The areas affected include...
Nearshore Waters from Wilmette Harbor to Calumet Harbor... Nearshore Waters from Calumet Harbor to Michigan City... Open Waters from Wilmette Harbor to Michigan City out to Mid Lake...
At 409 PM CDT, Doppler radar indicated strong thunderstorms, capable of producing localized wind gusts to around 30 knots. These thunderstorms were located along a line extending from near Diversy Harbor to near Midway Airport, moving east at 20 knots.