Hail and Damaging Winds in Wisconsin, July 30, 2006

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
853 PM CDT SAT JUL 29 2006

.UPDATE...
STILL A TRICKY FORECAST REST OF NIGHT. IT APPEARS THAT THE CHANCES
FOR SURFACE BASED INITIATION IS SLIM OVER WEST CENTRAL
MN...ALTHOUGH THERE IS STILL A FAIR AMOUNT OF CONVERGENCE ALONG
THE BOUNDARY AND NEAR THE INSTABILITY GRADIENT. HOWEVER...MID
LEVEL /700/ MB TEMPS ARE QUITE WARM AND HAVE WARMED 4 DEGREES AT
MPX SINCE THIS MORNING AND IS 2 DEGREES WARMER THAN LAST NIGHT AT
THIS TIME. 14C TEMPS ANALYZED INTO SW MN ON BOTH RUC AND LAPS AT
00Z. 21Z RUC WAS NOT TOO GOOD IN DEPICTING DEVELOPMENT...AND TOO
COOL ON 700 MB TEMPS. NAM-WRF WAS BETTER...BUT GFS WAS THE BEST.
QPF FIELD OVER NE MN WAS CLOSE TO GFS..AND ACTUALLY KEEPS ACTION
MOSTLY OUT OF CWA. WILL PROBABLY LEAN TOWARD CUTTING BACK ON
PRECIP EXCEPT FOR FAR N CWA AND INTO WISCONSIN. BEST AREA IN AN
ARC FROM CENTRAL MN...TO EAST CENTRAL AND ON INTO WI.

&&

.PREV DISCUSSION... /ISSUED 254 PM CDT SAT JUL 29 2006/

DISCUSSION...
SPOTTY CONVECTION CONTINUES TO TRICKLE ON THIS AFTERNOON FROM
BRAINARD TO EAU CLAIRE. OVERNIGHT OUTFLOW FROM THE STORMS THAT
PASSED ACROSS CENTRAL MN AND WEST CENTRAL WI VERY EVIDENT IN
VISIBLE IMAGERY THIS AFTERNOON ACROSS FAR SOUTHERN MN AND NE IA.
MAIN CONCERN IN THE SHORT TERM CENTERS AROUND SEVERE THUNDERSTORM
DEVELOPMENT TONIGHT. RUC...NAM-WRF AND GFS ALL SHOWING AN INTENSE
1000-850MB THERMAL BOUNDARY STRETCHING FROM ALONG THE ND/SD
BORDER INTO CENTRAL MN. RUC LOW LEVEL WINDS INDICATE SOUTH WINDS OF
25 KNOTS ALONG OUR FAR WESTERN MN BORDER ATTM POKING INTO THIS
BOUNDARY. APPEARS CONVECTION WILL INITIATE OVER SE ND LATE THIS
AFTERNOON AS INSTABILITY INCREASES AND A SHORT WAVE OVER EASTERN
MT AND SOUTHERN SASKATCHEWAN PUSHES ACROSS ND. NAM-WRF 250 MB WINDS
SHOW ANOTHER 90 KNOT WIND MAX TO ACCOMPANY THE SHORT WAVE TONIGHT
WITH FAVORABLE LAYER DIVERGENCE PROGGED ACROSS NORTHERN MN.
12Z NCAR ARW WRF SHOWS CONVECTION DEVELOPING AROUND 22Z NORTHWEST
OF THE CWA WITH ONE SUPERCELL TURNING RIGHT INTO OUR NW CWA.
EXPECT A RATHER LARGE AREA OF CONVECTION OVERNIGHT...BUT MAINLY TO
THE NORTH OF OUR CWA AS THE LOW LEVEL BOUNDARY IS FORECAST TO MOVE
INTO NORTHERN MN DURING THE NIGHT. WILL ALLOW CHANCE POPS INTO
CENTRAL MN AND WEST CENTRAL WI OVERNIGHT AND EARLY SUNDAY. SAME
SCENARIO WILL SET UP AGAIN SUNDAY AFTERNOON/NIGHT...BUT FEATURES
SHOULD BE FURTHER NORTH AND MORE NEAR THE CANADIAN BORDER. THE
NEXT THREAT OF THUNDERSTORMS WILL BE MONDAY NIGHT AND TUESDAY AS A
COLD FRONT WORKS SLOWLY INTO THE FORECAST AREA. SOME POTENTIAL FOR
SEVERE STORMS OVER EASTERN AND SOUTHERN AREAS OF THE CWA TUESDAY
AFTERNOON AND EVENING. OTHER SIGNIFICANT ISSUE IN THE SHORT TERM
IS THE HEAT. SEE NO REAL CHANGE TO 100 DEGREE PLUS READINGS SUNDAY
AND MONDAY. ACTUALLY...MONDAY IS THE BEST DAY FOR 100 TO 105
DEGREE TEMPERATURES WITH THE LOW LEVEL THERMAL AXIS RUNNING SW TO
NE ACROSS MN. MADE FEW CHANGES TO LOWS/HIGHS OTHER THAN TO RAISE WEST
CENTRAL MN INTO THE LOW 100S ON MONDAY. TUESDAY WILL STILL BE HOT
ADN HUMID OVER EASTERN AND SOUTHERN AREAS. CURRENT THINKING IS
THAT THE EXCESSIVE HEAT WATCH FOR HENNEPIN AND RAMSEY COUNTIES
WILL GET TURNED INTO AN EXCESSIVE HEAT WARNING SUNDAY MORNING WITH
HEAT ADVISORIES OVER THE REST OF THE CWA SUNDAY THROUGH MONDAY.
WILL ALLOW THE MIDNIGHT SHIFT TO MAKE THE FINAL CALL.

LONGER TERM...TUESDAY NIGHT THROUGH SATURDAY
THE DOMINANCE OF FAIR...BUT HOT WEATHER OVER THE UNITED STATES
CONTINUES TO BE THE MAIN FOCUS OF RECENT METEOROLOGICAL DISCUSSION.
WHILE STRONG WESTERLIES MEANDER AROUND A PRONOUNCED OMEGA BLOCK OVER
CANADA...THE ATMOSPHERE ABOVE THE CONTINENTAL UNITED STATES REMAINS
HIGHLY BAROTROPIC. AS SUCH...HOT WEATHER HAS BEEN OBSERVED AROUND
THE ENTIRE COUNTRY...FROM CALIFORNIA TO THE CAROLINAS.  STEMMING
FROM PROLONGED PERIODS OF LOWER THAN NORMAL PRESSURE AT THE NORTH
POLE AND HIGHER THAN NORMAL PRESSURE IN THE TROPICS...ALSO KNOWN AS
THE POSITIVE PHASE OF THE ARCTIC OSCILLATION...THIS CURRENT WEATHER
REGIME IS LIKELY TO CONTINUE INTO MID AUGUST OVER MUCH OF THE UNITED
STATES.  FORTUNATE FOR THE NORTHERN THIRD OF THE COUNTRY...SLIGHT
MERIDIONAL DEVIATIONS IN THE UPPER LEVEL FLOW ARE FORECAST TO
CONTINUE TO FLOW SOUTH ACROSS THE UPPER MISSOURI AND MISSISSIPPI
RIVER VALLEYS THROUGH THE END OF THE WEEK.

THE CURRENT EXTENDED PERIOD FORECAST IS HIGHLY INDICATIVE OF THESE
AFOREMENTIONED QUALITIES.  ALTHOUGH TEMPERATURES ARE FAR ABOVE
NORMAL IN THE SHORT TERM...A MIDWEEK FRONTAL PASSAGE WILL ACT TO
MODERATE CONDITIONS BACK TOWARDS SUMMER CLIMATOLOGICAL AVERAGES. THIS
SHOULD PROVIDE FOR A FAIR END TO THE WEEK...WITH MOSTLY MILD
TEMPERATURES...CLEAR AND DRY SKIES...NOT TO MENTION AN OPTIMISTIC
OUTLOOK FOR NEXT WEEKEND. SEVERAL MODELS...INCLUDING THE
ECMWF...CMC...AND GFS...DEPICT THE POSSIBILITY FOR PRECIPITATION IN
THE FRIDAY...SATURDAY...SUNDAY TIME FRAME...BUT DISAGREE
SIGNIFICANTLY IN THE TIMING AND COVERAGE.  FUTURE RUNS WILL HELP TO
CLARIFY THESE QUESTIONS...AS WELL AS TO WHAT DEGREE TROUGHING ON THE
WEST COAST WILL AMPLIFY AND MAINTAIN ITSELF.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...HEAT ADVISORY UNTIL 7 AM CDT SUNDAY FOR HENNEPIN-RAMSEY
     COUNTY(IES).

     EXCESSIVE HEAT WATCH FROM 7 AM CDT SUNDAY THROUGH LATE MONDAY
     NIGHT FOR HENNEPIN-RAMSEY COUNTY(IES).

WI...NONE.
&&

JPR/RAH/BVS

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
935 PM CDT SAT JUL 29 2006

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
301100-
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-
324 PM CDT SAT JUL 29 2006

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

.DAY ONE...TONIGHT

SEVERE THUNDERSTORMS ARE POSSIBLE OVERNIGHT FOR PORTIONS OF CENTRAL
MINNESOTA AND WEST CENTRAL WISCONSIN...GENERALLY TO THE NORTH OF A
LINE FROM ALEXANDRIA...TO CAMBRIDGE...TO EAU CLAIRE. THE TORNADO
THREAT HAS DIMINISHED OVER WEST CENTRAL MINNESOTA...BUT A HAIL AND
DAMAGING WIND THREAT CONTINUES...IF THUNDERSTORMS DEVELOP OVER
SOUTHEAST NORTH DAKOTA AND MOVE EAST SOUTHEAST...TOWARD CENTRAL
MINNESOTA AND WEST CENTRAL WISCONSIN.

A HEAT ADVISORY REMAINS IN EFFECT FOR THE TWIN CITIES TONIGHT AS
TEMPERATURES ONLY DROP TO AROUND 80 DEGREES. SEE THE LATEST NON
PRECIPITATION STATEMENT FOR ADDITIONAL DETAILS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THE DANGEROUS COMBINATION OF HEAT AND HIGH HUMIDITY WILL PERSIST
BOTH SUNDAY AND MONDAY ACROSS A LARGE PORTION OF CENTRAL AND
SOUTHERN MINNESOTA...AS WELL AS WEST CENTRAL WISCONSIN. AFTERNOON
HEAT INDICES OF 105 TO 110 CAN BE EXPECTED ON BOTH DAYS. MINIMUM
TEMPERATURES BETWEEN 75 AND 80 WILL ALSO RESTRICT THE AMOUNT OF HEAT
THAT WILL BE LOST AT NIGHT FROM BUILDINGS THAT LACK AIR
CONDITIONING. SEE THE LATEST NON PRECIPITATION STATEMENT FOR
ADDITIONAL DETAILS.

IN ADDITION...A COLD FRONT IS FORECAST TO MOVE ACROSS THE REGION
TUESDAY AND TUESDAY NIGHT AND SEVERE THUNDERSTORMS ARE POSSIBLE.
CONTINUE TO MONITOR FORECASTS AND OUTLOOKS FOR DETAILS ON THESE
SEVERE WEATHER CHANCES.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION MAY BE NEEDED TONIGHT.

JPR