

656 

WWUS20 KWNS 111935

SEL8

SPC WW 111935

TXZ000-120300-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 378

NWS STORM PREDICTION CENTER NORMAN OK

235 PM CDT THU JUN 11 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       NORTHWEST AND CENTRAL TEXAS



EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 235 PM UNTIL

1000 PM 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 75 STATUTE

MILES EAST AND WEST OF A LINE FROM 50 MILES EAST NORTHEAST OF

LUBBOCK TEXAS TO 55 MILES SOUTH SOUTHWEST OF TEMPLE TEXAS.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU8).



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 375...WW 376...WW 377...



DISCUSSION...STRONG SURFACE HEATING/DESTABILIZATION IS SUPPORTING

INITIAL THUNDERSTORM DEVELOPMENT NEAR THE INTERSECTION OF THE

DRYLINE AND A NW-SE OUTFLOW BOUNDARY NEAR BROWNWOOD.  A CORRIDOR OF

LOW 70S BOUNDARY LAYER DEW POINTS AND SURFACE TEMPERATURES OF 95-100

F NOSING INTO THE BOUNDARY INTERSECTION ZONE ARE RESULTING IN STRONG

INSTABILITY /MLCAPE AOA 4000 J/KG/.  LOW-LEVEL AND DEEP LAYER SHEAR

ARE SUFFICIENT FOR SUPERCELLS TO MOVE SEWD ALONG THE OUTFLOW

BOUNDARY...AND THESE STORMS WILL BE CAPABLE OF PRODUCING A COUPLE OF

TORNADOES...ISOLATED VERY LARGE HAIL...AND DAMAGING WINDS.  OTHER

ISOLATED STORM DEVELOPMENT MAY OCCUR FARTHER NW TOWARD THE AREA SE

OF LBB TO ABI ALONG THE STALLED BOUNDARY.  LATER THIS

AFTERNOON/EVENING...STORM MERGERS/INTERACTIONS COULD LEAD TO THE

FORMATION OF A CLUSTER OF HP SUPERCELLS/SMALL MCS WITH AN INCREASING

THREAT FOR DAMAGING WINDS.



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

600. MEAN STORM MOTION VECTOR 32020.





...THOMPSON

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