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348 

WWUS20 KWNS 141959

SEL2

SPC WW 141959

KSZ000-NEZ000-150200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 312

NWS STORM PREDICTION CENTER NORMAN OK

300 PM CDT FRI JUN 14 2013



THE NWS STORM PREDICTION CENTER HAS ISSUED A



* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

  A SMALL PART OF NORTHWEST AND NORTH CENTRAL KANSAS

  SOUTH CENTRAL NEBRASKA



* EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 300 PM UNTIL

  900 PM CDT.



* PRIMARY THREATS INCLUDE...

  A FEW DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

  A FEW LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 35

STATUTE MILES EITHER SIDE OF A LINE FROM 40 MILES SOUTH OF MCCOOK

NEBRASKA TO 20 MILES EAST NORTHEAST OF GRAND ISLAND NEBRASKA.

FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU2).



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.



&&



DISCUSSION...CONVECTION IS DEVELOPING NEWD ALONG THE SURFACE COLD

FRONT AS LOW-LEVEL LAPSE RATES STEEPEN AND CONVECTIVE INHIBITION IS

REMOVED.  THE INITIAL HIGH-BASED STORMS WILL POSE A RISK FOR

ISOLATED DAMAGING DOWNBURSTS...THOUGH THE RISK FOR ISOLATED LARGE

HAIL SHOULD INCREASE SOME AS THE STORMS WILL SPREAD INTO A

PROGRESSIVELY MORE UNSTABLE ENVIRONMENT WITH NEWD EXTENT IN NEB.

THE COMBINATION OF MODERATE-STRONG INSTABILITY AND MODEST VERTICAL

SHEAR WILL SUPPORT MULTICELL CLUSTERS AS THE PRIMARY CONVECTIVE

MODE.



AVIATION...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 24020.





...THOMPSON

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