

856 

WWUS20 KWNS 132017

SEL8

SPC WW 132017

OKZ000-TXZ000-140400-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 398

NWS STORM PREDICTION CENTER NORMAN OK

320 PM CDT SAT JUN 13 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       PART OF SOUTHWEST OKLAHOMA

       MUCH OF NORTHWEST TEXAS



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 320 PM UNTIL

1100 PM CDT.



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

GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 90 STATUTE

MILES NORTH AND SOUTH OF A LINE FROM 110 MILES WEST NORTHWEST OF

ABILENE TEXAS TO 5 MILES EAST SOUTHEAST OF WICHITA FALLS TEXAS.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU8).



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 397...



DISCUSSION...THUNDERSTORMS ARE DEVELOPING ON THE WESTERN EDGE OF A

VERY TO EXTREMELY UNSTABLE AIRMASS WITH MLCAPES AOA 4500 J/KG.

SHEAR SUFFICIENT TO SUPPORT SUPERCELLS WHICH COMBINED WITH THE

INSTABILITY WILL BE SUPPORTIVE OF VERY LARGE HAIL AND AT LEAST

ISOLATED TORNADOES.  STORMS WILL PROPAGATE INTO A PROGRESSIVELY MORE

FAVORABLE SHEAR ENVIRONMENT AS THEY MOVE ACROSS THE WATCH AREA.



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

SURFACE AND ALOFT TO 4 INCHES. EXTREME TURBULENCE AND SURFACE

WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO

600. MEAN STORM MOTION VECTOR 24020.





...HALES

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