

339 

WWUS20 KWNS 171251

SEL9

SPC WW 171251

TXZ000-171800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 159

NWS STORM PREDICTION CENTER NORMAN OK

750 AM CDT FRI APR 17 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       PORTIONS OF CENTRAL TEXAS



EFFECTIVE THIS FRIDAY MORNING AND AFTERNOON FROM 750 AM UNTIL 100

PM 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 65

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

SOUTHWEST OF HONDO TEXAS TO 40 MILES NORTHEAST OF TEMPLE TEXAS.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU9).



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...BAND OF STRONG/LOCALLY-SEVERE STORMS CONTINUES MOVING

EWD ACROSS CENTRAL TX...WITH SOME INCREASE IN CONVECTIVE INTENSITY

NOTED OVER THE PAST HOUR.  WITH CONTINUED NWWD ADVECTION OF

LOW-LEVEL MOISTURE AND SOME MODEST DIURNAL HEATING...ADDITIONAL

DESTABILIZATION SHOULD SUPPORT FURTHER STORM

DEVELOPMENT/INTENSIFICATION.  WITH VEERING/SHEAR SUPPORTIVE OF STORM

ROTATION -- SUPERCELL STORMS ARE EXPECTED -- BOTH WITHIN THE MAIN

CONVECTIVE BAND AND WITH MORE ISOLATED/CELLULAR DEVELOPMENT

OCCURRING AHEAD OF THIS BAND.  EXPECT LARGE HAIL AND

LOCALLY-DAMAGING WINDS WITH STRONGER STORMS.



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 25030.





...GOSS

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