

547 

WWUS20 KWNS 300555

SEL8

SPC WW 300555

TXZ000-301300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 638

NWS STORM PREDICTION CENTER NORMAN OK

1255 AM CDT THU JUL 30 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WEST CENTRAL TO NORTH CENTRAL TEXAS



EFFECTIVE THIS THURSDAY MORNING FROM 1255 AM UNTIL 800 AM CDT.



HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS TO 80

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 90 MILES WEST OF

ABILENE TEXAS TO 55 MILES EAST NORTHEAST OF DALLAS TEXAS.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU8).



REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE

FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY

DO PRODUCE TORNADOES.



OTHER WATCH INFORMATION...CONTINUE...WW 636...WW 637...



DISCUSSION...TWO STRONG/SVR FORWARD-PROPAGATING MCSS...ONE NEARING

KSPS AND THE OTHER E OF KLBB EXPECTED TO CONTINUE ESE AND

SE...RESPECTIVELY... THROUGH THE NEXT FEW HOURS.  AREA VWPS SHOW 30+

KT SE AND SLY MOIST LLJS AVAILABLE TO FEED BOTH SYSTEMS...AND DEEP

NNWLY SHEAR APPEARS STRONG ENOUGH AND FAVORABLY ORIENTED TO SUPPORT

MAINTENANCE OF THE SYSTEMS.  BOTH DMGG WET MICROBURSTS AND

MARGINALLY SVR HAIL MAY OCCUR.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70 KNOTS.

A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM MOTION

VECTOR 29040.





...CORFIDI

