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961 

WWUS20 KWNS 232126

SEL4

SPC WW 232126

INZ000-MIZ000-OHZ000-LEZ000-LMZ000-240500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 524

NWS STORM PREDICTION CENTER NORMAN OK

525 PM EDT FRI JUL 23 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN INDIANA

       SOUTHERN LOWER MICHIGAN

       FAR NORTHWEST OHIO

       LAKE ERIE

       LAKE MICHIGAN



EFFECTIVE THIS FRIDAY AFTERNOON AND SATURDAY MORNING FROM 525 PM

UNTIL 100 AM EDT.



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 40

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 25 MILES SOUTHWEST

OF BENTON HARBOR MICHIGAN TO 15 MILES EAST NORTHEAST OF DETROIT

MICHIGAN.  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 521...WW 522...WW 523...



DISCUSSION...TSTMS HAVE RAPIDLY DEVELOPED THIS EVENING ALONG A W-E

ORIENTED LOW-LEVEL BAROCLINIC ZONE IN PLACE ACROSS SRN LOWER MI.

AMBIENT AIR MASS IS HOT AND QUITE MOIST WITH MLCAPE OF 2500-3500

J/KG.  MOREOVER...AREA VWPS INDICATE A BELT OF STRONG WLY FLOW /I.E.

35-50 KT/ IN THE 1-3 KM AGL LAYER WHICH IS RESULTING IN A STRONGLY

SHEARED KINEMATIC ENVIRONMENT.  AS SUCH...THE POTENTIAL WILL EXIST

FOR SPLITTING SUPERCELLS AND/OR BOWING LINE SEGMENTS WITH THE

PRIMARY THREAT BEING DAMAGING WIND GUSTS.

AN ADDITIONAL CONVECTIVE SYSTEM CURRENTLY EVOLVING OVER ERN IA/NWRN

IL WILL RAPIDLY PROGRESS EWD INTO NRN IND LATER THIS EVENING.  HERE

TOO...ENVIRONMENT WILL FAVOR DAMAGING WIND GUSTS ALONG MCS TRACK.



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 550. MEAN STORM

MOTION VECTOR 27035.





...MEAD

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