUESDAY

AT 3 AM...A COLD FRONT WAS LOCATED ACROSS THE EASTERN DAKOTAS.
SOUTHERLY WINDS AHEAD OF THIS FRONT ARE BRINGING WARM AIR AND
MOISTURE NORTHWARD INTO THE FORECAST AREA. THE 22.00Z MODELS ARE
IN GOOD AGREEMENT THAT THIS FRONT WILL MOVE SLOWLY EAST ACROSS
MINNESOTA AND IOWA TODAY...AND THEN THIS FRONT RAPIDLY DISSIPATES
TONIGHT.

ONE QUESTION TODAY IS WHETHER WE WILL SEE SOME SUNSHINE
ACROSS SOUTHWEST AND CENTRAL WISCONSIN THIS AFTERNOON. LOOKING
UPSTREAM...THERE ARE SOME HOLES IN THE CLOUDS...AND THE NAM/WRF
SUGGEST THAT THIS AREA WILL MOVE INTO THE AFOREMENTIONED AREAS
DURING THIS TIME FRAME.

ANOTHER QUESTION FOR TODAY IS WHETHER THERE WILL BE ANY
PRECIPITATION. LIKE PREVIOUS DAYS...THE GFS...ECMWF...AND GEM SHOW
SOME LIGHT PRECIPITATION. MEANWHILE THE NAM/WRF HAS REMAINED DRY.
WITH THE BUFKIT SOUNDINGS CONTINUE TO SHOW THAT THE OMEGA IS
LOCATED ABOVE THE MOISTURE LAYER...IT WAS THE CONSENSUS TO REMOVE
THE RAIN CHANCES ACROSS THE AREA.

FROM TONIGHT INTO MONDAY MORNING...A SHORT WAVE TROUGH WILL MOVE
NORTHEAST ACROSS THE FORECAST AREA. THE BEST MOISTURE TRANSPORT
WITH THIS FEATURE CONTINUES TO REMAIN WEST AND NORTH OF OUR AREA.
DUE TO THIS...THE RAIN CHANCES INCREASED FROM 14 PERCENT IN
CENTRAL WISCONSIN TO AROUND 30 PERCENT IN SOUTHEAST MINNESOTA AND
NORTHEAST IOWA.

FROM MONDAY AFTERNOON THROUGH MONDAY EVENING...WE WILL LOCATED IN
AN AREA OF SUBSIDENCE BETWEEN THE DEPARTING SHORT WAVE TROUGH AND
YET ANOTHER MUCH STRONGER SHORT WAVE TROUGH APPROACHING THE REGION
FROM THE CENTRAL PLAINS. DUE TO THIS...THE PRECIPITATION CHANCES
WERE REMOVED FOR THIS TIME PERIOD.

FROM MONDAY NIGHT INTO TUESDAY...THE MODELS CONTINUE TO SHOW THAT
THE UPPER LEVEL TROUGH WILL BE DEEPENING ACROSS THE REGION AND
THIS IN TURN ENHANCES THE SURFACE CYCLOGENESIS. AT THIS TIME...IT
LOOKS LIKE THIS LOW WILL TRACK ACROSS IOWA. LIKE THE PREVIOUS SHIFT...
THE RAIN CHANCES WERE INCREASED ACROSS THE SOUTHERN HALF OF THE
FORECAST AREA. WITH MANY OF THE OPERATIONAL MODELS DRY ACROSS
NORTH CENTRAL WISCONSIN...THERE WAS A CONCERN THAT THE
PRECIPITATION CHANCES WERE A BIT TOO HIGH...SO THE RAIN CHANCES
WERE DECREASED A BIT.

.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY

ON TUESDAY NIGHT...THE 22.00Z MODELS...LIKE THEIR PREDECESSORS...
ARE CONTINUING TO SLOW DOWN THE SPEED OF THE LOW PRESSURE SYSTEM.
THIS WILL KEEP THE DEPTH OF THE WARM LAYER IN THE 4 TO 6K RANGE
AND IN TURN THE PRECIPITATION WILL REMAIN IN THE FORM OF RAIN. DUE
TO THIS...THE MENTION OF SNOW WAS REMOVED FROM THE FORECAST GRIDS.

FROM WEDNESDAY INTO THANKSGIVING...ANOTHER SHORT WAVE TROUGH WILL
MOVE INTO THE LARGER SCALE TROUGH OVER THE UPPER MISSISSIPPI RIVER
VALLEY. THIS WILL LIKELY RESULT IN ADDITIONAL CYCLOGENESIS ACROSS
THE REGION. THE GFS SHOWS THAT AN ENHANCED AREA OF FRONTOGENESIS
WILL MOVE EAST ACROSS THE FORECAST AREA ON WEDNESDAY...AND THEN
PIVOT BACK ACROSS THE AREA ON WEDNESDAY NIGHT AND THANKSGIVING.

THE MODEL SOUNDINGS CONTINUE TO SUGGEST THAT THE DEPTH OF THE WARM
AIR WILL DECREASE THROUGH THE DAY. AS THIS OCCURS...THE
PRECIPITATION WILL GRADUALLY CHANGE FROM RAIN INTO SNOW. LIKE
24 HOURS AGO...IT CONTINUES TO LOOK LIKE THERE WILL BE THE
POSSIBILITY OF ACCUMULATING SNOW FROM WEDNESDAY AFTERNOON INTO
THANKSGIVING. A MAJORITY OF THE GFS ENSEMBLE MEMBERS SHOW SOME
ACCUMULATIONS IN THE PRECIPITATION TYPE PLUMES. MOST OF THESE
MEMBERS SUGGEST SNOWFALL AMOUNTS LESS THAN 2 INCHES. HOWEVER THERE
ARE TWO GFS ENSEMBLE MEMBERS WHICH HAVE SNOWFALL TOTALS IN THE 3
TO 6 INCH RANGE. THE 22.00Z ECMWF CONTINUES TO GENERATE 4 TO 8
INCHES OF SNOW ACROSS THE SOUTHERN TWO THIRDS OF THE FORECAST
AREA. HOWEVER ITS LIQUID QPF LOOKS TO BE A BIT HIGH. WHILE THESE
MODELS GENERATE ACCUMULATING SNOW...THE GFS COBB DATA STILL SHOWS
NO ACCUMULATIONS. THIS SYSTEM DEFINITELY BEARS WATCHING THIS
WEEK.

&&

.AVIATION...TODAY AND TONIGHT

WEAK COLD FRONT WAS PRESSING INTO NORTHERN MN EARLY THIS
MORNING...WHILE AN UPPER LEVEL DISTURBANCE WAS MOVING NORTHEAST
ACROSS THE NORTHERN PLAINS //PER SATELLITE IMAGERY//. FOG/STRATUS
SATELLITE PRODUCT AND LATEST SFC OBS POINTED TO VARIABLE CLOUDINESS
ACROSS MUCH OF THE REGION...MOSTLY VFR...BUT ALSO POCKETS OF
MVFR/IFR. IN ADDITION...MUCH OF THE LOCAL AREA HAD SOME MVFR
FOG...IN THE 4-5SM BR RANGE.

THE UPPER LEVEL DISTURBANCE WILL CONTINUE TO LIFT INTO SOUTHERN
CANADA...WITH THE SOUTHERN PORTION OF THE COLD FRONT WASHING OUT AS
A RESULT. THE LOW LEVEL MOISTURE TRANSPORT HANGS JUST WEST OF THE
LOCAL AREA THROUGH MON...RUNNING NORTH TO SOUTH ACROSS MN/IA.
MEANWHILE...A WEST-EAST RUNNING TIME/HEIGHT X-SECTION ALSO KEEPS THE
DEEPER SATURATION WEST OF THE MISSISSIPPI RIVER. FEEL A PERIOD OF
MVFR CONDITIONS COULD IMPACT KRST/KLSE EARLY THIS MORNING...WITH THE
BETTER THREAT FOR KRST...AND MORE LIKELY DUE TO FOG RATHER THAN LOW
CEILINGS. WILL MONITOR TRENDS FOR 12Z TAF ISSUANCE. BUFKIT SOUNDINGS
WOULD FAVOR INCREASING CEILINGS BY MID/LATE MORNING...ALTHOUGH
CLOUDS SHOULD STAY AMPLE THROUGH TODAY/TONIGHT.

TONIGHT...THE LOW LEVEL MOISTURE TRANSPORT WILL WORK WITH THE DEEPER
SATURATION TO THE WEST...WEAK QG CONVERGENCE AND ISENTROPIC
UPGLIDE...TO PRODUCE SOME LIGHT -RA ACROSS MN/NORTHERN IA. SOME OF
THIS COULD SPREAD TO THE MISSISSIPPI RIVER...WITH A BETTER CHANCE
TO IMPACT KRST THAN KLSE. CEILINGS/VSBYS WILL ALSO LIKELY FALL INTO
THE MVFR/IFR RANGE AS A RESULT OF THE LIGHT PCPN.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

SHORT/LONG TERM...BOYNE
AVIATION...RIECK

000
FXUS63 KMKX 220940
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
340 AM CST SUN NOV 22 2009

FORECAST FOCUS ON DENSE FOG OVER SHEBOYGAN COUNTY THIS
MORNING...CLOUDS AND TEMPERATURES THROUGH MONDAY
NIGHT...PRECIPITATION CHANCES TUESDAY THROUGH THANKSGIVING DAY.

LATEST WATER VAPOR IMAGERY INDICATED AN UPPER LEVEL RIDGE OVER THE
CENTRAL GREAT LAKES REGION...WITH AN UPSTREAM UPPER TROUGH OVER
THE EASTERN ROCKIES. AT THE SURFACE...HIGH PRESSURE WAS LOCATED
OVER SOUTHEAST ONTARIO CANADA...WITH LIGHT SOUTHEAST WINDS ON THE
BACKSIDE OF THE HIGH OVER SOUTHERN WISCONSIN.

.TODAY...LIGHT WINDS AND MOSTLY CLEAR SKIES OVER THE FAR EASTERN
COUNTIES HELPING AREAS OF FOG MAINTAIN THEMSELVES. KSBM HAS BEEN
AROUND 1/4SM VISIBILITY FOR A FEW HOURS NOW...THOUGH MOST OF THE
DENSE FOG SEEMS TO BE IN LOW LYING AREAS. WILL KEEP DENSE FOG
ADVISORY GOING FOR SHEBOYGAN COUNTY UNTIL 9 AM CST. KETB ALSO
SHOWING SOME DENSE FOG AT TIMES...SO WILL ADD THEM TO THE DENSE
FOG ADVISORY.

SOME LIGHT FOG SEEN ACROSS THE REST OF THE FORECAST AREA...UNDER
MID LEVEL CLOUDS. THE FOG SHOULD MIX OUT BY MID MORNING ACROSS THE
AREA. THE MID LEVEL CLOUDS EXTEND TO EASTERN IOWA AND
SOUTH...THOUGH THERE ARE SOME BREAKS IN THE CLOUDS. WILL TREND
MOSTLY CLOUDY TO PARTLY SUNNY IN THE WESTERN COUNTIES TODAY...WITH
PARTLY SUNNY IN THE EAST. ANOTHER MILD DAY IN STORE...WITH HIGHS
IN THE MID 50S ACROSS THE AREA. THE CLOUDS MAY KEEP TEMPERATURES
DOWN SOME IN THE WESTERN COUNTIES.

.TONIGHT THROUGH MONDAY NIGHT...THE DRY LOW LEVELS EXPECTED OVER
THE AREA DURING THIS PERIOD SHOULD KEEP THE AREA PRECIPITATION
FREE. THE CLOUDS SHOULD GRADUALLY MIX OUT TONIGHT...THEN SLOWLY
RETURN MONDAY AND MONDAY NIGHT AHEAD OF THE DEVELOPING LOW IN THE
CENTRAL PLAINS. MILD TEMPERATURES ARE EXPECTED TO CONTINUE DURING
THIS TIME. EXPECT PATCHY FOG LATER TONIGHT INTO MONDAY
MORNING...AND AGAIN LATER MONDAY NIGHT...WITH A STRONG LOW LEVEL
TEMPERATURE INVERSION AND FAIRLY LIGHT WINDS.

.TUESDAY THROUGH SATURDAY...CONTINUED TO FOLLOW THE CONSISTENT
ECMWF MODEL WITH THE SYSTEM MOVING THROUGH THE REGION DURING THIS
TIME. AFTER CYCLOGENESIS IN THE CENTRAL PLAINS MONDAY NIGHT...THE
LOW MOVES TO FAR NORTHERN MISSOURI BY 00Z WEDNESDAY...THEN INTO
SOUTHERN WISCONSIN BY 12Z WEDNESDAY. GOOD LOW TO MID LEVEL
FRONTOGENESIS CROSSES THE AREA TUESDAY AND TUESDAY NIGHT...WITH A
STRONG UPPER LOW PASSING JUST SOUTH OF THE AREA. WENT WITH LIKELY
POPS FOR RAIN ACROSS THE AREA FROM WEST TO EAST TUESDAY AND
TUESDAY NIGHT.

ANOTHER STRONG UPPER LOW SWINGS FROM THE NORTHERN PLAINS SOUTHEAST
TO IOWA BY 00Z THURSDAY...THEN EAST TO NORTHERN ILLINOIS BY 12Z
THURSDAY...BEFORE SLOWLY MOVING EAST INTO OHIO BY 12Z FRIDAY. A
WEAK SURFACE LOW MOVES EAST ACROSS THE AREA DURING THANKSGIVING
DAY. QPF SEEMS HIGH GIVEN THE LACK OF FRONTOGENESIS ACROSS THE
AREA. STILL...925MB TEMPERATURES DROP TO AROUND ZERO BY 12Z
THURSDAY...LASTING THROUGH 00Z FRIDAY. THIS WILL BRING A GRADUAL
MIX OF LIGHT RAIN AND LIGHT SNOW...THEN TO ALL LIGHT SNOW BY
THANKSGIVING DAY. KEPT THE CHANCE POPS FOR WEDNESDAY THROUGH
THURSDAY NIGHT ACROSS THE AREA. LIGHT SNOW ACCUMULATIONS OF AN
INCH OR SO MAY BE POSSIBLE WEDNESDAY NIGHT INTO THANKSGIVING
DAY...SO KEEP UP WITH THE FORECAST.

&&

.AVIATION...RADIATIONAL FOG ONCE AGAIN THIS AM BUT ONLY MVFR VSBYS
OVER SOUTH CENTRAL WI DUE TO BKN CLOUD COVER AT 6-7 KFT. FEW-SCT
CLOUD COVER OVER FAR ERN WI SO VSBYS LESSER AND VARYING GREATLY
FROM MVFR VSBYS TO ISOLD VLIFR VSBYS AND VLIFR CIGS. MOST OF THE
FOG WILL LIFT BY 15Z TO 16Z BUT LOCAL MVFR VSBYS MAY REMAIN DUE TO
AIR POLLUTION IN POORLY MIXED ATMOSPHERE.

LGT SELY WINDS WILL PREVAIL TNT WITH MID LEVEL CLOUDS DECREASING.
RADIATIONAL FOG AND SCT STRATUS WILL DEVELOP ONCE AGAIN DURING THE
LATE EVENING AND OVERNIGHT. THERE WILL BE ENOUGH WIND TO PREVENT
WIDESPREAD DENSE FOG. WIDESPREAD VSBYS OF MVFR ARE EXPECTED WITH
AREAS OF IFR...AND ISOLD LIFR TO VLIFR ONCE AGAIN. LOCAL CIGS FROM
MVFR TO LIFR WILL DEVELOP WITH THE FOG.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR WIZ052-059.

LM...NONE.
&&

$$

SHORT/LONG TERM...08/WOOD
AVIATION/MARINE...20/GEHRING

000
FXUS63 KGRB 220937
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
337 AM CST SUN NOV 22 2009

.SHORT TERM...TODAY THROUGH MONDAY...THERE ARE SEVERAL FCST ISSUES
TO RESOLVE DURING THIS PERIOD...INCLUDING DENSE FOG POTENTIAL THIS
MORNING AND POSSIBLY AGAIN TONIGHT...AND PCPN TRENDS THROUGHOUT THE
PERIOD.

HIGH PRESSURE WAS SITUATED OVER THE EASTERN GREAT LKS EARLY THIS
MORNING AS A WEAK COLD FRONT APPROACHED FROM THE EASTERN DAKOTAS.
SOUTHERLY RETURN FLOW WAS ONGOING ACROSS WI...WITH THE ASSOCIATED
WAA CAUSING AREAS OF LOW/MID LEVEL CLOUDS TO DEVELOP...MAINLY
WEST OF THE FOX VALLEY. AREAS OF FOG HAD DEVELOPED OVER MUCH OF
NE/EC WI...WHERE CLOUD COVER WAS PATCHY AND THE SFC PRESSURE
GRADIENT WAS A BIT WEAKER. DESPITE BOUNDARY LAYER WINDS NEAR 20
KTS...PATCHY DENSE FOG HAD FORMED AT SEVERAL OBS SITES. THE
REGIONAL RADAR MOSAIC SHOWED ISOLD -SHRA DEVELOPING OVER SE MN.

PATCHY DENSE FOG HAS BEEN REPORTED ALONG THE LAKESHORE...AND AT
A FEW LOCATIONS FARTHER INLAND (IMT/CLI/EZS). EXPECT THICKENING
CLOUD COVER TO LIMIT THE COVERAGE AT THE INLAND LOCATIONS...BUT
THE LKSHR COUNTIES WILL LIKELY SEE ENOUGH BREAKS IN THE CLOUD
COVER TO SUPPORT CONTINUED DENSE FOG DEVELOPMENT. GLERL WATER
TEMPS FOR LK MICHIGAN SHOWED POCKETS OF COLD WATER (MID-UPPER
30S) NEAR THE SHORELINE FROM TWO CREEKS TO STURGEON BAY. WITH
DEW POINTS IN THE UPPER 30S NOTED AT SUE AND MTW AND A LIGHT SE
WIND...IT SEEMS LIKELY THAT AREAS OF DENSE FOG WILL CONTINUE NEAR
THE LKSHR. A FEW OF THE WEB CAMS...MOST NOTABLY AT ALGOMA...
VERIFIED THE PRESENCE OF SOME THICK FOG. SO...WILL START WITH A
DENSE FOG ADVISORY FOR THE LKSHR COUNTIES...AND ADJUST AS
CONDITIONS WARRANT THIS MORNING. COULD SEE A REPEAT PERFORMANCE
OVER OUR SE COUNTIES TONIGHT...AS MODELS SHOW THE POTENTIAL FOR
PARTLY CLOUDY SKIES AND DECREASING S-SE BOUNDARY LAYER WINDS.
WILL COVER WITH AREAS OF FOG FOR NOW.

MODELS HAVE DIFFERING SOLNS WITH REGARD TO PCPN TRENDS...ESP FOR
TODAY. THE GFS IS VERY AGGRESSIVE...AND DEVELOPS AROUND A TENTH
OF AN INCH OF QPF OVER NC WI TODAY. THIS SEEMS TO BE OVERDONE...
WITH ONLY WEAK WAA EXPECTED...AND UPSTREAM SOUNDINGS SHOWING A
LACK OF DEEP SATURATION AND MOISTURE SITUATED BLO 750 MB. THE
SREF SEEMS TO HAVE A BETTER HANDLE ON THE CURRENT TRENDS...KEEPING
ANY LGT SHOWER ACTIVITY FOCUSED MAINLY TO OUR WEST THROUGH THIS
EVG...THEN BRINGING SOME LGT QPF INTO C/NC WI AS THE RRQ OF THE
UPPER JET PULLS THROUGH LATE TONIGHT INTO MONDAY MORNING. SE WINDS
SHOVE THE MOISTURE WEST OF GRB CWA AGAIN BY MONDAY AFTERNOON...SO
WILL ONLY MENTION MORNING POPS ON MONDAY.

.LONG TERM...MONDAY NIGHT THROUGH SATURDAY
THE WELL ADVERTISED UPPER LOW ACROSS THE CENTRAL UNITED STATES
WILL BEGIN TO MORE TOWARDS THE STATE. A TRANQUIL NIGHT IS EXPECTED
MONDAY NIGHT UNDER MOSTLY CLOUDY SKIES.

MODELS CONTINUE TO STRUGGLE WITH EVOLUTION AND POSITION OF THE
UPPER LOW FROM TUESDAY NIGHT INTO THANKSGIVING DAY. THESE PROBLEMS
ALSO REFLECT DOWN TO THE SURFACE AND WILL HAVE AN IMPACT ON WHEN
PRECIPITATION WOULD BECOME MIXED WITH OR CHANGE TO SNOW.

BASED ON THE CONSISTENCY OF THE CANADIAN AND ECMWF AND THE LACK
OF CONSISTENCY OF THE GFS...HAVE TRENDED TOWARDS THE CANADIAN/ECMWF
MODEL FOR THE TUESDAY NIGHT THROUGH THANKSGIVING DAY PERIOD.
FOR TUESDAY NIGHT...THE MODELS ARE FORECASTING A SURFACE LOW TO
MOVE INTO EASTERN WISCONSIN BY 12Z WEDNESDAY. THIS WILL BRING A
GOOD CHANCE OF RAIN TO THE REGION TUESDAY NIGHT. 850MB
TEMPERATURES ARE EXPECTED TO HOVER AROUND 0 C OVER THE NORTH...BUT
925MB TEMPERATURES ARE TOO WARM TO SUPPORT SNOW. LATER SHIFTS MAY
NEED TO WATCH THIS PERIOD FOR EVAPORATIVE COOLING EFFECTS THAT COULD
CHANGE THE RAIN OVER TO SNOW AT THE ONSET. JUST TOO LOW OF A PROBABILITY
OF HAPPENING TO INCLUDE IN THIS FORECAST PACKAGE.

THE FORECAST BECOMES VERY COMPLICATED WEDNESDAY INTO THANKSGIVING DAY
AS THE CANADIAN/ECMWF INDICATE THE UPPER LOW BECOMES CONSOLIDATED
OVER THE WESTERN GREAT LAKES REGION ON WEDNESDAY. THE PROBLEMS
ON WEDNESDAY ARE HOW QUICK THE COLD AIR WORKS INTO THE FORECAST
AREA TO CHANGE THE RAIN OVER TO SNOW AND WHICH MODEL WILL DO BETTER
ON HANDLING OF THE CONSOLIDATION OF THE UPPER LOW. THE CANADIAN IS
MUCH QUICKER TO MOVING THE SYSTEM OFF TO THE EAST AND WOULD BRING
A QUICKER END TO THE PRECIPITATION. THE ECMWF IS CONSIDERABLY
SLOWER AND ALSO FURTHER SOUTH WITH UPPER LOW. THE MODEL ALSO
SUGGEST A WAVE MOVING ACROSS SOUTHEAST WISCONSIN THAT COULD BRING
AN ACCUMULATING SNOWFALL TO PORTIONS OF CENTRAL...NORTH CENTRAL
AND NORTHEAST WISCONSIN. NOT SURE I AM READY TO JUMP ON THAT
SOLUTION YET. HAVE LEANED TOWARD THE ECMWF SOLUTION FOR WEDNESDAY
NIGHT AND THANKSGIVING DAY. HAVE INCREASED PRECIPITATION CHANCES
FOR BOTH PERIODS. DID NOT MAKE SIGNIFICANT CHANGES TO THE
PRECIPITATION TYPE UNTIL THERE IS BETTER AGREEMENT OF THE MODELS.
&&

.AVIATION...SOUTHERLY RETURN FLOW WAS RESULTING IN INCREASING
LOW-LEVEL MOISTURE EARLY THIS MORNING. THIS WAS PRODUCING SEVERAL
LAYERS OF LOW/MID CLOUDS...INCLUDING SOME MVFR CIGS OVER NC WI.
OF GREATER CONCERN IS ONGOING FOG DEVELOPMENT OVER NE/EC WI...
WHERE PATCHIER CLOUD COVER...LIGHTER WINDS AND FLOW OFF LK MICH
WERE MORE SUPPORTIVE OF WIDESPREAD FOG. MOST LOCATIONS IN NE/EC
WI SHOULD SEE MVFR/IFR VSBYS IN FOG...BUT LCL VLIFR VSBYS/CIGS ARE
ANTICIPATED...ESPECIALLY NEAR THE LKSHR...THROUGH MID-MORNING.
ANOTHER ROUND OF FOG IS PSBL TONIGHT...ESP IN NE/EC WI. SCT
SHOWERS ARE EXPECTED TO DEVELOP IN PARTS OF C/NC WI LATE
TONIGHT...THEN CONTINUE INTO MON MORNING BEFORE ENDING.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR WIZ022-040-
050.

&&

$$
KIECKBUSCH/ECKBERG