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WWUS20 KWNS 290558

SEL0

SPC WW 290558

ILZ000-INZ000-MIZ000-LMZ000-291300-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 400

NWS Storm Prediction Center Norman OK

100 AM CDT Thu Jul 29 2021



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Northern Illinois

  Northern Indiana

  Southwestern Lower Michigan

  Lake Michigan



* Effective this Thursday morning from 100 AM until 800 AM CDT.



* Primary threats include...

  Scattered damaging winds likely with isolated significant gusts

    to 75 mph possible

  Isolated large hail events to 1.5 inches in diameter possible

  A tornado or two possible



SUMMARY...A quasi-linear convective system, with embedded severe

thunderstorms (including a supercell or two) will proceed

southeastward from Wisconsin across the watch area.  Some eastward

pivot or growth of this activity toward southwestern MI also is

possible.  Severe gusts will be the main concern, though the threat

exists for an embedded tornado or two, as well as isolated hail.



The severe thunderstorm watch area is approximately along and 110

statute miles east and west of a line from 40 miles east northeast

of Rockford IL to 65 miles south southeast of Valparaiso IN. For a

complete depiction of the watch see the associated watch outline

update (WOUS64 KWNS WOU0).



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 399...



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

1.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A

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

32035.



...Edwards

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