

867 

WWUS20 KWNS 162314

SEL7

SPC WW 162314

SCZ000-170300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 437

NWS STORM PREDICTION CENTER NORMAN OK

715 PM EDT TUE JUN 16 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL SOUTH CAROLINA



EFFECTIVE THIS TUESDAY EVENING FROM 715 PM UNTIL 1100 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 45

STATUTE MILES EITHER SIDE OF A LINE FROM 45 MILES NORTHEAST OF

COLUMBIA SOUTH CAROLINA TO 40 MILES WEST OF ORANGEBURG SOUTH

CAROLINA.  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.



OTHER WATCH INFORMATION...CONTINUE...WW 433...WW 434...WW

435...WW 436...



DISCUSSION...ISOLATED STORMS...SOME WITH SUPERCELL STRUCTURE...WILL

LIKELY CONTINUE TO SPREAD SSEWD ALONG THE IMMEDIATE COOL SIDE OF A

N-S BOUNDARY ACROSS CENTRAL SC.  STRONG SURFACE HEATING EARLIER IN

THE AFTERNOON WILL HELP MAINTAIN SUBSTANTIAL SURFACE-BASED

INSTABILITY INTO THE EARLY OVERNIGHT HOURS...WHILE VERTICAL SHEAR IS

SOMEWHAT ENHANCED ALONG THE WWD MOVING BOUNDARY.  LARGE HAIL AND

ISOLATED DAMAGING WINDS SHOULD BE THE MAIN SEVERE THREATS.



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 33015.





...THOMPSON

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