Dangerous avalanche conditions will develop this weekend across the high country, prompting the Colorado Avalanche Information Center to issue a special avalanche advisory on Wednesday.
The current avalanche danger is rated “considerable,” which is Level 3 on the CAIC’s 1-5 scale, for nearly every region of the mountains. CAIC forecasters expect it to worsen this weekend, prompting the advisory. The most dangerous avalanche conditions are likely to develop Saturday afternoon and into Sunday, the advisory said.
“We’re getting continued snowfall, and we’re going to see a pretty big wind event on Friday,” CAIC director Ethan Greene said Thursday. “We’re going to see avalanches breaking on more slopes, they’re going to be easier for people to trigger, and they’re going to be much larger, thus much more dangerous. All we want people to do is check the avalanche forecast, know what the avalanche conditions are where they’re going. We’re going to be putting out avalanche warnings in different parts of the state as this storm progresses.”
Following a relatively dry December and early January, an approaching system will deposit heavy snow on brittle slabs, complicated by high winds causing drifting snow, and those factors will set up prime conditions for avalanche activity. More than a dozen ski areas are expected to receive 20-40 inches of snow over the next five days.
“Observers reported triggering and seeing avalanches on Wednesday,” CAIC reported in its outlook for the northern mountains on Thursday. “Most were shallow or narrow. They will just get bigger as a series of storms will move across the Northern Mountains over the next few days. Expect periods of heavy snow and strong winds, which will drift snow onto easterly-facing aspects. The most dangerous spots will be the places where the new and wind-drifted snow is the deepest. The Park Range and Flat Tops will probably pass the tipping point first, with other areas only a day or two behind.”
The outlook is similar for the central mountains.
“Avalanche conditions are rapidly growing more dangerous with the combination of the new snow (finally!) and some pretty fierce winds forming wind-drifted slabs even below treeline,” CAIC said. “The new slab is developing over some very weak snow, and crust-facet combinations on southerly-facing slopes, from our prolonged drought period. Observers were already noting widespread collapsing.”
The southern mountains also will see increasing avalanche danger.
“By this weekend or early next week, the snowpack may reach critical levels and we could see a widespread natural avalanche cycle,” CAIC said. “This would leave us with very few safe places to travel.”
A long dry period, such as the one Colorado experienced in December and early January, causes the snowpack to change in structure and weaken.
“While that is sitting on the surface, that’s not that big of a deal, which is why we saw low danger last week,” Greene said. “When you start to pile (new) snow onto that weak snow that formed on the old surface, that’s a recipe for avalanches. The more snow, and the faster you pile it on, the more dangerous that’s going to be.”
There have been no avalanche fatalities so far this season in Colorado, according to CAIC records, but four backcountry tourers were caught in a slide in the Elk Mountains near Marble in November. In the 2022-23 season, 21 were caught, 16 partially buried and 11 killed.
