Iowa Supercells Explode with EF2+ Tornadoes, Surging Toward Wisconsin — SevereWX

Iowa Supercells Explode with EF2+ Tornadoes, Surging Toward Wisconsin

Urgent threat building across Iowa's heartland into Wisconsin this afternoon. Storms in north-central Iowa are rapidly turning surface-based, fueling supercells primed for significant severe weather. Expect EF2-EF3 tornadoes (120-145 mph winds), very large hail (1.5-2.5 inches, golf ball to tennis ball size), and damaging gusts to 80 mph. A modifying outflow boundary is boosting low-level rotation, making strong tornadoes highly likely.

This fury extends northeastward. Late afternoon supercells are poised to ignite along a cold front from northeast Iowa into northwest and north-central Wisconsin. A very moist, unstable air mass—combined with 50-60 kt shear—favors isolated supercells packing the same intense hazards: strong tornadoes, very large hail, and 75+ mph winds that could spike higher as storms cluster.

What does this mean? The Storm Prediction Center (SPC) issues Mesoscale Discussions (MDs) like these when small-scale weather features signal a high risk of severe storms in specific spots. With 95% odds of tornado watches for both areas (central Iowa now, northeast Iowa-Wisconsin soon), this is a heads-up: watches are imminent, and severe warnings will follow as storms organize.

Timing is key—central Iowa action peaks through early evening, while northeast Iowa-Wisconsin storms fire later. Stay vigilant from Des Moines northward to Madison.

Prepare now: Review your severe weather plan. Identify your safe shelter (interior room, away from windows). Download a radar app, enable Wireless Emergency Alerts, and monitor local NWS updates. If a tornado warning hits, take cover immediately—don't wait. Stay safe out there!

Issued: July 20, 2026 | SPC MD 1674/1675 | Follow @SevereWXdotNet for live updates.