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103 

WWUS20 KWNS 160139

SEL7

SPC WW 160139

ARZ000-KSZ000-MOZ000-OKZ000-160800-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 667

NWS STORM PREDICTION CENTER NORMAN OK

840 PM CDT WED SEP 15 2010



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       EXTREME NORTHWEST ARKANSAS

       EXTREME SOUTHEAST KANSAS

       SOUTHWEST MISSOURI

       NORTHEAST OKLAHOMA



EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 840 PM

UNTIL 300 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 60

STATUTE MILES EAST AND WEST OF A LINE FROM 65 MILES NORTH

NORTHEAST OF JOPLIN MISSOURI TO 40 MILES EAST OF TULSA OKLAHOMA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU7).



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 665...WW 666...



DISCUSSION...MERGING SUPERCELLS IN SE KS SHOULD LEAD TO MORE LINEAR

MCS FORMATION OVER THE NEXT FEW HOURS.  THE CONVECTION IS EXPECTED

TO MOVE ESEWD/SEWD ALONG A REMNANT OUTFLOW BOUNDARY NEAR THE OK/MO

BORDER...WITH RESIDUAL MODERATE INSTABILITY AND DEEP-LAYER VERTICAL

SHEAR SUPPORTING ORGANIZED BOWING SEGMENTS AND EMBEDDED SUPERCELL

STRUCTURES.  DAMAGING WINDS AND LARGE HAIL WILL BE THE MAIN

THREATS...PRIOR TO THE STORMS WEAKENING LATE TONIGHT AS THEY

ENCOUNTER A STRENGTHENING CAP AND WEAKER INSTABILITY.



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 500. MEAN STORM

MOTION VECTOR 30025.





...THOMPSON

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