Winter Storm in Wisconsin, February 28 to 29, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
221 PM CST TUE FEB 28 2012

.SHORT TERM...TONIGHT AND WEDNESDAY.

LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY INDICATES LOW
PRESSURE EMERGING FROM THE ROCKIES INTO WESTERN KANSAS THIS AFTERNOON...WITH
ITS ASSOCIATED WARM FRONT LIFTING NORTH ALONG THE KS/NE BORDER AND
ACROSS MISSOURI.  CONVECTION HAS DEVELOPED ALREADY AHEAD OF THE LOW
JUST AHEAD OF A POTENT DRY SLOT PUNCHING INTO NEBRASKA.  CLOSER TO
HOME...LEADING EDGE OF RETURN MOISTURE IS NOW PUSHING INTO SOUTHERN
WISCONSIN A TAD AHEAD OF SCHEDULE...AS EVIDENT BY A BAND OF RAIN AND
SNOW. EARLIER MODERATE SNOW OVER N-C WISCONSIN IS HANGING ON ALONG
THE U.P. BORDER WHERE THEY RECEIVED 2-3 INCHES OF SNOW.  BUT THE
MAIN PROBLEM FOR THIS FORECAST IS THE LOW OUT WEST AND HEAVY SNOW
POTENTIAL AS IT MOVES ACROSS THE REGION TONIGHT INTO WEDNESDAY.

TONIGHT...LOW PRESSURE OVER THE PLAINS WILL MOVE NORTHEAST AND
OCCLUDE AS IT MOVES INTO SOUTHWEST MINNESOTA BY 12Z WEDNESDAY.
AHEAD OF THE LOW...A 40-50KT LLJ WILL RAMP UP AND SHIFT INTO
NORTHERN ILLINOIS DURING THE OVERNIGHT HOURS.  THIS LLJ WILL
TRANSPORT RICH GULF OF MEXICO MOISTURE NORTHEAST WITH PWATS OF
UPWARDS OF 0.75 INCHES REACHING INTO CENTRAL WISCONSIN.  THIS IS
OVER 200 PCT OF NORMAL AND 2 STANDARD DEVIATIONS ABOVE NORMAL.
BEFORE THIS OCCURS THOUGH...LEADING EDGE OF THE RETURN MOISTURE ON
THE 285K SURFACE IS CREATING A BAND OF LIGHT RAIN AND SNOW WHICH
SHOULD APPROACH CENTRAL WISCONSIN LATE THIS AFTERNOON AND INTO THE
FOX VALLEY BY EARLY IN THE EVENING.  WET BULB TEMPS HAVE BEEN RISING
THIS AFTERNOON...BUT FIGURING SNOW OVER CENTRAL WISCONSIN...AND
RAIN/SNOW MIX OVER EAST-CENTRAL WHERE ONSHORE FLOW WILL CONTINUE.
THE MAIN SURGE OF PRECIPITATION SHOULD NOT ARRIVE UNTIL LATE INTO
THE EVENING AND THE OVERNIGHT HOURS WHEN FORCING VIA LLJ AND
MID-LEVEL FGEN LIFTS INTO THE REGION.  WITH MID-LEVEL LAPSE RATES OF
6.5-7 C/KM AND NEGATIVE EPV ABOVE THE FGEN LAYER...CONVECTION IS
DEFINITELY POSSIBLE WITH THE PRECIPITATION OVERNIGHT...AND UPSTREAM
OBS BEAR THIS OUT AS WELL.  THERMAL PROFILES VARY WIDELY BETWEEN THE
WARMER GFS AND THE COLDER ECMWF/NAM.  ALTHOUGH THERE IS PLENTY OF
WARM AIR TO OUR SOUTH...THE WARM LAYER IS MARGINALLY HIGH AT AROUND
800MB WHICH LEAVES THE POTENTIAL FOR CONVECTION TO WIPE OUT THAT
WARM NOSE...THEREBY KEEPING THE PROFILE NEAR OR JUST BELOW FREEZING
OVER CENTRAL AND EAST-CENTRAL WISCONSIN.  AS A RESULT...HAVE BOOSTED
SNOW AMOUNTS OVER CENTRAL WISCONSIN AND THE NORTHERN FOX VALLEY. AM
MOST CONFIDENT OF RAIN/SLEET MIXING IN OVER KEWAUNEE AND MANITOWOC
COUNTIES THANKS TO THE LAKE INFLUENCE.  SE WINDS WILL ALSO RAMP UP
OVERNIGHT WHICH COULD CREATE NEAR WHITE OUT VSBYS AT TIMES WITHIN
THE HEAVY SNOW.  WILL UPGRADE DOOR COUNTY TO WARNING CRITERIA...AS
THEY DO SURPRISINGLY WELL IN CASES LIKE THIS...WHERE COLDER AIR AT
925MB WILL HANG ON THE LONGEST.  OTHERWISE...CURRENT HEADLINES LOOK
GOOD FOR WARNING/ADVISORY CONFIGURATION.  THE NEXT SHIFT WILL HAVE
TO MONITOR FOR UPGRADES FOR THE NEXT ROW OF COUNTIES SOUTH OF THE
WARNING IF CONVECTION DOES COOL THE COLUMN ENOUGH FOR A MOSTLY SNOW
PTYPE.

WEDNESDAY...OCCLUDED LOW PRESSURE WILL SLOW AND MOVE FROM SW
MINNESOTA TO WESTERN WISCONSIN OVER THE COURSE OF THE DAY.  LOW
LEVEL WARM AIR WILL CONTINUE TO WRAP AROUND THE LOW INTO EASTERN
WISCONSIN DURING THE MORNING...WHILE THE DRY SLOW MOVES IN ALOFT.
MODERATE TO HEAVY SNOW WILL BE WIDESPREAD NORTH AND WEST OF THE DRY
SLOT OVER NORTHERN AND NORTHWEST WISCONSIN FOR MUCH OF THE MORNING.
BUT FARTHER SOUTH...THE DRY SLOT WILL MAKE IT DIFFICULT FOR ICE
CRYSTALS TO GET INTRODUCED INTO THE CLOUD...SO HAVE ADDED THE CHANCE
OF FREEZING DRIZZLE OVER CENTRAL AND PARTS OF NORTHEAST WISCONSIN.
RAIN OR DRIZZLE SHOULD BE MIXING WITH SNOW BY THE TIME OF THE
MORNING COMMUTE OVER THE FOX VALLEY AND LAKESHORE WHICH LOOKS TO BE
A SLOPPY MESS.  SHOULD ALSO SEE A PERIOD OF OF JUST RAIN/DRIZZLE AS
WELL...MID-MORNING THROUGH MID-AFTERNOON BEFORE COLDER AIR SURGES
EAST AS IT WRAPS AROUND THE LOW.  WITH ALL THIS IN MIND...TOTAL
SNOWFALL ACCUMULATION THROUGH 00Z THU LOOKS LIKE 10-15 INCHES OVER
N-C WISCONSIN...6-10 NORTH OF A MARSHFIELD TO STURGEON BAY
LINE...AND 3-7 INCHES FOR CENTRAL WISCONSIN AND MUCH OF THE FOX
VALLEY.  DID END HEADLINES EARLY FOR THE FOX VALLEY AND
LAKESHORE...AS SNOW CHANGING TO RAIN SHOULD CAUSE CONDITIONS TO
RAPIDLY IMPROVE BY 18Z WED.

.LONG TERM...WEDNESDAY NIGHT THROUGH NEXT TUESDAY.

PERIOD TO SEE SHIFT FROM OUR SPLIT FLOW PATTERN TO A MORE
CONSOLIDATED FLOW WITH TROF SHIFTING EAST THROUGH THE LAKES REGION
THIS WEEKEND. TEMPS FOR SAT AND SUN EXPECTED TO BE AOB NORMS. RIDGE
TO FOLLOW FOR MUCH OF THE WORK WEEK FOR A DRY AND MILD PERIOD.

WED NIGHT TO THU...STORM TO BE EXITING THE AREA WITH SNOW ENDING
WEST TO EAST. LEFT OUT OF GRIDS AT THIS TIME...THOUGH MODEL
SOUNDINGS INDICATE SOME FREEZING DRIZZLE POSSIBLE OVER THE EAST
BEHIND SYSTEM.  WEAK HIGH PRESSURE MOVES THROUGH DURING DAY
THU...SMALL CHANCE OF LAKE EFFECT FAR NW VILAS IN THE MORNING
THOUGH SUPPORT FOR THAT WEAKENS BY AFTERNOON.

THU NIGHT TO FRIDAY...MODELS STILL HAVING DIFFICULTY THIS
PERIOD...THOUGH STARTING TO GEL A BIT. TROF OF LOW
PRESSURE/DEVELOPING COLD FRONT MOVES EAST INTO STATE LATE THU
NIGHT. SIG WAA AHEAD OF SYSTEM AND SOME FGEN SAYS KEEP SMALL
POPS...MAINLY NORTH...UPPER SUPPORT WEAK THOUGH. ALL MODELS WANT TO
DEVELOP WAVE ON FRONT SOUTH OF STATE...BRING IT NE ALONG FRONT.
MOST TO OUR EAST...THOUGH GFS REMAINS CONSISTENT BRINGING LOW
THROUGH STATE. EITHER WAY KEPT CHANCE POPS HIGHEST EAST. SOME
CONCERN WITH PCPN TYPE...WILL GO FOR MIX EAST...THOUGH LATEST EC
BRINGING COLDER AIR FURTHER EAST.

WEEKEND...HINTS AT POSSIBLE CLIPPER SYSTEM SUN...AND POSSIBLE
LAKE EFFECT FAR NORTHWEST CWA WITH NORTHWEST FLOW.
&&

.AVIATION...LIGHT SNOW WITH IFR VSBYS WILL BE DIMINISHING THIS
AFTERNOON OVER N-C WISCONSIN WHILE THE REST OF THE AREA WILL BE
VFR.  THEN LOW PRESSURE WILL DEEPEN AS IT MOVES ACROSS THE PLAINS
TONIGHT.  A WARM FRONT WILL LIFT NE INTO THE NORTHERN MISSISSIPPI
VALLEY AND PROVIDE THE FOCUS FOR THE ARRIVAL OF HEAVY SNOW.  DRY AIR
WILL ERODE THE SNOW AS IT ARRIVES OVER NE WISCONSIN...BUT WILL BRING
IN THE SNOW INTO N-C WISCONSIN BY MID-EVENING...AND INTO THE FOX
VALLEY BY LATE EVENING.  MODERATE TO HEAVY SNOW WILL CONTINUE
THROUGH MUCH OF THE NIGHT ONCE IT ARRIVES.  WARMER TEMPERATURES
ALOFT WILL ARRIVE BY LATE TONIGHT INTO WEDNESDAY MORNING...WHICH
SHOULD CAUSE SLEET AND FREEZING DRIZZLE TO MIX IN OVER CENTRAL AND
EAST-CENTRAL WISCONSIN THROUGH MIDDAY.  WARMER AIR ARRIVES AT THE
SURFACE OVER E-C WISCONSIN IN THE MORNING...WHICH SHOULD LEAD TO
IMPROVING CONDITIONS.

MPC
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST
WEDNESDAY FOR WIZ038>040-048>050.

WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM CST
WEDNESDAY FOR WIZ035>037-045.

WINTER STORM WARNING FROM 6 PM THIS EVENING TO 6 PM CST
WEDNESDAY FOR WIZ005-010-011-018>020-030-031.

WINTER STORM WARNING FROM 9 PM THIS EVENING TO 6 PM CST
WEDNESDAY FOR WIZ012-013-021-073-074.

WINTER STORM WARNING FROM 9 PM THIS EVENING TO NOON CST
WEDNESDAY FOR WIZ022.

&&

MPC/TE

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREEN BAY WI
238 PM CST TUE FEB 28 2012

WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-292045-
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-
238 PM CST TUE FEB 28 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL AND NORTHEAST
WISCONSIN.

.DAY ONE...TONIGHT

HAZARDOUS WINTER DRIVING CONDITIONS ARE EXPECTED TONIGHT OVER
CENTRAL AND NORTHEAST WISCONSIN AS A WINTER STORM MOVES INTO THE
REGION. REFER TO THE LATEST WARNINGS...ADVISORIES AND STATEMENTS
FOR THE LATEST INFORMATION ON THIS WINTER STORM.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

WIDESPREAD DISRUPTIONS TO TRAVEL ARE EXPECTED TO CONTINUE INTO WEDNESDAY
DUE TO THE ONGOING WINTER STORM...ESPECIALLY NORTH OF HIGHWAY 29.

ANOTHER STORM SYSTEM MAY IMPACT TRAVEL ON FRIDAY. AT THIS TIME...
THERE IS CONSIDERABLE UNCERTAINTY IN THE TRACK OF THE STORM.
ANYONE WITH TRAVEL PLANS FRIDAY AND FRIDAY NIGHT SHOULD MONITOR
LATER FORECASTS FOR MORE SPECIFIC INFORMATION.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE REQUESTED TO FORWARD SNOWFALL MEASUREMENTS TO THE
NATIONAL WEATHER SERVICE IN GREEN BAY.

LMZ521-522-541>543-292045-
THE BAY OF GREEN BAY SOUTH OF A LINE FROM CEDAR RIVER MI TO ROCK
ISLAND PASSAGE-LAKE MICHIGAN FROM WASHINGTON ISLAND TO SHEBOYGAN-
238 PM CST TUE FEB 28 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST LAKE
MICHIGAN AND THE WATERS OF GREEN BAY.

.DAY ONE...THIS AFTERNOON AND TONIGHT

STRONG EAST WINDS ARE EXPECTED LATE TONIGHT INTO WEDNESDAY
MORNING...WITH A FEW GUSTS TO NEAR 35 KNOTS POSSIBLE.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THE PROBABILITY OF WIDESPREAD HAZARDOUS WEATHER IS LOW AT THIS TIME.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREEN BAY WI
254 PM CST TUE FEB 28 2012

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0252 PM     SNOW             7 NW RHINELANDER        45.70N 89.51W
02/28/2012  M5.0 INCH        ONEIDA             WI   TRAINED SPOTTER

            SNOWING ON AND OFF ALL DAY.

&&

ASHLEYW