This is the last Statewide update for 2018. Zone-specific backcountry avalanche forecasts begin tomorrow (11/15). Zone forecasts are published every day by 8 AM through the spring. 

The primary avalanche concern is that a backcountry rider can trigger a large avalanche that breaks on weak, collapsible snow layers near the ground. This problem is specific to northerly and east-facing terrain where a harder wind-drifted slabs sits on top of worrisome weak layers. The only way to avoid this issue is to avoid the above-mentioned slopes. Sheltered areas and southerly-facing slopes are relatively safe from these Persistent Slab avalanches.

In the past couple weeks riders have triggered numerous large and dangerous avalanches. A large number of these avalanches were in the Northern Mountains. Although this is where the majority of avalanche activity has been, large avalanches were reported from all over the state including the San Juan mountains. The avalanche danger is greatest in the Northern Mountains, especially the Front Range, as northern and eastern areas received the most recent snow. As you move south through the state, the avalanche danger tapers, but as recent avalanche activity shows, large avalanches can be triggered on wind-loaded slopes in any mountain range in Colorado.

If you are traveling on south-facing slopes be aware that the northerly wind of the last few days drifted snow into slabs on these sunny slopes. It will possible to trigger small avalanches in this wind-drifted snow. Wind Slab avalanches can be avoided by steering clear of areas of snow near ridgetop or on the walls of gully-features that feel hard and have a smooth looking appearance. Hollow sounding snow underfoot or machine is also a sign that you may be traveling on one of these slabs.

As the dry weather pattern continues, overall snowpack stability increases. Avalanches are harder to trigger and the amount of slopes where you can trigger an avalanche decrease. This doesn't mean avalanches are impossible and if you head for a wind-loaded northerly and east-facing slope, there is a chance you can trigger a large and dangerous avalanche.

The clear and cold weather is changing our snowpack and increasing the snowpack stability by weakening surface slabs. This is good for short-term stability but not a good weather pattern for our snowpack in the longer term. Under this weather regime weak layers will continue to flourish, both near the ground and near the surface, and our next major snow storm will once again lead to widespread avalanche activity.