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614 

WWUS20 KWNS 200133

SEL8

SPC WW 200133

INZ000-OHZ000-200600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 158

NWS STORM PREDICTION CENTER NORMAN OK

935 PM EDT TUE APR 19 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN INDIANA

       NORTHWEST OHIO



EFFECTIVE THIS TUESDAY NIGHT AND WEDNESDAY MORNING FROM 935 PM

UNTIL 200 AM EDT.



HAIL TO 1.5 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 75

STATUTE MILES EAST AND WEST OF A LINE FROM 50 MILES NORTH OF FORT

WAYNE INDIANA TO 55 MILES SOUTHWEST 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.



OTHER WATCH INFORMATION...CONTINUE...WW 154...WW 155...WW

156...WW 157...



DISCUSSION...WELL-DEVELOPED BOW ECHO AND COMMA HEAD WILL CONTINUE TO

MOVE QUICKLY ENEWD ALONG AND N OF THE SURFACE WARM FRONT/SURFACE

LOW.  DESPITE A STABLE BOUNDARY LAYER...STEEP LAPSE RATES AND

MODERATE INSTABILITY ALOFT...ALONG WITH HIGH-MOMENTUM FLOW...WILL

SUPPORT A THREAT OF DAMAGING WINDS.  AT THIS TIME...IT APPEARS THAT

ANY TORNADO THREAT WILL BE LIMITED BY THE COOL AIR NEAR THE

SURFACE...WITH THE ONLY POTENTIAL EXCEPTION IN THE GRANT-JAY COUNTY

AREA CLOSE TO THE WARM FRONT.



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

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70

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

MOTION VECTOR 25050.





...THOMPSON

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