Winter Weather — Grand & Summit Counties Below 9000 Feet, Colorado

2019-03-06 to 2019-03-07 · Grand & Summit Counties Below 9000 Feet, Colorado

Wider weather episode

A prolonged period of heavy snowfall during the first week of March produced historic avalanche conditions across the northern and central mountains of Colorado. Mountain highways including a large section of I-70 was closed on the 7th due to high to extreme avalanche danger. The snow was heaviest during the overnight hours when a concentrated band of heavy snow remained stationary over a large stretch of the Interstate 70 corridor, producing snowfall rates up to 2 inches per hour. Storm totals included: 24 inches near Mount Zirkel; 17 inches near Loveland Pass; 15.5 inches near Berthoud Falls; 15 inches near Silverthorne; 14.5 inches near Climax; 13 inches near Cameron Pass, Glendevey, Longs Peak and Mount Audubon; 12 inches near Alma, Gould and Guanella Pass; 11 inches near Frisco; with 6 to 10 inches elsewhere.

An avalanche that ruptured a natural gas line behind the Conoco station at Copper Mountain; and several other avalanches led to the closure of I-70 in both directions between Copper Mountain and Vail. The ruptured gas line created a power outage at the Eisenhower Tunnel. Colorado Department of Transportation (CDOT) crews were escorting 100 vehicles through the tunnel when the outage occurred. Interstate 70 between Silverthorne and Empire Junction was closed for about three hours in the area for avalanche mitigation. Arapahoe Basin ski area did not open on the 7th because of high avalanche danger on nearby Loveland Pass. The Colorado Avalanche Information Center deemed several of the backcountry zones EXTREME (5 of 5), including Vail and Summit County. This was the first time this designation has been used since they converted to a ten-zone forecast format back in 2006. The warning comes after multiple avalanches over the previous weekend and an avalanche that has shut down Interstate 70 between Frisco and Vail early on the morning of the 7th.

Source: NOAA Storm Events Database, event_id 799966. Narrative written by the NWS forecast office that issued the report.