

698 

WWUS20 KWNS 130242

SEL4

SPC WW 130242

OKZ000-130800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 774

NWS STORM PREDICTION CENTER NORMAN OK

945 PM CDT FRI AUG 12 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       OKLAHOMA



EFFECTIVE THIS FRIDAY NIGHT AND SATURDAY MORNING FROM 945 PM

UNTIL 300 AM CDT.



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 50

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 20 MILES SOUTH

SOUTHWEST OF CLINTON OKLAHOMA TO 15 MILES EAST OF MUSKOGEE

OKLAHOMA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).



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 773...



DISCUSSION...STRONG SQUALL LINE OVER WESTERN AND NORTHERN OK WILL

TRACK SOUTHEASTWARD ACROSS THE WATCH AREA THROUGH THE EARLY MORNING

HOURS.  FAVORABLE LOW/MID LEVEL LAPSE RATES AND STRONG DOWNDRAFT

POTENTIAL WILL AID SOUTHERN END OF LINE...WHILE MESOSCALE

ORGANIZATION AND STRONG WINDS ALOFT MAINTAIN THE NORTHERN END.

DAMAGING WINDS ARE THE MAIN THREAT WITH THESE STORMS.



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 29030.





...HART

