

393 

WWUS20 KWNS 182011

SEL8

SPC WW 182011

OKZ000-TXZ000-190300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 168

NWS STORM PREDICTION CENTER NORMAN OK

310 PM CDT SAT APR 18 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       CENTRAL OKLAHOMA

       NORTH CENTRAL TEXAS



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 310 PM UNTIL

1000 PM CDT.



HAIL TO 2.5 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 65

STATUTE MILES EAST AND WEST OF A LINE FROM 45 MILES EAST

NORTHEAST OF ALVA OKLAHOMA TO 60 MILES SOUTHEAST OF WICHITA FALLS

TEXAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).



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 165...WW 166...WW 167...



DISCUSSION...SCATTERED STRONG/SEVERE THUNDERSTORMS ARE EXPECTED TO

DEVELOP IN THE NEXT FEW HOURS OVER PARTS OF CENTRAL OK...AHEAD OF

APPROACHING MID LEVEL SHORTWAVE TROUGH OVER THE TX PANHANDLE.  STEEP

LAPSE RATES AND STRONG EFFECTIVE SHEAR WILL PROMOTE SUPERCELL

STRUCTURES CAPABLE OF VERY LARGE HAIL.  STORMS MAY BECOME MORE

LINEAR IN NATURE LATER THIS EVENING AS PRIMARY FORCING OVERSPREADS

REGION.



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

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 400. MEAN STORM

MOTION VECTOR 24035.





...HART

