Avalanche Forecast

Archived

Feb 22nd, 2023–Feb 23rd, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Glacier.

Sheltered terrain will provide the best skiing, and reduce exposure to brisk Northerly winds.

Confidence

Moderate

Avalanche Summary

Isolated natural avalanche observed on Wednesday along the highway corridor.

A natural cycle Tues AM, with the dramatic change in wind direction, saw numerous avalanches to sz 2-3, with isolated sz 4, especially from S'ly aspects. This came after 2 consecutive days of artillery control, which produced good results to sz 4.

Snowpack Summary

Up to 80cm of recent storm snow is being reworked by NE winds. These winds will reverse load terrain at treeline and in the alpine.

Several thin crusts are buried below the storm snow on steep solar aspects.

The deep persistent weakness at the base of the snowpack reacted to the large load delivered by last weekends storm, producing avalanches up to size 4. This layer will take a large trigger to trigger.

Weather Summary

Cold, dry air persists over the region till the weekend. Expect temperatures to be 10-20 deg below normal + wind!

Tonight: Cloudy w/ clear periods, Alp Low -30*C, Mod E winds

Thurs: Sunny w/ cloudy periods, Alp High -24*C, Light E winds

Fri: Sunny w/ cloudy periods, Alp High -23*C, Light SW winds

Terrain and Travel Advice

Avoid freshly wind loaded terrain features.
Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
Back off if you encounter whumpfing, hollow sounds, or shooting cracks.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.