Hail in Minnesota, July 24, 2007

AREA FORECAST DISCUSSION...UPDATED FOR AVIATION DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
800 PM CDT TUE JUL 24 2007

.DISCUSSION...
PATTERN SHIFT BEGINNING TO TAKE SHAPE TODAY BUT OVERALL WILL SEE
LITTLE CHANGE IN SENSIBLE WEATHER THROUGH THE PERIOD OTHER THAN
MODEST COOLING FOLLOWING THE PASSAGE OF A FRONT LATER THIS WEEK.
MORNING UPPER AIR ANALYSIS REVEALED LARGE AREA OF HEIGHT FALLS
ACROSS THE CONUS. UPPER RIDGE/HEAT DOME HAS MIGRATED A BIT FURTHER
NORTHEAST TODAY AS AN UPPER TROUGH SWINGS ACROSS BRITISH COLUMBIA AS
EVIDENCE BY SHARP HEIGHT FALLS ACROSS ALBERTA AND WESTERN MONTANA AS
WELL AS BEING VISIBLE ON WATER VAPOR IMAGERY. OTHER UPPER AIR
FEATURE OF NOTE IS CIRCULATION SPINNING OVER THE EASTERN OHIO
VALLEY. THIS FEATURE IS FORECAST TO MERGE INTO A LONGWAVE TROUGH
OVER THE EASTERN CONUS LATER THIS WEEK. LOCALLY...FEATURE OF
INTEREST FOR THE NEAR TERM IS MESO VORTEX SPINNING INTO THE
NORTHWEST CWA ATTM. LIGHT TO BRIEFLY MODERATE RAIN ALONG WITH
EMBEDDED THUNDER IS ACCOMPANYING THE CIRCULATION AS IT HEADS SOUTH
SOUTHEAST. HAVE INCLUDED CHANCE POPS ACROSS THE WESTERN CWA THROUGH
THE EVENING. BRIEF HEAVY DOWNPOURS MAY OCCUR AS THE SYSTEM MOVES
INTO MORE FAVORABLE AIRMASS.

NEXT CONCERN IS THE HEAT WEDNESDAY. CLOUD COVER ASSOCIATED WITH
VORTEX MAY LINGER IN THE MORNING OVER THE SOUTHWEST CWA...BUT
OTHERWISE EXPECT GENERALLY PARTLY CLOUDY SKIES. WITH SOUTHERN WINDS
ACROSS THE AREA...FAR WEST SITES WILL SEE SOME DOWNSLOPE EFFECT FROM
THE BUFFALO RIDGE AND HAVE CONTINUED WITH MID 90S THERE. HEAT
INDEX VALUES WILL BE PUSHING 105 ACROSS THE FAR WEST AND PUSHING THE
100 TO 105 RANGE ACROSS THE CENTRAL CWA WHERE TEMPERATURES ARE
EXPECTED TO REACH THE LOWER 90S.

THE BRITISH COLUMBIA TROUGH QUICKLY MOVES ACROSS CENTRAL CANADA AND
ACROSS HUDSON BAY BY THURSDAY. A SECOND SHORTWAVE ROTATES IN BEHIND
IT AND WILL HELP PUSH SFC LOW PRESSURE AND ASSOCIATED COOL FRONT
ACROSS THE CWA FROM NW TO SE THURSDAY AFTERNOON INTO FRIDAY MORNING.
HAVE MAINTAINED SIMILAR TIMING OF PASSAGE AND ATTENDANT PRECIP
CHANCES AS PREVIOUS FORECAST. PRECIP CHANCES CONTINUE TO LOOK
PROMISING WITH THIS EVENT. PRECIPITABLE WATER VALUES INCREASE TO
OVER 2 INCHES AHEAD OF THE BOUNDARY. UPPER LEVEL SUPPORT MAY COME
FROM A NORTHEAST TO SOUTHWEST ORIENTED SPEED MAX OVER THE WESTERN
PERIPHERY OF CUTOFF UPPER LOW. IT IS SUGGESTED THAT THE LOCAL AREA
MAY BE IN CLOSE ENOUGH PROXIMITY TO RECEIVE RIGHT ENTRANCE REGION
INFLUENCE AIDING UPWARD MOTION. SOME OF THE DETAILS THAT HAVE YET TO
BE RESOLVED SUCH AS THE PROXIMITY OF THE SFC BOUNDARY TO THE UPPER
FORCING. AM A BIT CONCERNED THAT THESE FEATURES MAY NOT FAVORABLY
ALIGN FOR DECENT PRECIP DEVELOPMENT BASED ON THE COMPLEX AND
TRANSITIONAL UPPER PATTERN TO BE IN PLACE.

THE PASSAGE OF THIS TROUGH ALSO SHUNTS THE UPPER RIDGE SOUTH OF THE
AREA AND WORKS TO PHASE THE CUTOFF LOW OVER THE LOWER GREAT LAKES
INTO A LONG WAVE TROUGH EXTENDING WELL UP INTO CANADA. THIS RESULTS
IN NORTHWEST FLOW OVER THE LOCAL AREA THROUGH THE WEEKEND. THIS WILL
ALLOW THE POSSIBILITY OF WEAK SHORTWAVES TO BRING SMALL PRECIP
CHANCES THROUGH THE WEEKEND. HAVE KEPT THIS PERIOD DRY FOR NOW AS
WILL HAVE TO WAIT TIL EXISTENCE AND TIMING OF THESE SHORTWAVES
BECOMES CLEAR.  ..MDB..

&&

.AVIATION.../00Z TAF CYCLE/
SLO MVG VORT APRCHG MVE DRIVING S AND GENERATING FEW SHWRS AND ISOL
TSTMS. THEY MAY BE VCNTY RWF TIL ARND 04Z. OTHW VRY MOIST LOW LVL
AM IS EXPECTED TO ONCE AGN DVLP AREAS FOG AT MOST TAF SITES.
WESTERN SITES MAY NOT GO QUITE AS LOW AS LAST NITE DUE TO MORE WIND.

&&

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

MDB/BAP

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
433 AM CDT TUE JUL 24 2007

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
250945-
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-
433 AM CDT TUE JUL 24 2007

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

.DAY ONE...TODAY AND TONIGHT

HOT AND HUMID CONDITIONS WILL OCCUR THIS AFTERNOON OVER WESTERN
AND PORTIONS OF CENTRAL MINNESOTA. AFTERNOON HIGHS WILL APPROACH
95 DEGREES WITH HEAT INDEX VALUES FROM 100 TO 105 DEGREES...MAINLY
ALONG AND WEST OF A LITTLE FALLS TO REDWOOD FALLS LINE.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

ANOTHER HOT AND HUMID AFTERNOON WILL OCCUR OVER WESTERN AND
CENTRAL MINNESOTA. AFTERNOON HIGHS WILL APPROACH 95 DEGREES WITH
HEAT INDEX VALUES AGAIN FROM 100 TO 105 DEGREES. A COLD FRONT WILL
MOVE ACROSS THE REGION THURSDAY AFTERNOON AND NIGHT. THUNDERSTORMS
ARE EXPECTED WITH THE FRONT AND A FEW OF THE STORMS MAY BE SEVERE
WITH LARGE HAIL AND DAMAGING WINDS. IN ADDITION...TORRENTIAL RAINS
ARE ALSO POSSIBLE DUE TO THE HIGH MOISTURE CONTENT IN THE
ATMOSPHERE.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY.

RAH