

590 

WWUS20 KWNS 282158

SEL9

SPC WW 282158

NEZ000-SDZ000-290400-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 909

NWS STORM PREDICTION CENTER NORMAN OK

500 PM CDT SUN SEP 28 2008



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       NORTH CENTRAL INTO NORTHEAST NEBRASKA

       SOUTHEAST SOUTH DAKOTA



EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 500 PM UNTIL

1100 PM 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 75

STATUTE MILES EAST AND WEST OF A LINE FROM 30 MILES WEST

NORTHWEST OF BROOKINGS SOUTH DAKOTA TO 45 MILES SOUTH OF ONEILL

NEBRASKA.  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.



DISCUSSION...THUNDERSTORMS WILL CONTINUE INCREASING THROUGH THE LATE

AFTERNOON/EVENING ACROSS THIS REGION AHEAD OF APPROACHING UPPER

TROUGH AND ASSOCIATED SURFACE COLD FRONT.  STEEP LAPSE RATES AND

STRENGTHENING SHEAR WILL SUPPORT THREATS OF LARGE HAIL AND ISOLATED

DAMAGING WINDS WITH THE STRONGER STORMS.



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 450. MEAN STORM

MOTION VECTOR 30015.





...EVANS

