

000 

WWUS20 KWNS 062320

SEL8

SPC WW 062320

IAZ000-KSZ000-MOZ000-NEZ000-070700-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 668

NWS STORM PREDICTION CENTER NORMAN OK

620 PM CDT THU SEP 6 2007



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN IOWA

       NORTH CENTRAL AND NORTHEAST KANSAS

       NORTHWEST MISSOURI

       CENTRAL AND EASTERN NEBRASKA



EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 620 PM

UNTIL 200 AM CDT.



HAIL TO 2.5 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 100

STATUTE MILES NORTH AND SOUTH OF A LINE FROM 10 MILES NORTH

NORTHWEST OF HASTINGS NEBRASKA TO 25 MILES SOUTHEAST OF

SHENANDOAH IOWA.  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.



OTHER WATCH INFORMATION...CONTINUE...WW 667...



DISCUSSION...THUNDERSTORMS CONTINUE TO INTENSIFY RAPIDLY WITHIN VERY

UNSTABLE AIR MASS OVER NERN KS EARLY THIS EVENING...WITH FURTHER

DEVELOPMENT EXPECTED AS STRONG SYSTEM OVERSPREADS THE CENTRAL

PLAINS.  LOW LEVEL SHEAR IS QUITE STRONG ATTM NEAR A SURFACE WARM

FRONT IN NERN KS/FAR NWRN MO...WITH DEEP LAYER SHEAR EXPECTED TO

STRENGTHEN WITH TIME ACROSS ENTIRE WW THIS EVENING.  STRONGER CORES

WILL LIKELY ORGANIZE INTO SUPERCELLS AND LINES/CLUSTERS WITH THREATS

OF LARGE HAIL AND DAMAGING WINDS.



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

TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60

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

MOTION VECTOR 27020.





...EVANS

