

934 

WWUS20 KWNS 221849

SEL6

SPC WW 221849

OKZ000-TXZ000-230200-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 326

NWS STORM PREDICTION CENTER NORMAN OK

150 PM CDT SUN MAY 22 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       CENTRAL OKLAHOMA

       NORTH-CENTRAL TEXAS



EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 150 PM UNTIL 900

PM CDT.



TORNADOES...HAIL TO 4 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE

MILES EAST AND WEST OF A LINE FROM 25 MILES NORTH NORTHWEST OF

MCALESTER OKLAHOMA TO 40 MILES SOUTH SOUTHWEST OF MINERAL WELLS

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

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.



OTHER WATCH INFORMATION...CONTINUE...WW 321...WW 322...WW

323...WW 324...WW 325...



DISCUSSION...ISOLATED STORM DEVELOPMENT IS ANTICIPATED ALONG THE

DRYLINE BY LATE AFTERNOON AS CONTINUED DAYTIME HEATING ERODES

REMAINING CONVECTIVE INHIBITION.  18Z FWD SOUNDING SHOWED THAT THE

WARM SECTOR IS ALREADY EXTREMELY UNSTABLE WITH MLCAPE VALUES

APPROACHING 5000 J/KG.  THIS DEGREE OF INSTABILITY COUPLED WITH

35-40 KT OF DEEP-LAYER SHEAR WILL SUPPORT INTENSE SUPERCELLS CAPABLE

OF DESTRUCTIVE HAIL.  THE THREAT FOR TORNADOES WILL INCREASE THIS

EVENING AS LOW-LEVEL SHEAR INTENSIFIES IN RESPONSE TO THE

DEVELOPMENT OF A SLY LLJ.



AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL

SURFACE AND ALOFT TO 4 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

500. MEAN STORM MOTION VECTOR 27020.





...MEAD

