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460 

WWUS20 KWNS 201901

SEL8

SPC WW 201901

IAZ000-ILZ000-KSZ000-MOZ000-LMZ000-210100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 628

NWS STORM PREDICTION CENTER NORMAN OK

200 PM CDT FRI AUG 20 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHEAST IOWA

       NORTHERN ILLINOIS

       NORTHEASTERN KANSAS

       NORTHERN MISSOURI

       LAKE MICHIGAN



EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 200 PM UNTIL 800

PM CDT.



HAIL TO 1.5 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 70

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 45 MILES WEST

SOUTHWEST OF CHILLICOTHE MISSOURI TO 60 MILES NORTHEAST OF

MARSEILLES ILLINOIS.  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.



OTHER WATCH INFORMATION...CONTINUE...WW 627...



DISCUSSION...MULTICELL STORMS AS WELL AS A FEW STORMS WITH MARGINAL

SUPERCELL CHARACTERISTICS WILL CONTINUE DEVELOPING EWD THROUGH NRN

MO...SERN IA INTO NRN IL AHEAD OF A PROGRESSIVE SHORTWAVE TROUGH.

POTENTIAL EXISTS FOR STORMS TO INTENSIFY AS THE BOUNDARY LAYER

DESTABILIZES WITH 2000-3000 J/KG MLCAPE ALREADY IN PLACE. ISOLATED

DAMAGING WIND AND LARGE HAIL WILL BE POSSIBLE THROUGH EARLY EVENING.



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

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 26035.





...DIAL

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