

099 

WWUS20 KWNS 252129

SEL8

SPC WW 252129

IAZ000-KSZ000-MOZ000-NEZ000-260500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 518

NWS STORM PREDICTION CENTER NORMAN OK

430 PM CDT WED JUL 25 2012



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN IOWA

       NORTH-CENTRAL AND NORTHEAST KANSAS

       FAR NORTHWEST MISSOURI

       EASTERN AND SOUTH-CENTRAL NEBRASKA



EFFECTIVE THIS WEDNESDAY AFTERNOON FROM 430 PM UNTIL MIDNIGHT CDT.



HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70

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



THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 85

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

SOUTHWEST OF CONCORDIA KANSAS TO 10 MILES NORTHEAST OF TEKAMAH

NEBRASKA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE

ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU8).



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...TSTMS ARE EXPECTED TO INCREASE IN COVERAGE AND

INTENSITY LATE THIS AFTERNOON AND EVENING AHEAD OF SLOW-MOVING COLD

FRONT AND PRE-FRONTAL WIND SHIFT WITHIN A THERMODYNAMIC ENVIRONMENT

CHARACTERIZED BY MLCAPE OF 2500-4000 J/KG AND DCAPE OF 1500-1900

J/KG.  THOUGH VERTICAL SHEAR WILL REMAIN MARGINAL FOR STORM

ORGANIZATION...THE DEGREE OF INSTABILITY WILL PROMOTE VIGOROUS

UP/DOWNDRAFTS CAPABLE OF DAMAGING WINDS AND SOME LARGE HAIL.



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

TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 29020.





...MEAD

