FXUS63 KMKX 020941
AFDMKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
341 AM CST WED DEC 2 2009

.SHORT TERM...
TODAY...FORECAST CONFIDENCE: HIGH
SFC LOW PRESSURE CENTERED OVER UPPER MI WILL SHIFT EAST INTO EASTERN 
ONTARIO THIS AFTERNOON. A COLD FRONT WILL CROSS WI FROM NW TO SE 
TODAY AND TONIGHT. WINDS AHEAD OF THE FRONT ARE GENERALLY LIGHT THIS 
MORNING. NW WINDS BEHIND THE FRONT WILL BE A LITTLE GUSTY THIS 
AFTERNOON. 

925MB WINDS WILL BE ON THE DECREASE ALL DAY TODAY...GOING FROM 
AROUND 1C AT MSN THIS MORNING TO -5C THIS EVENING...AND DOWN TO -10C 
BY THU MORNING. WITH MIXING TO 900MB FOR MUCH OF THE PERIOD...THESE 
TEMPS SHOULD INFLUENCE THE SFC TEMPS QUITE A BIT. HOWEVER...CLOUD 
COVER WILL BE THE COMPLICATING FACTOR. CLOUDS SHOULD FILL IN ACROSS 
SOUTHERN WI THIS MORNING AS HIGHER CLOUDS FROM THE SYSTEM TO OUR 
SOUTH CREEP NORTHWARD AND STRATUS ALONG THE COLD FRONT WORK THEIR 
WAY EASTWARD. 

TONIGHT...FORECAST CONFIDENCE: LOW
SFC LOW PRESSURE STRENGTHENING OVER TN THIS AFTERNOON WILL SHIFT 
NORTH INTO KY THIS EVENING AND INTO OH BY MIDNIGHT. MODELS AGREE 
THAT THE PRECIP SHIELD ON THE BACK SIDE OF THE SYSTEM COULD VERY 
WELL CLIP THE FAR SOUTHEAST TIP OF WI. THERE IS MORE OF A GRAY AREA 
AS TO HOW MUCH OF SE WI THE PRECIP WILL HIT. THERE WILL BE MID LEVEL 
DRY AIR CUTTING INTO THE CWA ON THE NORTHWEST WINDS...WHICH WILL 
INHIBIT THE WESTWARD SPREAD OF PRECIP FROM THE SYSTEM. THERE WILL 
LIKELY BE A SHARP GRADIENT IN THE PRECIP FIELD AND IT WILL BE 
SOMEWHERE AROUND THE WI/IL BORDER. PRECIP TYPE SHOULD BE ALL SNOW 
EXCEPT FOR A NARROW AREA ALONG THE LAKE MI SHORELINE. IN THIS 
AREA...LAKE TEMPS ARE STILL AROUND 42F AND MODEL SNDGS SHOW LOW 
LEVEL WIND CONVERGENCE AND WET BULB TEMPS ABOVE FREEZING UNTIL 06Z. 

IF THE PRECIP SHIELD DOES CLIP SE WI...MOST OF IT WOULD FALL BETWEEN 
00Z AND 06Z WHEN THE STRONGEST OMEGA...FGEN AND UPPER LEVEL 
DIVERGENCE ARE CLOSEST. THE BEST FORCING SHIFTS EAST AFTER 06Z...BUT 
AN APPROACHING JET STREAK WILL PUT SOUTHERN WI WITHIN THE LEFT EXIT 
REGION AND BENEATH A 500MB SHORTWAVE. THIS EXTRA BOOST COULD CAUSE A 
FEW SNOW SHOWERS IN THE CWA AFTER MIDNIGHT. LESS THAN A HALF INCH IS 
EXPECTED IN THE FAR SOUTHEAST CORNER...AS QPF SHOULD BE LIGHT. 

THURSDAY AND FRIDAY...FORECAST CONFIDENCE: MEDIUM 
POSSIBILITY OF LIGHT SNOW SHOWERS OR AT LEAST FLURRIES ACROSS THE 
REGION WITH COLD...CYCLONIC FLOW OVERHEAD. BUFKIT MODEL SNDGS SHOW 
RELATIVELY MOIST AIR THROUGH MUCH OF THE ATMOSPHERE AND STEEP LOW 
LEVEL LAPSE RATES ON THU. THE FCST SNDGS ARE A LITTLE DRIER AND 
GENERALLY MORE WESTERLY WINDS FOR FRI...SO JUST MENTIONED FLURRIES 
WITH SCHC POPS. 

.LONG TERM...
SATURDAY THROUGH SUNDAY...FORECAST CONFIDENCE: MEDIUM 
DRIER AIR IS EXPECTED TO WORK INTO THE LOWER LEVELS ON SAT...AS WELL 
AS WESTERLY WINDS ALOFT AND SOUTHERLY WINDS NEAR THE SFC. KEPT SAT 
AND SUN DRY. TEMPS SHOULD MODERATE A LITTLE ON SUN WITH 925MB WAA. 

SUNDAY NIGHT...FORECAST CONFIDENCE: MEDIUM 
BOTH GFS AND ECMWF SHOW POTENTIAL FOR LIGHT SNOW EVENT ACROSS 
CENTRAL WI SUN NIGHT INTO MON...WHICH WOULD CLIP OUR NORTH AND 
NORTHWEST CWA. ADDED MENTION OF CHANCE POPS TO FCST.

&&

.AVIATION...VFR CONDITIONS EXPECTED THROUGH LATE THIS AFTERNOON. 
HIGH CLOUDS SPREAD IN QUICKLY EARLY THIS MORNING AND LOWER STEADILY 
THROUGH THE DAY AS STRONG LOW PRESSURE LIFTS OUT OF THE LOWER 
MISSISSIPPI VALLEY TODAY. AS THE LOW REACHES THE KENTUCKY/OHIO 
VALLEY AREA BY 00Z THU...LOOK FOR MVFR CIGS TO DEVELOP QUICKLY 
ACROSS SOUTHEAST WISCONSIN AROUND THAT TIME. THESE LOWER CIGS ARE 
NOT EXPECTED TO REACH KMSN. THE LOW MOVES QUICKLY NORTHEAST WITH 
CIGS LIFTING BACK INTO VFR LEVELS BY OR SHORTLY AFTER 06Z THU AS DRY 
AIR RETURNS ON BRISK NORTH WINDS. IN ADDITION TO THE LOWER 
CLOUDS...SOME LIGHT SNOW COULD CLIP SOUTHEAST WISCONSIN THIS 
EVENING. NO ACCUMULATIONS ARE EXPECTED. 

&&

.MARINE...THE STRONG LOW PRESSURE SYSTEM TRACKING FROM THE LOWER 
MISSISSIPPI VALLEY TO THE OHIO VALLEY TODAY...AND THEN TO THE 
EASTERN GREAT LAKES TONIGHT WILL BRING UP THE WINDS ACROSS LAKE 
MICHIGAN LATE THIS AFTERNOON. WINDS WILL VEER TO THE NORTHEAST THIS 
AFTERNOON AND INCREASE ABOVE SMALL CRAFT ADVISORY LEVELS BY EVENING. 
OVERNIGHT...THE WINDS REMAIN BRISK...BUT BACK TO THE NORTHWEST. 
WINDS WILL SUBSIDE BELOW SMALL CRAFT ADVISORY LEVELS BY LATE MORNING 
ON THURSDAY AS THE LOW PULLS AWAY. 

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO NOON CST 
     THURSDAY FOR LMZ643>646.

&&

$$

SHORT/LONG TERM...13/MRC
AVIATION/MARINE...05/DAVIS