FXUS63 KGRB 150853
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
253 AM CST TUE DEC 15 2009

.SHORT TERM...TODAY/TONIGHT/WEDNESDAY. PATCHY CLOUDS WITH PERIODS
OF SW-- WERE LINGERING OVER ERN WI EARLY THIS MORNING AS
APPROACHING ARCTIC HIGH WRINGS THE MOISTURE OUT. MEANWHILE A VORT
CENTERED OVER DLH AT 08Z WILL ALSO MOVE EASTWARD OVER THE FORECAST
AREA THIS MORNING. ADDITIONAL CLOUDS WITH SCATTERED SNOW SHOWERS
AND FLURRIES WITH THIS VORT CLOUDS WILL AFFECT THE MORNING HOURS.
EXTRAPOLATION OF THIS FEATURES SUGGESTS THE BACK EDGE WITH
CLEARING REACHES NC AND CENTRAL WI BETWEEN 6 AM AND 8 AM AND THEN
BETWEEN 8 AM TO 11 AM FOR THE REST OF THE AREA.  WILL MENTION WC
TO NEAR -20 THIS MORNING OVER THE WEST HALF BUT NO ADVISORY.

LES POTENTIAL FOR SCATTERED SNOW SHOWERS OR FLURRIES AT LEAST FOR
THE FAR NORTH TODAY.  BUT WIND COMPONENT IN THE BOUNDARY LAYER
BECOMES TOO WESTERLY AND AIR MASS BECOMES DRY.

OTHERWISE CLEAR SKIES AND LIGHT WINDS WITH THE HIGH PRESSURE RIDGE 
WILL ALLOW TEMPS TO PLUMMET WELL BELOW ZERO TONIGHT. QUITE A
DIFFERENCE BETWEEN OVERNIGHT LOWS BETWEEN NAM -10 AND MAV OF 0
FOR GRB ALONE.  WILL SPLIT THE DIFFERENCE THERE BUT WILL LEAN
TOWARD THE COOLER MET GUIDANCE FOR TONIGHT AS THE COLD CLOUD BIAS MAV
BRINGS CLOUDS IN QUICKER TONIGHT TO MODIFY TEMPS.  SOME CLOUDS MAY
MAKE A PUSH LATE TONIGHT BUT SAT LOOPS SHOWS RETURN CLOUDS OVER SW
SD AND NE AND PATCHY AT BEST.

PROBLEM WITH THE RETURN WAA CLOUDS CONTINUES INTO WED AND EFFECTS
ON TEMPS. WILL USE A BLEND OF GUID TEMPS WHICH IS NEAR GOING
FORECASTS OF MAINLY IN THE TEENS. WITH THE SUBZERO TEMPS FOR WED
MORNING...WC READINGS ARE LOW BUT WINDS EXPECTED TO BE LIGHT IN
THE RIDGE AXIS AS WELL TO HOLD OFF ANY WC HEADLINE FOR NOW.

.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY.
HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN WEDNESDAY NIGHT...
BRINGING ANOTHER COLD NIGHT TO THE REGION. HIGH CLOUDS WILL BE ON 
THE INCREASE ALONG WITH LIGHT SOUTHERLY WINDS SHOULD KEEP IT 
WARMER THAN TUESDAY NIGHT. WEAK SYSTEM WILL MOVE ACROSS THE
REGION ON THURSDAY. A LOT OF DRY AIR TO OVERCOME...BUT THERE SHOULD
BE SOME FLURRIES OVER THE NORTH. THE GFS/ECMWF/WRF MODEL SOUNDINGS
SUGGEST THE FLURRIES COULD END AS FREEZING DRIZZLE. JUST NOT SURE
IF THE LOWER LEVEL MOISTURE WILL BE AROUND WITH CANADIAN HIGH
OVERHEAD. WILL CONTINUE THE MENTION OF FLURRIES AND WILL REASSESS
ON LATER SHIFTS.

MODELS CONTINUE TO SHOW UPPER LOW OVER EAST CANADA ROTATING
SOUTHWESTWARD INTO THE WESTERN GREAT LAKES REGION OVER THE WEEKEND.
STILL MANY ISSUES TO WORK OUT WITH DETAILS OF THIS SYSTEM. IT
LOOKS LIKE THE BEST CHANCE OF SNOW WILL BE SATURDAY NIGHT AND SUNDAY
AS MAIN SHORTWAVE SWINGS ACROSS THE REGION. THE MODELS ARE SHOWING
A SURFACE REFLECTION WITH THIS FEATURE THAT COULD PRODUCE A LIGHT 
ACCUMULATING SNOWFALL OUTSIDE THE LAKE EFFECT SNOW BELT REGION
OF VILAS COUNTY. HIGHER AMOUNTS ARE EXPECTED OVER THE SNOWBELT REGION
OF VILAS COUNTY DURING THE PERIOD DUE TO NORTHERLY FETCH OFF THE 
WARMER WATERS OF LAKE SUPERIOR. AS WE GET CLOSER TO THE EVENT...WE 
CAN FINE TUNE THE DETAILS DEPENDING ON THE DIRECTION OF THE LOW LEVEL
FLOW. 

HIGH PRESSURE SHOULD BUILD INTO WISCONSIN EARLY NEXT WEEK.
&&

.AVIATION...PATCHY MVFR CONDITIONS WILL CONTINUE THIS MORNING BUT
WILL IMPROVE TO VFR CONDITIONS BETWEEN 12Z-14Z OVER CENTRAL AND
NORTH CENTRAL WISCONSIN AND BETWEEN 14Z AND 16Z OVER NORTHEAST WI.
&&

.MARINE...WILL EXTEND THE SCA TODAY FOR AREAL COORDINATION AND TO
HANDLE THE GUSTY CAA WINDS BEHIND THE VORT THIS MORNING.
&&

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

$$
TDH/ECKBERG