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WWUS20 KWNS 212149

SEL9

SPC WW 212149

IAZ000-ILZ000-INZ000-MIZ000-WIZ000-LMZ000-220500-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 429

NWS Storm Prediction Center Norman OK

450 PM CDT Fri Jul 21 2017



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Central and Eastern Iowa

  Northern Illinois

  Northern Indiana

  Southwest Lower Michigan

  Southern Wisconsin

  Lake Michigan



* Effective this Friday afternoon from 450 PM until Midnight CDT.



* Primary threats include...

  Scattered damaging wind gusts to 70 mph likely

  Scattered large hail and isolated very large hail events to 2

    inches in diameter possible

  A tornado or two possible



SUMMARY...Multiple clusters of storms should continue to intensify

through late afternoon and early evening and spread

east-southeastward across the region. Damaging winds will be the

primary concern, although some severe hail may occur and a tornado

or two cannot be ruled out, particularly across parts of Iowa into

northern Illinois along a boundary.



The severe thunderstorm watch area is approximately along and 60

statute miles north and south of a line from 30 miles north of Des

Moines IA to 15 miles south southeast of South Bend IN. For a

complete depiction of the watch see the associated watch outline

update (WOUS64 KWNS WOU9).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



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 428...



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 550. Mean storm motion vector

27025.



...Guyer

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