

935 

WWUS20 KWNS 212016

SEL2

SPC WW 212016

ARZ000-LAZ000-TXZ000-220400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 612

NWS STORM PREDICTION CENTER NORMAN OK

315 PM CDT TUE JUL 21 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       PARTS OF SOUTHERN ARKANSAS

       PARTS OF NORTHERN LOUISIANA

       PARTS OF NORTHEAST TEXAS



EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 315 PM UNTIL

1100 PM 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 70

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 5 MILES NORTH

NORTHEAST OF MONROE LOUISIANA TO 30 MILES WEST NORTHWEST OF

LONGVIEW TEXAS.  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...AIR MASS IN ADVANCE OF COLD FRONT VICINITY OF RED RIVER

CONTINUES TO DESTABILIZE WITH MLCAPES AOA 2000 J/KG AND LITTLE

REMAINING CINH.  THUNDERSTORMS WILL INCREASE IN NUMBER AND INTENSITY

FROM N TO S ACROSS THE WATCH WITH SUFFICIENT SHEAR FOR ISOLATED

SUPERCELLS.  PRIMARY THREAT WILL BE WIND DAMAGE ASSOCIATED WITH

STRONGER UPDRAFTS...HOWEVER ISOLATED BRIEF TORNADOES WILL ALSO BE

POSSIBLE WITH ANY SUPERCELL.



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 27025.





...HALES

