

540 

WWUS20 KWNS 150112

SEL4

SPC WW 150112

IAZ000-MNZ000-150800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 584

NWS STORM PREDICTION CENTER NORMAN OK

815 PM CDT TUE JUL 14 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL AND NORTHERN IOWA

       SOUTHEAST MINNESOTA



EFFECTIVE THIS TUESDAY NIGHT AND WEDNESDAY MORNING FROM 815 PM

UNTIL 300 AM CDT.



HAIL TO 2.5 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 75

STATUTE MILES EAST AND WEST OF A LINE FROM 30 MILES NORTH

NORTHEAST OF MASON CITY IOWA TO 70 MILES SOUTH OF FORT DODGE

IOWA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).



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 583...



DISCUSSION...THUNDERSTORMS HAVE BEGUN TO INTENSIFY ALONG A COLD

FRONT OVER NORTHWEST IA AND SOUTHWEST MN.  THESE STORMS WILL BECOME

MORE NUMEROUS THROUGH THE EVENING AND SPREAD EAST-SOUTHEASTWARD

ACROSS THE WATCH AREA.  SUPERCELLS CAPABLE OF LARGE HAIL AND

DAMAGING WINDS ARE EXPECTED.



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

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 28030.





...HART

