A large avalanche, reported to the Colorado Avalanche Information Center Feb. 13, released on Mount Victoria near Frisco. The report does not make clear the time or cause of the slide, which occurred on the J Chute, a long, mostly treeless area visible from town.
The CAIC report estimated that the slide started at 10,900 feet and came to a stop around 9,800 feet, covering portions of the popular Mount Royal Trail. The slide created a large debris field at a trail intersection about a quarter mile from the Mount Royal trailhead. The Summit Daily News confirmed the approximate length of the slide and estimated the debris field to be a few hundred feet long and close to 100 feet wide with a number of small trees and branches in it. The slide was reported within a few days of fatal avalanches near Keystone and Leadville.
“Based on what the report is indicating, it’s certainly big enough to kill someone,” CAIC deptuty director Brian Lazar said of the Frisco slide. “It seems like a natural. It’s possible someone triggered it and went away.”
Summit County resident Mark Koob, who reported the slide to CAIC, later said he believed it was likely a naturally caused slide. Koob told the Daily he came across the debris field in the afternoon on Thursday, Feb. 13, and did not see any other tracks in the area. He said the slide looked fresh at the time and had not been there when he was in the area two days earlier. Koob also reported high winds that afternoon and the night prior to discovering the slide.
The avalanche occurred along a popular backcountry ski line accessible from Frisco and near the historic Masontown mining site, which was destroyed by an avalanche in 1926. While the slope does not typically have such large slides, it is a clear avalanche path.
“That has been a producer in the past,” CAIC forecaster John Snook said of the location. “This year it doesn’t surprise me that it ran larger.”
The slide is part of a growing trend this season, Lazar said. “It’s not out of character for what we’re seeing this year. A lot of these paths that haven’t run in quite some time are running this year.”
The combination of 75 and 100 inches of snow in the span of a few weeks in February and high winds loading slopes has made the potential for avalanches especially high in recent weeks.
“Unusual weather brings unusual avalanches,” Snook said. “A lot of these slides are as big as they’ve been in 20 years.”
Ten people have died in avalanche-related accidents in the western United States since Feb. 8. While Colorado averages six avalanche fatalities a season, there have already been six to date. Typically, March and April are the snowiest months and produce more slides.
“The danger isn’t going away anytime soon,” Snook said.
While CAIC forecasters are reporting that the snowpack in the area has stabilized somewhat in the last week, they warn that an already dangerous season is expected to continue with more snow in the forecast. Even with the lowered risk, a large, deep persistent slab slide remains a possibility.
Should a slope release, it could create a potentially large and lethal avalanche, Snook said. Forecasters refer to such avalanches as low probability, high consequence, slides.
Warm temperatures in the last few days likely will have resulted in a weak frozen layer in the snowpack that additional snowfall could have trouble bonding with, making slides likely.
“If we get more snow, it could make the snowpack pretty touchy,” Snook said, looking toward the weekend forecast. “With more weather coming, we need people to stay wary.”