Winter Weather Advisory 5, NWS Twin Cities, MN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
933 PM CST SAT MAR 11 2006

.UPDATE...
MUCH OF THEN 00Z NAM HAS COME IN AND IS STILL TRENDING TOWARD WHAT
THE GFS HAD BEEN SUGGESTING THE LAST FEW RUNS. IN FACT..THE NAM
IS SUGGESTING THAT THE BETTER MID LEVEL /700-600/ TEMP GRADIENT
MAY BE A LITTLE FARTHER NORTH INTO CENTRAL MN. DPROG/DT ON THE
NAM IS ALSO IS A TOUCH SLOWER AND ALLOWING A BIT BETTER DIFLUENT
UPPER FLOW TO DEVELOP. BEST QG CONV IN 850-500 LAYER STILL OVER
SOUTH CENTRAL MN THOUGH. WILL NOT CHANGE THE WATCH AT THIS TIME
BUT WILL EXPAND CATEGORICAL POPS MORE INTO CENTRAL MN.

SHOULD BE PERIOD OF MOSTLY CLEAR SKIES OVERNIGHT WITH GOOD
SUBSCIDENCE ESPECIALLY EAST AND UPDATED FOR THIS EARLIER.

&&

.PREV DISCUSSION... /ISSUED 336 PM CST SAT MAR 11 2006/

DISCUSSION...TONIGHT THROUGH TUESDAY

LOW PRESSURE EXITING NORTHERN MN ATTM WITH THE TRAILING COLD FRONT
PUSHING ACROSS THE FAR EASTERN CWA. CLOUDINESS IN THE WAKE OF THE
FRONT EXPECTED TO DIMINISH THIS EVENING AS HIGH PRESSURE BUILDS
IN FROM THE DAKOTAS. MODEL SOLUTIONS STILL VARY ON THE DETAILS FOR
A LOW PRESSURE SYSTEM PASSING SOUTH OF HERE SUNDAY NIGHT AND
MONDAY. THE NAM HAS TRENDING NORTHWARD OVER THE LAST SEVERAL RUNS
WITH BRINGING SIGNIFICANT PRECIPITATION INTO FAR SOUTHERN MN AND
WEST CENTRAL WI SUNDAY NIGHT AND EARLY MONDAY IN ASSOCIATION WITH
STRONG FRONTOGENESIS IN THE 600-700MB LAYER. HOWEVER...THE
STRUCTURE OF THE 700MB LOW AND ITS MOVEMENT ALMOST DUE EAST ACROSS
NORTHERN IA JUST DOES NOT LOOK RIGHT. THE GFS ON THE OTHER HAND
HAS THE 700MB LOW MOVING MORE ACROSS SE MN SUNDAY NIGHT WITH THE
BEST MID LEVEL RESPONSE TO THE FRONTOGENESIS DEVELOPING FROM
REDWOOD FALLS TO THE TWIN CITIES AND SPREADING EASTWARD ACROSS
WEST CENTRAL WI BY MONDAY MORNING. COLLABORATION WITH OTHER
OFFICES WAS TO PUT MUCH OF THE WEIGHT BEHIND THE GFS AND ISSUE
WINTER STORM WATCHES FOR LATE SUNDAY INTO MONDAY. 18Z NAM NOW
COMING IN AND THE 700 MB LOW TRACK HAS CHANGED AND NOW MOVES
ACROSS SE MN SUNDAY NIGHT. 18Z NAM -FN VECTOR DIVERGENCE IN THE
600-700MB LAYER IS QUITE STRONG FROM SOUTH CENTRAL MN THROUGH WEST
CENTRAL WI SUNDAY NIGHT AND ACTUALLY COVERS THE WATCH AREA QUITE
NICELY. CAME UP WITH AT LEAST 6 INCHES OF SNOW IN THE WATCH AREA
WITH NO TROUBLE BASED ON HPC QPF AND ACTUALLY HAVE SOME 7 TO 8
INCH AMOUNTS FROM MANKATO THROUGH RED WING TO EAU CLAIRE. GOOD
AGREEMENT IN THE NAM AND GFS THAT THE SYSTEM ENDS RATHER QUICKLY
MONDAY MORNING. SOME SNOW SHOWER ACTIVITY POSSIBLE TUESDAY OVER
THE NE HALF OF THE CWA AS A SHORT WAVE MOVES SE ACROSS THE WESTERN
GREAT LAKES.

LONGER TERM...TUESDAY NIGHT THROUGH FRIDAY

MID/UPPER NORTHWEST FLOW WILL PREVAIL ACROSS THE UPPER MIDWEST
DURING THE EXTENDED PERIOD. EXPECT PROGGED 850 MB TEMPERATURES
BETWEEN -10C AND -15C TO RESULT IN BELOW NORMAL SURFACE TEMPERATURES
THROUGH THE WEEK. THE GFS...ECMWF...AND CANADIAN MODELS ALL DRIVE A
SHORTWAVE TROUGH FROM THE WESTERN CONUS ACROSS THE NORTHERN/CENTRAL
PLAINS DURING THE MIDDLE OF THE WEEK. ALTHOUGH THE PLACEMENT OF THE
ASSOCIATED SURFACE TROUGH IS SOMEWHAT UNCERTAIN AT THIS POINT...THE
AFOREMENTIONED MODELS DRIVE IT SOMEWHERE ACROSS THE NE/IA/KS/MO
BORDERS. HAVE INCREASED POPS TO 30-40 PERCENT FOR SNOW ACROSS SOUTH
CENTRAL MINNESOTA BETWEEN THE WEDNESDAY AFTERNOON/NIGHT TIME FRAME.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER STORM WATCH FROM SUNDAY EVENING THROUGH MONDAY MORNING
     FOR ANOKA-BLUE EARTH-BROWN-CARVER-CHISAGO-DAKOTA-FARIBAULT-
     FREEBORN-GOODHUE-HENNEPIN-LE SUEUR-MARTIN-MCLEOD-NICOLLET-
     RAMSEY-REDWOOD-RENVILLE-RICE-SCOTT-SIBLEY-STEELE-WASECA-
     WASHINGTON-WATONWAN COUNTY(IES).

WI...WINTER STORM WATCH FROM SUNDAY EVENING THROUGH MONDAY MORNING
     FOR BARRON-CHIPPEWA-DUNN-EAU CLAIRE-PEPIN-PIERCE-POLK-RUSK-
     ST. CROIX COUNTY(IES).

&&

JPR/RAH/LS

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
246 PM CST SAT MAR 11 2006

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
121315-
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-
246 PM CST SAT MAR 11 2006

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THERE IS A POTENTIAL FOR A BAND OF SIGNIFICANT SNOWFALL ACROSS
SOUTH CENTRAL AND EAST CENTRAL MINNESOTA INTO WEST CENTRAL
WISCONSIN LATE SUNDAY INTO MONDAY AS A LOW PRESSURE SYSTEM PASSES
JUST SOUTH OF THE REGION. WHILE SOME UNCERTAINTY STILL EXISTS
REGARDING THE EXACT TRACK OF THE LOW PRESSURE SYSTEM...THE MOST
SIGNIFICANT SNOWFALL IS EXPECTED TO FALL ALONG AND SOUTH OF A LINE
FROM NEW ULM...TO THE TWIN CITIES METRO...TO BLOOMER WISCONSIN.
LOCATIONS IN THIS AREA MAY SEE 6 OR MORE INCHES OF SNOW BY MIDDAY
MONDAY.

MORE SNOW IS POSSIBLE FOR MUCH OF SOUTH CENTRAL MINNESOTA
ON WEDNESDAY INTO THURSDAY MORNING AS ANOTHER LOW PRESSURE
SYSTEM LIFTS OUT OF THE SOUTHERN ROCKIES INTO THE CENTRAL PLAINS.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY OR TONIGHT.

LS