Winter Storm in Minnesota, December 9 to 10, 2003

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
345 AM CST TUE DEC 9 2003

.SHORT TERM...THROUGH THURSDAY
MAIN FORECAST CONCERN WILL BE THE IMPENDING WINTER STORM AND ITS
AFFECT ON THE FORECAST AREA THROUGH WEDNESDAY.

DATA ANALYSIS AT 08Z HAS NEARLY STATIONARY/COLD FRONT BISECTING WI
FROM NORTHEAST TO SOUTHWEST. THIS FRONT THEN EXTENDS SOUTHWEST
THROUGH EASTERN IA AND EVENTUALLY TIES INTO DEVELOPING LOW OVER
OKLAHOMA. SIGNIFICANT AREA OF -SN HAS BEEN BREAKING OUT OVERNIGHT
AHEAD OF THE LOW ACROSS PORTIONS OF NEB THROUGH EASTERN SD AND INTO
FAR SOUTHWEST CORNER OF MN. RUC SHOWS THIS IN RESPONSE TO SOME
FRONTOGENETIC FORCING IN THE 700-500 MB LAYER ACROSS THAT AREA.
FURTHER SOUTHEAST ACROSS IA...SOME -RA IN RESPONSE TO WEAK
ISENTROPIC LIFT ACROSS STATIONARY FRONT WAS MAKING ITS WAY NORTHEAST
TOWARD SOUTHWEST PART OF CWA.

FOLLOWING GFS CLOSELY FOR THIS FORECAST PACKAGE AS IT HAS THE BEST
RUN TO RUN CONSISTENCY. ETA ALSO HAS BEEN TRENDING TOWARD THE GFS
SOLUTION THIS LAST RUN.

FOR TODAY...WENT AHEAD AND PULLED TRIGGER ON WINTER STORM WARNING
ACROSS THE WEST FOR TODAY INTO TONIGHT...ACROSS THE CENTRAL  FOR
THIS AFTERNOON INTO WEDNESDAY...AND ACROSS THE EAST TONIGHT AND
WEDNESDAY. LOW OVER OK WILL CONTINUE TO ORGANIZE INTO THIS AFTERNOON
AND THEN MAKES ITS SURGE INTO SOUTHEAST MO BY THIS EVENING. STRONG
ISENTROPIC LIFT/MOISTURE TRANSPORT ON THE 290K SURFACE AHEAD OF THE
LOW AND ACROSS THE FRONT...COMBINED WITH FRONTOGENETIC FORCING FROM
850-500 MB WILL GET PRECIPITATION GOING TODAY. TOP-DOWN SOUNDING
ANALYSIS SHOWS IT WILL BE WARM ENOUGH IN THE SOUTH AND EAST FOR ALL
RAIN...WHILE ACROSS THE NORTHWEST SOME MODERATE SNOW ACCUMULATION
WILL TAKE PLACE THIS MORNING. THIS SNOW WILL SUBSIDE A LITTLE BY
NOON OR SO...THEN KICK IN WITH FERVOR BY THIS EVENING AS THE LOW
APPROACHES. THERE WILL EXIST THE POTENTIAL FOR 1-3 INCHES TODAY
NORTHWEST OF A LINE FROM FROM MEDFORD WI THROUGH AUSTIN MN.

FOR TONIGHT...LOW TRACKS FROM MO NORTHEAST INTO CENTRAL IL BY WED
12Z. THIS PUTS HEAVIEST SNOW BAND AXIS FROM NEAR MEDFORD WI THROUGH
CHARLES CITY IOWA...IN LINE WITH BEST 700-500 FRONTOGENETIC FORCING.
THE REMAINING SOUTHEAST CUT OF ZONES WILL SEE A TRANSITION TO ALL
SNOW BY MIDNIGHT. REMOVED IP MIX WORDING AS TOP-DOWN SUGGESTS A R/S
MIXTURE TRANSITION TO ALL SNOW. POTENTIAL EXISTS FOR 3-6 INCHES
OVERNIGHT IN THE HEAVIER SNOW AXIS. ALSO LEFT BLOWING SNOW WORDING
IN ACROSS THE WEST AS WINDS REALLY START PICKING UP BEHIND LOW.

ON WEDNESDAY...LOW CONTINUES ITS NORTHEAST TRACK ACROSS SOUTHERN
LAKE MI INTO LOWER MI BY THU 00Z. STRETCHING DEFORMATION AXIS WILL
REMAIN N-S ACROSS CENTRAL CWA THROUGH MUCH OF THE DAY FOR ANOTHER
COUPLE OF INCHES EAST OF THE RIVER. WINDS WILL BE A FACTOR ALSO AS
COLDER AIR AND LESSER MOISTURE CONTENT OF THE SNOW WILL PROBABLY
CAUSE EXTENSIVE BLOWING OF THE SNOW. WEST OF THE RIVER SNOW WILL
TAPER OFF BY NOON OR SO.

LINGERED A CHANCE OF -SN INTO FIRST HALF OF WEDNESDAY NIGHT...MAINLY
EAST OF THE RIVER IN CYCLONIC FLOW.

COLD SURFACE HIGH PRESSURE BUILDS INTO THE AREA FROM THE NORTHERN
PLAINS THURSDAY FOR QUIET CONDITIONS. LINGERING CYCLONIC FLOW/
COLD AIR ALOFT WILL LIKELY PRODUCE QUITE A BIT OF CLOUDINESS THOUGH.

GOING TEMPERATURES IN GRIDS LOOK GOOD AND DID NOT ALTER TOO MUCH.

.LONG TERM...THURSDAY NIGHT THROUGH MONDAY

THE DAY SHIFT FORECAST FOR THIS TIME PERIOD STILL LOOKS GOOD...SO NO
CHANGES MADE AT THIS TIME.

&&

.ARX...WATCHES/WARNINGS/ADVISORIES...
IA...WINTER STORM WARNING TODAY AND TONIGHT...
     IAZ008-009-018-019
     WINTER STORM WARNING THIS AFTERNOON THROUGH WEDNESDAY...
     IAZ010-011-029-030.
MN...WINTER STORM WARNING TODAY AND TONIGHT...
     MNZ079-086>088-094-095.
     WINTER STORM WARNING THIS AFTERNOON THROUGH WEDNESDAY...
     MNZ096-
WI...WINTER STORM WARNING TODAY AND TONIGHT...
     WIZ032-033
     WINTER STORM WARNING THIS AFTERNOON THROUGH WEDNESDAY...
     WIZ017-029-034-041>044-053>055-061.

&&

DAS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LA CROSSE WI
538 AM CST TUE DEC 9 2003

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-032>034-
041>044-053>055-061-101200-
ADAMS-ALLAMAKEE-BUFFALO-CHICKASAW-CLARK-CLAYTON-CRAWFORD-DODGE-
FAYETTE-FILLMORE-FLOYD-GRANT-HOUSTON-HOWARD-JACKSON-JUNEAU-LA CROSSE-
MITCHELL-MONROE-MOWER-OLMSTED-RICHLAND-TAYLOR-TREMPEALEAU-VERNON-
WABASHA-WINNESHIEK-WINONA-
INCLUDING THE CITIES OF...AUSTIN...BLACK RIVER FALLS...
CHARLES CITY...DECORAH...LA CROSSE...MAUSTON...MEDFORD...
NEILLSVILLE...OELWEIN...PLATTEVILLE...PRAIRIE DU CHIEN...
RICHLAND CENTER...ROCHESTER...SPARTA/TOMAH...VIROQUA...WAUKON...
WINONA
538 AM CST TUE DEC 9 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST IOWA...
SOUTHEAST MINNESOTA...AND CENTRAL AND SOUTHWEST WISCONSIN.

.DAY ONE...TODAY AND TONIGHT

A COLD FRONT EXTENDING FROM CENTRAL WISCONSIN INTO EASTERN IOWA WILL
REMAIN NEARLY STATIONARY TODAY BEFORE SHIFTING SLOWLY EAST TONIGHT.
AN AREA OF LOW PRESSURE OVER OKLAHOMA THIS MORNING WILL MOVE
NORTHEAST ALONG THE FRONT INTO ILLINOIS BY LATE TONIGHT. A BAND OF
SNOW HAS ALREADY DEVELOPED OVER MINNESOTA AND SOUTH DAKOTA. THIS
BAND OF SNOW IS EXPECTED TO PRIMARILY REMAIN JUST NORTH OF THE AREA
BUT COULD CLIP SECTIONS OF SOUTHEAST MINNESOTA INTO NORTH CENTRAL
WISCONSIN. AS THE LOW MOVES INTO ILLINOIS TONIGHT...A MORE
SIGNIFICANT AREA OF SNOW IS EXPECTED TO MOVE ACROSS THE REGION. THIS
SNOW SHOULD CONTINUE THROUGH THE NIGHT AND COULD BE HEAVY AT TIMES.
IN ADDITION...NORTH WINDS WILL INCREASE TO 15 TO 25 MPH AFTER
MIDNIGHT WHICH WILL HELP TO CREATE AREAS OF BLOWING AND DRIFTING
SNOW. A WINTER STORM WARNING IS IN EFFECT FOR THIS PERIOD. SEE
PRODUCT MKEWSWLSE /WWUS43/ FOR THE LATEST DETAILS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THE LOW WILL MOVE FROM ILLINOIS INTO MICHIGAN WEDNESDAY. THE SNOW
WILL CONTINUE THROUGH WEDNESDAY MORNING BEFORE TAPERING OFF DURING
THE AFTERNOON. HOWEVER...THE NORTH WINDS WILL REMAIN QUITE STRONG
AND SHOULD STILL PRODUCE AREAS OF BLOWING AND DRIFTING SNOW. THE
BEST THREAT FOR SIGNIFICANT SNOWFALL WEDNESDAY APPEARS TO BE
ALONG AND EAST OF A LINE FROM OELWEIN IOWA...TO LA CROSSE TO MEDFORD
WISCONSIN. THE WINTER STORM WARNING IS IN EFFECT THROUGH WEDNESDAY
FOR THIS AREA.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE REQUIRED.  HOWEVER...REPORTS OF
SNOWFALL WILL BE GREATLY APPRECIATED FOR THE NEXT COUPLE OF DAYS.

04