

792 

WWUS20 KWNS 252214

SEL9

SPC WW 252214

IAZ000-MNZ000-WIZ000-260600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 519

NWS STORM PREDICTION CENTER NORMAN OK

515 PM CDT WED JUL 25 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN IOWA

       SOUTHERN MINNESOTA

       SOUTHWEST WISCONSIN



EFFECTIVE THIS WEDNESDAY AFTERNOON AND THURSDAY MORNING FROM 515

PM UNTIL 100 AM 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 85

STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES WEST

SOUTHWEST OF DENISON IOWA TO 30 MILES NORTH NORTHWEST OF LA

CROSSE WISCONSIN.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 518...



DISCUSSION...TSTMS ARE EXPECTED TO INCREASE IN COVERAGE ALONG THE

COLD FRONT THIS EVENING AS REGION IS GLANCED BY A WEAK MIDLEVEL

IMPULSE MOVING INTO CNTRL/SRN MN.  THERMODYNAMIC ENVIRONMENT IS

CHARACTERIZED BY A HOT...MOIST BOUNDARY LAYER WITH MLCAPE OF

2500-3500 J/KG.  WHEN COUPLED WITH MODEST DEEP...WLY SHEAR...SETUP

WILL FAVOR MULTICELLS AND LINE SEGMENTS CAPABLE OF DAMAGING WINDS

AND LARGE HAIL.



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 28020.





...MEAD

