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000 

WWUS20 KWNS 121048

SEL2

SPC WW 121048

OKZ000-121600-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 512

NWS STORM PREDICTION CENTER NORMAN OK

545 AM CDT THU JUL 12 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHERN AND CENTRAL OKLAHOMA



EFFECTIVE THIS THURSDAY MORNING FROM 545 AM UNTIL 1100 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 75

STATUTE MILES EITHER SIDE OF A LINE FROM 30 MILES NORTH NORTHWEST

OF ENID OKLAHOMA TO 55 MILES SOUTHEAST OF OKLAHOMA CITY OKLAHOMA.

 FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU2).



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.



DISCUSSION...WELL FORMED MCS OVER NWRN OK EARLY THIS MORNING WILL

CONTINUE A GENERAL SSEWD MOTION ACROSS CENTRAL OK THROUGH THE REST

OF THE MORNING.  AIR MASS IS VERY UNSTABLE ACROSS SWRN OK TO THE

SOUTH OF AN INSTABILITY GRADIENT/SURFACE FRONT EXTENDING FROM SERN

OK INTO NWRN OK.  MOST LIKELY CORRIDOR FOR MCS TRACK WILL BE ALONG

THIS FRONT AND SLIGHTLY INTO GREATER INSTABILITY OVER PARTS OF WRN

OK.  WIND GUSTS APPROACHING SEVERE LEVELS WILL BE COMMON ALONG

LEADING GUST FRONT...WITH NARROW PATHS OF STRONGER WINDS/WIND DAMAGE

LIKELY WITH SMALL-SCALE CIRCULATIONS WITHIN BROADER MCS.  VERY MOIST

PROFILES WITH HIGH WBZ/FREEZING LEVELS SHOULD MITIGATE HAIL

GROWTH...BUT WILL ENHANCE RAINFALL RATES.



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 550. MEAN STORM

MOTION VECTOR 31030.





...EVANS

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