Hail in Minnesota, May 8, 2006

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
303 PM CDT MON MAY 8 2006

.DISCUSSION...TONIGHT THROUGH THURSDAY
FCST CHALLENGE REMAINS CONVECTION TONIGHT AND SLIGHT SEVERE
POTENTIAL. BETWEEN WHOLES IN DEBRIS CLOUDS...CURRENT GOES VIS
LOOP REVEALS TOWERING CU ACROSS WESTERN CWA AND ERN SD. FIRST
CELLS HAVE FORMED AS THE CAP HAS BROKE DURING PEAK HEATING. MSAS
DIAGNOSTIC DATA REVEALING SFC MOISTURE CONV AHEAD OF THE
FRONT...A SIGN OF A PRE-FRONTAL BOUNDARY WHICH IS TRIGGERING THIS
ACTIVITY. EXPECT DEVELOPMENT TO CONTINUE AND SLOWLY PUSH INTO WRN
CWA WITH THE POSSIBILITY OF A STRONG TO SEVERE STORM. THIS
CONVECTION SHOULD WEAKEN NEAR SUNDOWN AS THE FRONT IN THIS AREA IS
NOT THAT STRONG AND THE RUC MODEL DROPS INSTABILITY VALUES
QUICKLY. AS AN UPPER LEVEL JET MOVES OUT OF THE ROCKIES AND SECOND
SHORTWAVE SEEN ON MORNING H5 ANALYSIS AND WV LOOP MOVES INTO
NEBRASKA...MORE ORGANIZED CONVECTION IS LIKELY TO GET GOING TO OUR
SW. THIS LOOKS TO SKIRT CLOSE TO OUR SRN BOUNDARY WITH ELEVATED
CONV LIKELY AHEAD OF THIS FEATURE AS A CLOSED SFC LOW DEVELOPS
ATOP CTRL MN BY LATE EVNG. WET BULB ZERO HEIGHTS AROUND 9K FT WILL
LEAD TO HAIL POTENTIAL AND WINDS WILL BE A THREAT WITH THE MORE
ORGANIZED THUNDERSTORM ACTIVITY.

12Z AND NOW 18Z GUIDANCE CONTINUES TO SLOW FRONTAL PASSAGE. GFS
AND ECMWF ARE THE SLIGHTLY MORE PREFERRED MODELS WITH SYNOPTIC
FEATURES FROM TUES ON. ALMOST CONSTANT POPS IN THROUGH THAT TIME
BUT LOW QPF AND SHOWERY ACTIVITY EXPECTED MORESO THAN GENERAL RAIN.
FRONT HANGING IN WRN WI WORTHY OF UPPING POPS IN THAT AREA ON
TUES. SKIES LIKELY TO BE CHAOTIC THOUGH SOME SUN IS EXPECTED IN
WRN AREAS...AND WITH A WEST WIND HAVE BUMPED UP TEMPS. SECONDARY
COLD FRONT PUSH COMES LATE TUES NIGHT AND DROPPING H8 TEMPS WILL
LEAD TO TEMPS BELOW NRML TO WELL BELOW NRML BY THURS. AS UPPER LOW
MOVES OVER AREA WITH -25 TO -28C H5 TEMPS BY WEDS NIGHT...PRECIP
CHCS WILL INCREASE SLIGHTLY. BUT DEEP SFC LOW FROM SRN STREAM MOVES
NNE TO THE GREAT LAKES BY WEDS NIGHT AND THAT WILL HOLD MUCH OF
THE MOISTURE TO OUR EAST. 500-1000MB THICKNESS ACTUALLY BELOW
5400M...BUT LOW LEVEL AIR STILL WARM SO -SHRA EXPECTED.

LONGER TERM...THURSDAY NIGHT THROUGH MONDAY
GFS ENSEMBLE MEAN SHOWS LARGE UPPER LOW DRIFTING SLOWLY EAST
THURSDAY AND FRIDAY IN THE VICINITY OF LOWER MICHIGAN.  SOME HINT
THAT BY SATURDAY IT WILL STRETCH OUT FROM NW TO SE JUST TO OUR NORTH
AND EAST...AS WESTERN RIDGE BUILDS NORTH SOMEWHAT. THIS WOULD ARGUE
FOR DRY WX AND COOL NW FLOW. THUS WILL CONTINUE THE CURRENT
FORECAST...WHICH BRINGS AN END TO SMALL CHC POPS IN OUR WISCONSIN
COUNTIES FRIDAY NIGHT. WILL ALSO LOWER TEMPS A LITTLE BIT.
OPERATIONAL GFS AND UKMET ALLOW SHORT WAVE TO HEAD FOR MN SUNDAY
AMID WEAKENING RIDGE AND ZONAL FLOW... WHEREAS ECMWF KEEPS THE WRN
RIDGE NICE AND STRONG...AND IN FACT REINFORCES THE GREAT LAKES LOW.
DESPITE A LOT OF SPREAD IN THE SPAGHETTI CHARTS...THE GFS ENSEMBLE
SUGGESTS THE GREAT LAKES LOW WILL REMAIN A MAJOR PLAYER...SO WILL
STEER TOWARD THE ECMWF.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&

MTF/TDK

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
347 PM CDT MON MAY 8 2006

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
092100-
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-
347 PM CDT MON MAY 8 2006

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

.DAY ONE...LATE THIS AFTERNOON AND TONIGHT

THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS LATE THIS
AFTERNOON AND THIS EVENING ACROSS WESTERN...CENTRAL...AND SOUTHERN
MINNESOTA. THE AREA UNDER THIS RISK IS GENERALLY WEST OF A LINE
FROM LITTLE FALLS TO ALBERT LEA. A BROKEN LINE OF THUNDERSTORMS
WILL MOVE INTO THE FAR WESTERN OUTLOOK AREA DURING THE LATE
AFTERNOON AND LIKELY TRACK INTO WEST CENTRAL MINNESOTA BY EARLY
EVENING. THE PRIMARY THREAT FROM ANY OF THESE THUNDERSTORMS WILL
BE LARGE HAIL. THESE WILL LIKELY WEAKEN BY MID EVENING.

THUNDERSTORMS WILL BE POSSIBLE THROUGHOUT THE EVENING ACROSS
SOUTHERN AND CENTRAL MINNESOTA. THE PRIMARY THREAT FROM THESE WILL
BE LARGE HAIL AND DAMAGING WINDS. MORE COVERAGE IN SHOWERS AND
THUNDERSTORMS IS EXPECTED AFTER MIDNIGHT ACROSS EASTERN MINNESOTA
AND WESTERN WISCONSIN...BUT THE MAIN THREAT LOOKS TO BE PEA SIZE
HAIL.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

THUNDERSTORMS WILL BE POSSIBLE ACROSS EAST CENTRAL MINNESOTA AND
WEST CENTRAL WISCONSIN ON TUESDAY. PEA SIZE HAIL MAY BE POSSIBLE
WITH THESE THUNDERSTORMS.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION MAY BE NEEDED IN
WESTERN...CENTRAL...AND SOUTHERN MINNESOTA DURING THE LATE AFTERNOON OR
EARLY EVENING HOURS. SPOTTERS ARE ENCOURAGED TO STAY IN TUNE WITH
THE LATEST FORECAST UPDATES THROUGH EARLY EVENING.

MTF