FXUS63 KGRB 262037
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
237 PM CST THU NOV 26 2009

.SHORT TERM...TODAY THROUGH FRIDAY. DEPARTING SYSTEM WILL BRING LIGHT
PRECIPITATION IN EASTERN WISCONSIN TO AN END BY MIDDAY. LAKE EFFECT
SNOW SHOWERS WILL CONTINUE IN FAR NORTHCENTRAL WISCONSIN THROUGH THE
DAY BUT DO NOT EXPECT MUCH ACCUMULATION AS GROUND IS WARM AND 850MB
TEMPERATURES ARE REALLY NOT THAT COLD. WINDS ARE CONDUCIVE FOR LAKE
EFFECT SNOW BUT INVERSION HEIGHT IS LOW AND DRIER AIR IS MOVING IN.

EXPECT SOME CLEARING TONIGHT DESPITE THE EXTENSIVE CLOUDS CURRENTLY
UPSTREAM AS THERE IS DECENT SUBSIDENCE...BUT AM RELUCTANT TO GO WITH
REALLY CLEAR SKIES AS THE MANY LAKES IN MINNESOTA...WISCONSIN AND SOUTHERN
CANADA ARE UNFROZEN AND WILL HELP MOISTEN LOW LEVELS. WENT A FEW DEGREES
ABOVE MOS GUIDANCE DUE TO THE UNCERTAINTY OF CLOUD COVER AND WARM GROUND.

FRIDAY SHOULD BE PARTLY SUNNY AND SEASONABLE...THE FIRST DAY WITH NEAR
NORMAL HIGH TEMPERATURES IN A LONG TIME. IT WILL STILL BE A FEW DEGREES
ABOVE NORMALS BUT MUCH CLOSER TO WHAT WE EXPECT AT THIS TIME OF YEAR.

.LONG TERM...FRI NGT THRU NXT THU. THE FIRST HALF OF THE EXTENDED
FCST WL BE DOMINATED BY A SLOWLY PROGRESSIVE LONGWV TROF ACROSS
THE LWR 48 WITH A MORE DOMINANT SRN BRANCH KEEPING GULF MSTR TIED
TO THE SRN STATES. MAIN FCST PBLM ARISES TOWARD THE MIDDLE PART OF
NXT WEEK AS A STG NRN BRANCH SYSTEM DIGS SE AND ATTEMPTS TO PHASE
WITH THE SRN STREAM. EXACTLY HOW THESE TWO SYSTEMS INTERACT WL
DETERMINE SNOW POTENTIAL FOR NE WI.

WEAKENING UPR RDG PUSHES INTO THE GREAT LKS FRI NGT...THEREBY
KEEPING QUIET CONDITIONS GOING OVR NE WI. EVEN THO SKY CONDITIONS
WL BE MOSTLY CLR OR PARTLY CLDY AND WNDS ARE GOING TO BE LGT...
TEMPS WL NOT FALL TOO MUCH AS WARMER AIR ALOFT ARRIVES THRU THE
NGT. LOOK FOR READINGS TO RANGE FROM THE LWR 20S NEAR THE MI
BORDER...TO AROUND 30 DEGS NEAR LK MI.

A WEAK CDFNT WL MOV THRU MOST OF WI ON SAT...BUT FORCING AND LIFT
ARE PRACTICALLY NON-EXISTENT...THUS EXPECT TO SEE A DRY FROPA.
ONLY CHG MADE TO THE PREV FCST WAS TO ADD MORE CLDS TO THE NORTH
AS MSTR TOPS THE UPR RDG UNDERNEATH A 110 KT JET MAX.

ATTN SHIFTS TO THE WEST WHERE THE LONGER TROF IS FCST TO MOV
ACROSS THE NRN PLAINS SAT NGT. MDLS INDICATE A SHEARED SHRTWV WL
BE MOVG ACROSS THE UPR MIDWEST INTO LK SUPERIOR. THIS FEATURE APRS
TO BE TOO FAR AWAY TO IMPACT OUR WEATHER. OTHER THAN A GRADUAL
INCREASE IN THE CLDS OVR THE FCST AREA...HAVE KEPT THE DRY FCST
GOING. THIS CLD CVR WL HELP TO HOLD TEMPS UP SAT NGT WITH MOST
LOCATIONS SETTLING INTO THE 25-30 DEG RANGE. ONLY EXCEPTION TO BE
NEAR LK MI WHERE 30-35 SHOULD SUFFICE.

MDLS ARE IN DECENT AGREEMENT IN BRINGING THE LONGWV TROF FROM
ONTARIO SWWD THRU THE UPR MIDWEST TO THE CNTRL PLAINS ON SUNDAY.
NW WNDS COUPLED WITH 8H TEMPS OF AROUND -10C OVR WRN LK SUPERIOR
COULD GENERATE SOME LGT LK EFFECT SNOW SHWRS FOR VILAS CNTY ON
SUNDAY. OTHERWISE...HARD PRESSED TO FIND ANY TRIGGER TO PRODUCE
PCPN ACROSS THE REST OF NE WI. HAVE KEPT THE MENTION OF A FEW
FLURRIES OR SPRINKLES AS THERE IS SOME LIFT INDICATED ALOFT FROM
THE RGN ENTRANCE RGN OF THE UPR JET.

LONGWV TROF REACHES THE WRN GREAT LKS SUNDAY NGT...HOWEVER BEST
FORCING PASSES WELL TO OUR NORTH SO HAVE DECIDED TO PULL ALL POPS
ACROSS THE FCST AREA. A NEW TWIST TO MON'S FCST IS A 130 KT JET
DIVING SE TOWARD THE UPR MIDWEST ON THE BACKSIDE OF THE LONGWV
TROF. BOTH THE ECMWF AND CANADIAN MDLS SHOW A STG SHRTWV
ACCOMPANYING THIS JET. HAVE KEPT A MINIMAL POP FOR CNTRL WI AS THE
STRONGEST FORCING IS STILL TO OUR WEST. THE JET AND SHRTWV RACE
THRU WI MON NGT AND MAY STILL BE ABLE TO KICK OFF SOME LGT SNOW
SHWRS OR FLURRIES. IMPROVING CONDITIONS EXPECTED LTR MON NGT INTO
TUE AS A WEAK SFC RDG MOVS ACROSS WI. PROGRESSIVE NATURE OF THE
MEAN FLOW WL ALREADY HAVE THE SFC RDG TO OUR EAST BY TUE AFTERNOON.
THIS WL BACK THE WNDS TO THE SOUTH AND ALLOW FOR SOME WARMER AIR
ALOFT TO START WORKING BACK INTO THE RGN. HAVE BUMPED TUE'S MAX
TEMPS UP A COUPLE OF DEGS FROM THE PREV FCST.

STG NRN STREAM UPR TROF DIGS S-SE INTO THE NRN/CNTRL PLAINS ON WED
AND BEGINS TO INTERACT WITH A SRN STREAM SYSTEM LOCATED OVR THE
OZARKS. NE WI TO SIT BETWEEN THESE SYSTEMS ON WED...THUS NO PCPN
MENTIONED YET. THE SRN TROF GETS PULLED NE TOWARD THE ERN GREAT
LKS RGN ON THU AS THE NRN TROF HEADS EAST INTO THE WRN GREAT LKS.
AT THIS TIME...IT APRS THAT MOST (IF NOT ALL) THE PCPN ASSOCIATED
WITH THE SRN SYSTEM WL PASS JUST TO OUR SOUTH AND EAST. THIS
LEAVES FAVORABLE Q-G FORCING FROM THE NRN STREAM TROF TO GENERATE
A CHC OF SNOW ACROSS THE FCST AREA. TOO EARLY TO DETERMINE ANY
ACCUMULATIONS...HOWEVER MAIN FOCUS WOULD POINT TO N-CNTRL WI WHERE
CYCLONIC FLOW WOULD HELP TO BRING LK EFFECT SNOW SHWRS INTO THAT
PART OF THE STATE. TEMPS TOWARD THE END OF NXT WEEK WL SETTLE
CLOSER TO SEASONAL NORMALS FOR EARLY DEC.
&&

.AVIATION...CIGS AND VSBYS WILL BE RISING TODAY AS DRIER AIR
ARRIVES ON GUSTY NORTHWEST WINDS. EXPECT VFR BY LATE AFTERNOON IN
MOST PLACES. RAIN AND SNOW SHOWERS WILL BE ENDING BY 15Z AT
GRB/ATW/OSH/MTW/SUE WHILE SNOW SHOWERS LIKELY AT LNL/EGV/ARV MUCH
OF THE DAY. MAINLY VFR TONIGHT AND FRIDAY.
&&

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

$$
TE/AK