Mesoscale Discussion 1925 NWS Storm Prediction Center Norman OK 1142 AM CDT Tue Aug 11 2026 Areas affected...northeast Illinois into far southwest lower Michigan and northern and central Indiana Concerning...Severe Thunderstorm Watch 563...565... SUMMARY...Damaging winds with significant gusts up to 75-85 mph are expected to continue with the ongoing bow echo. DISCUSSION...An intense bow echo with a history of 85-95+ mph wind gusts across Chicagoland has shifted into far northwest IN as of 1635Z. Considerable downstream convection present from the vicinity of the bow echo to north of Muncie has hindered daytime heating and resultant air mass destabilization within the inflow region of the bow echo. LAT...LON 40898785 41428750 41698735 41848649 41828585 41638518 40958502 40538500 40268510 40088535 39968574 39878640 40358759 40898785 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH MOST PROBABLE PEAK WIND GUST...75-90 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN