000
FXUS63 KGRB 112143
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
343 PM CST MON FEB 11 2008

.SHORT TERM...TONITE AND TUESDAY...FORECAST FOCUS ON
TEMPERATURES AND SNOW CHANCES.

THE LOW PRESSURE SYSTEM...AND ASSOCIATED BAND OF SNOW HAVE SLOWED
IN THEIR NORTHWARD PROGRESSION TODAY. GIVEN THE MOSTLY CLEAR SKIES
EXPECTED TO CONTINUE INTO THE EVENING HOURS WILL LOWER MINS TO THE
MAV VALUES AS RECENT TRENDS HAVE BEEN COLDER AND CLOSER TO THE MAV.

WITH THE SLOWER SNOW PROGRESSION...THE BULK OF THE SYNOPTIC SNOW
WILL NOT REACH THE CWA UNTIL AFTER MIDNIGHT. ACROSS THE LAKE
MICHIGAN LAKESHORE COUNTIES WINDS BECOME CONDUCIVE FOR LAKE EFFECT
WITH AN EASTERLY FETCH ACROSS LAKE MICHIGAN SHORTLY AFTER MIDNITE.
DESPITE FAVORABLE DELTA T VALUES IN THE UPPER TEENS...THE AMOUNT
OF LAKE EFFECT WILL BE LIMITED BY THE 90 MILE FETCH ACROSS THE
LAKE. GIVEN THIS TIMING WILL ADJUST POPS TO BE HIGHEST LATE
TONIGHT AND EARLY TUESDAY MORNING...BEFORE THE LOW MOVES TO THE
EAST AND WINDS BECOME NORTHWESTERLY TUESDAY AFTERNOON.

AT THIS TIME THE BULK OF THE SNOW LOOKS TO BE ACROSS THE
SOUTHEAST CWA WHERE AROUND 3 INCHES OF SNOW COULD FALL IN 18
HOURS...BELOW SNOW ADVISORY CRITERIA. NORTHERN WISCONSIN WILL
SEE THE LEAST SNOW AND WILL PROBABLY NOT GET MORE THAN A
DUSTING...IF ANY SNOW AT ALL.

.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY. POTENTIAL SNOWSTORM FOR
THURSDAY IS THE CHIEF WEATHER MAKER FOR THIS PERIOD. UPPER TROUGH
APPROACHING BRITISH COLUMBIA COAST THIS AFTERNOON IS FORECAST BY
THE MODELS TO DROP SOUTHEAST TONIGHT AND TUESDAY. THE JET ENERGY
IS FORECAST TO SPLIT WITH SOME MOVING ACROSS THE NORTHERN PLAINS
AND SOME HEADED TOWARDS THE DESERT SOUTHWEST. THE ECMWF HAS BEEN
VERY CONSISTENT WITH THIS SYSTEM FOR THE PAST THREE DAYS...AND THE
12 UTC GFS NOW HAS A SIMILAR FORECAST. LIGHT SNOW SHOULD ARRIVE IN
CENTRAL WISCONSIN WEDNESDAY NIGHT...WITH MODERATE SNOW EXPECTED
ACROSS THE ENTIRE REGION THURSDAY. 

ANOTHER SYSTEM MIGHT BRING SOME SNOW SATURDAY NIGHT AND
SUNDAY...THOUGH THE BEST DYNAMICS LOOK TO BE NORTH OF WISCONSIN.
SMALL CHANCE OF LAKE EFFECT SNOW SHOWERS FROM LAKE SUPERIOR
WEDNESDAY AND FRIDAY...BUT WINDS NOT IDEAL AND HIGH RESOLUTION
MODIS VISIBLE SATELLITE PICTURES AVAILABLE AT 

HTTP://COASTWATCH.GLERL.NOAA.GOV/MODIS/MODIS.CGI/MODIS?REGION=M&PAGE=1

SHOW THAT THE WESTERN FOURTH OF LAKE SUPERIOR IS ICING UP. SO LAKE
EFFECT POTENTIAL IS SMALL FOR NOW.
&&

.AVIATION...VFR CONDITIONS EXPECTED THIS EVENING...WITH
CONDITIONS LOWERING TO MVFR SOUTH TO NORTH TONIGHT AS AREA OF LIGHT
SNOW MOVES NORTH. MVFR CONDITIONS EXPECTED TO LAST INTO TUESDAY AS
LIGHT SNOW SLOWLY ENDS FROM WEST TO EAST.
&&

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

$$
KURIMSKI/RDM

----------------------------------------------------------------------

000
FXUS63 KGRB 160959
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
359 AM CST SAT FEB 16 2008

.SYNOPSIS...SPLIT FLOW ACRS THE CONUS WL CONSOLIDATE AND AMPLIFY
EARLY IN THE FCST PERIOD. THE RESULTING PATTERN WL HAVE RIDGES NEAR
BOTH COASTS...AND A DEEP TROF FM HUDSON BAY SWD INTO THE ERN STATES.
THE TREND AFTER EARLY NEXT WK WL BE FOR A MORE SUSTAINED AND
SUBSTANTIAL SPLIT FLOW TO DEVELOP EWD ACRS NOAM. THE FCST AREA WL
MOST LIKLEY BE SITUATION BETWEEN STREAMS...OR ON THE NRN EDGE OF THE
SRN STREAM. 

HVY PCPN EXPECTED EARLY AS SRN STREAM SHRTWV EJECTS AND CONSOLIDATES
INTO DEEP ERN TROF. THEN GENERALLY LGT AMNTS AFTER THAT. TEMPS WL
AVERAGE BLO NORMAL FOR MUCH OF THE FCST PERIOD...THEN REBOUND LATE
AS THE SPLIT DEVELOPS.
&&

.SHORT TERM...TDA/TNGT/SUN/SUN NGT. FOCUS IS ON MAJOR WINTER STORM.
SYSTEM LOOKED TYPICAL FOR A PHASING FLOW SYSTEM A FEW DAYS AGO. NOW
IT LOOKS LIKE ALL THE PHASING WL DO IS EJECT THE SRN STREAM SHRTWV
RIGHT AT US...WITH THE CYCLONE BASICALLY BEING A MORE CLASSIC STORM.

NEW GUID HAS EDGED WWD. SOME MODEL DIFFERENCES FOR FAR E-C WI ON
WHETHER OR NOT THERE WL BE A WARM LAYER EARLY TOMORROW...AND THAT WL
HAVE A BIG IMPACT ON SNOWFALL. NAM WARMER AND GFS COLDER. ECMWF
BETWEEN. STUCK CLOSE TO ECMWF WHICH SUGGESTED SOME SLEET/FZRA OVER
E-C EARLY TOMORROW. ALSO...ALTHOUGH MODELS DON/T SHOW IT...THINK
E-C MAY GET CLIPPED WITH DRY SLOT LATER TOMORROW AFTN. KNOCKED
TOTALS BACK A BIT ALONG THE LAKESHORE. BUT WITH HEAVIEST SNOW
TYPICALLY RIGHT ON THE WRN EDGE OF THE DRY SLOT...DIDN/T WANT TO
BACK DOWN TOO FAR AS LCN OF DRY SLOT WL BE CRITICAL AND VERY HIGH
TOTALS COULD OCCUR JUST TO THE WEST. ALSO THINK IT/S LIKLELY THERE
WL BE SOME THUNDERSNOW...BUT WL HOLD OFF ADDING THAT TO THE MIX
FOR NOW. WITH SYSTEM NOW DIRECTED RIGHT UP AT THE AREA...
ISALLOBARIC ACCELERATION COULD GET THE WIND REALLY CRANKED UP
TOMORROW AFTN. IT/S NOT OUT OF THE QUESTION THAT THE PARTS OF E-C
WI THAT AVOID THE DRY SLOT COULD NEED A BLIZZARD WARNING.

HIGH CONFIDENCE IN WARNING FM SW-NE ACRS THE FCST AREA. BUT
CONFIDENCE ON WRN AND ERN EDGES MUCH LOWER. STILL PLENTY OF TIME...
SO WL EXPAND WATCH ANOTHER SET OF COUNTIES TO THE NW AND KEEP
WATCH FOR NOW.

WITH THIS NOW BEING A MORE CLASSIC STORM SYSTEM...WINDS WL BECOME A
FACTOR EARLIER THAN PREVIOUSLY ANTICIPATED. HIT WINDS AND BLOWING
SNOW EARLIER AND HARDER.

.LONG TERM...CYCLONIC UPPER FLOW CONTINUES MONDAY AND TUESDAY AS
UPPER LOW LIFTS OUT FROM LOWER MICHIGAN AND POLAR VORTEX DROPS
SOUTH TOWARDS THE GREAT LAKES FROM HUDSONS BAY. LAKE EFFECT SNOW
LIKELY OVER NORTHCENTRAL WISCONSIN MONDAY. WINDS AND TEMPERATURES ARE
FAVORABLE AND THERE APPEARS TO BE SOME RESIDUAL SYNOPTIC SCALE
MOISTURE AS WELL. THE THING THAT MIGHT KEEP THIS FROM BEING A
SIGNIFICANT EVENT IS THE ICE COVER ON WESTERN LAKE SUPERIOR. MODIS
VISIBLE SATELLITE PICTURES FROM FRIDAY AFTERNOON SHOW A DECENT
AMOUNT OF ICE OVER THE WESTERN FOURTH OR SO. EVEN SO...THINK
SEVERAL INCHES OF SNOW IS POSSIBLE IN FAR NORTHCENTRAL WISCONSIN.

MAYBE SOME SNOW SHOWERS FROM A WEAK CLIPPER SYSTEM TUESDAY
AFTERNOON OR EVENING...THEN A MORE SIGNIFICANT SYNOPTIC SCALE SYSTEM IS
POSSIBLE THURSDAY NIGHT AND FRIDAY...THOUGH THERE ARE SUBSTANTIAL
DIFFERENCES IN THE MODELS AS TO THE TRACK OF THE SYSTEM.
&&

.AVIATION...GENERALLY VFR CONDITIONS EXPECTED FOR THE TAF PERIOD...
WITH THINGS GOING DOWNHILL FAST AFTER THAT.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WATCH SUNDAY AND SUNDAY NIGHT
WIZ011>013-019>022-030-031-035>040-045-048>050-073-074-

&&

$$
SKOWRONSKI/RDM