

198 

WWUS20 KWNS 202304

SEL3

SPC WW 202304

ARZ000-MOZ000-210500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 793

NWS STORM PREDICTION CENTER NORMAN OK

605 PM CDT SAT AUG 20 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN ARKANSAS

       SOUTHERN MISSOURI



EFFECTIVE THIS SATURDAY NIGHT FROM 605 PM UNTIL MIDNIGHT CDT.



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 65

STATUTE MILES EAST AND WEST OF A LINE FROM 55 MILES NORTH

NORTHWEST OF WEST PLAINS MISSOURI TO 40 MILES WEST SOUTHWEST OF

BATESVILLE ARKANSAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU3).



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...SCATTERED INTENSE THUNDERSTORMS HAVE DEVELOPED ACROSS

SOUTHERN MO AND NORTHERN AR.  THESE STORMS WILL PERSIST ACROSS THE

WATCH AREA FOR MUCH OF THE EVENING...IN AN ENVIRONMENT CHARACTERIZED

BY MLCAPE VALUES OF 3000-4000 J/KG AND 20-30 KNOTS OF EFFECTIVE

SHEAR.  THE STRONGEST CELLS WILL BE CAPABLE OF LARGE HAIL AND

DAMAGING WINDS.



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 550. MEAN STORM

MOTION VECTOR 27025.





...HART

