Hail and Damaging Winds in Minnesota, July 3 to 4, 2003

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
355 PM CDT THU JUL 3 2003

PER SPC MESOSCALE ANALYSIS PAGE...CAP HOLDING OVER ALMOST ENTIRE
AREA.  SPECIAL 18Z MPX SOUNDING SHOWD WARM TEMPS IN LAYER FM 7H TO
8H.  CIN HAS LOWERED TO AROUND -50 J/KG IN WI PTN OF CWA...BUT
FORCING MECHANISM LACKING WITH LIGHT LOW LEVEL WIND FLOW.  HENCE
SHOULD BE A QUIET EVE AS S/W TROF IN ERN NODAK/NWRN MN DAMPENING OUT
AND NOT RESULTING IN ANYTHING SIGNIFICANT.  ALSO AIRMASS MORE STABLE
IN THIS AREA AS WELL.  GFS AND ETA COMING INTO AGREEMENT ON S/W
TROUGH IN WRN NE/NERN CO WL ACT AS MAIN SYNOPTIC SCALE FORCING LATER
TNGT AND FRI MRNG AS IT PUSHES EAST/NORTHEAST THROUGH TIGHTENING
BAROCLINIC ZONE.  GOOD AGREEMENT ON RIGHT REAR QUADRANT OF UPR JET
ON BOTH SHORT TERM MODELS WITH IMPRESSIVE UPR LEVEL DIVERGENCE
PUSHING THRU SRN MN DURING THIS PERIOD.  NOSE OF LOW LEVEL JET INTO
NRN IA/SRN MN AS WELL WITH STRONG MOISTURE FLUX CONVERGENCE.
ELEVATED LAPSE RATES APPROACH 8 DEGREES LATE TNGT AS WELL.  SYNOPTIC
ENVIRONMENT COULD BE FAVORING BOW ECHO/DERECHO IN PARTS OF ERN
NE/SERN SODAK/IA...PSBLY CLIPPING SRN MN LATE TNGT.  OF COURSE THIS
WL MOST LKLY MINIMIZE POPS FARTHER NORTH.

WEAKENING SFC FRONT ACRS NRN CWA FRI AFTN WITH WK INSTABILITY...SO
KEPT LOW POPS IN THIS AREA.  OTHERWISE NEXT THREAT FOR SIGGY PRECIP
SATURDAY NGT INTO SUN WHEN STRONG THETA-E ADVECTION ACCOMPANIES LOW
LEVEL JET INTO NRN IA/SRN MN.  GFS MUCH MORE AGGRESSIVE ON STRONG
FORCING OVR ETA...SO WL NEED TO WATCH NEXT SEVERAL RUNS ON HOWS THIS
PLAYS OUT.

UKMO/ECMWF/CANADIAN SHOWING DRIER NWLY FLOW FOR MONDAY WHILE GFS
SHOWING LINGERING BAROCLINIC ZONE VCNTY OF NRN IA.  DPROG/DT SHOWS
LACK OF CONSISTENCY WITH GFS...SO WL CONT DRY FORECAST FOR NOW.

.MSP...NONE.

MBK

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-041000-

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1200 PM CDT THU JUL 3 2003

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

.DAY ONE...TODAY AND TONIGHT

A STRONG COMPLEX OF THUNDERSTORMS OVERNIGHT ACROSS MUCH OF CENTRAL
MINNESOTA AND WEST CENTRAL WISCONSIN HAS GREATLY STABILIZED THE
ATMOSPHERE ACROSS THE AREA...AND HAS ALLOWED A WEAK COLD FRONT TO
DRIFT THROUGH ALL BUT FAR SOUTH CENTRAL MINNESOTA INTO WEST CENTRAL
WISCONSIN. DRIER AIR WILL SLOWLY FILTER INTO MINNESOTA AND WESTERN
WISCONSIN THIS AFTERNOON BEHIND THIS BOUNDARY. THEREFORE...FORECAST
INSTABILITY AND WINDS WHICH WOULD HAVE BEEN CONDUCIVE TO SIGNIFICANT
SEVERE THUNDERSTORM DEVELOPMENT...HAVE BEEN PUSHED SOUTH AND EAST OF
THE AREA. ALSO...DEEP WARM AIR ALOFT WILL INHIBIT THUNDERSTORM
GROWTH POTENTIAL THROUGH MUCH OF THE AFTERNOON. THE MODERATE RISK OF
SEVERE THUNDERSTORMS HAS BEEN DOWNGRADED BY THE STORM PREDICTION
CENTER...TO A SLIGHT RISK WHICH STILL ENCOMPASSES ALL OF CENTRAL AND
SOUTHERN MINNESOTA AND WESTERN WISCONSIN.

DESPITE THE DECREASE IN EXPECTED COVERAGE OF SEVERE WEATHER...STRONG
TO SEVERE THUNDERSTORMS MAY STILL DEVELOP IN TWO AREAS.
FIRST...ISOLATED SEVERE THUNDERSTORMS MAY STILL DEVELOP ALONG AND
JUST BEHIND THE SLOWLY MOVING COLD FRONT THIS AFTERNOON AND EVENING
FROM FAR SOUTH CENTRAL MINNESOTA TOWARDS EAU CLAIRE. THESE STORMS
WOULD POSE A DAMAGING WIND AND LARGE HAIL THREAT...AND AN ISOLATED
BRIEF TORNADO COULD NOT BE RULED OUT. THE MORE LIKELY SCENARIO WOULD
OCCUR LATER TONIGHT...MAINLY AFTER MIDNIGHT...AS A DISTURBANCE
MOVING OUT OF THE INTERMOUNTAIN WEST MAY INITIATE A COMPLEX OF
THUNDERSTORMS IN EASTERN SOUTH DAKOTA...MOVING QUICKLY THROUGH
SOUTHERN MINNESOTA INTO WESTERN WISCONSIN BY SUNRISE FRIDAY. THESE
STORMS WOULD POSE A DAMAGING WIND THREAT...AS WELL AS LARGE HAIL AND
VERY HEAVY RAINFALL.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

A SLIGHT RISK OF SEVERE WEATHER IS INDICATED FOR FRIDAY OVER EAST
CENTRAL AND SOUTHERN MINNESOTA AS WELL AS ALL OF WEST CENTRAL
WISCONSIN.

STORMS WILL POSSIBLY DEVELOP AGAIN FRIDAY AFTERNOON ALONG THE
STALLED FRONTAL BOUNDARY IN IOWA. THESE STORMS COULD AFFECT SOUTHERN
AND EAST CENTRAL MINNESOTA...AND WEST CENTRAL WISCONSIN LATE IN THE
AFTERNOON OR EVENING.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION MAY BE NEEDED LATE THIS AFTERNOON AND
OVERNIGHT.

BINAU