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014 

WWUS20 KWNS 302311

SEL8

SPC WW 302311

OKZ000-TXZ000-310600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 68

NWS STORM PREDICTION CENTER NORMAN OK

610 PM CDT SAT MAR 30 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST AND SOUTH-CENTRAL OKLAHOMA

       NORTH-CENTRAL TEXAS



EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 610 PM

UNTIL 100 AM 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 55

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

OF WICHITA FALLS TEXAS TO 40 MILES SOUTHEAST OF DURANT OKLAHOMA.

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 66...WW 67...



DISCUSSION...TSTMS ARE DEVELOPING WITHIN A ZONE OF WEAK PRE-FRONTAL

CONVERGENCE OVER SWRN AND S-CNTRL OK WHERE TEMPERATURES HAVE WARMED

TO AROUND 80 F.  MODEL-DERIVED SOUNDINGS INDICATE THAT THE PRESENCE

OF A RELATIVELY MOIST BOUNDARY LAYER AND STEEP LOW TO MIDLEVEL LAPSE

RATES ARE RESULTING IN A MODERATELY UNSTABLE ENVIRONMENT WITH MLCAPE

VALUES OF 1500-2000 J/KG.  WHEN COUPLED WITH 35-40 KT OF DEEP NWLY

SHEAR...THE SETUP WILL BE SUPPORTIVE OF SUPERCELLS CAPABLE OF LARGE

HAIL /SOME EXCEEDING TWO INCHES IN DIAMETER/ AND LOCALLY DAMAGING

WIND GUSTS.  EXPECT MATURE STORMS TO MOVE SSEWD ACROSS THE RED RIVER

INTO N-CNTRL TX LATER THIS EVENING INTO TONIGHT.



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 500. MEAN STORM

MOTION VECTOR 32020.





...MEAD

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