

945 

WWUS20 KWNS 151753

SEL7

SPC WW 151753

INZ000-KYZ000-MIZ000-OHZ000-LEZ000-LHZ000-160100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 617

NWS STORM PREDICTION CENTER NORMAN OK

155 PM EDT SUN AUG 15 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHEAST INDIANA

       FAR NORTHERN KENTUCKY

       SOUTHEAST LOWER MICHIGAN

       WESTERN AND CENTRAL OHIO

       LAKE ERIE

       LAKE HURON



EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 155 PM UNTIL 900

PM 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 60

STATUTE MILES EAST AND WEST OF A LINE FROM 30 MILES EAST

SOUTHEAST OF CINCINNATI OHIO TO 50 MILES NORTHEAST OF TOLEDO

OHIO.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).



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.



DISCUSSION...DEVELOPING TSTMS ARE EXPECTED TO INCREASE IN COVERAGE

AND INTENSITY THIS AFTERNOON IN ADVANCE OF LARGE-SCALE UPPER TROUGH

AND ASSOCIATED COLD FRONT.  PRE-FRONTAL AIR MASS IS QUITE MOIST WITH

DEW POINTS IN THE 70S...AND WHEN COUPLED WITH STRONG DIABATIC

HEATING...EXPECT MLCAPE TO APPROACH 2000-3000 J/KG LATER TODAY.

STRENGTHENING MID AND HIGH-LEVEL WIND FIELD IN CONJUNCTION WITH

UPPER TROUGH IS RESULTING IN 40-50 KT OF DEEP WLY SHEAR...SUPPORTIVE

OF SUPERCELLS AND BOWING STRUCTURES CAPABLE OF DAMAGING WINDS AND

HAIL.



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 28030.





...MEAD

