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IAZ000-KSZ000-NEZ000-200300-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 281

NWS STORM PREDICTION CENTER NORMAN OK

325 PM CDT SAT MAY 19 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       SOUTHWEST IOWA

       CENTRAL AND EASTERN KANSAS

       SOUTH CENTRAL AND EASTERN NEBRASKA



EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 325 PM UNTIL

1000 PM CDT.



HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 75

MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 65

STATUTE MILES EAST AND WEST OF A LINE FROM 25 MILES WEST

NORTHWEST OF TEKAMAH NEBRASKA TO 30 MILES EAST SOUTHEAST OF

MEDICINE LODGE KANSAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE

THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).



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...THUNDERSTORMS ARE BEGINNING TO DEVELOP OVER CENTRAL KS

ALONG A COLD FRONT IN RESPONSE TO INCREASING LARGE SCALE ASCENT IN

ADVANCE OF AN UPPER TROUGH MOVING INTO THE CENTRAL PLAINS.  STRONG

HEATING COUPLED WITH FOCUSED UPWARD MOTION IS EXPECTED TO CONTINUE

WEAKENING THE CAP WITH ADDITIONAL STORMS DEVELOPING NWD INTO PARTS

OF NEB.  STEEP LAPSE RATES ARE CONTRIBUTING TO MLCAPE OF 1500-2000

J/KG...AND 30-40 KT SHEAR WILL ENHANCE STORM INTENSITY AND

ORGANIZATION.  LARGE HAIL WILL BE LIKELY WITH STRONGER CELLS...AND

PRESENCE OF A RELATIVELY DEEP AND WELL-MIXED PBL WILL PROMOTE SEVERE

WIND GUSTS AS WELL.



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

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 65

KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM

MOTION VECTOR 24025.





...WEISS

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