

129 

WWUS20 KWNS 211932

SEL1

SPC WW 211932

OKZ000-TXZ000-220300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 701

NWS STORM PREDICTION CENTER NORMAN OK

235 PM CDT THU OCT 21 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       PARTS OF SOUTHWEST OKLAHOMA

       PARTS OF WESTERN TEXAS



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 235 PM UNTIL

1000 PM 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 60

STATUTE MILES EAST AND WEST OF A LINE FROM 50 MILES NORTHWEST OF

ALTUS OKLAHOMA TO 30 MILES SOUTH OF FORT STOCKTON TEXAS.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU1).



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...AIR MASS CONTINUES TO DESTABILIZE AHEAD OF THE OUTFLOW

FROM MORNING MCS AND IN ADVANCE OF THE AZ UPPER LOW. WITH MLCAPES

NOW AROUND 1500 J/KG ALONG WITH INCREASINGLY FAVORABLE DEEP LAYER

SHEAR WITH APPROACH OF JET MAX OVER NRN MEXICO...STRONG/SEVERE

THUNDERSTORMS SHOULD DEVELOP ACROSS THE WATCH AREA THRU THE

REMAINDER OF THE AFTERNOON.  CONDITIONS FAVORABLE FOR SUPERCELLS

WHICH WOULD ENHANCE BOTH LARGE HAIL AND WIND DAMAGE POTENTIAL.



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 500. MEAN STORM

MOTION VECTOR 24030.





...HALES

