EF3 Tornado — Boulder, Colorado

2015-06-04 · near Highland, Boulder, Colorado

Event narrative

The tornado first touched about 3 miles south of Berthoud, and then tracked to the west/northwest and lifted about 6 miles southwest of Berthoud. The majority of the damage was EF1, with some areas of EF2, and a few small areas of EF3. At least 25 homes between Longmont and Berthoud were damaged; three of them destroyed. No injuries were reported as the winds tore apart homes and rolled vehicles.

Wider weather episode

Severe thunderstorms broke out across Boulder, Denver, Elbert, Jefferson and Larimer Counties. Two large and long lived tornadoes developed in Larimer County near Berthoud and near Simla in Elbert County. The tornado that occurred along the Boulder and Larimer county line was rated an EF3 at it's highest damage point, with maximum winds estimated at 135 to 140 mph. The path length was 6 miles long with a width of one quarter mile at times. In Elbert County, 17 tornadoes touched down, with EF1 damage observed southwest and southeast of Simla. Four homes suffered severe damage; two were uninhabitable. In addition, two other homes suffered moderate damage with slight damage reported to eight other residences. Large hail up to baseball size occurred in Elbert County, with hail up to tennis ball size observed in Boulder County. The hail damaged cars and homes; breaking windows and windshields.

View location on OpenStreetMap → (40.2500, -105.0800)

Source: NOAA Storm Events Database, event_id 574167. Narrative written by the NWS forecast office that issued the report.