Avalanche Forecast

Archived

Dec 8th, 2025–Dec 9th, 2025

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Lizard.

More snow and rain fell last night than expected!

Avoid exposure to avalanche terrain, natural avalanches are expected.

Confidence

Moderate

Avalanche Summary

We expect natural avalanches within the storm snow on Tuesday.

Snowpack Summary

By Tuesday morning, storm totals have reached over 80 cm in the high alpine. Higher elevations are likely heavily wind affected, with deep and reactive deposits. Lower elevations are likely rain soaked. Exact snow/rain line through the night is unknown.

A layer of faceted snow or surface hoar sits in the upper snowpack, with a crust from mid November buried 60–90 cm deep. Lower in the snowpack, there are several crusts, and in some areas, weak, sugary facets can be found near the ground.

Snowpack depths range from 80–150 cm and thin rapidly at lower elevations. Many slopes at treeline and below may reach threshold for avalanche activity with this storm.

Weather Summary

Monday Night
Cloudy. 20 to 35 mm of precipitation as snow or rain at treeline. 70 km/h southwest ridgetop wind. Treeline temperature -1 °C. Freezing level 1900 m.

Tuesday
Mostly sunny. 50 km/h west ridgetop wind. Treeline temperature -4 °C. Freezing level 1700 m.

Wednesday
Mostly cloudy. 5 to 15 cm of snow. 50 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 1400 m.

Thursday
Mostly cloudy. 5 to 20 mm of precipitation as snow or rain at treeline. 50 km/h west ridgetop wind. Treeline temperature 0 °C. Freezing level 1900 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Make conservative terrain choices and avoid overhead hazard.
Don't let storm day fever lure you into consequential terrain.
A moist or wet snow surface, pinwheeling, and natural avalanches are all indicators of a weakening snowpack.
Be cautious of buried obstacles, especially below treeline.

Problems

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Loose Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.