

000 

WWUS20 KWNS 210932

SEL2

SPC WW 210932

IAZ000-MNZ000-211700-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 432

NWS STORM PREDICTION CENTER NORMAN OK

430 AM CDT THU JUN 21 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHEAST IOWA

       SOUTHERN MINNESOTA



EFFECTIVE THIS THURSDAY MORNING FROM 430 AM UNTIL NOON CDT.



HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 55

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 5 MILES NORTH OF

ORTONVILLE MINNESOTA TO 20 MILES EAST NORTHEAST OF ROCHESTER

MINNESOTA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).



REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE

FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH

AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR

THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS

AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY

DO PRODUCE TORNADOES.



OTHER WATCH INFORMATION...CONTINUE...WW 431...



DISCUSSION...SCTD TSTMS/SUPERCELLS EXPECTED TO DEVELOP ESE FROM THE

SD BORDER ALONG AND N OF STALLED FRONT AS INCREASING UPR

DIVERGENCE/MOISTURE OVERSPREAD REGION.  WIND PROFILES SUGGEST INFLOW

AIR WILL ORIGINATE OVER SD...WHERE AMPLE MOISTURE IS PRESENT TO

SUPPORT LARGE HAIL AND POSSIBLY LOCALLY DAMAGING WIND AS MOIST

UPDRAFTS PENETRATE STEEP LAPSE RATE PLUME IN SRN MN.  ACTIVITY IN

ERN END OF WATCH MAY CONSOLIDATE INTO SHORT SE-MOVING BANDS.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 30030.





...CORFIDI

