

959 

WWUS20 KWNS 111546

SEL3

SPC WW 111546

INZ000-MIZ000-OHZ000-LMZ000-112100-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 423

NWS Storm Prediction Center Norman OK

1145 AM EDT Wed Aug 11 2021



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Northern Indiana

  Southwest Lower Michigan

  Extreme northwest Ohio

  Lake Michigan



* Effective this Wednesday morning and afternoon from 1145 AM

  until 500 PM EDT.



* Primary threats include...

  Scattered damaging winds and isolated significant gusts to 75

    mph likely

  Isolated large hail events to 1.5 inches in diameter possible

  A tornado or two possible



SUMMARY...A storm cluster with a history of severe gusts across

northeast Illinois is expected to continue moving eastward and

likely expand northward this afternoon across northern Indiana into

southwest Lower Michigan.  Damaging winds up to 75 mph will be the

main threat, though isolated large hail of 1 to 1.5 inch diameter

will be possible with the strongest storms, and a tornado or two may

also occur with embedded circulations.



The severe thunderstorm watch area is approximately along and 70

statute miles east and west of a line from 40 miles north of Grand

Rapids MI to 35 miles southwest of Fort Wayne IN. For a complete

depiction of the watch see the associated watch outline update

(WOUS64 KWNS WOU3).



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 422...



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

26040.



...Thompson

