April 2026 Downburst — Jefferson County, MO

A downburst on April 27, 2026 drove 65 mph winds and quarter-size hail across Arnold, Imperial and High Ridge, with the heaviest tree damage reported along the Highway 21 corridor.

Downbursts behave differently from a broad squall line. They dump a concentrated column of air that spreads outward at ground level, which can strip one street and leave the next untouched. That is why so many Jefferson County homeowners assume they escaped a storm — a neighbor two blocks over has obvious damage and they do not.

The failure mode here is usually a broken seal rather than a missing shingle. The shingle lifts, the sealant strip tears, and the shingle lays back down looking normal. It is only during the next heavy rain that water gets underneath. Ridge-top homes in Imperial and Hillsboro are the most exposed.