

000 

WWUS20 KWNS 091726

SEL5

SPC WW 091726

MDZ000-OHZ000-PAZ000-WVZ000-100000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 575

NWS STORM PREDICTION CENTER NORMAN OK

125 PM EDT THU AUG 9 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EXTREME WESTERN MARYLAND

       OHIO

       WESTERN PENNSYLVANIA

       NORTHERN WEST VIRGINIA



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 125 PM UNTIL

800 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 NORTH AND SOUTH OF A LINE FROM 40 MILES NORTH OF

DAYTON OHIO TO 15 MILES EAST OF LATROBE PENNSYLVANIA.  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 573...WW 574...



DISCUSSION...STORMS HAVE BEEN INTENSIFYING ALONG A LOW LEVEL BNDRY

ACROSS NERN OH...AND THERE IS POTENTIAL FOR NEW STORMS TO DEVELOP

WWD ACROSS PARTS OF WRN OH IN ADVANCE OF SEVERAL MCV FEATURES MOVING

ACROSS SRN LOWER MI AND INDIANA.  RELATIVELY CLEAR SKIES HAVE

ALLOWED TEMPERATURES TO WARM TO NEAR 90F...AND WITH DEW POINTS IN

THE LOW 70S AIR MASS IS MODERATELY UNSTABLE WITH MLCAPE OF 1500-2500

J/KG.  WESTERLY MID LEVEL WINDS OF 30-40 KT ARE CONTRIBUTING TO

SUFFICIENT DEEP LAYER SHEAR TO ENHANCE STORM ORGANIZATION.  WARM MID

LEVEL TEMPERATURES/HIGH FREEZING LEVELS MAY TEMPER HAIL THREAT BUT

STEEP LOW LEVEL LAPSE RATES WILL ENHANCE THREAT FOR DAMAGING WIND

GUSTS.



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 27025.





...WEISS

