

874 

WWUS20 KWNS 090841

SEL6

SPC WW 090841

IAZ000-MNZ000-NEZ000-SDZ000-091500-



URGENT - IMMEDIATE BROADCAST REQUESTED

SEVERE THUNDERSTORM WATCH NUMBER 566

NWS STORM PREDICTION CENTER NORMAN OK

345 AM CDT THU JUL 9 2009



THE NWS STORM PREDICTION CENTER HAS ISSUED A

SEVERE THUNDERSTORM WATCH FOR PORTIONS OF



       PARTS OF NORTHWEST IOWA

       PARTS OF SOUTHWEST MINNESOTA

       PARTS OF NORTHEAST NEBRASKA

       LARGE PART OF EASTERN SOUTH DAKOTA



EFFECTIVE THIS THURSDAY MORNING FROM 345 AM UNTIL 1000 AM 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 60

STATUTE MILES EITHER SIDE OF A LINE FROM 20 MILES WEST NORTHWEST

OF HURON SOUTH DAKOTA TO 40 MILES EAST NORTHEAST OF SIOUX CITY

IOWA.  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.



OTHER WATCH INFORMATION...CONTINUE...WW 564...WW 565...



DISCUSSION...BOWING LINE SEGMENTS CONTINUE TO DEVELOP S OF E ACROSS

ERN SD INTO INSTABILITY AXIS.  WITH 50KT OF DEEP LAYER SHEAR AND

WELL DEVELOPED COLD POOL...POTENTIAL FOR DAMAGING WINDS WILL

CONTINUE SEWD FOR SEVERAL MORE HOURS.



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 29035.





...HALES

