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024 

WWUS20 KWNS 270745

SEL7

SPC WW 270745

TXZ000-271500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 197

NWS STORM PREDICTION CENTER NORMAN OK

245 AM CDT MON APR 27 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WEST-CENTRAL TEXAS



EFFECTIVE THIS MONDAY MORNING FROM 245 AM UNTIL 1000 AM 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 75

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

ABILENE TEXAS TO 50 MILES WEST SOUTHWEST OF JUNCTION TEXAS.  FOR

A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU7).



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...THIS SEVERE THUNDERSTORM WATCH REPLACES

TORNADO WATCH NUMBER 196. WATCH NUMBER 196 WILL NOT BE IN EFFECT

AFTER 245 AM CDT.



DISCUSSION...ELEVATED TSTMS CONTINUE TO INCREASE IN COVERAGE AND

INTENSITY EARLY THIS MORNING FROM THE PERMIAN BASIN INTO EDWARDS

PLATEAU REGION.  THIS ACTIVITY IS LIKELY BEING DRIVEN BY AN ENHANCED

ZONE OF LOW-LEVEL ASCENT FOCUSED ALONG A RESIDUAL OUTFLOW BOUNDARY.

THE COMBINATION OF STEEP MIDLEVEL LAPSE RATES...MUCAPE OF 1500-2000

J/KG AND 40-50 KT OF EFFECTIVE BULK SHEAR WILL CONTINUE TO SUPPORT

EMBEDDED SUPERCELL STRUCTURES WITH THE MAIN THREAT BEING LARGE HAIL.



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 24020.





...MEAD/CORFIDI

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