

529 

WWUS20 KWNS 100002

SEL8

SPC WW 100002

IAZ000-MNZ000-NEZ000-SDZ000-100700-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 568

NWS STORM PREDICTION CENTER NORMAN OK

705 PM CDT THU JUL 9 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       WESTERN IOWA

       SOUTHWEST MINNESOTA

       NORTHEAST NEBRASKA

       SOUTHEAST SOUTH DAKOTA



EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 705 PM

UNTIL 200 AM 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 25 MILES WEST

NORTHWEST OF WORTHINGTON MINNESOTA TO 15 MILES SOUTH SOUTHWEST 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...CU/TCU FIELD AND SCATTERED THUNDERSTORMS ARE BEGINNING

TO INCREASE OVER NORTHEAST NEB/SOUTHEAST SD...AND WILL LIKELY TRACK

EASTWARD INTO IA THROUGH THE EVENING.  OTHER STORMS MAY REDEVELOP

THROUGH THE EVENING OVER THIS SAME AREA AS LOW LEVEL JET INCREASES.

STRONG INSTABILITY AND 50-60 KNOTS OF EFFECTIVE SHEAR WILL PROMOTE

SUPERCELLS CAPABLE OF VERY LARGE HAIL AND DAMAGING WINDS.



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 500. MEAN STORM

MOTION VECTOR 27030.





...HART

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