Winter Storm in Wisconsin, February 17, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
400 PM CST SAT FEB 16 2008

.SHORT TERM...TONIGHT AND SUNDAY
MAJOR WINTER STORM BREWING ACROSS THE SOUTHERN PLAINS THIS AFTERNOON.
THE STORM IS PROJECTED TO MOVE INTO LOWER MICHIGAN BY SUNDAY NIGHT.
A HEAVY SWATH OF SNOW IS EXPECTED ACROSS NORTH EAT WISCONSIN. SOME
QUESTIONS LINGERING ON HOW FAR WEST THE HEAVY SNOW WILL MAKE IT
INTO NORTH CENTRAL AND CENTRAL WISCONSIN...AND ALONG LAKE MICHIGAN
WHERE A MIXED BAG OF PRECIPITATION IS EXPECTED SUNDAY MORNING
BEFORE CHANGING OVER TO ALL SNOW DURING THE AFTERNOON.

A BAND OF HEAVY SNOW FROM 6 TO 12 INCHES IS EXPECTED EAST OF A
WISCONSIN RAPIDS TO IRON MOUNTAIN LINE WITH LIGHTER AMOUNTS TO
THE NORTH AND WEST. MODELS SHOWING STRENGTHENING SURFACE CYCLONE...
IMPRESSIVE PRECIPITABLE WATER ACROSS THE SOUTHERN PLAINS OF 250
PERCENT OF NORMAL...AND COUPLED JET STRUCTURE WHICH PLACES NORTHEAST
WISCONSIN IN THE AREA OF BEST LIFT. NEAR THE LAKE...IT WILL COME
DOWN TO EVAPORATIVE COOLING AND STRONG VERTICAL LIFT AND HOW
THAT WILL OFFSET THE WARM LAYER AROUND 850MB. BUFKIT SOUNDINGS
SUGGESTING BEST LIFT IN THE -10 C TO -15 C RANGE AND NEARLY ISOTHERMAL
LAYER NEAR 0 C WHICH WILL PROMOTE DECENT SNOWFLAKE GROWTH.
ON THE BACK SIDE OF THE SYSTEM...STRONG NORTH OR NORTHEAST WINDS
WILL CREATE CONSIDERABLE BLOWING AND DRIFTING SNOW. NEAR WHITE
OUT CONDITIONS ARE EXPECTED ACROSS NORTHEAST WISCONSIN SUNDAY
AFTERNOON INTO SUNDAY EVENING.

SEE THE LATEST WINTER WEATHER MESSAGE FOR HEADLINES AND AMOUNTS.

.LONG TERM...SUNDAY NGT THRU NXT SAT. MAIN FCST CONCERN INITIALLY
IS THE BACKSIDE PCPN CHCS ASSOCIATED WITH DEPARTING MAJOR STORM
SUNDAY NGT INTO MON AS WELL AS LK EFFECT POTENTIAL FOR N-CNTRL AS
COLDER AIR AND FAVORABLE TRAJS INTERACT. HEADED TOWARD THE LONGER
TERM...MDLS CONT TO ADVERTISE A DE-AMPLIFICATION OF THE MEAN FLOW
ACROSS THE CONUS NXT WEEK. THE FLOW EVENTUALLY SPLITS TOWARD THE
END OF THE WEEK WITH MORE ACTIVE SRN BRANCH KEEPING BULK OF ANY
PCPN TO THE SOUTH OF NE WI. THIS TREND WOULD ALSO BRING TEMPS
CLOSER TO NORMAL LEVELS FOR LATE FEB.

SFC LOW TO CONT TRACKING NE INTO SE ONTARIO SUNDAY NGT BUT
COMBINATION OF WRAP-AROUND MSTR...CYCLONIC FLOW AND STG CAA WL
KEEP MAINLY LGT SNOW GOING THRU THE NGT. BEST LIFT AND FORCING
ALREADY PULLING OUT SUNDAY EVENING...HOWEVER ANOTHER INCH OR TWO
OF SNOW IS PSBL OVR ERN WI. BIGGER ISSUE COULD BE THE BLOWING AND
DRIFTING SNOW AS NW WNDS OF 15 TO 30 MPH WITH HIGHER GUSTS
EXPECTED. ANOTHER SITN THAT NEEDS TO BE ADDRESSED IS THE POTENTIAL
LK EFFECT FOR N-CNTRL WI AS THE CAA TAKES OVR. TRAJS BECOME
FAVORABLE BY LATE SUNDAY EVENING WITH DELTA-T VALUES APPROACHING
20 AND LITTLE IN THE WAY OF AN INVERSION. THE NW CORNER OF VILAS
CNTY MAY APPROACH 3 INCHES OF ADDL LK EFFECT SNOW SUNDAY NGT...
BUT PREFER TO HOLD OFF ON ADDL HEADLINES FOR NOW AND ALLOW
SYNOPTIC HEADLINES TO HAVE PRECEDENCE DUE TO ITS MORE IMMEDIATE
IMPACT. WL INSTEAD MENTION IN THE HWO.

LITTLE CHG EXPECTED INTO MON AS CYCLONIC FLOW PERSISTS AND SHARP
UPR TROF VIRTUALLY OVRHD. CHC OF SNOW SHWRS ARE NECESSARY ALTHO
ANY ACCUMULATIONS WOULD BE NEGLIGIBLE. THE LK EFFECT SNOW SHWRS
OVR N-CNTRL WI ON THE OTHER HAND TO BE MORE PROBLEMATIC WITH
ANOTHER INCH OR TWO PSBL FOR THE SNOWBELT RGN. CAA WL LIMIT MUCH
OF A TEMP RISE OVR NE WI WITH READINGS ONLY IN THE TEENS.

CYCLONIC FLOW FINALLY STARTS TO LOSE ITS GRIP OVR NE WI MON NGT AS
A RDG OF HI PRES SLIDES INTO THE UPR MIDWEST. MOST OF THE AREA WL
ONLY SEE SOME LINGERING FLURRIES MON EVENING BEFORE ENDING. CHC OF
LK EFFECT TO CARRY OVR INTO MON NGT FOR VILAS CNTY ALTHO WNDS
BACKING A BIT WOULD LIMIT ADDL ACCUMULATIONS. NE WI STILL UNDER NW
FLOW ALOFT ON TUE WITH A POLAR VORTEX DROPPING SE TOWARD LK HURON.
A WEAK CLIPPER SYSTEM AND ASSOCIATED CDFNT PUSH TOWARD THE WRN
GREAT LKS BY THE AFTERNOON...BUT MSTR APRS LIMITED AT THIS TIME.
SINCE THE RDG OF HI PRES STILL IN THE PROCESS OF DEPARTING TUE
MORNING...CURRENT THINKING IS THAT MOST OF ANY LGT SNOW WOULD HOLD
OFF TIL LATE IN THE DAY AND ONLY AFFECT CNTRL WI. TEMPS LW CONT TO
STRUGGLE WITH THE READINGS AROUND 15 DEGS BLO NORMAL.

COMBINATION OF THE CLIPPER...FROPA AND SHRTWV TO PASS THRU THE RGN
TUE NGT SO HAVE CONTINUED THE MINIMAL POP ACROSS THE ENTIRE FCST
AREA. ANOTHER SHOT OF ARCTIC AIR SURGES INTO THE GREAT LKS ALTHO
THE COLDEST OF THE AIRMASS TO BE TO OUR EAST. MAY HAVE TO LINGER A
SNOW CHC FOR VILAS CNTY AS WNDS TURN NORTH BEHIND THE FNT.
CANADIAN HI PRES TO THEN SETTLE SOUTH OVR THE AREA ON WED WITH
SKIES BECMG PARTLY CLDY. HI PRES TO BE THE DOMINANT WEATHER
FEATURE THRU THU ALBEIT IT WL BE SHIFTING TO OUR EAST. NEED TO
KEEP AN EYE ON A SRN STREAM STORM WHICH IS PROGGED TO EXTEND FROM
THE SRN PLAINS TO THE MID-MISSISSIPPI VALLEY ON THU. WHILE ANY
PCPN SHOULD REMAIN TO OUR SOUTH...EXPECT TO SEE MID/HI CLDS
OVERSPREAD CNTRL/E-CNTRL WI DURING THE DAY.

AS THIS SRN STREAM LIFTS NE INTO THE OHIO RIVER VALLEY THU NGT...
THE NRN EDGE OF THE PCPN SHIELD MAY REACH INTO SRN SECTIONS OF WI.
JUST A SLGT SHIFT NORTH WOULD BRING LGT SNOW INTO THE SRN SECTIONS
OF OUR FCST AREA...THUS HAVE ADDED A SML CHC POP FOR THESE
LOCATIONS AND CONTINUED THIS TREND INTO FRI. ANOTHER AREA OF HI
PRES IS EXPECTED TO PUSH INTO THE GREAT LKS FRI NGT INTO SAT ALTHO
CLDS COULD BE INCREASING ONCE AGAIN AS THE NXT SRN STREAM STORM
STRENGTHENS OVR THE PLAINS AND GULF MSTR GETS PULLED NORTH TOWARD
WI.
&&

.AVIATION...VFR CONDITIONS CONDITIONS WILL GIVE WAY TO IFR
CONDITIONS LATE TONIGHT OR SUNDAY MORNING. HEAVY SNOW AND BLOWING
SNOW ACROSS NORTHEAST WISCONSIN WILL CREATE SIGNIFICANT DELAYS.
IT IS POSSIBLE THAT SOME AIRPORTS LIKE GREEN BAY...APPLETON AND
MANITOWOC WILL CLOSE TO TOMORROW AFTERNOON AS WHITE OUT CONDITIONS
ARE EXPECTED SUNDAY AFTERNOON AND EVENING.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 6 AM SUNDAY TO MIDNIGHT CST SUNDAY
NIGHT FOR WIZ030-031-035>040-045-048>050.

WINTER STORM WARNING FROM 9 AM SUNDAY TO MIDNIGHT CST SUNDAY
NIGHT FOR WIZ011>013-019>022-073-074.

SNOW AND BLOWING SNOW ADVISORY FROM 9 AM SUNDAY TO MIDNIGHT CST
SUNDAY NIGHT FOR WIZ005-010-018.

&&

ECKBERG/KALLAS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREEN BAY WI
408 PM CST SAT FEB 16 2008

WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-171645-
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-
408 PM CST SAT FEB 16 2008

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

.DAY ONE...TONIGHT

LIGHT SNOW MAY MOVE INTO THE AREA...GENERALLY SOUTH OF HIGHWAY 29
LATE TONIGHT. THE LIGHT SNOW WILL CREATE SLICK ROADS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH SATURDAY

A MAJOR WINTER STORM WILL BRING HEAVY SNOW AND CONSIDERABLE
BLOWING AND DRIFTING SNOW SUNDAY AND SUNDAY NIGHT. THE HEAVY
SNOW WILL CREATE SIGNIFICANT TRAVEL DELAYS BY CAR. IF YOU
ARE TRAVELING BY AIR...CHECK YOUR LOCAL CARRIER TO SEE IF
FLIGHT ARE LEAVING YOUR AIRPORT AS WHITEOUT CONDITIONS COULD
CLOSE SOME AIRPORTS FOR A TIME SUNDAY AFTERNOON AND SUNDAY
EVENING.

A PROLONGED PERIOD OF LAKE-EFFECT SNOW SHOWERS IS EXPECTED ACROSS
THE SNOWBELT OF NORTH-CENTRAL WISCONSIN SUNDAY AFTERNOON THROUGH
TUESDAY MORNING. SEVERAL INCHES OF ACCUMULATION WILL BE POSSIBLE.

.SPOTTER INFORMATION STATEMENT...

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

LMZ521-522-541>543-171645-
THE BAY OF GREEN BAY SOUTH OF A LINE FROM CEDAR RIVER MI TO ROCK
ISLAND PASSAGE-LAKE MICHIGAN FROM WASHINGTON ISLAND TO SHEBOYGAN-
408 PM CST SAT FEB 16 2008

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

.DAY ONE...TONIGHT

A GALE WARNING IS IN EFFECT TONIGHT...CREATING HAZARDOUS
CONDITIONS FOR SMALL CRAFTS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH SATURDAY

GALE FORCE NORTH WINDS ARE LIKELY LATE SUNDAY AFTERNOON INTO MONDAY
MORNING. HEAVY SNOW AND BLOWING SNOW WILL CAUSE VISIBILITIES TO
DROP BELOW ONE MILE SUNDAY AFTERNOON INTO SUNDAY NIGHT.

ECKBERG/KALLAS