

114 

WWUS20 KWNS 011938

SEL8

SPC WW 011938

IAZ000-ILZ000-INZ000-LMZ000-020300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 318

NWS STORM PREDICTION CENTER NORMAN OK

240 PM CDT MON JUN 1 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SMALL PART OF EASTERN IOWA

       NORTHERN ILLINOIS

       NORTHERN INDIANA

       LAKE MICHIGAN



EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 240 PM UNTIL

1000 PM 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 65

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 30 MILES SOUTH

SOUTHWEST OF MOLINE ILLINOIS TO 20 MILES EAST SOUTHEAST OF FORT

WAYNE INDIANA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).



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.



DISCUSSION...STORMS WILL INCREASE ALONG AND JUST S OF E/W BOUNDARY

ACROSS NRN IN AND IL.  WITH AN UNSTABLE AND VIRTUALLY UNCAPPED WARM

SECTOR ALONG WITH 30-40KT OF SHEAR...STORMS WILL INCREASE TO SEVERE

LEVELS AS THEY SPREAD DEVELOP E/SEWD THRU THE AFTERNOON.



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 27030.





...HALES

