

157 

WWUS20 KWNS 152302

SEL6

SPC WW 152302

ARZ000-MOZ000-TNZ000-160400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 586

NWS STORM PREDICTION CENTER NORMAN OK

605 PM CDT WED JUL 15 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHEAST ARKANSAS

       THE MISSOURI BOOTHEEL

       WESTERN TENNESSEE



EFFECTIVE THIS WEDNESDAY EVENING FROM 605 PM UNTIL 1100 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 45

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 20 MILES SOUTH

SOUTHWEST OF WALNUT RIDGE ARKANSAS TO 45 MILES EAST NORTHEAST OF

JACKSON TENNESSEE.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).



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 585...



DISCUSSION...THE THUNDERSTORM CLUSTER MOVING SEWD FROM MO INTO NE AR

HAS SHOWN SIGNS OF COLD POOL INTENSIFICATION AND ACCELERATION IN THE

PAST HOUR...AND THERE HAVE BEEN RECENT WIND OBSERVATIONS OF 44 KT

WINDS WITH THIS CLUSTER IN NE AR.  DESPITE RATHER MODEST FLOW OVER

NE AR/WRN TN...A HOT/MOIST BOUNDARY LAYER AND ASSOCIATED STRONG

INSTABILITY WILL SUPPORT A THREAT FOR DAMAGING DOWNBURST WINDS AND

MARGINALLY SEVERE HAIL THROUGH LATE EVENING.



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 30030.





...THOMPSON

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