

113 

WWUS20 KWNS 241500

SEL9

SPC WW 241500

ARZ000-MOZ000-OKZ000-242100-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 59

NWS STORM PREDICTION CENTER NORMAN OK

1000 AM CDT TUE MAR 24 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHWEST ARKANSAS

       SOUTHWEST MISSOURI

       EASTERN OKLAHOMA



EFFECTIVE THIS TUESDAY MORNING AND AFTERNOON FROM 1000 AM UNTIL

400 PM 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 EAST AND WEST OF A LINE FROM 50 MILES NORTH

NORTHWEST OF FORT LEONARD WOOD MISSOURI TO 35 MILES EAST

SOUTHEAST OF MCALESTER OKLAHOMA.  FOR A COMPLETE DEPICTION OF THE

WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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...A LINE OF THUNDERSTORMS ALONG A COLD FRONT WILL PERSIST

INTO THIS AFTERNOON AS A STRONG SHORTWAVE TROUGH ROTATES ENEWD FROM

WRN OK TO SW MO.  THOUGH INSTABILITY IS SOMEWHAT MARGINAL AND

CONFINED TO A NARROW CORRIDOR AHEAD OF THE FRONT...THE FOCUSED

ASCENT AND STRONG LOW-MID LEVEL WINDS/SHEAR WILL SUPPORT EMBEDDED

BOW ECHO AND POSSIBLY SUPERCELL STRUCTURES WITHIN THE LINE.

DAMAGING WINDS AND ISOLATED LARGE HAIL SHOULD BE THE MAIN

THREATS...THOUGH AN ISOLATED TORNADO CANNOT BE RULED OUT WITH

EMBEDDED ROTATING STORMS.



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 500. MEAN STORM

MOTION VECTOR 23045.





...THOMPSON

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