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052 

WWUS20 KWNS 202046

SEL5

SPC WW 202046

OKZ000-TXZ000-210400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 525

NWS STORM PREDICTION CENTER NORMAN OK

345 PM CDT MON JUN 20 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       MUCH OF CENTRAL OKLAHOMA

       MUCH OF NORTHWEST TEXAS



EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 345 PM UNTIL

1100 PM CDT.



...THIS IS A PARTICULARLY DANGEROUS SITUATION...



EXTREMELY DAMAGING THUNDERSTORM WIND GUSTS TO 80 MPH...LARGE HAIL

TO 3.5 INCHES IN DIAMETER...AND DANGEROUS LIGHTNING ARE POSSIBLE

IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 55

STATUTE MILES EAST AND WEST OF A LINE FROM 25 MILES NORTHEAST OF

PONCA CITY OKLAHOMA TO 45 MILES WEST OF STEPHENVILLE TEXAS.  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 523...WW 524...



DISCUSSION...THUNDERSTORMS SHOULD DEVELOP ALONG THE DRY LINE ON WRN

EDGE OF WATCH BY 22Z. STORMS WILL RAPIDLY BECOME SEVERE GIVEN THE

AVAILABLE VERY UNSTABLE AIR MASS IN ADVANCE OF THE UNSEASONABLY

STRONG UPPER TROUGH . SUPERCELLS WILL BE INITIAL MODE BUT QUICKLY

EVOLVE INTO LINE SEGMENTS AND BOWS.  VERY LARGE HAIL ALONG WITH A

POTENTIAL OF SIGNIFICANT DAMAGING WINDS WILL ACCOMPANY BOTH THE

SUPERCELLS AND THE MORE LINEAR MODE THAT EVOLVES BY THIS EVENING. IN

ADDITION BRIEF TORNADOS ARE POSSIBLE WITH BOTH MODES



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

TO 3.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70

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

MOTION VECTOR 24030.





...HALES

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