Avalanche Forecast

A couple of large (size 2-3) persistent slab, human-triggered avalanches have been reported within the last 7 days. 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.

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

In alpine terrain, recent winds and warm temperatures have created a variety of wind-affected surfaces. Recently formed hard surfaces and surface crusts had new surface hoar and facets on top before being buried by small amounts of new snow earlier this week. This new layer should be monitored closely moving forward as new snow arrives.

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.

Wednesday night

Mostly cloudy. Trace amounts of new snow. Temperature -15 C overnight. North winds at 15 km/h in the alpine.

Thursday

A mix of sun and cloud. No new snow. Temperature rising to -8 C into the afternoon. A light north breeze.

A mix of sun and cloud. Flurries possible. Temperature -7 C. Light, variable winds.

A mix of sun and cloud. Flurries possible. Temperature low -13 C high -7 C. Light, variable winds.

More details can be found in the Mountain Weather Forecast.

• In times of uncertainty conservative terrain choices are our best defense.
• Use caution on large alpine slopes, especially around thin areas that may propagate to deeper instabilities.
• Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
• Persistent slabs have potential to pull back to lower angle terrain.
• Make observations and assess conditions continually as you travel.