FXUS63 KGRB 010947
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
347 AM CST TUE DEC 1 2009

.SHORT TERM...TODAY INTO WEDNESDAY

FIRST CLIPPER SYSTEM EXITED AREA LAST EVENING...NEXT SYSTEM NOW
MOVING THROUGH THE NORTHERN PLAINS...WITH SURFACE LOW EXPECTED TO
PASS NEAR DULUTH THIS EVENING...EASTERN LAKE SUPERIOR WEDNESDAY MORNING.

WAA REGIME KICKS IN TODAY AHEAD OF THE SYSTEM WITH MAINLY
INCREASING MID LEVEL CLOUDINESS EXPECTED. DYNAMICS PASS NORTH OF
CWA WITH MODELS VERY CONSISTENT ON KEEPING QPF NORTH OF WI BORDER
TONIGHT. WILL CONTINUE WITH CURRENT SLIGHT CHANCE INHERITED IN GRIDS.
SOUTHWESTERLY WINDS AHEAD THIS SYSTEM EXPECTED TO BRING A MILD DAY
TO THE REGION FOR THE FIRST DAY OF DECEMBER. HIGHS SHOULD CLIMB
INTO THE UPPER 30S OVER THE NORTH TO THE MIDDLE 40S SOUTH.
SUBTRACTED A DEGREE OR TWO FROM PREVIOUS GRIDS WITH EXPECTED
CLOUDS.

BEHIND SYSTEM...WINDS SHIFT TO THE WEST THEN NORTHWEST FOR
POTENTIAL LAKE EFFECT WEDNESDAY AFTERNOON OVER VILAS COUNTY AND
VCNTY. LOW LEVEL FLOW LINES UP AROUND 18Z. DELTA T'S REMAIN
CONDITIONAL THROUGH DAY PERIOD...WITH RATHER STRONG SUBSIDENCE
THROUGH MID DAY. WILL GO WITH LIKELY POPS IN THE AFTERNOON...
THOUGH LIMIT ACCUMULATIONS AS SHOWERS EXPECTED TO REALLY GET GOING
WED NIGHT PERIOD.

.LONG TERM...WED NGT THRU NXT MON. MAIN WEATHER FOCUS REMAINS ON
POTENTIAL LK EFFECT EVENT ACROSS N-CNTRL WI DURING THE WED NGT
INTO THU TIME FRAME. OTHERWISE...NO MAJOR STORM SYSTEMS ON THE
HORIZON THAT WOULD IMPACT NE WI THRU EARLY NXT WEEK. TEMPS TO
STEADILY TREND DOWNWARD WITH READINGS AVERAGING CLOSER TO SEASONAL
NORMALS FOR EARLY DECEMBER.

SRN STREAM INTENSIFYING SFC LOW IS FCST TO TRACK FROM THE OHIO
RIVER VALLEY NEWD TO THE ERN GREAT LKS RGN WED NGT. EVEN WITH A
SLIGHTLY MORE WRN TRACK PROVIDED BY THE NAM/UKMET (LK ERIE)...THIS
TRACK IS JUST TOO FAR TO OUR EAST TO BRING SYNOPTIC SNOW TO NE WI.
INSTEAD...FCST FOCUS WL CONT TO BE POTENTIAL LK EFFECT SNOW SHWRS
FOR N-CNTRL WI. TRAJS DO BECOME MORE FAVORABLE WED NGT (N-NW) AND
DELTA-T VALUES ARE IN THE UPR TEENS. PBLM IS THAT LOW-LVL INVERSION
HGTS ARE AROUND 4K FT AND LOW-LVL MSTR IS MARGINAL. LIKELY POPS WL
REMAIN NECESSARY OVR VILAS CNTY...BUT ACCUMULATIONS WOULD BE LGT
(PERHAPS AN INCH OR TWO). THE REMAINDER OF THE FCST AREA SHOULD
SEE EITHER SCT LGT SNOW SHWRS OR FLURRIES WITH LITTLE IF ANY
ACCUMULATION. 

BROAD UPR TROF SETTLES OVR THE GREAT LKS ON THU WHICH WL KEEP
PLENTY OF CLDS IN OUR VCNTY ALONG WITH A CONTINUING CHC OF SNOW
SHWRS OR FLURRIES. OVR N-CNTRL WI...BACKING WNDS THRU THE DAY
SHOULD LEAD TO A GRADUALY DECREASE IN LAKE EFFECT SNOWS. PERHAPS
ANOTHER INCH IS PSBL IN THE MORNING...BUT TRAJS BECOME MORE
UNFAVORABLE BY THE AFTERNOON. CYCLONIC FLOW OVR THE REMAINDER OF
THE RGN WL GENERATE ONGOING PCPN CHCS WITH LITTLE OF ANY SNOW
ACCUMULATION. ONE NOTICEABLE DIFFERENCE ON THU WL BE THE COOLER
TEMPS AS READINGS TO ONLY REACH THE MID 20S NORTH...MID 30S NEAR
LK MI. 

UPR TROF SLIDES A BIT TO THE EAST THU NGT...BUT REMAINS A FIXTURE
OVR THE GREAT LKS RGN. AS THE UPR TROF SLOWLY MOVS TO THE EAST...
SFC WNDS ARE FCST TO BACK EVEN MORE AND ARE EXPECTED TO ALMOST BE
DUE WEST AFT MIDNGT. HARD TO SEE MUCH LK EFFECT SNOWS REACHING
VILAS CNTY FROM THIS DIRECTION...THUS HAVE DOWNPLAYED THE POPS/
SNOW ACCUMULATIONS FOR VILAS. REST OF NE WI COULD SEE WDLY SCT
SNOW SHWRS OR FLURRIES THRU THE NGT. MORE TYPICAL DEC TEMPS IN
STORE OVR THE RGN WITH MINS DROPPING INTO THE TEENS INLAND/LWR 20S
NEAR LK MI.

NOT A WHOLE OF CHG ANTICIPATED HEADED INTO FRI AS THE UPR TROF
SLOWLY MIGRATES E-NE...BUT REMAINS THE MAIN WEATHER PLAYER FOR NE
WI. MDLS APR TO INDICATE A TRANSITORY SFC TROF WL ROTATE SOUTH
THRU WI DURING THE DAY...THUS CANNOT RULE OUT A FEW SNOW SHWRS.
WOULDN'T BE SURPRISED IF FLURRIES TURNS OUT TO BE THE ONLY THING
MOST OF US SEE ON FRI. MAX TEMPS CONT TO RUN A FEW DEGS BLO NORMAL
FOR EARLY DEC. LINGERING UPR TROF FINALLY SHOWS SIGNS OF PULLING
AWAY FRI NGT INTO SAT...THEREFORE PCPN CHCS TO GRADUALLY DIMINISH
AS WELL. MORE OF AN ISSUE APRS OVR THE ERN PACIFIC AS THE GFS
MAINTAINS A STG UPR RDG...WHEREAS THE ECMWF UNDERCUTS THE UPR RDG
WITH AN UPR LOW BEARING DOWN ON THE PAC NW. INITIALLY...THIS CHG
WL NOT IMPACT OUR WEATHER THRU SAT WITH LINGERING LOW-LVL MSTR
KEEPING CLDS AROUND THRU MOST OF FRI NGT BEFORE SOME SUNSHINE
POKES THRU ON SAT.

FOR THE END OF THE WEEKEND INTO EARLY NXT WEEK...MEAN FLOW ACROSS
THE CONUS MAY ACTUALLY BECOME MORE ZONAL IN NATURE WITH THE BULK
OF ANY PCPN LOCATED WEST OF THE ROCKIES ASSOCIATED WITH THE UPR
LOW WHICH THE MAJORITY OF MDLS FAVOR. A WEAK FNTL BNDRY MAY CROSS
WI ON SUNDAY...BUT WITH MSTR LACKING...DO NOT EXPECT MUCH TO
HAPPEN WITH THIS FEATURE. PREV SHIFT HAD MENTIONED A MINIMAL CHC
OF LGT SNOW SHWRS AND PREFER TO ALLOW DAYSHIFT ANOTHER LOOK BEFORE
PULLING OUT THE PCPN. THE ZONAL FLOW SHOULD ALLOW TEMPS TO GET
BACK TO NORMAL LEVELS FOR BOTH SUNDAY AND MON.
&&

.AVIATION...MAINLY MID LEVEL CLOUDINESS EXPECTED THROUGH DAY
PERIOD WITH CIGS LOWERING AS LOW PRESSURE SYSTEM MOVES INTO
WESTERN LAKES THIS EVENING. SNOW SHOWER ACTIVITY EXPECTED TO STAY
MAINLY NORTH OF WI TONIGHT...THOUGH SOME GUSTY WINDS EXPECTED
WESTERN TAF SITES LATE TONIGHT WITH/BEHIND FRONT.
&&

.MARINE...WINDS EXPECTED TO CONTINUE TO DIMINISH THROUGH THE
MORNING PERIOD...THUS SCA ALLOWED TO EXPIRE. WINDS TO ONCE MORE
PICK UP LATE TONIGHT INTO WED BEHIND COLD FRONT.
&&

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

$$
TE/KALLAS