

000 

WWUS20 KWNS 200613

SEL6

SPC WW 200613

TXZ000-201400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 426

NWS STORM PREDICTION CENTER NORMAN OK

115 AM CDT WED JUN 20 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN AND CENTRAL TEXAS



EFFECTIVE THIS WEDNESDAY MORNING FROM 115 AM UNTIL 900 AM CDT.



HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70

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



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 65

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 55 MILES NORTHWEST

OF BIG SPRING TEXAS TO 20 MILES EAST OF DALLAS TEXAS.  FOR A

COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE

UPDATE (WOUS64 KWNS WOU6).



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 424...WW 425...



DISCUSSION...STRONG FORWARD-PROPAGATING MCS EXPECTED TO CONTINUE

GENERALLY SSE...FOSTERED PRIMARILY BY PROPAGATION OF NEW CELLS INTO

30+ KT SSELY LLJ.  DEGREE OF SFC-BASED INSTABILITY /STEEP LOW TO MID

LEVEL LAPSE RATES/ AND QUALITY OF MOISTURE INFLOW /DEWPOINTS IN THE

70S/ SUGGEST CONTINUED POTENTIAL FOR DAMAGING WIND GUSTS DRIVEN BY

MAINLY BY PRECIPITATION LOADING...ALONG WITH OCCASIONAL SVR HAIL



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

TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 600. MEAN STORM

MOTION VECTOR 35035.





...CORFIDI

