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000 

WWUS20 KWNS 192222

SEL4

SPC WW 192222

OKZ000-TXZ000-200700-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 424

NWS STORM PREDICTION CENTER NORMAN OK

520 PM CDT TUE JUN 19 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       THE OKLAHOMA PANHANDLE

       THE TEXAS PANHANDLE



EFFECTIVE THIS TUESDAY AFTERNOON AND WEDNESDAY MORNING FROM 520

PM UNTIL 200 AM CDT.



HAIL TO 2 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 85

STATUTE MILES EAST AND WEST OF A LINE FROM 20 MILES NORTH OF

GUYMON OKLAHOMA TO 35 MILES SOUTH SOUTHEAST OF AMARILLO TEXAS.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU4).



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 418...WW 419...WW

420...WW 421...WW 422...WW 423...



DISCUSSION...SCATTERED THUNDERSTORMS WILL LIKELY DEVELOP ACROSS THE

WRN TX PANHANDLE AND ALONG A DIFFUSE BOUNDARY IN THE OK PANHANDLE

THROUGH THIS EVENING.  VERTICAL SHEAR IS MARGINAL FOR SUPERCELLS IN

THE NRN PORTION OF THE WATCH...AND WEAKER TO THE SOUTH.

HOWEVER...EXTREME INSTABILITY WILL SUPPORT STRONG UPDRAFTS AND AN

ATTENDANT THREAT FOR LARGE HAIL...AS WELL AS STRONG DOWNBURST

POTENTIAL.  THE THREAT FOR DAMAGING WINDS MAY INCREASE LATER THIS

EVENING AS DEVELOPING STORMS MERGE INTO LARGER CLUSTERS...OR AS

ONGOING STORMS IN WRN KS SPREAD SWD INTO THE OK AND NRN TX

PANHANDLES IN ASSOCIATION WITH A STRENGTHENING COLD POOL.



AVIATION...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 600. MEAN STORM

MOTION VECTOR 36015.





...THOMPSON

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