FXUS63 KGRB 031011
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
411 AM CST THU DEC 3 2009

.SHORT TERM...TODAY THROUGH FRIDAY

AT 09Z...DEEP SURFACE LOW OVER EASTERN LAKE ERIE...WITH WESTERN
EDGE OF SYNOPTIC SNOWS THAT BRIEFLY REACHED INTO EASTERN MANITOWOC
COUNTY NOW OVER LOWER MI. GUSTY NORTHERLY FLOW NOW DIMINISHING
OVER CWA.

00Z MODEL GUIDANCE IN GENERAL AGREEMENT THIS PERIOD. UPPER TROF
EXTENDING SOUTH OUT OF HUDSON BAY REGION TO LINGER OVER THE
WESTERN LAKES. ENERGY/VORT NOW OVER EASTERN SOUTH DAKOTA TO MOVE
THROUGH SOUTHERN WI LATE THIS AFTERNOON AND EVENING. MODELS
SHOWING LAPSE RATES BETWEEN 6 AND 6.5 AT LOW/MID LEVELS. THIS AND
WEAK LIFT WILL LIKELY LEAD TO ISOLD TO SCT SNOW SHOWER ACTIVITY.
HAVE BUMPED UP POPS OVER THE SOUTH TODAY AND THIS EVENING.

QUESTION OF FORECAST IS WHAT TO DO WITH LES ADVISORY. FLOW
THROUGHOUT THE NIGHT HAS BEEN TOO NORTHERLY/NORTHEASTERLY AT 850MB
FOR LES INTO NORTH CENTRAL WI. EARLIER REPORTS/WEBCAMS SUGGEST
LITTLE ACCUMULATION SO FAR. CURRENT RADAR/OB SITES SHOWING MAIN
BAND INTO VCNTY ASHLAND. WINDS BEGINNING TO BACK...WITH ORIENTATION
OF BANDS OVER UPPER MI BECOMING MORE NORTH/SOUTH. WINDS TO BACK TO
THE NORTHWEST THROUGH THE REST OF THE EARLY MORNING HOURS WITH CONDITIONS
STILL FAVORABLE FOR ACCUMULATING SNOWS TODAY OVER NW VILAS...SO
WILL KEEP ADVISORY GOING FOR TODAY. HAVE BACKED DOWN ON TOTALS
THOUGH.

WINDS OVERNIGHT HAVE KEPT TEMPERATURES UP OVER REGION. MADE SLIGHT
ADJUSTMENT TO PREVIOUS TEMP GRIDS...LEANING TOWARDS SREF GUIDANCE
WHICH IS VERIFYING WELL ON MAX TEMPS.

.LONG TERM...FRI NGT THRU NXT WED. LARGER SCALE CONTS TO SHOW A
CLOSED UPR HI OVR THE ERN PACIFIC NWD INTO ALASKA AND A DEVELOPING
UPR LOW OVR NRN CANADA. THIS SCENARIO WOULD ALLOW ARCTIC AIR TO
BEGIN DROPPING SOUTH TOWARD THE INTERNATIONAL BORDER. A SERIES OF
MID-LVL CIRCULATIONS ARE FCST TO UNDERCUT THE PACIFIC UPR HI AND
MOV ACROSS THE CONUS BRINGING A COUPLE CHCS OF SNOW TO NE WI. FCST
CHALLENGE REMAINS SERIOUS MDL DIFFERENCES WITH THE STRENGTH AND
SPD WITH WHICH THESE MID-LVL SYSTEMS MOV ACROSS THE COUNTRY.

NE WI TO REMAIN ON THE SRN FRINGE OF THE INITIAL UPR TROF FRI NGT
SO CANNOT RULE OUT SOME PASSING FLURRIES AT TIMES. OTHERWISE...
LOOK FOR A GOOD DEAL OF CLDS TO LINGER THRU THE NGT WITH A MORE
SEASONAL AIRMASS OVRHD. MIN TEMPS SHOULD EASILY DROP INTO THE
TEENS INLAND WITH A FEW TYPICAL COLD SPOTS IN THE NORTH DIPPING
CLOSE TO 10 DEGS. ONLY LOCATIONS NEAR LK MI MAY HOLD AROUND THE 20
DEG MARK.

A NEW PRONOUNCED UPR TROF IS FCST TO DIG SOUTH INTO THE NRN
ROCKIES ON SAT WITH LEE-SIDE CYCLOGENESIS DEVELOPING OVR SE CO.
THIS NEW SYSTEM WL HELP TO REINFORCE THE SOUTHERLY WNDS FROM TX
N-NE INTO THE WRN GREAT LKS. A WEAK SHOT OF WAA MAY ALLOW THE
START OF A BRIEF WARM-UP ACROSS NE WI. MAX TEMPS ON SAT MAY COME
DOWN TO EXACTLY HOW MUCH SUN CAN BREAK THRU THE CLDS. FOR NOW...
HAVE LEANED TOWARD THE WARMER MAV GUID.

THIS UPR TROF CONTS TO DIG SE INTO THE CNTRL ROCKIES SAT NGT AS A
WEAK CDFNT PUSHES EAST ACROSS THE UPR MIDWEST. STILL NO TRIGGERING
MECHANISM OVR WI SO HAVE KEPT THE DRY FCST GOING. SOUTHERLY WNDS
WL PREVENT TEMPS FROM FALLING TOO FAR WITH THE ONLY EXCEPTION
PERHAPS OVR VILAS CNTY WHERE FRESH SNOWPACK WOULD ALLOW READINGS
TO APPROACH 10 DEGS. THE CDFNT QUICKLY SWEEPS ACROSS WI SUNDAY
MORNING...BUT MSTR IS RATHER MEAGER AND FORCING/LIFT ARE WEAK.
HAVE PRETTY MUCH BOUGHT INTO THE ECMWF SOLN WITH BOTH THE SPD OF
THE CDFNT AND A GENERAL WEAKENING OF THE UPR TROF OVR THE CNTRL
PLAINS. THE GFS JUST APRS TOO AGGRESSIVE IN TRYING TO DROP ADDL
ENERGY SWD AND OVERLY DEVELOPING THE UPR TROF. WHILE THERE COULD
BE A FEW FLURRIES AROUND ON SUNDAY...NOT ENUF CONFIDENCE TO RUIN A
DRY FCST SO KEPT THEM OUT FOR NOW. 

MDL DIFFERENCES CONT SUNDAY NGT INTO MON WITH RESPECT TO THE
STRENGTH OF THE UPR TROF AS IT PUSHES TOWARD/INTO THE GREAT LKS
RGN. ECMWF REMAINS THE WEAKEST WITH MORE OF AN OPEN WAVE...THE GFS
IS THE SLOWEST/MORE BROAD AND THE CANADIAN IS QUICKER WITH A
TIGHTER CIRCULATION. DO NOT LIKE TO MAKE WHOLESALE CHGS WHEN THE
MDLS DIFFER BY SO MUCH...THUS HAVE KEPT THE GIST OF THE PREV FCST
WITH A TOUCH HIGHER POP OVR CNTRL/E-CNTRL WI. EITHER WAY...THIS
DOES NOT APR TO BE A MAJOR SNOW PRODUCER WITH MOST LOCATIONS
REMAINING AT AN INCH OR LESS.

THE MDLS DO APR TO BE TRYING TO GET BETTER ALIGNED WITH THE NXT
SYSTEM EXPECTED TO ORGANIZE OVR THE SRN PLAINS ON TUE. AS ANOTHER
UPR TROF PUSHES INTO THE UPR MIDWEST TUE NGT...THE SFC LOW IS
PROGGED TO LIFT NE INTO THE TN VALLEY AND THEN MOV ALONG THE
APPALACHIAN CHAIN ON WED. THIS TRACK IS SURE TO CHG SEVERAL TIMES
IN THE COMING DAYS...BUT THE EARLY INDICATIONS ARE THAT THE BRUNT
OF PCPN WOULD AGAIN SLIDE JUST TO OUR SOUTH AND EAST.
&&

.AVIATION...LOW PRESSURE OVER THE REGION WILL KEEP MORE CLOUDS
THAN NOT OVER THE REGION WITH CIGS RANGING BETWEEN MVFR AND LOW
VFR. SNOW SHOWER ACTIVITY WILL BECOME MORE WIDESPREAD OVER
NORTH CENTRAL WI THIS MORNING AS COLD AIR MOVES OVER LAKE
SUPERIOR...ISOLD SHOWERS OR FLURRIES FURTHER SOUTH.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR 
WIZ005.

&&

$$
TE/KALLAS