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000 

WWUS20 KWNS 190301

SEL9

SPC WW 190301

OHZ000-PAZ000-LEZ000-191000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 539

NWS STORM PREDICTION CENTER NORMAN OK

1100 PM EDT WED JUL 18 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN AND CENTRAL OHIO

       FAR NORTHWEST PENNSYLVANIA

       LAKE ERIE



EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 1100 PM

UNTIL 600 AM EDT.



HAIL TO 1 INCH 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 60 MILES WEST OF

FINDLAY OHIO TO 35 MILES SOUTH SOUTHEAST OF YOUNGSTOWN OHIO.  FOR

A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 531...WW 534...WW

536...WW 537...WW 538...



DISCUSSION...BAND OF STRONG/SVR TSTMS EXPECTED TO MOVE/DEVELOP ESE

INTO WW AREA AS CIRCULATION ASSOCIATED WITH NRN IL MCS CONTINUES

ESEWD.  WHILE LOW-LVL INSTABILITY WILL GRADUALLY DIMINISH

OVERNIGHT...PERSISTENT MOIST WSWLY LOW LVL FLOW BENEATH MODERATE WNW

MID/UPR LVL WINDS WILL CREATE SETUP SUPPORTIVE OF A FEW SUSTAINED

STORMS WITH SMALL-SCALE BOWING SEGMENTS/WET MICROBURST POTENTIAL.

FARTHER NE...ISOLD CELLS WITH A POTENTIAL FOR SVR HAIL MAY PERSIST

FOR AWHILE ACROSS LK ERIE/FAR NW PA...CLOSER TO STRONGER/COOLER NW

FLOW ALOFT.



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

TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS.

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

VECTOR 30035.





...CORFIDI

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