The Colorado Avalanche Information Center has a message for backcountry enthusiasts eager to take advantage of the new snowfall in the high country: “Avoid it.”
The avalanche danger was listed as “high” for nearly every mountain range across Colorado on Tuesday, including the San Juan Mountains of Southwest Colorado.
“Our bottom-line statement is: Travel in backcountry terrain is not recommended,” said Scott Toepfer, avalanche forecaster with the center. “It’s just pretty darn dangerous, and it’s really hard to find where a safe place might be because we may see some avalanches running historic distances and sizes under these kind of conditions.”
Coal Bank and Molas passes reopened about 3 p.m. Tuesday after being closed about 24 hours because of avalanche danger and mitigation work.
Arapahoe Basin evacuated skiers, snowboarders and employees Tuesday because of avalanche concerns on Loveland Pass. Monarch Mountain ski area, which got 28 inches of snow the last two days, also closed Tuesday because of avalanche control work on Monarch Pass.
A portion of Interstate 70 was shut down early Tuesday after an avalanche dumped up to 15 feet of snow on Vail Pass, trapping three commercial vehicles, according to the Colorado Department of Transportation. No one was injured, CDOT said.
Other passes around the state were closed intermittently through the day for avalanche control.
Freeze-thaw cycles can create unstable conditions and lead to greater avalanche danger in the mountains. But the biggest concern Tuesday was the sheer amount of snow received across the Colorado Rockies, Toepfer said.
It snowed 24 inches in 12 hours Monday on Coal Bank Pass – “an eye-opener,” Toepfer said – with strong winds creating intense areas of accumulation.
“Snowfall rates of 2 inches an hour are always going to bring about some problems,” he said. “But we also had some really strong south and southwest winds gusting into the 70s (mph). And then the San Juan snowpack is always notoriously weak underneath; so that is playing some role as well.”
A backcountry skier triggered an avalanche Monday in the Lime Creek area, between Coal Bank and Molas passes, that covered a 200-foot section of U.S. Highway 550 with 8 feet of snow. The skier escaped without injury, “a very lucky person, from what I understand,” Toepfer said.
A 45-mile stretch of road between Durango and Ouray, which includes Coal Bank, Molas and Red Mountain passes, closed midday Monday until a portion reopened about 3 p.m. Tuesday, when Coal Bank and Molas passes opened under chain-law restrictions. Red Mountain Pass remains closed with no estimated time of reopening.
Normally, the avalanche danger mitigates after a few days of settling, but with more storms expected this week, the danger is likely to remain high into next week, he said.
Snowpack statewide went from about 60 percent of average a few weeks ago to 150 percent of normal this week, he said.
“It’s not done yet,” he said. “It doesn’t look like a break anytime soon.”
Indeed, forecasters are calling for more storm activity Wednesday in Southwest Colorado, with up to an inch of snow in Durango and 4-8 inches in the San Juan Mountains. An organized storm system is expected to arrive Friday, bringing more snow, said Dennis Phillips, meteorologist with the National Weather Service in Grand Junction.
“Maybe late weekend, or for sure, early next week, there’s a couple day breaks before we get into another pattern,” he said.