WWUS20 KWNS 211954

SEL0  

SPC WW 211954

IAZ000-ILZ000-INZ000-WIZ000-LMZ000-220300-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 610

NWS Storm Prediction Center Norman OK

255 PM CDT Fri Aug 21 2026



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of 

  Eastern Iowa

  Northern and Central Illinois

  Far Northwest Indiana

  Southern Wisconsin

  Lake Michigan



* Effective this Friday afternoon and evening from 255 PM until

  1000 PM CDT.



* Primary threats include...

  Scattered large hail and isolated very large hail events to 2

    inches in diameter possible

  Scattered damaging wind gusts to 70 mph possible

  A tornado or two possible



SUMMARY...Scattered severe thunderstorms are forecast to develop

through the remainder of the afternoon and into the evening.  A few

supercells and eventually some severe multicells organizing into a

linear cluster are expected.  The threat for large hail and severe

gusts will accompany the stronger storms.  A tornado is possible,

especially with a supercell favorably interacting with a stalled

outflow boundary across parts of the Watch area.  This activity will

likely shift southward with time during the evening.



The severe thunderstorm watch area is approximately along and 90

statute miles east and west of a line from 20 miles east northeast

of Lonerock WI to 15 miles southeast of Bloomington IL. 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 608...WW 609...



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 500. Mean storm motion vector

33020.



...Smith