Mesoscale Discussion 1921 NWS Storm Prediction Center Norman OK 0900 AM CDT Tue Aug 11 2026 Areas affected...southern Wisconsin...northern Illinois...and far northwest Indiana Concerning...Severe Thunderstorm Watch 563... Valid 111400Z - 111600Z The severe weather threat for Severe Thunderstorm Watch 563 continues. SUMMARY...The potential for significant wind gusts up to 75-85 mph is expected to persist with an evolving bow echo this morning. DISCUSSION...An MCS with a history of producing wind gusts of 70-80 mph is currently evolving into a broader bowing configuration over east-central IA and far northwest IL as of 1355Z. The bow echo is expected to track along a residual outflow boundary from a downstream MCS, which extends east-southeast through the south side of the greater Chicago metropolitan area into far northwest IN.