

289 

WWUS20 KWNS 202139

SEL3

SPC WW 202139

ARZ000-OKZ000-TXZ000-210500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 893

NWS STORM PREDICTION CENTER NORMAN OK

340 PM CST SUN NOV 20 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST ARKANSAS

       EXTREME SOUTHEAST OKLAHOMA

       NORTH CENTRAL AND NORTHEAST TEXAS



EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 340 PM UNTIL

1100 PM CST.



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 60

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 30 MILES WEST OF

WACO TEXAS TO 35 MILES EAST OF DE QUEEN 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 THUNDERSTORMS HAVE BEGUN TO FORM OVER NORTH

CENTRAL TX AHEAD OF AN APPROACHING UPPER TROUGH.  AMPLE LOW LEVEL

MOISTURE AND SUFFICIENT CAPE...COUPLED WITH STRONG WINDS

ALOFT...WILL PROMOTE ORGANIZED OR EVEN SUPERCELL STORMS THROUGH THE

EVENING.  LOW LEVEL VERTICAL SHEAR IS NOT PARTICULARLY STRONG

SUGGESTING THE TORNADO THREAT IS REDUCED.  HOWEVER...STRONG UPDRAFTS

AND STEEP MID LEVEL LAPSE RATES WILL FAVOR THE RISK OF LARGE HAIL IN

STRONGER STORMS.



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 450. MEAN STORM

MOTION VECTOR 24030.





...HART

