

785 

WWUS20 KWNS 222257

SEL6

SPC WW 222257

NEZ000-SDZ000-230500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 906

NWS STORM PREDICTION CENTER NORMAN OK

600 PM CDT MON SEP 22 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       MUCH OF WESTERN NEBRASKA

       MUCH OF CENTRAL AND PARTS OF WESTERN SOUTH DAKOTA



EFFECTIVE THIS MONDAY NIGHT FROM 600 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 65

STATUTE MILES EAST AND WEST OF A LINE FROM 55 MILES EAST OF

SIDNEY NEBRASKA TO 30 MILES NORTH OF MOBRIDGE SOUTH DAKOTA.  FOR

A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH

OUTLINE UPDATE (WOUS64 KWNS WOU6).



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 WILL INCREASE RAPIDLY IN NUMBER AND

INTENSITY ALONG AND AHEAD OF VIGOROUS COLD FRONT NOW MOVING EWD INTO

WRN NE/SWRN SD.  WITH MLCAPES TO 1500 J/KG AND 40-50 KT OF SHEAR IN

ADVANCE OF S/WV TROUGH MOVING THRU WY...SUPERCELLS ARE POSSIBLE.

PRIMARY THREAT WILL BE LARGE HAIL AND DAMAGING WINDS.  STORMS WILL

EVOLVE INTO A LINE LATER THIS EVENING AS THEY MOVE FURTHER E ACROSS

THE WATCH.



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 24035.





...HALES

