Hail in Minnesota, April 30, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
408 AM CDT MON APR 30 2007

.DISCUSSION...
FORECAST CONCERNS ARE THUNDERSTORM CHANCES AND MAGNITUDE OF SEVERE
TODAY INTO THIS EVENING.

DEVELOPING WARM SECTOR ALOFT HAS DRIVEN SHOWER ACTIVITY EARLY THIS
MORNING OVER ND AND HAS DEVELOPED ACCUS AND SOME LIGHTER RETURNS
INTO MINNESOTA. 06Z RUC AND 00Z GFS MODELS HAVE A SOLID HANDLE ON
THIS AND TRANSLATE/EVOLVE THE STRONG LOW TO MID LEVEL THETA-E
ADVECTION INTO CENTRAL MINNESOTA THIS MORNING AND WESTERN
WISCONSIN NEAR NOON. UPPER RIGHT ENTRANCE SUPPORT IS ALSO SEEN.
MUCH ACTIVITY THAT DEVELOPS FROM THIS WILL LIKELY BE SHOWERY AT
FIRST GIVEN PROGGED ELEVATED CONVECTIVE VALUES...THOUGH BETTER
THUNDER CHANCES ARRIVE THIS AFTERNOON.

LATEST SURFACE ANALYSIS INDICATES THE FRONT THAT PASSED YESTERDAY
HAS LOST MOMENTUM PUSH FROM THE NORTH OVER IOWA AND SHOULD START A
RETREAT NORTHWARD AS A WARM FRONT DURING THE DAY. THE KEY WILL BE
WHERE THE LOW AND THIS IMMEDIATELY ADJACENT WARM FRONTAL BOUNDARY
WILL BE AT THE 21-00Z TIME FRAME...WITH A DIFFERENCE OF A COUNTY
OR TWO MAKING THE DIFFERENCE ON SURFACE BASED CONVECTION
POTENTIAL. HAVE OPTED TO USE THE SHORT RANGE ENSEMBLE PLACEMENT ON
THIS WHICH IS CLOSE TO THE HIGH RESOLUTION NAM AND RUC LOCATIONS.
VISUAL TRENDS AND THICKNESSES INDICATE DEBRIS CLOUDS FROM THE
NORTH WILL NOT STIFLE HEATING IN SOUTHERN MN TODAY AND WITH A
RETURN OF SIMILAR 850-1000MB AIR AS THAT SEEN YESTERDAY WOULD NOT
BE SURPRISED TO SEE 90F REACHED AGAIN DOWN THERE. CONVECTIVE TEMPS
ARE UP TO THOSE VALUES AND MEAN LAYER CIN IS STRONG IN THE EARLY
AFTERNOON. WITH PLENTY OF SUN EXPECTED IN THAT AREA AND MID LEVEL
COOLING FROM AN APPROACHING NORTHERN STREAM SHORTWAVE...EXPECT THE
CAP TO WEAKEN ENOUGH WITH SOME ISOLATED TO SCATTERED SURFACE
BASED CONVECTION DEVELOPING WITHIN THE LATE AFTERNOON TIME FRAME
AROUND THE I-90 CORRIDOR. PROBABILISTIC CONVECTIVE INDICES
FROM THE ENSEMBLE INDICATES A GOOD CHANCE FOR EXPLOSIVE UPDRAFT
DEVELOPMENT. PLACEMENT OF THESE STORMS WITH RESPECT TO THE
BOUNDARY AND 0-3KM HELICITY AND SHEAR VALUES STILL SUPPORT
TORNADIC POTENTIAL IN THAT AREA OF SOUTH CENTRAL MINNESOTA.
AFOREMENTIONED CLOUD ACTIVITY TO THE NORTH MAY EVEN FURTHER
DIABATICALLY STRENGTHEN THE DEGREE OF THE SYNOPTIC SURFACE
BOUNDARY AND INCREASE THE LOW LEVEL SHEAR VALUES MORESO. HAIL WILL
BE A THREAT ACROSS THIS AREA AND A FEW COUNTIES NORTH AND
NORTHEAST WHERE ELEVATED SUPERCELLS ARE POSSIBLE.

BEYOND THE WEATHER PATTERN STILL APPEARS FAIRLY QUIET FOR A GOOD
PART OF THIS WEEK. SOME PATCHY FOG MAY BE POSSIBLE TONIGHT
DEPENDING ON WHERE RAIN OCCURS AS THE WINDS SLACKEN. SURFACE
RIDGING OVER THE AREA DURING THE MIDDLE OF THE WEEK MAY GENERATE
SOME FROST IN NORTHERN AND EASTERN COUNTIES DURING WEDNESDAY OR
THURSDAY MORNINGS. A LONG WAVE TROUGH WILL ESTABLISH ITSELF BY THE
END OF THE WEEK WHICH STILL IMPLIES BUILDING RAIN CHANCES THROUGH
THE WEEKEND.

&&

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

MTF

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
508 AM CDT MON APR 30 2007

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
011100-
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-
508 AM CDT MON APR 30 2007

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

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER SOUTH CENTRAL
MINNESOTA INTO A SMALL PORTION OF WEST CENTRAL WISCONSIN THIS
AFTERNOON AND EVENING. THE SEVERE WEATHER THREAT IN MINNESOTA
GENERALLY EXTENDS ALONG AND SOUTH OF A ST. JAMES TO RED WING
LINE...AND IN WEST CENTRAL WISCONSIN GENERALLY SOUTH OF I-94. THE
PRIMARY THREAT FROM SEVERE THUNDERSTORMS WILL BE LARGE
HAIL...THOUGH THE ATMOSPHERE WILL BE CONDUCIVE FOR TORNADOES AND
DAMAGING WINDS IN SOUTH CENTRAL MINNESOTA. A LOW PRESSURE SYSTEM
AND A STRONG WARM FRONT DEVELOPING TODAY INTO FAR SOUTHERN
MINNESOTA WILL BE RESPONSIBLE FOR THE SEVERE WEATHER THREAT.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION MAY BE NEEDED AFTER 2 PM THIS AFTERNOON
INTO THIS EVENING IN SOUTH CENTRAL MINNESOTA INTO WEST CENTRAL
WISCONSIN.

MTF