Avalanche danger in the Vail area is high for next few days
Fresh, heavy snow atop an unstable base is a recipe for big, serious slides right now
It’s OK to revel in all our recent snow, but it’s probably best to play in it within the confines of a ski resort.
Because of a lot of fresh snow on top of older, unstable snow, the Colorado Avalanche Information Center issued a warning Monday for essentially all of the state’s mountains. That warning called for “considerable” avalanche danger. The Tuesday prediction for the Vail/Summit County area called for “high” danger near and above treeline, with considerable danger below treeline.
CAIC director Ethan Greene said all of the avalanche danger ratings are on a sliding scale, so there are days when considerable danger is actually closer to a high rating than a moderate one.
“We’re just barely below high (in that area),” Greene said, adding that with additional snow and strong winds in the forecast, the snowpack is likely to become even more unstable.
The Colorado Department of Transportation shut down Interstate 70 over Vail Pass on Monday to do avalanche mitigation work along the highway. That added to an earlier closure due to accidents on the road.
Spokeswoman Elise Thatcher said that department’s avalanche mitigation crews look for snowpack stability, as well as the moisture content, of the new snow.
This is heavier snow
The moisture content of recent snow is higher than normal, which can exacerbate a slope’s tendency to slide. In addition, high winds can further pack down fresh snow, making the new layer heavier — and more likely to slide.
Along state highways, crews try to do as much mitigation work as possible to keep down the size of slides. Those smaller slides are less likely to snarl traffic and are generally easier to clean up.
The results of Monday’s work were “ideal,” Thatcher said, with snow running almost to the roadway, where it’s more easily cleared.
No one’s doing mitigation work in the backcountry.
There, slides will either self-trigger or, more often, get triggered by people skiing, snowshoeing or snowmobiling nearby.
Greene said an unstable snowpack can trip up even experienced backcountry users. The difference between a safe and hazardous path is sometimes a matter of just a few feet, he said.
Greene urged anyone planning a backcountry trip to get the latest information from the center’s website.
The center’s website also offers educational resources and advice on what to take into the backcountry. Greene advised people headed there to take, at minimum, an avalanche transceiver, a probe pole and a shovel.
Maybe stay in bounds
Greene said when conditions are as hazardous as they are now, it’s probably unwise to head into the backcountry right now. As conditions start to moderate, Green advises people to stay in well-leveled areas — those with slope pitches of 30 degrees or less.
But even in those conditions, Greene said, people need to look at the surrounding area to ensure there are no steeper slopes that might run into those more-level areas.
Greene said the center Sunday posted a photo of a slide triggered on “essentially flat” terrain. The slide came from a steeper hill just a few hundred feet away from an area with more flatness.
People “need to take the avalanche danger really seriously,” Greene said. “On days like (Monday), there’s a bunch of new snow and the riding is good. But’s it’s easy to trigger a slide.”
Given the lack of early season snow, the center has recorded just one avalanche death this season: a Dec. 24 slide reported near Cameron Pass, west of Fort Collins.
Last winter was a bad one, Greene, said, with 12 deaths. That tied the state’s record since it began recording avalanche fatalities.
Here’s the National Weather Service forecast for Vail through Jan. 1:
Tuesday: Snow showers likely before noon. High near 28 and breezy.
Wednesday: A 50% chance of snow showers. High near 24, with wind gusts up to 30 mph possible.
Thursday: Snow showers likely. Mostly cloudy, with a high near 28.
Friday: Snow showers, with a high near 31.
Saturday: A chance of snow showers, with a high near 20.