Extreme Cold and Winter Weather in Minnesota, February 9 to 10, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LA CROSSE WI
310 AM CST SAT FEB 9 2008

.SHORT TERM...TODAY THROUGH MONDAY NIGHT

MAIN FORECAST CONCERN IS WITH THE SURGE OF ARCTIC AIR ACROSS THE
AREA TODAY AND TONIGHT WITH RESULTING SNOW CHANCES...WINDS AND
BITTER WIND CHILLS.

07Z SURFACE ANALYSIS SHOWS A WEAK SURFACE LOW OVER EASTERN
WISCONSIN THAT WAS RESPONSIBLE FOR SOME LIGHT SNOW. FARTHER TO THE
NORTHWEST THE ARCTIC COLD FRONT WAS MOVING THROUGH NORTH DAKOTA.
BETWEEN THESE TWO SYSTEMS A LARGE STRATUS DECK WAS FOUND ACROSS
WESTERN WISCONSIN...NORTHERN IOWA AND MINNESOTA.

09.00Z MODELS IN GOOD AGREEMENT...ALTHOUGH GFS IS FASTER WITH THE
SYSTEM TO AFFECT THE AREA ON MONDAY. GIVEN LOW LEVEL EASTERLY FLOW
EXPECTED WILL SIDE CLOSER TO THE SLOWER NAM/WRF IN THIS TIME FRAME.

IN THE SHORT TERM...WITH FRONT LAGGING WELL TO THE NORTHWEST THIS
MORNING HAVE SLOWED DOWN ARRIVAL OF COLDEST AIR WITH HIGH
TEMPERATURES EXPECTED THIS MORNING. SREF HOURLY TEMPERATURES HAS A
GOOD HANDLE AND USED THIS FOR THE GRIDS TODAY. OTHERWISE...STRONG
WAVE ASSOCIATED WITH THE FRONT TO DIVE ACROSS THE AREA. 500MB-300MB
LAYER QG CONVERGENCE STRONGEST ACROSS THE NORTHERN ZONES ALONG WITH
A BROAD AREA OF ISENTROPIC LIFT IN THE 280K-290K LAYER WILL LEAD
TO SOME SNOW SHOWERS AS THE FRONT PASSES THROUGH. ANY ACCUMULATIONS
WILL BE LIGHT AND LESS THAN ONE INCH. MORE OF A PROBLEM WILL BE THE
STRONG WINDS IN THE WAKE OF THE FRONT. TIGHT PRESSURE GRADIENT IN ITS
WAKE WITH GOOD MOMENTUM TRANSFER TO THE SURFACE AS LAPSE RATES
STEEPEN WILL RESULT IN STRONG NORTHWEST WINDS THIS AFTERNOON AND
TONIGHT. BUFKIT SOUNDINGS ACROSS THE AREA SUPPORTING GUSTS TO 40 MPH
WITH SOME TO 50 MPH ACROSS THE HIGHER TERRAIN AREAS. ADD TO THE FACT
THE STRONG COLD ADVECTION WILL DROP TEMPERATURES STEADILY THROUGH
THE AFTERNOON AND TONIGHT WILL LEAD TO BITTER WIND CHILLS ALONG WITH
AREAS OF BLOWING SNOW. WILL CONTINUE THE WINTER WEATHER ADVISORIES
AND UPGRADE WIND CHILL WATCH TO A WARNING AS WIDESPREAD WIND CHILLS
BETWEEN 35 BELOW ZERO AND 45 BELOW ZERO EXPECTED AFTER MIDNIGHT
TONIGHT AND CONTINUING INTO SUNDAY MORNING.

HIGH PRESSURE BUILDS IN FROM THE NORTHWEST TONIGHT AND WILL SETTLE
OVER THE AREA FOR SUNDAY AND SUNDAY NIGHT. AS THE HIGH SLIDES EAST
OF THE AREA LATE SUNDAY NIGHT...WARM ADVECTION ON ITS BACK SIDE
BEGINS ACROSS THE WESTERN ZONES. THUS COLDEST TEMPERATURES SUNDAY
NIGHT/MONDAY MORNING WILL BE FOUND ACROSS THE EASTERN ZONES.

BY MONDAY...ANOTHER WAVE IN THE NORTHWEST FLOW DROPS TOWARD THE AREA
ON MONDAY. AGAIN PREFER THE SLOWER NAM/WRF AS IT HAS SUPPORT FROM
THE 09.00Z ECMWF. WARM ADVECTION AHEAD OF TROUGH TO PRODUCE
WIDESPREAD LIFT ACROSS THE AREA...ESPECIALLY MONDAY AFTERNOON AND
EVENING. HAVE RAISED POPS DURING THIS TIME FRAME INTO HIGH CHANCE
CATEGORY. IF THIS SIGNAL REMAINS CONSISTENT A FURTHER RAISE IN THE
POPS WILL BE WARRANTED. THIS SYSTEM HAS THE POTENTIAL FOR SOME
ACCUMULATIONS.

.LONG TERM...TUESDAY THROUGH SATURDAY

BOTH THE 09.00Z ECMWF AND GFS SHOW OVERALL PATTERN SHIFTING FROM
NORTHWEST FLOW ACROSS THE AREA AT THE BEGINNING OF THE PERIOD...TO
A MORE ZONAL AND PERHAPS SOUTHWEST FLOW BY THE WEEKEND AS A LARGE
TROUGH MOVES INTO THE WESTERN CONUS. BOTH MODELS CONTINUE TO SHOW
THAT THE ARCTIC FRONT WILL WAFFLE BACK AND FORTH ACROSS THE AREA
DURING THE REMAINDER OF NEXT WEEK. AS THIS OCCURS...WE WILL SEE
OCCASIONAL BOUTS OF COLD AIR AND CHANCES OF SNOW. CURRENT GRIDS
LOOK ON TRACK AND MADE NO CHANGES.

&&

.AVIATION...
IFR/MVFR CEILINGS WILL REMAIN PLENTIFUL THROUGH TODAY...AS LOW LEVEL
MOISTURE REMAINS TRAPPED BELOW AN INVERSION. HOWEVER...A COLD FRONT
WILL SWEEP THROUGH TODAY...WITH HIGH PRESSURE THEN BUILDING IN FROM
THE NORTHERN PLAINS ON SUN MORNING. APPRECIABLE SUBSIDENCE AND
DRYING INDICATED VIA WEST-EAST RUNNING X-SECTIONS WOULD SUPPORT
CLEARING SKIES THIS EVENING. BUFKIT SOUNDINGS WOULD HOLD ONTO SOME
LOW CLOUDS THROUGH SUN MORNING THOUGH. CONFIDENCE IS NOT HIGH WITH
EITHER THE AGGRESSIVE CLEARING...OR THE CONTINUING IFR/MVFR
CEILINGS. WILL CUT THE DIFFERENCE FOR NOW...PLAYING SOME CLEARING
SKIES IN FOR THE OVERNIGHT HOURS.

MEANWHILE...WINDS WILL BE ON THE INCREASE BY THIS AFTERNOON AS THE
PRESSURE GRADIENT TIGHTENS. STRONG NORTHWEST WINDS WILL THEN PERSIST
INTO SUNDAY MORNING. NOT A LOT OF SNOW IS EXPECTED WITH THE
FRONT...GENERALLY LESS THAN AN INCH...BUT THE STRONG WINDS COULD
RESULT IN BLOWING/DRIFTING CONDITIONS IN THE OPEN AND UNSHELTERED
AREAS. SOME MVFR VSBYS AT KRST WILL BE POSSIBLE FROM TIME TO TIME
THIS AFTERNOON/EVENING AS A RESULT.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 9 AM TODAY TO MIDNIGHT CST
     TONIGHT FOR WIZ017-WIZ029-WIZ032-WIZ033-WIZ034-WIZ041.

     WIND CHILL WARNING FROM MIDNIGHT TONIGHT TO 12 PM SUNDAY
     FOR WIZ017-WIZ029-WIZ032-WIZ033-WIZ034-WIZ041-WIZ042-
     WIZ043-WIZ044-WIZ053-WIZ054-WIZ055-WIZ061.

     WINTER WEATHER ADVISORY FROM 12 PM TODAY TO MIDNIGHT CST
     TONIGHT FOR WIZ042-WIZ043-WIZ044-WIZ053-WIZ054-WIZ055-
     WIZ061.

MN...WINTER WEATHER ADVISORY FROM 9 AM TODAY TO MIDNIGHT CST
     TONIGHT FOR MNZ079-MNZ086-MNZ087-MNZ088-MNZ094- MNZ095-
     MNZ096.

     WIND CHILL WARNING FROM MIDNIGHT TONIGHT TO 12 PM SUNDAY FOR
     MNZ079-MNZ086-MNZ087-MNZ088-MNZ094-MNZ095-MNZ096.

IA...WINTER WEATHER ADVISORY FROM 9 AM TODAY TO MIDNIGHT CST
     TONIGHT FOR IAZ008-IAZ009-IAZ010-IAZ018-IAZ019.

     WIND CHILL WARNING FROM MIDNIGHT TONIGHT TO 12 PM SUNDAY
     FOR IAZ008-IAZ009-IAZ010-IAZ011-IAZ018-IAZ019-IAZ029-IAZ030.

     WINTER WEATHER ADVISORY FROM 12 PM TODAY TO MIDNIGHT CST
     TONIGHT FOR IAZ011-IAZ029-IAZ030.

&&

SHORT/LONG TERM....RABERDING
AVIATION...........RIECK

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LA CROSSE WI
500 AM CST SAT FEB 9 2008

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-032>034-
041>044-053>055-061-101100-
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-
500 AM CST SAT FEB 9 2008

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

.DAY ONE...TODAY AND TONIGHT

DANGEROUS WIND CHILLS OF 35 TO 45 BELOW WILL DEVELOP TONIGHT...
AS A STRONG AREA OF LOW PRESSURE MOVES ACROSS THE NORTHERN GREAT
LAKES. FROST BITE CAN DEVELOP IN AS LITTLE AS 10 MINUTES WITH WIND
CHILLS THIS COLD.

THIS SYSTEM WILL ALSO BRING SOME LIGHT SNOW...ALTHOUGH ACCUMULATIONS
OF ONLY AN INCH OR LESS ARE EXPECTED AT THIS TIME. HOWEVER...STRONG
NORTHWEST WINDS OF 25 TO 35 MPH...WITH HIGHER GUSTS...WILL INTERACT
WITH THE FALLING SNOW...AND ALREADY FALLEN SNOW. AREAS OF BLOWING AND
DRIFTING SNOW WILL RESULT FOR THIS AFTERNOON AND TONIGHT. SOME WHITE-
OUT CONDITIONS WILL BE POSSIBLE IN THE OPEN AND UNSHELTERED AREAS OF
SOUTHEAST MINNESOTA AND NORTHEAST IOWA...ALONG WITH AREA RIDGE-
TOPS...THIS AFTERNOON AND EVENING.

WINTER WEATHER HEADLINES ARE IN EFFECT TODAY INTO SUNDAY MORNING
TO ACCOUNT FOR THESE DANGEROUS WINTER CONDITIONS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

DANGEROUS WIND CHILLS WILL LINGER SUNDAY MORNING...IN THE 35 TO 45
BELOW RANGE. CONDITIONS WILL IMPROVE BY THE AFTERNOON THOUGH...AS THE
WINDS DECREASE AND TEMPERATURES WARM.

NEXT...AN UPPER AIR DISTURBANCE WILL BRING SNOW CHANCES BACK TO THE
REGION FOR MONDAY INTO TUESDAY. SOME LIGHT ACCUMULATIONS LOOK
POSSIBLE AT THIS TIME. ANOTHER DISTURBANCE WILL BRING MORE SNOW
CHANCES FOR WEDNESDAY NIGHT INTO THURSDAY.

.SPOTTER INFORMATION STATEMENT...

ANY SNOWFALL OR WIND GUST REPORTS FROM TODAY AND TONIGHT WOULD BE
APPRECIATED. OTHERWISE...SPOTTER ACTIVATION WILL NOT BE NEEDED.

.EMERGENCY MANAGEMENT COORDINATION...

NO CALL IS SCHEDULED.

RIECK