

165 

WWUS20 KWNS 180355

SEL0

SPC WW 180355

ARZ000-OKZ000-181100-



URGENT - IMMEDIATE BROADCAST REQUESTED

TORNADO WATCH NUMBER 120

NWS STORM PREDICTION CENTER NORMAN OK

1055 PM CDT WED APR 17 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* TORNADO WATCH FOR PORTIONS OF

  NORTHWEST ARKANSAS

  SOUTH CENTRAL TO EASTERN OKLAHOMA



* EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 1055

  PM UNTIL 600 AM CDT.



* PRIMARY THREATS INCLUDE...

  SEVERAL TORNADOES POSSIBLE

  SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  SEVERAL LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE



THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 65 STATUTE

MILES EAST AND WEST OF A LINE FROM 40 MILES NORTH NORTHWEST OF

FAYETTEVILLE ARKANSAS TO 30 MILES SOUTH SOUTHWEST OF ARDMORE

OKLAHOMA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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...THIS TORNADO WATCH REPLACES TORNADO

WATCH NUMBER 116. WATCH NUMBER 116 WILL NOT BE IN EFFECT AFTER

1055 PM CDT. CONTINUE...WW 118...WW 119...



DISCUSSION...EARLIER SUPERCELLS ALONG AND JUST AHEAD OF THE COLD

FRONT HAVE BEEN WEAKENING GRADUALLY...AS CONVECTION BEGINS TO EVOLVE

INTO MORE LINEAR STRUCTURES.  GIVEN THE PRESENCE OF 1000-1500 J/KG

MLCAPE IN THE WARM SECTOR AND STRONG VERTICAL SHEAR...ORGANIZED

BOWING SEGMENTS AND SOME EMBEDDED SUPERCELL STRUCTURES WILL REMAIN

POSSIBLE OVERNIGHT.  THE MORE COMMON SEVERE STORM THREAT WILL BE

DAMAGING WINDS AND LARGE HAIL...BUT EMBEDDED CIRCULATIONS/

MESOVORTICES COULD POSE A RISK OF A TORNADO OR TWO.



AVIATION...TORNADOES AND 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

500. MEAN STORM MOTION VECTOR 24040.





...THOMPSON

