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WWUS20 KWNS 072346

SEL4

SPC WW 072346

TXZ000-080700-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 254

NWS STORM PREDICTION CENTER NORMAN OK

645 PM CDT MON MAY 7 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       THE TEXAS BIG BEND AND THE TRANS PECOS REGION OF TEXAS



EFFECTIVE THIS MONDAY NIGHT AND TUESDAY MORNING FROM 645 PM UNTIL

200 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 65 STATUTE

MILES EITHER SIDE OF A LINE FROM 40 MILES NORTH OF MARFA TEXAS TO

35 MILES SOUTH SOUTHWEST OF DRYDEN TEXAS.  FOR A COMPLETE

DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE

(WOUS64 KWNS WOU4).



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 253...



DISCUSSION...TSTMS/POSSIBLE SUPERCELLS EXPECTED TO DEVELOP N/NW

ACROSS REGION THROUGH THE EVENING AS LOW LEVEL MOISTURE INFLOW

STRENGTHENS AHEAD OF NEGATIVE TILT UPPER IMPULSE LIFTING N ACROSS

NRN MEXICO.  BACKED LOW LEVEL FLOW AND UPSLOPE COMPONENTS SUGGEST

POSSIBILITY FOR SUSTAINED ACTIVITY WITH LARGE HAIL AND POSSIBLE

TORNADOES.



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

550. MEAN STORM MOTION VECTOR 22025.





...CORFIDI

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