Thurmont, MD Hail Storm – July 2026

Thurmont, MD — Early evening on July 4, 2026, a multi-cell thunderstorm produced hail up to 2.38 inches in diameter across parts of Thurmont. The system generated a sustained sequence of warnings and radar detections across the local area.

What Happened

The first NWS alert associated with this event issued at 6:04 PM EDT. The sequence totaled 39 alerts through 9:52 PM EDT. Most notices carried NWS warning only language for 0.75-inch hail. Dual-polarization radar detected a significant core at 6:15 PM EDT that registered a radar-derived hail signature near 2.07 inches in diameter. A second radar-detected peak occurred at 7:38 PM EDT with a 1.07-inch signature. A spotter-verified report of 0.75-inch hail arrived at 7:26 PM EDT. Alerts continued intermittently for the remainder of the evening, largely indicating quarter-size hail across the broader warning area.

The event behaved like a multi-cell complex with repeated updraft redevelopment. Warnings and radar detections moved through the Thurmont metro area over roughly a four-hour span. Local advisories were the primary delivery mechanism for immediate public notice; radar-derived detections and a spotter report provided additional ground-radar corroboration.

Damage Assessment

Observed hail sizes ranged from roughly 0.75 inch to a maximum verified 2.38 inches in the Thurmont area. Hail at or above 2.38 inches is large enough to crack or shatter vehicle glazing and to cause severe damage to asphalt shingles and thin metal roofing. Hail in the 1.0-inch range can dent vehicles and damage siding and skylights. Quarter-size hail reported repeatedly across warning polygons can still result in cosmetic panel dents and broken exterior fixtures when driven by high winds.

A spotter-verified 0.75-inch report at 7:26 PM EDT indicates localized ground confirmation in the western sector of the metro area. The sequence of NWS warning only notices suggests widespread quarter-size hail signatures along the warning corridor, punctuated by the radar-detected larger cores at 6:15 PM EDT and 7:38 PM EDT.

What Contractors Should Know

Prioritize roof and glazing inspections in areas along the radar-detected cores and where spotter reports originated. Inspect for fractured shingle tabs, displaced granules, cracked vents, dented metal flashing, and fractured skylight glazing. Photograph damage with a visible scale and note the time and location for each image. Check vehicles and light external equipment for panel dents and glass damage. Record serial numbers and VINs where applicable for claims.

Perform temporary water-intrusion mitigation immediately where holes or split shingles are found. Apply secure tarps and replace failed flashing to prevent secondary water damage. Document all temporary repairs and schedule full-condition assessments for roofing and exterior cladding within 48–72 hours. Coordinate with property owners on insurance timelines and provide clear written estimates for final repairs.