Avalanche Forecast

A couple of large (size 2-3) persistent slab, human-triggered avalanches have been reported over the weekend. Avalanches have occurred near ridgetops in north-to-northeast alpine terrain. Both avalanches have shown an impressive capability of propagating large distances. Here is a link to the most recent human-triggered size 3 avalanche.

Uncertainty remains about the distribution and extent of the problem.

If you are out in the backcountry please consider filling out a Mountain Information Network report.

In alpine terrain, recent winds have created a variety of wind-affected surfaces. New snow and wind will create thin wind slabs in exposed terrain features. Recently formed hard surfaces and surface crusts had new surface hoar and facets on top before being buried. This new layer should be monitored closely moving forward.

Persistent weak layers of surface hoar and/or facets exist in north facing alpine features behind ridge lines, creating a number of recent, scary human-triggered avalanches.

Below roughly 1700 m a widespread, supportive, melt-freeze crust is present, with moist snow below.

Tuesday night

Cloudy with light snow, 2 to 5 cm. Treeline temperatures -5 to -10 C. Moderate northeast alpine winds.

Wednesday

Cloudy, no precipitation. Treeline temperature -15 to -20 C. Moderate northeast alpine winds.

Cloudy, no precipitation. Treeline temperature -15 to -20 C. Moderate alpine winds.

A mix of sun and cloud. No precipitation. Treeline temperatures -15 to -20 C. Light northeast winds.

More details can be found in the Mountain Weather Forecast.

• In times of uncertainty conservative terrain choices are our best defense.
• Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
• Make observations and assess conditions continually as you travel.
• Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
• Wind slabs may be poorly bonded to the underlying crust.