FXUS63 KGRB 032107
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
307 PM CST THU DEC 3 2009

.SYNOPSIS...THE DOMINANT LNGWV FEATURE CONTROLLING THE WX ACRS
NOAM DURING THE NEXT WK WL BE STG RIDGE OVER THE ALASKA/GULF OF
ALASKA RGN. MODELS STILL HAVING SOME TROUBLE RESOLVING THE EXACT
STRUCTURE OF THE RIDGE LATE IN THE WEEKEND AND EARLY NEXT WK...BUT
HAVE SETTLED DOWN SOME FROM YDA. TREND SEEMS TO BE TOWARD A
SHARPER RIDGE. THOUGH STILL VERY WARY ABOUT PUTTING TOO MUCH FAITH
IN THE RECENT MODEL TRENDS...THE SHARPER RIDGE WOULD FAVOR MORE
DOWNSTREAM TROFFING...INCREASE THE PROSPECT FOR HAVING A MAJOR
WINTER STORM MOVE THROUGH THE CENTRAL U.S. DURING THE MIDDLE OF
THE WK...AND LIKELY WL RESULT IN A SHOT OF COLD AIR DURING THE
LATTER PART OF NEXT WK.

TEMPS EXPECTED TO RUN NR OR A LITTLE BLO NORMAL FOR THE FCST
PERIOD. PCPN FOR THE PERIOD WL PROBABLY COME DOWN TO WHAT HAPPENS
WITH TWO MAIN SYSTEMS...WEAKER WAVE RIDING NEWD IN WSWLY UPR FLOW
LATE IN THE WEEKEND...AND STRONGER SYSTEM THATS POSSIBLE NEXT WK.

PATTERN LIKELY TO CHG SIGNIFICANTLY AGAIN AT THE VERY END OF THE
FCST PERIOD AND BEYOND. FLOW AT HIGH LATITUDES SEEMS DESTINED TO
DEGENERATE INTO VERY BLOCKY PATTERN...WITH INCREASINGLY STG BAND
OF LOW-AMPLITUDE WESTERLIES BREAKING THROUGH TO THE SOUTH. THAT
WOULD ALLOW PACIFIC AIR TO BECOME RE-ESTABLISHED ACRS THE
AREA...AND BRING MODERATING TEMPS.
&&

.SHORT TERM...TNGT AND FRI. ALLOWED LAKE-EFFECT SNOW ADVISORY TO
EXPIRE. VSBYS JUST RECENTLY CAME DOWN SOME...BUT NOWHERE NEAR
ENOUGH GOING ON THE EXTEND ADVISORY. WL MENTION SOME MINOR
ADDITIONAL ACCUMULATIONS IN THE SNOWBELT. AREA OF SHSN OVER MN
COULD WORK INTO THE AREA EVEN AFTER WINDS BACK TOO WLY FOR LAKE-
EFFECT.

SHSN ALSO DEVELOPING ACRS THE SERN 1/2 OF THE FCST AREA LATE THIS
AFTN. BEST FORCING WITH UPR TROF WL PASS S OF THE AREA. WL CONT TO
GO WITH SCT SHSN THIS EVENING...THEN TAPER BACK TO JUST FLURRIES
AFTER MIDNIGHT. MINS FROM PREV FCST LOOKED PRETTY GOOD...SO NOT
MUCH CHG.

FORCING MUCH WEAKER TOMORROW...BUT AFTN SFC CHART STILL SHOWED
PLENTY OF FLURRIES BACK THROUGH THE NRN PLAINS. WK STICK WITH PREV
FCST AND KEEP CHC OF FLURRIES GOING TOMORROW. MAX TEMPS LOOKED RIGHT
ON TARGET SO PRETTY MUCH STUCK WITH WHAT WE HAD GOING.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
TRANQUIL PATTERN EXPECTED FRIDAY NIGHT WITH SCATTERED FLURRIES.
ON SATURDAY...HIGH PRESSURE SLIDES TO THE EAST ON SATURDAY AS 
A WEAK COLD FRONT PUSHES INTO MINNESOTA SATURDAY AFTERNOON. 
THE COLD FRONT WILL PUSH INTO NORTHEAST WISCONSIN ON SUNDAY
AFTERNOON WITH LITTLE FANFARE. A FEW FLURRIES MAY BE FOUND 
ACROSS NORTH CENTRAL WISCONSIN BEHIND THE FRONT.

FOR SUNDAY NIGHT AND MONDAY...A WEAK WAVE IS EXPECTED TO 
MOVE ALONG THE FRONT. LIGHT SNOW SHOULD BREAK OUT ACROSS
MUCH OF THE FORECAST SUNDAY NIGHT...THEN DIMINISH ON MONDAY
AS SYSTEM MOVES AWAY FROM WISCONSIN.  INCREASE SNOW CHANCES
WITH HIGHEST CHANCES OVER THE SOUTH. DEPENDING ON WHERE FRONT
SETS UP...MAY NEED TO INCREASE SNOW CHANCES OVER THE NORTH. 
IF MODELS CONTINUE CURRENT TRENDS...LATER SHIFTS WILL MORE THAN
LIKELY RAISE SNOW CHANCES EVEN FURTHER. ACCUMULATIONS OF 1 TO 3
INCHES ARE EXPECTED. THERE IS SOME CONCERN FOR LAKE/BAY ENHANCEMENT
NEAR THE SHORE LINE TUESDAY NIGHT INTO WEDNESDAY AS WINDS TURN
EAST TO NORTHEAST. SNOWFALL TOTALS MAY BE LOCALLY HIGHER ALONG 
THE BAY AND LAKE. WILL LET LATER SHIFTS FINE TUNE THOSE DETAILS.
SOME DISCREPANCIES ON POTENTIAL LAKE EFFECT ACROSS VILAS COUNTY
MONDAY AFTERNOON AND MONDAY NIGHT. MODELS HAVE VARYING SOLUTIONS
ON HOW LONG WINDS OR MAGNITUDE OF THE WINDS WILL BE FOR A FAVORABLE
LAKE EFFECT SNOW EVENT FOR VILAS COUNTY. WILL LINGER A CHANCE OF 
SNOW SHOWERS OVER THE NORTH MONDAY NIGHT TO ACCOUNT FOR THIS
SCENARIO.

ATTENTION TURNS TO MID WEEK STORM. THE CANADIAN MODEL HAS BEEN
CONSISTENT WITH BRINGING SIGNIFICANT STORM INTO THE REGION. 
THE 12Z ECMWF HAS LATCHED ONTO THIS SCENARIO...THEREFORE INCREASE
SNOW CHANCES TUESDAY NIGHT INTO WEDNESDAY. I AM SURE THE MODELS
WILL CONTINUE TO FLIP FLOP...BUT ENOUGH CONFIDENCE WARRANTS 
A HIGH CHANCE FOR SNOW. SNOWFALL TOTALS FOR THIS EVENT COULD 
ALSO BE ENHANCED BY THE LAKE AND BAY IF TRACK IF FAR ENOUGH
SOUTH TO KEEP THE REALLY COLD AIR IN PLACE. PLENTY OF TIME TO
WATCH THIS SYSTEM.
&&

.AVIATION...MVFR CIGS PREVAILED ACRS THE N...WITH LOW-END VFR CIGS
IN THE S. PLENTY OF CLDS WL LINGER TNGT AND FRI. EXPECT CIGS TO
EDGE DOWN TNGT...AND BACK UP SOME ON FRI.
&&

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

&&

$$
SKOWRONSKI/ECKBERG