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000 

WWUS20 KWNS 181920

SEL9

SPC WW 181920

NEZ000-SDZ000-190200-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 569

NWS STORM PREDICTION CENTER NORMAN OK

220 PM CDT WED JUN 18 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       MUCH OF WESTERN NEBRASKA

       MUCH OF THE WESTERN HALF OF SOUTH DAKOTA



EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 220 PM UNTIL

900 PM CDT.



HAIL TO 3 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 95

STATUTE MILES EAST AND WEST OF A LINE FROM 35 MILES SOUTH

SOUTHWEST OF IMPERIAL NEBRASKA TO 75 MILES NORTH OF PHILIP SOUTH

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

WATCH OUTLINE UPDATE (WOUS64 KWNS WOU9).



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 568...



DISCUSSION...THUNDERSTORMS WILL INCREASE IN NUMBER AND INTENSITY

ACROSS THE WATCH AREA DURING THE NEXT SEVERAL HOURS AS HEATING

INCREASES INSTABILITY AND WEAKENS THE CAP. STEEP LAPSE RATES AND

VEERING SHEAR PROFILES SUPPORT DEVELOPMENT OF SUPERCELLS.  PRIMARY

THREAT WILL BE VERY LARGE HAIL AND DAMAGING DOWNBURST WINDS

PARTICULARLY WITH ANY SUPERCELL.



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

TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 32025.





...HALES

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