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245 

WWUS20 KWNS 231815

SEL2

SPC WW 231815

INZ000-MIZ000-OHZ000-LEZ000-LHZ000-240200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 342

NWS STORM PREDICTION CENTER NORMAN OK

215 PM EDT MON MAY 23 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN INDIANA

       SOUTHERN AND EASTERN LOWER MICHIGAN

       NORTHWEST OHIO

       LAKE ERIE

       LAKE HURON



EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 215 PM UNTIL

1000 PM EDT.



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 60

STATUTE MILES EAST AND WEST OF A LINE FROM 35 MILES NORTH

NORTHEAST OF MOUNT CLEMENS MICHIGAN TO 50 MILES SOUTH SOUTHWEST

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

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).



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 338...WW 339...WW

340...WW 341...



DISCUSSION...TSTMS ARE DEVELOPING ALONG COLD FRONT MOVING EWD

THROUGH REGION WITHIN AN UNCAPPED AND MODERATELY UNSTABLE AIR MASS

WITH MLCAPE OF 1500-2000 J/KG.  REGIONAL VWP DATA INDICATE THE

PRESENCE OF A 50-60 KT JET STREAK LOCATED IN THE 700-500 MB

LAYER...RESULTING IN MORE THAN SUFFICIENT VERTICAL SHEAR FOR

SUPERCELLS AND LINE SEGMENTS CAPABLE OF MAINLY DAMAGING WINDS AND

HAIL.



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 26030.





...MEAD

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