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706 

WWUS20 KWNS 302351

SEL8

SPC WW 302351

ARZ000-010700-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 258

NWS STORM PREDICTION CENTER NORMAN OK

650 PM CDT SAT APR 30 2011



THE NWS STORM PREDICTION CENTER HAS ISSUED A

TORNADO WATCH FOR PORTIONS OF



       ARKANSAS



EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 650 PM

UNTIL 200 AM CDT.



TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND

GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE

AREAS.



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 50 STATUTE

MILES NORTH AND SOUTH OF A LINE FROM 40 MILES SOUTH OF FORT SMITH

ARKANSAS TO 30 MILES SOUTH OF JONESBORO ARKANSAS.  FOR A COMPLETE

DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE

(WOUS64 KWNS WOU8).



REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR

TORNADOES AND 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.



OTHER WATCH INFORMATION...CONTINUE...WW 257...



DISCUSSION...TSTMS HAVE RECENTLY INCREASED IN COVERAGE AND INTENSITY

FROM NE OF BVX TO W OF HOT...LIKELY IN RESPONSE TO A LOW-AMPLITUDE

IMPULSE LIFTING NEWD FROM THE ARKLATEX.  THIS INITIAL ACTIVITY

APPEARS TO BE AT LEAST SLIGHTLY ELEVATED.  HOWEVER...GIVEN THE WARM

AND MOIST BOUNDARY LAYER IN PLACE NAMELY ALONG AND S OF THE I-40

CORRIDOR...POTENTIAL WILL EXIST FOR STORMS TO BECOME SURFACE-BASED

WITHIN A KINEMATIC ENVIRONMENT CHARACTERIZED BY 0-1 KM SRH OF

250-300 M2/S2 PER LITTLE ROCK VWP.  WHILE LARGE HAIL WILL BE THE

PRIMARY HAZARD...TORNADOES WILL BE POSSIBLE WITH ANY SUPERCELLS THAT

CAN BECOME SURFACE-BASED.



AVIATION...TORNADOES AND 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 24030.





...MEAD

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