Heavy Snow in Minnesota, November 9 to 10, 2006

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
924 PM CST THU NOV 9 2006

.UPDATE...A NARROW BAND OF PRECIPITATION HAS BROKEN OUT FROM NEAR
KULM ACRS KRGK TO NEAR KEAU THIS EVENING WHICH IS ASSOCIATED WITH
STRONG MID-TROP FRONTOGENETIC FORCING DIAGNOSED ON THE 40KM NAM
THIS EVENING. USING THIS PARAMETER ALONG WITH ISENTROPIC FORECASTS
FROM THE SAME MODEL...WE ISSUED A SNOW ADVISORY FOR OUR SOUTH
CENTRAL AND SOUTHEAST MN COUNTIES INTO WESTERN WISCONSIN.

&&

.PREV DISCUSSION... /ISSUED 334 PM CST THU NOV 9 2006/

DISCUSSION...
VERY INTERESTING FORECAST THE NEXT 24 HOURS AS LOW PRESSURE OVER
OKLAHOMA MOVES NORTHEAST TO OHIO. 12Z NAM AND GFS ARE ACTUALLY
VERY SIMILAR IN THE TIMING OF THE SURFACE/UPPER AIR FEATURES
THROUGH FRIDAY EVENING. HOWEVER...THE LAYER MOISTURE IS MUCH
GREATER ON THE GFS. BOTH MODELS DEVELOP FULL WIND FRONTOGENESIS ACROSS
CENTRAL AND SOUTHERN MN TONIGHT. THE FWF THEN INTENSIFIES INTO AN ARC
SHAPED BAND OVER THE SE CWA FRIDAY MORNING. THE BAND THEN MOVES
EAST OF THE CWA BY 18Z. -FN VECTOR DIVERGENCE WOULD SUPPORT A
STRONG BANDED PRECIPITATION EVENT JUST OUTSIDE OF OUR CWA ON
FRIDAY. THE 12Z NAM SEEMED TOO DEFICIENT IN QPF GIVEN THE FORCING
SEEN WHILE THE GFS LOOKS WAY OVERDONE. ANOTHER PROBLEM IS THE
NORTHERLY FLOW IN THE LOW LEVELS WITH SURFACE DEW POINTS IN THE
LOWER TO MIDDLE 20S. THE DRY NORTHERLY FLOW IS NOT GOING TO CHANGE
AND THIS SHOULD TEMPER THE WET QPF FROM THE GFS. 09Z SREF SUGGESTS
ABOUT A QUARTER OF AN INCH OF QPF FROM THE TWIN CITIES ON EAST AND
SOUTH LATE TONIGHT AND FRIDAY. THIS DOESNT SEEM RIGHT LOOKING AT
THE LAYER FWF AND -FN VECTOR DIVERGENCE AND THE DRY AIR DOWN LOW.
IN THE END...KEPT PRECIPITATION AMOUNTS ABOUT AS PREVIOUSLY
FORECAST WITH A TENTH TO TWO TENTHS TOTAL TONIGHT THROUGH FRIDAY
ALONG AND EAST OF A LINE FROM FAIRMONT THROUGH RED WING TO
STANLEY. HENCE...WILL STICK WITH AROUND 2 INCHES OF SNOW THROUGH
FRIDAY AFTERNOON FROM ALBERT LEA TO EAU CLAIRE WITH LESSER AMOUNTS
TO THE NORTH AND WEST. HIGH PRESSURE BUILDS IN QUICKLY FRIDAY
NIGHT WITH CLEARING AND TEMPERATURES DROPPING INTO THE TEENS. NEXT
PRECIPITATION EVENT STILL SET TO SPREAD INTO THE CWA ON SUNDAY.
RAISED POPS A LITTLE AS TIMING/FORCING LOOK PRETTY GOOD. LATER
SHIFTS MAY HAVE TO RAISE EVEN MORE. COBB PRECIPITATION TYPE SHOWS
SNOW CHANGING TO RAIN WITH IT BEING A WAA CASE. A RETURN TO DRY
WEATHER ON MONDAY.

THE TUESDAY THROUGH THURSDAY PERIOD HAS HIGH UNCERTAINTY. THE 12Z GFS
SOLUTION LOOKS UNREASONABLE WITH A 500MB LOW CUTTING OFF JUST
SOUTH OF HERE. WE HAVE SEEN THIS FORECAST SEVERAL TIMES THIS FALL. THE
12Z ECMWF WOULD FAVOR THE 500MB LOW NEAR LAKE WINNIPEG. USED HPC
GUIDANCE HEAVILY WHICH WAS A BLEND OF THE GFS ENSEMBLE AND THE
ECMWF. THIS FAVORS SMALL CHANCES FOR PRECIPITATION IN THE TUESDAY
AND WEDNESDAY PERIODS.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...SNOW ADVISORY UNTIL 12 PM CST FRIDAY FOR BLUE EARTH-BROWN-DAKOTA-
     FARIBAULT-FREEBORN-GOODHUE-LE SUEUR-MARTIN-NICOLLET-RICE-
     SCOTT-STEELE-WASECA-WATONWAN COUNTY(IES).

WI...SNOW ADVISORY FROM 4 AM TO 12 PM CST FRIDAY FOR CHIPPEWA-DUNN-
     EAU CLAIRE-PEPIN-PIERCE COUNTY(IES).

&&

WET/LS

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
951 PM CST THU NOV 9 2006

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
110400-
DOUGLAS-TODD-MORRISON-MILLE LACS-KANABEC-STEVENS-POPE-STEARNS-
BENTON-SHERBURNE-ISANTI-CHISAGO-LAC QUI PARLE-SWIFT-CHIPPEWA-
KANDIYOHI-MEEKER-WRIGHT-HENNEPIN-ANOKA-RAMSEY-WASHINGTON-
YELLOW MEDICINE-RENVILLE-MCLEOD-SIBLEY-CARVER-SCOTT-DAKOTA-
REDWOOD-BROWN-NICOLLET-LE SUEUR-RICE-GOODHUE-WATONWAN-BLUE EARTH-
WASECA-STEELE-MARTIN-FARIBAULT-FREEBORN-POLK-BARRON-RUSK-
ST. CROIX-PIERCE-DUNN-PEPIN-EAU CLAIRE-
951 PM CST THU NOV 9 2006

...SNOW ADVISORY IN EFFECT ACROSS PORTIONS OF CENTRAL AND SOUTH
CENTRAL MINNESOTA AND WEST CENTRAL WISCONSIN...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL AND
SOUTH CENTRAL MINNESOTA...AND WEST CENTRAL WISCONSIN.

.DAY ONE...TONIGHT

A MIX OF LIGHT RAIN AND SNOW WILL SPREAD ACROSS CENTRAL AND
SOUTHERN MINNESOTA AND WEST CENTRAL WISCONSIN AROUND
MIDNIGHT...AND QUICKLY TRANSITION TO SNOW DURING THE OVERNIGHT
HOURS. A SNOW ADVISORY HAS BEEN ISSUED FOR AREAS ALONG AND SOUTH
OF A NEW ULM...TO HASTINGS...TO BLOOMER WISCONSIN LINE FROM
TONIGHT THROUGH NOON FRIDAY.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

SNOWFALL AMOUNTS IN THE ADVISORY AREA OF 2 TO 4 INCHES ARE
EXPECTED BY LATE MORNING FRIDAY. IN ADDITION...THE BULK OF THE
SNOW IS EXPECTED TO FALL PRIOR TO AND DURING THE MORNING
COMMUTE...WHICH WILL LIKELY CREATE TRAVEL PROBLEMS. LESSER
SNOWFALL AMOUNTS AROUND ONE INCH ARE ANTICIPATED TO THE NORTH OF
THE ADVISORY AREA...GENERALLY ALONG A REDWOOD FALLS...TO
MINNEAPOLIS...TO LADYSMITH LINE. THE SNOWFALL WILL TAPER OFF IN
MOST OF MINNESOTA BY NOON...AND ACROSS WEST CENTRAL WISCONSIN
DURING THE EARLY AFTERNOON.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS AND SNOWFALL OBSERVERS ARE URGED TO REPORT SNOWFALL
AMOUNTS TO THE NATIONAL WEATHER SERVICE.

LS