

024 

WWUS20 KWNS 212109

SEL3

SPC WW 212109

TXZ000-220400-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 73

NWS STORM PREDICTION CENTER NORMAN OK

410 PM CDT WED APR 21 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       THE SOUTHERN TEXAS PANHANDLE AND TEXAS SOUTH PLAINS



EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 410 PM UNTIL

1100 PM CDT.



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 75 STATUTE

MILES NORTH AND SOUTH OF A LINE FROM 75 MILES WEST NORTHWEST OF

PLAINVIEW TEXAS TO 15 MILES SOUTHEAST OF CHILDRESS 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...CONTINUE...WW 72...



DISCUSSION...SURFACE HEATING/MIXING HAS REMOVED MUCH OF THE

CONVECTIVE INHIBITION ALONG A STALLED FRONT...AND THUNDERSTORM

DEVELOPMENT WILL BE POSSIBLE IN THE NEXT COUPLE OF HOURS ALONG THE

FRONT AND IMMEDIATELY NE OF A WEAK MESOLOW NW OF LBB.  MODERATE

INSTABILITY IS PRESENT ALONG THE BOUNDARY...AND DEEP-LAYER VERTICAL

SHEAR IS SUFFICIENT FOR SUPERCELLS.  THE PRIMARY INITIAL THREAT WILL

BE LARGE HAIL...THOUGH A COUPLE OF TORNADOES WILL ALSO BE POSSIBLE

TOWARD EVENING AS LOW-LEVEL MOISTURE AND SHEAR CONTINUE TO INCREASE

GRADUALLY.



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 28015.





...THOMPSON

