FXUS63 KGRB 022027
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
227 PM CST WED DEC 2 2009

.SYNOPSIS...THE DOMINANT LNGWV FEATURE IMPACTING THE WX ACRS NOAM
DURING THE NEXT 7-10 DAYS WL BE STG RIDGE OVER THE ALASKA/GULF OF
ALASKA RGN. MODELS CONT TO STRUGGLE GREATLY TRYING TO RESOLVE THE
EXACT STRUCTURE OF THE RIDGE DURING THE LATTER PART OF THE FCST
PERIOD. THAT HAS A HUGE IMPACT ON THE WX ACRS THE FCST AREA. A
SHARPER RIDGE WOULD LIKELY MEAN A SIG SNOWSTORM SOMEWHERE IN THE
MIDWEST NEXT WEEK...FOLLOWED BY A BLAST OF ARCTIC AIR LATE IN THE
WEEK. A MORE CLOSED AND CIRCULAR STRUCTURE TO THE NRN EXTENT OF THE
RIDGE WOULD YIELD A FLATTER FLOW ACRS THE CONUS...WITH A COUPLE
MUCH WEAKER SFC SYSTEMS AND A LESS PRONOUNCED INTRUSTION OF ARCTIC
AIR. LATEST GUID LEANS TOWARD THE LATTER SCENARIO...BUT IT/S STILL
FAR TOO EARLY TO PROJECT A WINNER IN THIS RACE.

HAVE MUCH MORE CONFIDENCE IN FCSTG A RETURN TO NR OR A LITTLE NORMAL
TEMPS FOR THE FCST PERIOD. AN ADVISORY-TYPE LAKE-EFFECT SNOW EVENT
IS EXPECTED IN THE LAKE-SUPERIOR SNOWBELT TNGT AND THU. THE REST OF
THE FCST AREA WL PROBABLY SEE ONLY LGT PCPN THROUGH EARLY NEXT WK.
&&

.SHORT TERM...TNGT AND THU. ALREADY POSTED LAKE-EFFECT SNOW ADVISORY
FOR VILAS COUNTY DURING LATE MORNING UPDATE. THAT STILL LOOKS ON
TRACK. CONDITIONS QUITE VARIABLE...AND HIGH OVC IS THIN ENOUGH THAT
VIS STLT SHOWS SNOW BANDS WORKING INTO NORTHERN VILAS. BANDS ARE
SHIFTG S OR SSW RATHER THAN SSE...AN INDICATION FLOW IS BECOMING
MORE NELY THAN IDEAL FOR GETTING PERSISTENT BAND TO SET-UP OVER NW
VILAS COUNTY. THAT FITS WITH PREVIOUS THINKING...THAT TRAJ WOULD
KEEP THINGS IN CHECK THROUGH THIS EVENING. LATER TNGT...WHEN
DEEPENING SFC LOW LIFTG NEWD FM THE LOWER MISSISSIPPI RIVER VALLEY
REACHES THE LOWER GREAT LAKES...WINDS SHOULD SETTLE INTO MORE
FAVORABLE NNW DIRECTION. THAT SHOULD RESULT IN BEST SNOWS
OCCURRING FM 09Z-15Z THU. OVERALL...STILL LOOKS LIKE AN ADVISORY
EVENT.

LATEST STLT AND RADAR TRENDS SUGGEST SYSTEM SNOWS WITH
AFOREMENTIONED STORM MAY GET CLOSER TO THE FCST AREA THAN MODELS
WERE FCSTG. ALSO STILL SOME CONCERN FOR LAKE-EFFECT OFF LAKE
MICHIGAN. DIDN/T REALLY CHG PREV FCST...KEPT CHC SHSN NEAR THE
LAKE AND CHC FLURRIES INLAND. THE NLY FLOW TNGT COULD BRING SOME
LAKE SUPERIOR SHSN INTO NORTHERN DOOR COUNTY...SO WL CONT TO CARRY
SOME LGT ACCUMULATIONS IN THAT AREA.

CLOUDS AND WINDS SHOULD ACTUALLY SERVE TO HOLD TEMPS UP A BIT
TNGT...SO EDGED UP MINS JUST A BIT. ALSO EDGED MAXES DOWN THU AS WE
PROBABLY WON/T GET TOO MUCH RECOVERY DURING THE DAY.

.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
UPPER TROUGH SWINGS ACROSS THE REGION THURSDAY NIGHT. GFS/WRF
INDICATING A DECENT SHORTWAVE AND STEEP MID LEVEL LAPSE RATES
MOVING ACROSS THE SOUTHEAST HALF OF WISCONSIN. DIFFERENCES NOTED
IN THE MODELS ON THE PLACEMENT OF THIS FEATURE...BUT WILL NEED TO 
WATCH THE FAR SOUTHEAST FOR AN ACCUMULATING SNOWFALL. FOR NOW HAVE
SMALL CHANCES OF SNOW SHOWERS WITH THIS FEATURE. OVER THE REMAINDER
OF THE REGION...WILL HAVE A CHANCE OF FLURRIES EXCEPT IN THE SNOWBELT
REGION. WILL LINGER SOME SNOW SHOWER ACTIVITY INTO THE EVENING
BEFORE LOW LEVEL WINDS BECOME TO WESTERLY AFTER MIDNIGHT FOR LAKE
EFFECT SNOW SHOWERS. 

LINGERED A CHANCE OF FLURRIES FRIDAY AND FRIDAY EVENING AS UPPER
TROUGH REMAINS ACROSS THE REGION. MODELS CONTINUE TO DIFFER WITH
SYSTEM ON SUNDAY NIGHT AND MONDAY...AND THEN DURING THE MIDDLE 
OF NEXT WEEK. HAVE LOW CHANCES FOR LIGHT SNOW WITH BOTH FEATURES...
BUT CONFIDENCE IS LOW FOR AN ACCUMULATING SNOWFALL ON SUNDAY NIGHT
AND MONDAY. THE MID WEEK STORM HAS BEEN PUSHED FURTHER SOUTH BY
THE GFS/ECMWF ON THIS RUN...BUT EXPECT SOME FLIP FLOPPING DEPENDING
ON HOW THE MODELS HANDLE THE WEST COAST RIDGE AND DOWNSTREAM UPPER
TROUGHING ACROSS THE CENTRAL UNITED STATES.

BELOW NORMAL TEMPERATURES SHOULD BE EXPECTED ON FRIDAY WITH TEMPERATURES
RETURNING CLOSER TO NORMAL SATURDAY AND SUNDAY. DEPENDING ON HOW THE
MODELS HANDLE THE WEST COAST RIDGING AND DOWNSTREAM TROUGH EARLY
NEXT WEEK WILL DETERMINE HOW COLD IT WILL GET BY THE MIDDLE OF
NEXT WEEK. THE FORECAST PACKAGE WILL HAVE BELOW NORMAL TEMPERATURES
FOR MUCH OF NEXT WEEK.
&&

.AVIATION...MVFR CIGS PRETTY WIDESPREAD ACRS THE NW 2/3 OF THE FCST
AREA. WOULD EXPECT MVFR CIGS TO EXPAND SE ACRS THE REST OF THE AREA
DURING THE EVENING. COULD GET SOME BREAKS ALMOST ANYWHERE BUT IN THE
SNOWBELT LATER TNGT...BUT OVERALL EXPECT MVFR CONDITIONS TO BE THE
RULE.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...

LAKE EFFECT SNOW ADVISORY UNTIL 3 PM THURSDAY
WIZ005-

&&

$$
SKOWRONSKI/ECKBERG