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URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 13

NWS STORM PREDICTION CENTER NORMAN OK

1005 PM CST TUE JAN 24 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       SOUTH CENTRAL TEXAS



EFFECTIVE THIS TUESDAY NIGHT AND WEDNESDAY MORNING FROM 1005 PM

UNTIL 500 AM CST.



TORNADOES...HAIL TO 2 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 85 STATUTE

MILES EAST AND WEST OF A LINE FROM 25 MILES NORTHWEST OF AUSTIN

TEXAS TO 35 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.



DISCUSSION...ASCENT IN ADVANCE OF A MIDLEVEL LOW OVER FAR W TX WILL

SPREAD EWD OVERNIGHT FROM THE RIO GRANDE TO S CENTRAL TX.  A

MOIST/UNSTABLE AIR MASS IS ALREADY IN PLACE ACROSS S TX...AND THE

CAP WILL WEAKEN SUFFICIENTLY TO SUPPORT THUNDERSTORM DEVELOPMENT

FROM THE LAREDO AREA NEWD.  MEANWHILE...LOW-LEVEL SHEAR IS

RELATIVELY STRONG ALONG THE CORRIDOR OF A 40+ KT LLJ /EFFECTIVE SRH

AOA 300 M2 PER S2/...WITH DEEP-LAYER SHEAR IN THE RANGE FAVORABLE

FOR SUPERCELLS.  A TORNADO OR TWO WILL BE POSSIBLE WITH THE INITIAL

/MORE DISCRETE/ STORMS EXPECTED TO FORM IN THE NEXT COUPLE OF HOURS

NEAR THE RIO GRANDE...ALONG WITH LARGE HAIL.  THE DAMAGING WIND RISK

WILL INCREASE SOME LATER TONIGHT AS STORMS EVOLVE INTO A LARGER

LINEAR MCS AND MOVE EWD.



AVIATION...TORNADOES AND 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 23030.





...THOMPSON

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