

209 

WWUS20 KWNS 130353

SEL5

SPC WW 130353

ARZ000-MOZ000-OKZ000-130900-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 575

NWS STORM PREDICTION CENTER NORMAN OK

1050 PM CDT SUN AUG 12 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTHWEST AND WEST CENTRAL ARKANSAS

       FAR SOUTHWEST MISSOURI

       NORTHEAST AND EAST CENTRAL OKLAHOMA



EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 1050 PM UNTIL

400 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 80

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

MUSKOGEE OKLAHOMA TO 20 MILES EAST NORTHEAST OF RUSSELLVILLE

ARKANSAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU5).



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 573...WW 574...



DISCUSSION...SCTD TSTMS...INCLUDING POSSIBLE SUSTAINED

STORMS/SUPERCELLS...

EXPECTED IN ZONE OF WEAK WAA ON NW FRINGE OF FAIRLY RICH LOW LVL

MOISTURE PLUME EXTENDING NWD FROM LA/SRN AR.  CLOUD LAYER SHEAR WILL

BE ENHANCED BY 20-30 KT MID LVL NWLY FLOW ASSOCIATED WITH UPR

IMPULSE CROSSING THE LWR MO VLY.  STEEP MID LVL LAPSE RATES AND

NOCTURNAL VEERING OF LOW LVL FLOW MAY YIELD A THREAT FOR SVR HAIL

AND LOCALLY DMGG WIND. A TORNADO CANNOT BE RULED OUT...BUT NOCTURNAL

STABILIZATION OF THE BOUNDARY LAYER SHOULD KEEP ANY SUCH THREAT

BRIEF/ISOLD.



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 30020.





...CORFIDI

