FXUS63 KMPX 091214
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
614 AM CST WED DEC 9 2009
.UPDATE...
ADDED 12Z TAF DISCUSSION BELOW
&&
.DISCUSSION...
MAIN FORECAST CONCERNS (SHORT TERM) ARE ASSOCIATED WITH SFC WINDS
AND HOW STRONG THEY WILL DEVELOP THIS MORNING...AND IF BLIZZARD
CONDITIONS ARE MET.
SEVERAL MESOSCALE FEATURES ARE NOTED ON REGIONAL RADAR AND
SATELLITE IMAGES EARLY THIS MORNING THAT HAS DEPICTED AN ENHANCED
AREA OF LIFT AND THUS INCREASED REFLECTIVITY OF SN/+SN. SFC WINDS
HAVE STARTED TO INCREASE SLOWLY FROM EARLIER THIS EVENING...WITH
SEVERAL AWOS/ASOS'S IN THE FAR WEST REPORTING GUSTS OF 35 TO 45
MPH. HOWEVER...DUE TO LIMITED SNOWFALL IN THESE AREAS...VSBYS HAVE
BEEN 1/2SM OR HIGHER. MOST AREAS HAVE BEEN AVERAGING BETWEEN 1 &
2SM. STILL...LATEST 13KM RUC CONTINUES THE TREND OF INCREASING
WINDS OVERNIGHT WITH SUSTAINED WINDS OF 30 TO 40 MPH...AND NEAR
50 MPH IN OPEN COUNTRY WHERE THE CURRENT BLIZZARD WARNING IS IN
EFFECT BETWEEN 09/15Z.
AS FOR SNOWFALL AND ACCUMULATIONS FOR THE NEXT 12/18 HRS...HAVE
BASICALLY FOLLOWED THE RICH COLUMN OF OMEGAS/MOISTURE WHICH IS
MAXIMIZED BETWEEN 92H/60H...AND IS SHOWING THE BEST CONTINUED
SNOWFALL ALONG A LINE FROM RICE LAKE WISCONSIN...TO
HASTINGS/ALBERT LEA MINNESOTA THROUGH 18Z. THIS IS WHERE THE BEST
POTENTIAL OF 8 TO 12 INCHES WILL EXIST BEFORE TAPERING OFF TO
FLURRIES THIS AFTERNOON. SEVERAL COUNTIES IN WEST-CENTRAL
WISCONSIN WILL ALSO BE CLOSE TO 10-12" BEFORE IT TAPERS OFF LATER
TODAY...BUT THIS WILL LIKELY BE ASSOCIATED WITH ANOTHER SHORT WAVE
ACROSS SOUTHERN IOWA EARLY THIS MORNING. THE MEAN 50H SHORT WAVE
ACROSS THE EASTERN DAKOTAS WILL LIKELY BE THE MAIN PLAYER FOR
ENDING THE -SN OR AT LEAST THE ACCUMULATING SNOWFALL LATER TODAY.
THIS AXIS WILL BE NEAR THE MN/SD/ND BORDER BY 12Z...THEN SLOWLY
MOVING INTO WESTERN WISCONSIN BY 00Z. THERE MAY BE SOME LINGERING
-SN WITH MINOR ACCUMULATIONS ACROSS RICE LAKE/LADYSMITH AREA
DURING THE EVENING...BUT MOST AREAS SHOULD SEE THE END OF
MEASURABLE PRECIPITATION BY LATER THIS AFTN.
AS FOR WINDS...THE STRONGEST AND MOST EFFECTIVE IN TERMS OF
PRODUCING BLIZZARD OR NEAR BLIZZARD CONDITIONS WILL BE FROM 09Z TO
18Z TODAY. WINDS SHOULD SLOWLY DECREASE THIS AFTN AS THE MAIN SFC
LOW MOVES EAST INTO THE EASTERN GREAT LAKES REGION.
AFTER THIS EVENING...A QUIET WEATHER PATTERN SHOULD DEVELOP AS THE
EXITING STORM TODAY WILL BE ACROSS SOUTHEASTERN CANADA...WITH A
SIGNIFICANT LONG WAVE TROUGH (NW TO SE ACROSS SOUTHERN
CANADA...INTO THE NE U.S.) BEGINS TO CONTROL THE WEATHER PATTERN
ACROSS THE UPPER MIDWEST. ALTHOUGH CURRENT ENSEMBLE MEMBERS AND
THE GENERAL MEAN OF THE ARCTIC BOUNDARY WILL BE CLOSE TO THE
AREA...I DON'T THINK ANY TYPE OF SUBSTANTIAL WARM-UP IS
ANTICIPATED IN OUR AREA UNTIL THIS PATTERN CHANGES...OR UNTIL A
STORM SYSTEM ACROSS THE ROCKIES BY EARLY NEXT WEEK...BEGINS TO
BUCKLE THIS LONG WAVE TROUGH AND ALLOW FOR MODIFIED PACIFIC AIR TO
FILTER INTO OUR REGION. THEREFORE...TOO MANY UNCERTAINTIES IN THE
EXTENDED PERIOD TO CHANGE. ..JLT..
&&
.AVIATION.../12Z TAF ISSUANCE/
DEEP LOW PRESSURE CENTER VCNTY CHI CAUSING VERY STRONG WINDS OF
NEAR 30 KNOTS SUSTAINED WITH GUSTS TO NEAR 40 KNOTS OVER SOUTHERN
MN MAINLY SOUTH OF TAFS SITES...BUT 25 TO 28 KNOTS WILL BE COMMON
OVER MOST OF THE TAF SITES THIS MORNING WITH A GRADUAL DECREASE
THIS AFTERNOON. OTHERWISE CIGS HAVE LIFTED TO MAINLY MVFR OVER TAF
SITES EXCEPT FOR KEAU WHERE LIGHT TO MODERATE SNOW CONTINUES.
VSBYS TO REMAIN IN THE IFR CATEGORY THIS MORNING WITH THE LOWER
VALUES KEAU TO KMSP TO KRWF. MAIN FORCING FOR ADDITIONAL SNOW WILL
BE OVER EAST CENTRAL AND WEST CENTRAL WISCONSIN TO AFFECT
KMSP...KRNH AND KEAU. THERE IS ALSO A RISK FOR IFR CIGS AND VSBYS
DOWN TO 1/2SM AND 005 UNTIL ABOUT 15Z FOR KRNH AND KMSP AND UNTIL
18Z FOR KEAU. ADDTIONAL SNOWFALL FOR KMSP COULD BE ANOTHER INCH TO
POSSIBLY AN INCH AND A HALF. UP TO 2 INCHES ADDITIONAL FOR KRNH
AND KEAU. OTHEWISE CIGS WILL GENERALLY LIFT TO MVFR FOR MN TAF
SITES LATER THIS MORNING AND CONTIUE INTO THE AFTERNOON. IFR TO
LIFR CIGS AND VSBYS WILL CONTINUE IN KRNH AND KEAU THROUGH THE
MORNING...THE LIFTING TO MVFR IN THE AFTERNOON. MOST SITES SHOULD IMPROVE
TO VFR AFTER 00Z FOR MN SITES AND AFTER 06Z WI TAF SITES.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...BLIZZARD WARNING UNTIL MIDNIGHT CST TONIGHT FOR BLUE EARTH-BROWN-
CARVER-DAKOTA-FARIBAULT-FREEBORN-GOODHUE-LE SUEUR-MARTIN-
MCLEOD-NICOLLET-RICE-SCOTT-SIBLEY-STEELE-WASECA-WATONWAN.
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR BENTON-
DOUGLAS-KANABEC-KANDIYOHI-MEEKER-MILLE LACS-MORRISON-POPE-
STEARNS-STEVENS-SWIFT-TODD.
WINTER STORM WARNING UNTIL MIDNIGHT CST TONIGHT FOR ANOKA-
CHISAGO-HENNEPIN-ISANTI-RAMSEY-SHERBURNE-WASHINGTON-WRIGHT.
BLIZZARD WARNING UNTIL 6 PM CST THIS EVENING FOR CHIPPEWA-LAC
QUI PARLE-REDWOOD-RENVILLE-YELLOW MEDICINE.
WI...BLIZZARD WARNING UNTIL MIDNIGHT CST TONIGHT FOR CHIPPEWA-DUNN-
EAU CLAIRE-PEPIN-PIERCE.
WINTER STORM WARNING UNTIL MIDNIGHT CST TONIGHT FOR BARRON-POLK-
RUSK-ST. CROIX.
&&
$$
JLT/JPR
