Terril, IA Hail Storm – May 2026

A severe hail storm tracked through Terril, Iowa on May 15, 2026, producing 3.54-inch hail and prolonged radar-detected hail swaths in the late afternoon and early evening.

What Happened

The storm triggered 61 NWS alerts between 5:23 PM CDT and 1:20 AM CDT. Early warnings at 5:23 PM CDT reported 1.0-inch hail in NWS warning-only messages. Dual-polarization radar then showed repeated hail detections through the evening, with frequent radar-derived reports in the 1.0–1.8 in range and several radar-plus-spotter detections above 1.5 in.

Spotters logged concentrated activity in the 7:20–8:15 PM CDT window. Multiple spotter-verified Local Storm Reports recorded 2.5-inch stones around 7:22 PM CDT and again near 7:45 PM CDT. A separate spotter entry at 7:34 PM CDT recorded 2.0-inch hail. At 7:25 PM CDT a field report noted broken car windows. Radar and spotter reports aligned in time and location across the Terril metro, producing a long-lived hail track that persisted into the night with smaller 0.75–1.25 in detections after 10:00 PM CDT.

The sequence shows initial NWS warning-only alerts followed by sustained dual-polarization radar detections and multiple spotter confirmations. Several radar detections near 8:09 PM CDT and 8:31 PM CDT were accompanied by spotter observations in and around Terril, indicating repeated cores of larger hail moving through the same corridor.

Damage Assessment

Field reports and spotter records indicate surface impacts concentrated on and near Terril between 7:20 PM CDT and 8:15 PM CDT. Multiple spotters reported 2.5-inch hail during that interval. One spotter account at 7:25 PM CDT specifically described broken windows on a car. Additional spotter entries described 2.0-inch stones at 7:34 PM CDT and ping-pong-ball size hail at 7:57 PM CDT.

Observed impacts in the spotter stream point to several damage signatures. Vehicles within the reported 2.0–2.5 in swath are at elevated risk for dented body panels and cracked glass; one field report already documents broken auto glass. Roof observations should focus on areas that coincide with the 7:22–7:45 PM CDT cluster of reports. Where spotters recorded multiple larger stones, inspectors should expect shingle granule loss, split fiberglass, and dented metal components on outbuildings and HVAC covers.

Later-night NWS warning-only alerts and radar detections reported mostly 0.75–1.25 in hail. Those smaller reports are concentrated after 10:00 PM CDT and are less likely to have produced structural failure but can increase cumulative shingle wear in locations already hit by larger stones earlier in the event.

What Contractors Should Know

Prioritize inspections in the Terril corridor where spotters logged 2.5-inch hail near 7:22 PM CDT and 7:45 PM CDT. Start with a drive-by documentation pass to map addresses, then perform close-up roof inspections on structures within those clusters. Photograph hail damage with timestamps and GPS when possible. Log vehicle damage reports separately; the field report of broken car windows at 7:25 PM CDT identifies a spot to canvass for additional vehicle claims.

Terril, IA Hail Storm – May 2026

NWS WARNING AREAS · 61

What Happened

Damage Assessment

What Contractors Should Know

Storm Details

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