Severe Thunderstorm Warning 136, NWS Twin Cities, MN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
300 AM CDT MON AUG 25 2003

FORECAST PROBLEM INVOLVE THUNDERSTORMS CHANCES TODAY TONIGHT...AND
AGAIN WEDNESDAY NIGHT AND THURSDAY...

SCATTERED THUNDERSTORMS MOVING EASTWARD ACROSS SOUTHERN MINNESOTA
SOUTH OF A GRANITE FALLS TO RED WING LINE ARE ELEVATED
(AT 0745Z) AND ASSOCIATED WITH 850 MB THETA E- ADVECTION. THESE ARE
EXPECTED TO WEAKEN AFTER DAYBREAK AS LOW LVL JET WEAKENS DIURNALLY.
00Z ETA BUFKIT SOUNDINGS SHOW AN IMPRESSIVE CAP ACROSS THE CWA THIS
AFTERNOON. CIN VALUES (00Z ETA) DROP BELOW -50 J/KG BY 00Z TUE OVER
WEST CENTRAL MN...BUT A LOOK AT 925 MB ETA WINDS FOR SAME TIME
SUGGEST VERY WEAK CONVERGENCE ALONG INCOMING FRONTAL ZONE. NORTH OF
OUR CWA IMPRESSIVE 300 MB DIVERGENCE 00Z TUE ASSOCIATED WITH COUPLED
JET STRUCTURE. DINES COMPENSATION MAY RESULT IN SUBSIDENCE OVER CWA
LATER THIS AFTERNOON AND EVENING. WOULD DROP POPS BELOW 30 PERCENT
IF IT WERE NOT FOR THE K INDEX ABOVE 40 ACROSS MUCH OF OUR CWA TODAY
INTO THIS EVENING.

AFTER TODAY/THIS EVENING...NEXT CHANCE FOR RAIN IS WEDNESDAY NIGHT
INTO THURSDAY. LEFT GRIDS PRETTY MUCH IN TACT...LATER SHIFTS CAN
RAISE POPS. DID BEEF UP CONDITIONAL QPF VALUES. VERY GOOD RUN TO RUN
CONTINUITY ON GFS FOR WEDNESDAY NIGHT AND THURSDAY REGARDING
LOCATION OF SURFACE TROUGH...700 MB TROUGH...AND QPF LOCATION AND
AMOUNTS.

.MSP...NONE.

NAISTAT

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-261100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
500 AM CDT MON AUG 25 2003

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

.DAY ONE...TODAY AND TONIGHT
A SIGHT RISK OF SEVERE THUNDERSTORMS IS EXPECTED ACROSS MUCH OF
CENTRAL AND SOUTHERN MINNESOTA INTO WEST CENTRAL WISCONSIN...MAINLY
THIS AFTERNOON AND INTO THE EVENING.  A FRONTAL BOUNDARY OVER
NORTHERN IOWA WILL MOVE NORTH AS A WARM FRONT INTO SOUTHERN
MINNESOTA TODAY.  MEANWHILE...A COLD FRONT WILL ADVANCE ACROSS
THE EASTERN DAKOTAS INTO WESTERN MINNESOTA BY LATE AFTERNOON.
SCATTERED THUNDERSTORMS WILL BE ONGOING OVER MUCH OF SOUTHERN
MINNESOTA EARLY THIS MORNING...BUT SHOULD WANE FROM WEST TO EAST
DURING BY MID TO LATE MORNING OVER MUCH OF THE SOUTH. SOME
HAIL...HEAVY DOWNPOURS AND GUSTY WINDS ARE EXPECTED TO OCCUR WITH
THIS ACTIVITY.  AS THE FRONT OVER IOWA LIFTS NORTHEAST OVER SOUTHERN
MINNESOTA DURING THE AFTERNOON...THUNDERSTORM REDEVELOPMENT IS
ANTICIPATED.  AS THE COLD FRONT SWEEPS INTO THE WEST THIS
AFTERNOON...THUNDERSTORMS ARE ALSO EXPECTED TO DEVELOP ALONG THIS
FRONT.   DAMAGING WINDS AND LARGE HAIL WILL BE THE PRIMARY THREAT
WITH THE AFTERNOON STORMS...BUT AN ISOLATED TORNADO MAY BE POSSIBLE
IN THE VICINITY OF THE WARM FRONT AS IT LIFTS INTO SOUTHERN
MINNESOTA.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON INTO TONIGHT.