FXUS63 KGRB 021704 AAA
AFDGRB
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GREEN BAY WI
1104 AM CST WED DEC 2 2009
.UPDATE...WENT AHEAD AND ISSUED A LAKE-EFFECT SNOW ADVISORY FOR
VILAS COUNTY. SNOW ALREADY GOING PRETTY GOOD IN THE IWD AREA...
WITH VSBYS NOW AT 1/4SM. STILL SOME CONCERN THAT WINDS FLOP A
LITTLE TOO NELY THIS EVENING. BEST PERIOD OF FAVORABLE
TRAJECTORIES MAY BE FROM 06Z-12Z. IN ANY CASE...GIVEN WHAT IS
GOING ON NOW...WE SHOULD HAVE A LONG ENOUGH TIME PERIOD OF AT
LEAST MARGINALLY FAVORABLE CONDITIONS TO REACH ADVISORY CRITERIA.
MORE NLY TRAJECTORIES MAY ALSO BRING SOME ACCUMULATING SNOW INTO
FAR NORTHERN DOOR COUNTY TNGT. UPPED POPS FOR THAT AREA AND HIT A
LITTLE HARDER IN THE RECENTLY ISSUED GRID/ZFP UPDATE.
SKOWRONSKI
&&
.PREV DISCUSSION...ISSUED AT 440 AM CST WED DEC 2 2009...
SHORT TERM...TODAY AND THURSDAY...
AT 09Z LOW PRESSURE WAS LOCATED OVER CENTRAL LAKE SUPERIOR WITH COLD
FRONT EXTENDING FROM NEAR MARINETTE TO WAUTOMA. AREA OF LOWER
COLDS EXTENDED TO THE WEST BEHIND FRONT...WITH SNOW ACTIVITY NORTH
OVER MN ARROWHEAD. TO THE SOUTH...UPPER LOW OVER CENTRAL TX
SENDING HIGH CLOUDS UP INTO WI.
SPLIT FLOW PATTERN OVER CENTRAL/EASTERN U.S. WITH WI WEATHER
INFLUENCED BY NORTHERN STREAM WITH UPPER TROF/LOW DEVELOPING
SOUTHEAST INTO WI THIS PERIOD. DEEPENING SOUTHERN SYSTEM TO PASS
THROUGH OHIO VALLEY WED NIGHT...MAINLY TIGHTENING UP GRADIENT OVER
STATE. MODELS CONTINUE TO BRUSH FAR SOUTHEAST WITH QPF. BRIEF
PERIOD WITH WINDS SHIFTING JUST EAST OF NORTH TONIGHT. LOOKS TOO
BRIEF FOR ANY ORGANIZED LES OFF THE LAKE MICHIGAN ATTM.
MAIN CONCERN THIS PERIOD LES POTENTIAL OFF LAKE SUPERIOR FROM THIS
AFTERNOON INTO THU. WINDS LINE UP WELL BY THIS AFTERNOON...THOUGH
BUFFY CROSS SECTIONS INDICATE THAT INSTABILITY LIMITED...WITH LAKE
INDUCED OMEGA WELL BELOW AREA OF BEST SNOW GROWTH THIS AFTERNOON.
WITH CONTINUING CAA BETTER INSTABILITY TONIGHT INTO THU. WILL
PLACE BEST ACCUMULATIONS FROM 6Z TONIGHT INTO 18Z THU. WINDS THIS
EVENING SHIFT A BIT TOO NORTHERLY...RETURNING TO PRIME NW FLOW
AFTER MIDNIGHT AS EASTERN LOW MOVES TO VCNTY LAKE ERIE. HAVE
BACKED OFF ON SNOW ACCUMULATIONS FOR THIS MORNING AND
AFTERNOON...WITH A MAX NEAR 6 INCHES IN FAR NW VILAS COUNTY FOR
THE 36 HOUR PERIOD. WILL HIGHLIGHT WITH SPS AS TOTALS REMAIN BELOW
ADVISORY CONDITIONS.
TEMPERATURES WILL BEGIN TO TAKE TURN DOWNWARD TODAY AS CAA BECOMES
ESTABLISHED. RATHER MILD TEMPERATURES SEEN AT THIS TIME OVER CWA.
HAVE CAUTIOUSLY BUMPED FEW HIGHS UP TODAY.
LONG TERM...THU NGT THRU NXT TUE. PRIMARY DICTATOR OF WEATHER
MOVG ACROSS THE COUNTRY DURING THIS TIME FRAME WL BE A LRG UPR RDG
OVR THE ERN PACIFIC NWD INTO THE GULF OF ALASKA. THIS UPR RDG WL
ALLOW FOR COLD CANADIAN AIR TO SPILL SOUTH INTO THE WRN CONUS
WHILE A SERIES OF WEAK SHRTWV TROFS QUICKLY MOV ALONG THE SRN
STREAM TOWARD THE GREAT LKS. SIGGY MDL DIFFERENCES ARISE TOWARD
THE END OF THE PERIOD WITH RESPECT TO A POTENTIAL WINTER STORM
SOMEWHERE OVR THE COUNTRY.
AS THE INITIAL UPR TROF SETTLES OVR THE WRN GREAT LKS RGN WED
NGT...WNDS ARE EXPECTED TO BACK MORE WESTERLY WHICH SHOULD KEEP
BETTER LK EFFECT SNOW SHWR ACTIVITY NORTH OF THE MI BORDER.
OTHERWISE...THE REST OF THE FCST AREA WL SEE PLENTY OF CLD CVR
WITH MAINLY SPORATIC FLURRIES AS COLDER AIR SETTLES OVR THE RGN. A
COLD NGT IN STORE AS TEMPS DROP TO THE MID TEENS IN THE NORTH TO
THE LWR 20S NEAR LK MI.
THE UPR TROF ESSENTIALLY SITS AND SPINS OVR NRN SECTIONS OF THE
GREAT LKS ON FRI...THEREBY KEEPING A HEALTHY DOSE OF CLDS AROUND.
MDLS SHOW LITTLE IN THE WAY OF ANY SERIOUS SHRTWVS IN OUR VCNTY SO
NOTHING MORE THAN SOME FLURRIES ANTICIPATED. TEMPS TO CONT THEIR
DOWNWARD TREND WITH MAX READINGS ONLY REACHING THE LWR 20S NORTH...
LWR 30S NEAR LK MI.
WE WL BE WATCHING ANOTHER VORT LOBE ROTATE SWD ON THE WRN EDGE OF
THE UPR TROF INTO THE UPR MIDWEST FRI NGT. THIS FEATURE APRS TO BE
TOO FAR WEST TO IMPACT OUR WEATHER INITIALLY...THUS ANOTHER NGT OF
CLDS AND COLD TEMPS. LOOK FOR READINGS ONCE AGAIN TO PUSH THE MID
TEENS IN THE NORTH TO THE LWR 20S NEAR LK MI. THIS VORT LOBE THEN
TURNS SE THEN EAST ON SAT AND PUSHES INTO THE WRN GREAT LKS RGN.
STILL SOME DEBATE ON WHETHER THIS FEATURE WL COME INTO WI SAT OR
SAT NGT...BUT AT THIS TIME...DO NOT ANTICIPATE MUCH MORE THAN
WIDELY SCT LGT SNOW SHWRS OR FLURRIES. HAVE EDGED TEMPS UP A BIT
ON SAT AS SW WNDS TO BE IN PLACE AHD OF THE VORT LOBE.
THE WEAKENING VORT LOBE SHOULD DEPART THE RGN SAT NGT AND TURNS
THE WNDS TO A NORTHERLY DIRECTION OVR LK SUPERIOR. THERE MAY BE A
STRAY SNOW SHWR OR TWO THAT COULD REACH VILAS CNTY SAT NGT AND
SUNDAY AS WELL WHICH PREV SHIFT ALREADY COVERED. THE REST OF NE WI
SHOULD JUST SEE PARTLY CLDY SKIES WITH TEMPS CLOSE TO SEASONAL
NORMS.
BOTH THE 00Z ECMWF AND GFS NOW BRING A WEAK SHRTWV TROF (AND
EMBEDDED SHRTWV) ACROSS THE MIDWEST SUNDAY NGT AND INTO SRN
SECTIONS OF THE GREAT LKS ON MON. THERE APRS TO BE ENUF FORCING
AND DIFFLUENT FLOW ALOFT TO JUSTIFY ADDING A SML POP TO SUNDAY
NGT'S FCST. PREV SHIFT ALREADY HAD A CHC POP FOR MON...SO DID NOT
MAKE ANY CHGS TO THAT PART OF THE FCST. MDLS CONT TO STRUGGLE
BADLY WITH THE NXT MAJOR SYSTEM EXPECTED TO DVLP OVR THE SRN
PLAINS TOWARD THE MIDDLE OF NXT WEEK. THE GFS IS MUCH MORE
ENERGETIC LOOKING THAN THE ECMWF WITH SIGNIFICANT IMPLICATIONS ON
NE WI WEATHER. DUE TO THIS VAST DIFFERENCE IN INTENSITY AND
LOCATION...PREFER TO NOT TOUCH TUE'S FCST AND HOPE THAT THE MDLS
GET INTO BETTER SYNC IN THE COMING DAYS.
AVIATION...COLD FRONT MOVING THROUGH NORTHEAST WI PASSING THROUGH GRB
AROUND 12Z. WINDS EXPECTED TO BECOME GUSTY FROM THE WEST THEN
SHIFTING NORTHWEST THIS AFTERNOON. AREA OF LOWER/MVFR CIGS BEHIND
FRONT TO MOVE INTO RHI...CWA...MFI THIS MORNING. VFR CONDITIONS
WILL CONTINUE EAST. LAKE EFFECT SNOW SHOWERS WILL BRING TEMPORARY
IFR CONDITIONS TO RHI AND NORTH LATE AFTERNOON AND TONIGHT. FEW
LOWER CIGS POSSIBLE LAKESHORE AREA THIS EVENING WITH LAKE INDUCED CLOUDS.
MARINE...COLDER AIR FLOWING OVER THE WARMER WATERS OF LAKE AND
BAY TO CREATE HAZARDOUS CONDITIONS FOR SMALL CRAFT THROUGH THU.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
LAKE EFFECT SNOW ADVISORY UNTIL 3 PM THURSDAY
WIZ005-
&&
$$
