It remains possible to trigger a very large persistent slab avalanche breaking 2-6' deep in the snowpack. New snow has created storm snow avalanche problems. Staying off slopes steeper than 30 degrees is advised to avoid triggering an avalanche.
This forecast is sponsored by CB Const, Inc.
Despite the warm weather and rain in late January, poor snowpack structure still exists. The thick crust that now resides under the new since 2/1 may not be enough to protect you from triggering a persistent slab avalanche. Triggering an avalanche would have serious consequences. If you want to avoid avalanches you should stay off of slopes greater than 30 degrees.
3-6" of fresh snow sits on a melt-freeze crust from the prolonged period of warm weather and rain that ended 2/1. As the SE winds increase throughout the day wind slabs will begin to form on west through northeast slopes. Look for drifts, cornices, textured snow, and cracking as signs you are on a wind slab. These slabs will form on top of lower-density snow with a thick crust below them. This is an excellent recipe for an avalanche, just add a trigger. Don't be that trigger, remember that this fresh snow lies on top of a dangerous snowpack. If you are on a slope steep enough to trigger a wind slab, it's also steep enough for a persistent slab.
WAC Motorized Ambassador, Gary Olson posted this observation showing an avalanche that failed within the new snow.
Cracking in new wind-blown snow on a small test slope.
Photo: Nick Burks
While snowfall totals in the Elkhorns are not huge, there is enough new snow to create new snow instabilities. Wind slabs, storm slabs, and dry loose avalanches are possible. The firm crust that sits below this new snow creates an excellent sliding surface for any avalanche that gets started. Despite this crust, the snowpack below is still sensitive and weak. All these factors make for a complex environment to travel through. When the complexity and consequences are high, it's best to keep it simple and choose terrain less than 30 degrees. Continued vigilance is necessary to avoid getting caught in a powerful destructive avalanche.
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