

603 

WWUS20 KWNS 211957

SEL1

SPC WW 211957

NEZ000-SDZ000-220300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 341

NWS STORM PREDICTION CENTER NORMAN OK

200 PM MDT SAT JUN 21 2014



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  WESTERN NEBRASKA

  WESTERN AND CENTRAL SOUTH DAKOTA



* EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 200 PM UNTIL

  900 PM MDT.



* 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 LIKELY



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 80

STATUTE MILES EAST AND WEST OF A LINE FROM 10 MILES SOUTH OF

SIDNEY NEBRASKA TO 30 MILES NORTH NORTHEAST OF MOBRIDGE SOUTH

DAKOTA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



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...CONTINUE...WW 340...



DISCUSSION...THUNDERSTORMS WILL CONTINUE TO DEVELOP OVER WESTERN NEB

AND WESTERN SD THIS AFTERNOON...AND WILL SPREAD EASTWARD ACROSS THE

WATCH AREA THROUGH THE EARLY EVENING.  STRONG INSTABILITY AND

SUFFICIENT VERTICAL SHEAR MAY RESULT IN A FEW SUPERCELL STORMS

CAPABLE OF LARGE HAIL AND DAMAGING WINDS.



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 26025.





...HART

