FXUS63 KGRB 012057
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
257 PM CST TUE DEC 1 2009

.SYNOPSIS...THOUGH IT/S EXACT CONFIGURATION AND LOCATION WL
CHANGE SOME DURING THE FCST PERIOD...THE DOMINANT LNGWV FEATURE
IMPACTING THE WX ACRS NOAM DURING THE NEXT 7-10 DAYS WL BE STG
RIDGE OVER THE ALASKA/GULF OF ALASKA RGN. THE HIGH UPR HEIGHTS NOW
IN PLACE OVER NWRN NOAM WL LEAD TO THE FORMATION OF COLD AIR MASSES
OVER NWRN CANADA...AT LEAST SOME OF WHICH WL HEAD SEWD INTO THE
CONUS. THAT WL SEND TEMPS IN THE FCST AREA BACK TO NR OR A LITTLE
BLO NORMAL LEVELS BY LATE THIS WEEK AND DURING THE UPCOMING
WEEKEND. WHETHER OR NOT WE HAVE A PERIOD OF SIG BLO NORMAL TEMPS
BEYOND THE END OF THE FCST PERIOD WL DEPEND ON HOW EXTENSIVE OF A
SNOW COVER DEVELOPS...AND THE EXACT EVOLUTION OF UPR RIDGE. AS
ALWAYS...MODELS REALLY STRUGGLING WITH STRUCTURE OF THE RIDGE IN
LATER PERIODS.

SHOULD END UP WITH SEVERAL INCHES OF SNOW IN THE SNOWBELT OF LAKE-
SUPERIOR DURING THE MIDDLE TO LATTER PART OF THE WEEK. FOR THE REST
OF THE AREA...THERE DOES SEEM TO BE A WINDOW OF OPPORTUNITY FOR
CLASSIC PANHANDLE HOOK TYPE STORM SYSTEM AT THE VERY END OF THE
FCST PERIOD AND JUST BEYOND. WHETHER OR NOT THAT MATERIALIZES ONCE
AGAIN GOES BACK TO EXACT STRUCTURE OF NWRN NOAM RIDGE.

WELCOME TO WINTER!
&&

.SHORT TERM...TONIGHT AND WEDNESDAY
LOW PRESSURE ACROSS NORTHERN MINNESOTA IS EXPECTED TO MOVE NORTHEAST
TO LAKE SUPERIOR TONIGHT...THEN INTO ONTARIO ON WEDNESDAY. A COLD
FRONT NOW DRAPED ACROSS WESTERN MINNESOTA SOUTHWARD INTO KANSAS
WILL MOVE INTO CENTRAL AND NORTH CENTRAL WISCONSIN AROUND 06Z...
AND THEN INTO NORTHEAST WISCONSIN BY 12Z. THIS FRONT WILL BRING
AN END TO THE VERY MILD CONDITIONS ACROSS THE REGION. JUST BEHIND
THE FRONT...WINDS WILL BECOME GUSTY FOR A PERIOD OF TIME AS THE 
COLD AIR FILTERS INTO THE REGION. DID NOT USE A DIURNAL CURVE 
FOR HOURLY TEMPERATURES TONIGHT AS WINDS REMAIN UP THIS EVENING
DUE TO MILD SOUTHWESTERLY FLOW. BEGAN TO DROP TEMPERATURES AFTER
MIDNIGHT AS COLD FRONT PUSHES INTO EAST CENTRAL WISCONSIN.

ON WEDNESDAY...LOW LEVEL FLOW BECOMES VERY FAVORABLE FOR LAKE
EFFECT SNOW SHOWERS ACROSS NORTH CENTRAL WISCONSIN. WILL CONTINUE
WITH THE LIKELY CHANCES OVER VILAS COUNTY...BUT DID INCREASE SNOW
CHANCES ACROSS ONEIDA AND PORTIONS OF FOREST AND FLORENCE
COUNTIES. A COUPLE INCHES OF SNOW ARE POSSIBLE BY LATE WEDNESDAY
AFTERNOON OVER THE SNOWBELT REGION WITH LIGHTER AMOUNTS JUST TO 
THE SOUTH. DID ADD A CHANCE OF FLURRIES DURING THE AFTERNOON
HOURS OVER THE SOUTH AS LOW CLOUDS MOVE SOUTHWARD. STAYED NEAR THE
3 HOURLY TEMPERATURES FOR MAX TEMPERATURES ON WEDNESDAY DUE TO
CLOUD COVER AND COLD ADVECTION AT 850MB.

.LONG TERM...WED NGT THROUGH NEXT TUE. SITN LOOKS FAVORABLE FOR
GETTING SOME LAKE-EFFECT OFF LAKE SUPERIOR WED NGT AND INTO THU
MORNING. MODELS OFFERED VARYING IDEAS ON JUST HOW LONG FAVORABLE
TRAJECTORIES WL OCCUR. BUT GIVEN SUFFICENT LAKE-SFC/AIR TEMPERATURE
DIFFERENCES AND THE FACT THAT INCOMING AIR MASS WILL NOT BE
EXTREMELY DRY AT FIRST...WOULD EXPECT SEVERAL INCHES OF
ACCUMULATION. AT THIS POINT...COMFORTABLE WITH LIKELY POPS AND
MENTION OF SNOW TOTALS IN GRIDS/ZONES AND MENTION OF SITN IN HWO.
STILL PLENTY OF TIME TO POST A HEADLINE ONCE CONFIDENCE IN DURATION
OF FAVORABLE TRAJECTORIES IS A LITTLE CLEARER.

MAJOR STORM SYSTEM LIFTG THROUGH THE OHIO RIVER VALLEY COULD ALSO
PULL THE FLOW IN E-C WI ARND ENOUGH TO GENERATE SOME LAKE-EFFECT OFF
LAKE MICHIGAN WED NGT. BUT LAKE-SFC/AIR TEMPERATURE DIFFERENCES MORE
MARGINAL THAN OFF LAKE SUPERIOR...AND WE ALSO MAY BE FIGHTING SOME
SUBSIDENCE ON NW FLANK OF THE OHIO VALLEY STORM SYSTEM. KEPT CHC
POPS FOR SHSN NEAR THE LAKE...AND FLURRIES INLAND FOR WED NGT. FLOW
SHOULD BACK NWLY ENOUGH TO SHUT-OFF CHC OF LAKE-EFFECT THU.

UPPER TROUGH LINGERING OVER THE AREA WL LIKELY LEAD TO PERIODS OF
LGT SNOW OR FLURRIES FOR THE LATTER PART OF THE WEEK. ALWAYS
POSSIBLE THAT WK DISTURBANCE WORKING THROUGH THE FLOW COULD PRODUCE
AN INCH OF SNOW IN ANY PERIOD...BUT IMPOSSIBLE TO PINPOINT AT THIS
POINT SO WENT WITH MAINLY JUST FLURRIES FOR NOW.

WK SYSTEM DROPPING THROUGH THE RGN COULD BRING SOME LGT SNOW AND
ANOTHER ROUND OF LAKE-EFFECT LATER IN THE WEEKEND. THEN BY THAT
POINT...ALL ATTENTION WL BE FOCUSED ON EVOLUTION OF THE PATTERN AND
POTENTIAL FOR MORE SIG SNOW AND COLD NEXT WK.
&&

.AVIATION...VFR CEILINGS WILL GIVE WAY TO MVFR CEILINGS LATER TONIGHT
NORTHWEST OF AN IRON MOUNTAIN TO WAUTOMA LINE. CEILINGS NORTH OF A
TOMAHAWK TO IRON MOUNTAIN WILL LOWER INTO THE IFR CATEGORY FOR
VISIBILITIES AND CEILINGS DUE TO SNOW SHOWERS...ESPECIALLY OVER 
VILAS COUNTY. THERE WILL SOME MINOR SNOW ACCUMULATION LESS THAN AN 
INCH AT KRHI WEDNESDAY AFTERNOON. MORE SNOW IS EXPECTED TO THE NORTH
ACROSS VILAS COUNTY. SNOW SHOWERS WILL CONTINUE INTO WEDNESDAY NIGHT
AND THURSDAY. A COUPLE INCHES OF SNOW ARE POSSIBLE KRHI WITH
ACCUMULATIONS OVER 4 INCHES LIKELY OVER NORTHERN VILAS COUNTY.
&&

.MARINE...A COLD FRONT WILL SWEEP ACROSS THE AREA LATER TONIGHT. 
COULD BE A BRIEF PERIOD WHERE WINDS REACH SMALL CRAFT ADVISORY 
CRITERIA WITH GUSTS AROUND 25 KNOTS. NORTHWEST WINDS WILL INCREASE
AGAIN WEDNESDAY AFTERNOON...ESPECIALLY OVER THE NORTHERN DOOR 
COUNTY.
&&

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

$$
ECKBERG/SKOWRONSKI