Mercersburg, PA Hail Storm – May 2026

A severe hail storm tracked through Mercersburg, PA on May 20, 2026, producing 1.83-inch stones and prompting repeated NWS warnings in the late afternoon and early evening. The storm sequence generated 42 NWS alerts from 1:03 PM to 6:58 PM EDT, with both radar-detected returns and a spotter-verified observation.

What Happened

The storm initiated in the early afternoon and persisted into early evening. NWS issued 42 alerts across a roughly six-hour span, beginning at 1:03 PM and ending at 6:58 PM. Most alerts were labeled NWS warning only. At 4:50 PM a dual-polarization radar signature indicated hail-sized returns consistent with larger stones. A Skywarn spotter submitted a photograph and reported hail around 5:25 PM; the local storm report described the observation as spotter-verified 1-inch hail with time estimated from radar.

Radar and warning timelines show repeated hail detections across the Mercersburg warning area from mid-afternoon through early evening. The pattern included intermittent stronger returns near 4:50 PM and sustained, smaller-hail returns recorded through 6:58 PM. The spotter submission provides ground-truth imagery for the afternoon activity near the town center.

Damage Assessment

Field reports and radar returns indicate localized surface impact concentrated near Mercersburg between mid-afternoon and early evening. The Skywarn photo documents hail accumulation consistent with penny-sized stones at 5:25 PM in the Mercersburg vicinity. No additional local storm reports filed to the NWS from Mercersburg report structural collapse or large-scale vehicle damage tied to this event.

Dual-polarization radar showed a stronger return near 4:50 PM that did not correspond to multiple independent ground reports in the Mercersburg public record. Observations therefore point to uneven hail distribution across the warning area, with isolated pockets of measurable hail documented by the spotter and radar signatures.

What Contractors Should Know

Inspect roofs installed on properties in and immediately around Mercersburg first. Begin with sections facing the storm track and those near tree lines where hail can be funneled. Look for granular loss, pitting on asphalt shingles, and circular bruises on metal roofing. Photograph damage with time-stamped images and note exact parcel addresses for claims work.

Check parked vehicles and low-profile equipment documented within the Mercersburg warning area for paint damage and denting. Prioritize late-model vehicles and those parked outdoors during the 4:30 PM to 6:30 PM window. Skylights and polycarbonate panels may show impact fractures that are not immediately obvious from ground level.

Document all inspections against the warning area timeline issued by the NWS on May 20. Use the spotter image timestamp and the 4:50 PM radar return as verification anchors when compiling estimates. Maintain a conservative approach when assessing replacement versus repair on marginal shingle bruising; some hail signatures may not warrant full replacement.