This is an archived forecast related to a fatality on that day

Issued on:Wed, Feb 12, 2025 at 4:30 PM

Avalanche Danger for Friday, Feb 14
Above and Near Treeline: 2 - Moderate
Below Treeline: 1 - Low

You can trigger an avalanche in drifted slabs at upper elevations. Soft drifts over 8 inches deep, or hard drifts that support your weight are the most suspect. Cracking in the new snow is a sign you could trigger a slide. Avoid lens-shaped pillows of snow where you see them on steep slopes directly below ridges and in gullies.

Avalanches can step down into older drifts and grow larger. Some could break in weak snow near the ground. You might not see any warning signs before you trigger a deeper avalanche. Drifted rocky slopes with variable snow cover are the most likely place to trigger a deeper avalanche.

Look for safer riding on slopes less than about 30 degrees and in the trees sheltered from the wind.

Avalanche Problems (2)
Problem: Persistent Slab
Aspect/Elevation: N-E Near and Above Treeline, SE Above Treeline
Likelihood: Possible
Size: Small to Large
What you need to know about these avalanches: Persistent Slab avalanches can be triggered days to weeks after the last storm. They often propagate across and beyond terrain features that would otherwise confine Wind and Storm Slab avalanches. In some cases they can be triggered remotely, from low-angle terrain or adjacent slopes. Give yourself a wide safety buffer to address the uncertainty.

Problem: Wind Slab
Aspect/Elevation: N-E-S Near and Above Treeline
Likelihood: Possible
Size: Small to Large
What you need to know about these avalanches: Wind Slab avalanches release naturally during wind events and can be triggered for up to a week after a wind event. They form in lee and cross-loaded terrain features. Avoid them by sticking to wind sheltered or wind scoured areas.

Northern Mountains Regional Discussion

An atmospheric river begins to make its way into the region tomorrow afternoon and snowfall begins Thursday night for most of the state. This system will pump moisture into the state over the weekend with unsettled weather continuing through next week. Expect the avalanche danger to rise across the Northern Mountains on Friday or Saturday depending on the location. We issued an Avalanche Watch for the Park Range and Flat Top Mountains beginning Thursday night. That said, the avalanche danger will be static for tomorrow. The day will start clear and very cold before the storm arrives. Areas with a Wind Slab problem today keep it for tomorrow, but the danger won’t increase.

For tomorrow, you can expect to find Wind Slab avalanches at upper elevations across the region. In areas without a Persistent Slab avalanche problem listed, the travel advice is simple. Avoid steep slopes with drifted snow. If you see cracking in the surface snow, avoid slopes steeper than about 35 degrees. You’re most likely to find problematic drifts directly below ridges, in gullies, and below convex rollovers. In areas with both problems, the message is a little more complex.

Persistent Slab avalanches are most likely in Summit County and on the west side of the Continental Divide from Interstate 70 north to Cameron Pass. Observers reported triggering two large avalanches in the past five days; one near Cameron Pass and one near Vail Pass. As always, there is a lot of uncertainty whenever there are buried weak layers. Were these slides isolated incidents over a large area, or were they a sign of things to come with the incoming storm? Hard to say, but we’ll find out soon enough. I guess that we’ll see more of this activity in the thinner areas of the Northern Mountain mentioned above. We split up the large zone that represented this area into three smaller zones based on forecasted snow totals and when we expect the danger to rise. The danger will rise in the northern Front Range and Gore Range on Friday. The less favored eastern Summit County area doesn’t see a change until Saturday. Slopes with variable snow cover and lots of exposed obstacles that can act as trigger points are the most likely place to trigger one of these slides. Look to sheltered, lower elevation areas less than about 30 degrees to avoid this problem.

We’re entering a dynamic period. Check back tomorrow and double-check the forecast in the mornings as the storm starts to play out to get the most up-to-date forecast. Enjoy the new snow and tailor your decision-making to the appropriate problems. In areas where we expect more Persistent Slab activity, you’ll need wider margins for error.