

613 

WWUS20 KWNS 170056

SEL1

SPC WW 170056

ARZ000-LAZ000-MSZ000-TXZ000-170500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 591

NWS STORM PREDICTION CENTER NORMAN OK

755 PM CDT THU JUL 16 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHEAST AND EAST CENTRAL ARKANSAS

       NORTHERN LOUISIANA

       NORTHWEST AND WEST CENTRAL MISSISSIPPI

       EXTREME NORTHEAST TEXAS



EFFECTIVE THIS THURSDAY NIGHT FROM 755 PM UNTIL MIDNIGHT 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 45

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 40 MILES SOUTHWEST

OF SHREVEPORT LOUISIANA TO 10 MILES NORTHEAST OF GREENWOOD

MISSISSIPPI.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



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 588...WW 589...WW 590...



DISCUSSION...CONVECTIVE COMPLEX OVER AR HAS ORGANIZED INTO A BOWING

LINEAR SYSTEM MOVING EWD/SEWD AT 20-25 KT.  A STRONG COLD POOL HAS

DEVELOPED IN ASSOCIATION WITH THE SYSTEM...AND NEW UPDRAFTS ALONG

THE LEADING EDGE OF THE MULTIPLE GUST FRONTS HAVE FORMED IN A

DISCONTINUOUS MANNER.  STRONG WIND GUSTS ARE LIKELY TO OCCUR AS THE

STORMS MOVE INTO A VERY WARM AND MOIST ENVIRONMENT OVER THE NEXT FEW

HOURS.



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 550. MEAN STORM

MOTION VECTOR 27020.





...WEISS

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