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812 

WWUS20 KWNS 182230

SEL5

SPC WW 182230

ILZ000-INZ000-OHZ000-190500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 345

NWS STORM PREDICTION CENTER NORMAN OK

630 PM EDT FRI JUN 18 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EASTERN ILLINOIS

       CENTRAL INDIANA

       NORTHWEST OHIO



EFFECTIVE THIS FRIDAY NIGHT AND SATURDAY MORNING FROM 630 PM

UNTIL 100 AM EDT.



HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 80

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



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60

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

DECATUR ILLINOIS TO 25 MILES SOUTH SOUTHEAST OF FINDLAY OHIO.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU5).



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 342...WW 343...WW 344...



DISCUSSION...SEVERE BOW ECHO WILL CONTINUE TO SPREAD EAST/SOUTHEAST

INTO VERY UNSTABLE AIRMASS ACROSS PARTS OF INDIANA AND ILLINOIS NEXT

FEW HOURS. FLANKING SWRN PORTION OF THIS BOW WAS MOVING OUT OF

EXISTING WATCHES AND DEEP CONVECTION WITH THIS PART OF THE SYSTEM

WILL HAVE THE POTENTIAL TO PRODUCE LARGE HAIL AS WELL AS DAMAGING

WIND GUSTS ACROSS ERN ILLINOIS AND CENTRAL INDIANA NEXT FEW HOURS.

APEX OF THE BOW...MOVING AT NEARLY 50KT...TRACKS INTO NORTHWEST OHIO

IN LESS THAN 3 HOURS. WHILE INSTABILITY DOES DIMINISH WITH EASTERN

EXTENT...EXPECT SYSTEM TO MAINTAIN SUFFICIENT STRUCTURE AND MOMENTUM

TO RESULT IN AN INCREASING POTENTIAL FOR DAMAGING WINDS INTO THIS

AREA LATER THIS EVENING.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM

MOTION VECTOR 29035.





...CARBIN

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