

733 

WWUS20 KWNS 110036

SEL1

SPC WW 110036

ILZ000-INZ000-MIZ000-OHZ000-LMZ000-110700-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 421

NWS Storm Prediction Center Norman OK

840 PM EDT Tue Aug 10 2021



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Northeastern Illinois

  Northern Indiana

  Western and central Lower Michigan

  Extreme northwestern Ohio

  Lake Michigan



* Effective this Tuesday night and Wednesday morning from 840 PM

  until 300 AM EDT.



* Primary threats include...

  Scattered damaging winds and isolated significant gusts to 75

    mph possible

  Isolated large hail events to 1.5 inches in diameter possible



SUMMARY...An organized complex of thunderstorms, with a history of

measured severe gusts in IL and WI, will continue to pose a

damaging-wind threat across Lake Michigan and into parts of MI and

northern IN before weakening tonight.



The severe thunderstorm watch area is approximately along and 70

statute miles east and west of a line from 30 miles south southeast

of South Bend IN to 15 miles west northwest of Traverse City MI. For

a complete depiction of the watch see the associated watch outline

update (WOUS64 KWNS WOU1).



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 419...WW 420...



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 550. Mean storm motion vector

27035.



...Edwards

