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WWUS20 KWNS 290030

SEL9

SPC WW 290030

ILZ000-INZ000-LMZ000-290500-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 359

NWS Storm Prediction Center Norman OK

730 PM CDT Tue Aug 28 2018



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Northeastern Illinois

  Extreme northwestern Indiana

  Lake Michigan



* Effective this Tuesday night from 730 PM until Midnight CDT.



* Primary threats include...

  Scattered damaging wind gusts to 70 mph possible

  Isolated large hail events to 1.5 inches in diameter possible



SUMMARY...A well-developed bow echo (now crossing the Mississippi

River from Iowa into northwestern Illinois) should persist for

another few hours while moving across northern/northeastern

Illinois, immediately north of a residual outflow boundary.  The

bowing segment will be accompanied by a continued threat for

damaging winds, and perhaps some hail with the strongest embedded

updrafts.



The severe thunderstorm watch area is approximately along and 45

statute miles north and south of a line from 60 miles southwest of

Rockford IL to 90 miles east northeast of Marseilles IL. 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 356...WW 357...WW 358...



AVIATION...A few severe thunderstorms with hail surface and aloft to

1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A

few cumulonimbi with maximum tops to 600. Mean storm motion vector

27045.



...Thompson

