

000 

WWUS20 KWNS 250340

SEL3

SPC WW 250340

TXZ000-251100-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 183

NWS STORM PREDICTION CENTER NORMAN OK

1040 PM CDT TUE APR 24 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       CENTRAL AND SOUTH CENTRAL TEXAS



EFFECTIVE THIS TUESDAY NIGHT AND WEDNESDAY MORNING FROM 1040 PM

UNTIL 600 AM CDT.



TORNADOES...HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE

MILES EAST AND WEST OF A LINE FROM 40 MILES NORTH OF AUSTIN TEXAS

TO 25 MILES WEST SOUTHWEST OF LAREDO TEXAS.  FOR A COMPLETE

DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE

(WOUS64 KWNS WOU3).



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...THIS TORNADO WATCH REPLACES TORNADO

WATCH NUMBER 179. WATCH NUMBER 179 WILL NOT BE IN EFFECT AFTER

1040 PM CDT. CONTINUE...WW 180...WW 181...WW 182...



DISCUSSION...INTENSE THUNDERSTORMS CONTINUE INVOF THE RIO GRANDE

RIVER LATE THIS EVENING WHERE AIR MASS IS VERY UNSTABLE.  MODERATE

TO STRONGLY UNSTABLE AIR MASS AND INTENSE LOW-DEEP LAYER SHEAR WILL

PERSIST ACROSS WW OVERNIGHT IN ADVANCE OF APPROACHING UPPER LOW AND

SURFACE COLD FRONT.  THIS WILL SUPPORT THREAT OF SEVERE

THUNDERSTORMS/SUPERCELLS...INCLUDING TORNADOES...WITH STORMS

DEVELOPING OVER THIS REGION OVERNIGHT.



AVIATION...TORNADOES AND 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 24035.





...EVANS

