

000 

WWUS20 KWNS 200420

SEL5

SPC WW 200420

OKZ000-TXZ000-201000-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 425

NWS STORM PREDICTION CENTER NORMAN OK

1120 PM CDT TUE JUN 19 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTH CENTRAL AND SOUTHWEST OKLAHOMA

       NORTHWEST TEXAS



EFFECTIVE THIS TUESDAY NIGHT AND WEDNESDAY MORNING FROM 1120 PM

UNTIL 500 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 50

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 80 MILES WEST OF

CHILDRESS TEXAS TO 40 MILES NORTH NORTHEAST OF DURANT OKLAHOMA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU5).



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 423...WW 424...



DISCUSSION...THE ONGOING MCS/S IN CENTRAL/WRN OK AND THE NE TX

PANHANDLE WILL CONTINUE TO DEVELOP SWD ON CONVECTIVE OUTFLOW.  A

SEPARATE STORM CLUSTER HAS PRODUCED ANOTHER BOUNDARY FROM THE TX

SOUTH PLAINS INTO THE ERN TX PANHANDLE...WHICH COULD SERVE AS A

FOCUS FOR ADDITIONAL STRONG/SEVERE STORM DEVELOPMENT AS STORMS MERGE

WITH THIS BOUNDARY FROM THE NORTH.  STRONG INSTABILITY STILL EXISTS

TO THE SOUTH OF THE ONGOING STORMS...WHICH SHOULD HELP MAINTAIN SOME

INTENSE UPDRAFTS CAPABLE OF PRODUCING AT LEAST MARGINALLY SEVERE

HAIL.  THE PRIMARY SEVERE THREAT WILL BE DAMAGING WINDS WITH

MERGING/MATURING COLD POOLS.



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 35025.





...THOMPSON

