Heavy Training Storms Raise Flash‑Flood and Hail Risk Across the Central and Upper Midwest

Overview

• Radar and MRMS on Monday morning showed training thunderstorms over central Illinois producing verified hourly rates of about 1 to just over 2 inches with isolated pockets that could add 2 to 4+ inches.
• The Weather Prediction Center says areas from central Illinois into the Lower Ohio Valley and northwestern Tennessee face a near‑term flash‑flood threat that could persist through the late morning.
• The Upper Mississippi Valley, Wisconsin and Michigan’s western Upper Peninsula saw increasing potential for training heavy rain over the next 3–5 hours with hourly rates near 1–2 inches and possible flash flooding.
• The Storm Prediction Center maintains Severe Thunderstorm Watch 518 for the Minnesota Arrowhead, far northern Wisconsin and the western U.P. where elevated storms may produce 1.00–1.75‑inch hail and isolated damaging gusts up to roughly 55–70 mph.
• Forecasters caution that short‑range models have struggled to represent the ongoing convection so exact timing and placement of the heaviest rain and strongest storms remain uncertain and may change in real time.