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276 

WWUS20 KWNS 120257

SEL7

SPC WW 120257

IAZ000-KSZ000-MOZ000-NEZ000-OKZ000-120900-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 147

NWS STORM PREDICTION CENTER NORMAN OK

1000 PM CDT SUN MAY 11 2014



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  EXTREME SOUTHWEST IOWA

  SOUTH CENTRAL TO NORTHEAST KANSAS

  EXTREME NORTHWEST MISSOURI

  EXTREME SOUTHEAST NEBRASKA

  NORTHWEST AND NORTH CENTRAL OKLAHOMA



* EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 1000 PM

  UNTIL 400 AM CDT.



* PRIMARY THREATS INCLUDE...

  SCATTERED LARGE HAIL LIKELY WITH ISOLATED VERY LARGE HAIL EVENTS

    TO 2.5 INCHES IN DIAMETER POSSIBLE

  SCATTERED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  A TORNADO OR TWO POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 50

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

FALLS CITY NEBRASKA TO 45 MILES WEST SOUTHWEST OF ENID OKLAHOMA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU7).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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...THIS SEVERE THUNDERSTORM WATCH REPLACES

TORNADO WATCH NUMBER 142...TORNADO WATCH NUMBER 143. WATCH NUMBER

142 143 WILL NOT BE IN EFFECT AFTER 1000 PM CDT. CONTINUE...WW

144...WW 145...WW 146...



DISCUSSION...CONVECTIVE OUTFLOWS AND A SURGING COLD FRONT ARE

BEGINNING TO TRANSITION THE STORM MODE FROM DISCRETE SUPERCELLS TO

MORE LINEAR STORMS...WHICH WILL SUPPORT PRIMARY RISKS OF LARGE HAIL

AND DAMAGING WINDS OVERNIGHT.  IN THE SHORT TERM...A TORNADO CANNOT

BE RULED OUT WITH LINGERING SEMI-DISCRETE SUPERCELLS IN CENTRAL KS

AND SW IA.



AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM

MOTION VECTOR 26030.





...THOMPSON

