Winter Storm Watch 3, NWS Green Bay, WI

Brown County, WI, Calumet County, WI, Door County, WI, Florence County, WI, Forest County, WI, Kewaunee County, WI, Langlade County, WI, Lincoln County, WI, Manitowoc County, WI, Marathon County, WI, Marinette County, WI, Menominee County, WI, Oconto County, WI, Oneida County, WI, Outagamie County, WI, Portage County, WI, Shawano County, WI, Vilas County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI, Wood County, WI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
346 AM CST TUE FEB 24 2009

.SHORT TERM...TODAY THROUGH WEDNESDAY. SFC HIGH OFF TO THE EAST
WITH WARM AIR ADVECTION REGIME BEGINNING SEEN ON SATELLITE WITH
INCREASE IN MID LEVEL CLOUDINESS OVER STATE. CONCERNS THIS PERIOD
ON PRECIPITATION POTENTIAL AND TYPE LATE TUE INTO WED MORNING.

DISTURBANCES IN ZONAL FLOW OVER UPPER MIDWEST EXPECTED
TO MOVE THROUGH WESTERN LAKES ON WED. AT THE SURFACE...LOW
EXPECTED TO DEVELOP AND LIFT NORTHEAST TO THE WEST OF CWA. LOW TO
DRAG COLD FRONT OVER STATE WED MORNING. CONCERNS WITH THIS
SYSTEM...AVAILABILITY OF MOISTURE...PCPN TYPE. MODEL SOUNDINGS DO NOT
SHOW GOOD SATURATION. 850 TEMPS RISE TO AROUND ZERO BY WED
MORNING IN WAA AHEAD OF LOW...SURFACE TEMPS MEANWHILE WILL LINGER
BELOW FREEZING. HAVE GONE WITH LIKELY POPS IN THE NORTH WHERE
THERE WILL BE BETTER MOISTURE AND DYNAMICS AS LFQ OF JET NOSES IN. STAYING
WITH CHANCE IN THE SOUTH. BACKED OFF ON QPF TOTALS OVER REGION.
LITTLE CHANGE MADE TO PCPN TYPE WITH MIX OF SNOW AND FREEZING PCPN
EXPECTED. AS COLD FRONT MOVES THROUGH...EXPECT ANY LINGERING PCPN
TO BE IN FORM OF SNOW.

.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY
SOME LAKE EFFECT SNOW SHOWERS WILL CONTINUE ACROSS VILAS COUNTY
WEDNESDAY EVENING. 850MB WINDS ARE EXPECTED TO TURN TO THE WEST
BY MIDNIGHT...THEREFORE REMOVED ANY MENTION OF SNOW SHOWERS
BETWEEN MIDNIGHT AND 6 AM THURSDAY.

MAIN STORM SYSTEM EXPECTED TO MOVE ACROSS THE AREA THURSDAY INTO
THURSDAY NIGHT. MODELS HAVE TRENDED NORTH ON THIS RUN WITH MOST OF
THE MODELS TAKING THE LOW FROM BETWEEN MILWAUKEE TO NEAR CHICAGO.
THE GFS WAS THE OUTLIER WITH THE SYSTEM PASSING TO THE SOUTH OF
INDIANAPOLIS. IF YOU LOOK AT THE GFS 850MB THERMAL PROFILE...ONE
WOULD EXPECT THE SYSTEM TO MOVE FURTHER NORTH THAN WHAT THE MODEL
INDICATED. WRF/ECMWF INDICATED A COUPLED JET STRUCTURE TO REALLY
AID UPWARD VERTICAL MOTION THURSDAY INTO THURSDAY NIGHT.
STRENGTHENING 140 KNOT JET STREAK NORTH OF WISCONSIN WILL PUT THE
AREA IN THE FAVORED RIGHT ENTRANCE REGION OF THE JET STREAK. TO
THE SOUTH...THE AREA WILL BE IN THE FAVORED LEFT EXIT REGION OF
THE JET. THE MODELS DIFFER ON HOW QUICK THE NORTHERN JET STREAK
PULLS OUT OF THE REGION THURSDAY NIGHT.

BASED ON THE MODEL QPF...MUCH OF THE AREA SOUTH OF AN IRON
MOUNTAIN TO WAUSAU LINE COULD SEE SNOWFALL TOTALS OF GREATER THAN
6 INCHES. LOCALLY HIGHER AMOUNTS UP TO 10 INCHES COULD BE POSSIBLE
NEAR LAKE MICHIGAN AS WINDS TURN NORTHEAST FOR A PERIOD OF TIME
THURSDAY EVENING. ECMWF QPF TOTALS RECENTLY HAVE BEEN OVERDONE...
SO HAVE DISCOUNTED THE MODEL OUTPUT FOR THE TIME BEING. WILL ALSO
NEED TO WATCH THE FAR SOUTHEAST TO SEE IF THE 0 C 850MB ISOTHERM
MAKES INTO THE FAR SOUTHEAST PORTION OF THE FORECAST AREA AND
COULD CAUSE PRECIPITATION TYPE ISSUES. THIS COULD IMPACT SNOWFALL
TOTALS SOUTH AND EAST OF GREEN BAY BASED ON THE 00Z MODEL RUNS.
CURRENT RUNS WOULD SUGGEST SNOW AT THE MOMENT...BUT THE ECMWF HAS
BEEN SHIFTING THE 0 C ISOTHERM NORTH AND SOUTH ON THE LAST SEVERAL
RUNS. WOULD NOT BE SURPRISED IF THE 12Z ECMWF WHICH HAD THE LOW
GOING NEAR MILWAUKEE COMES TRUE WHICH COULD REALLY BRING MIXED
PRECIPITATION TO THE FAR SOUTHEAST PORTION OF THE FORECAST AREA.

BEHIND THE SYSTEM...NORTHERLY WINDS WILL INCREASE THURSDAY
AFTERNOON INTO THURSDAY NIGHT. THIS WILL CAUSE SIGNIFICANT
BLOWING AND DRIFTING OF THE SNOW. IF THE MODELS MAINTAIN THERE
CURRENT TRENDS...WINTER STORM WATCHES MAY BE POSTED WITH THE
AFTERNOON PACKAGE OR AT THE LATEST ON THE MORNING PACKAGE ON
WEDNESDAY.

SECONDARY COLD FRONT PUSHES ACROSS THE STATE ON SATURDAY...BRINGING
A CHANCE OF SNOW TO THE FORECAST AREA. SIGNIFICANT DIFFERENCES
BETWEEN THE GFS/ECMWF ON HOW MUCH COLD WILL BE ACROSS THE REGION
ON SUNDAY. HAVE NOT MADE ANY SIGNIFICANT CHANCES TO THE MAX
TEMPERATURE GRID FOR SUNDAY. IF 00Z ECMWF HOLDS TRUE...MAX
TEMPERATURES WILL NEED TO BE LOWERED.
&&

.AVIATION...VFR CONDITIONS EXPECTED THROUGH THE DAY WITH MAINLY
MID AND HIGH CLOUDINESS. CIGS TO LOWER LATE TONIGHT FROM WEST TO
EAST AHEAD OF COLD FRONT WITH INCREASING CHANCE OF SNOW/ZR TOWARDS
DAYBREAK. MARGINAL LLWS FOR PERIOD THIS AM LLVL FLOW INCREASES
FROM THE SW.
&&

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

TE/ECKBERG

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREEN BAY WI
448 AM CST TUE FEB 24 2009

WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-251100-
VILAS-ONEIDA-FOREST-FLORENCE-NORTHERN MARINETTE-LINCOLN-LANGLADE-
MENOMINEE-NORTHERN OCONTO-DOOR-MARATHON-SHAWANO-WOOD-PORTAGE-
WAUPACA-OUTAGAMIE-BROWN-KEWAUNEE-WAUSHARA-WINNEBAGO-CALUMET-
MANITOWOC-SOUTHERN MARINETTE-SOUTHERN OCONTO-
448 AM CST TUE FEB 24 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL AND
NORTHEAST WISCONSIN.

.DAY ONE...TODAY AND TONIGHT

LIGHT SNOW...SLEET AND OR FREEZING RAIN IS POSSIBLE TONIGHT INTO
WEDNESDAY MORNING AS MILDER AIR WORKS INTO THE REGION. SLIPPERY
ROADS AND SIDEWALKS ARE EXPECTED.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

A WINTER STORM MAY BRING A SIGNIFICANT SNOWFALL THURSDAY AND
THURSDAY NIGHT TO PORTIONS OF CENTRAL AND NORTHEAST WISCONSIN.
THERE IS STILL UNCERTAINTY IN THE STORM TRACK AND THE RESULTING
PRECIPITATION TYPE AND SNOWFALL AMOUNTS. STAY TUNED FOR SUBSEQUENT
FORECASTS FOR THE LATEST ON THIS DEVELOPING WINTER STORM.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE REQUESTED TO FORWARD ANY REPORTS OF FREEZING
PRECIPITATION TO THE NATIONAL WEATHER SERVICE IN GREEN BAY.

LMZ521-522-541>543-251100-
THE BAY OF GREEN BAY SOUTH OF A LINE FROM CEDAR RIVER MI TO ROCK
ISLAND PASSAGE-LAKE MICHIGAN FROM WASHINGTON ISLAND TO SHEBOYGAN-
448 AM CST TUE FEB 24 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST LAKE
MICHIGAN.

.DAY ONE...TODAY AND TONIGHT

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

TE/RE