Avalanche Forecast
Issued: Feb 15th, 2024 4:00PM
The alpine rating is Persistent Slabs and Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeStart on small slopes, and downgrade your objective if you find signs of instability like shooting cracks or whumpfs.
Touchy slabs have been surprising backcountry users.
Summary
Confidence
Moderate
Avalanche Summary
On Wednesday, several rider-triggered slab avalanches continued to be reported on all aspects at treeline and above, up to size 2.
On Tuesday, numerous similar avalanches were reported up to size 2.5.
Some of these avalanches are failing on buried sun crust and surface hoar 20-25 cm below the snow surface, and others are failing on a firm crust 30-50 cm deep.
Many of these avalanches surprised people with wider than expected propagation and remote triggering from afar.
Snowpack Summary
A sun crust likely exists on steep south facing aspects. 15 to 25 cm of snow overlies a variety of surfaces including a weak layer of small surface hoar in sheltered areas and/or another thin sun crust on solar aspects.
The widespread crust buried in early February is down 30 to 50 cm and is proving to be touchy to human and machine triggers. In most places this crust is widespread up to 2400 m.
Various weak layers persist in the mid to lower snowpack, however, triggering these layers is unlikely where they are bridged by a thick crust.
Weather Summary
Thursday Night
Clear. No new snow expected. Light northeast ridgetop wind. Treeline temperature around -10 °C.
Friday
Sunny. No new snow expected. Light east or northeast ridgetop wind. Treeline temperature around -6 °C.
Saturday
Sunny. No new snow expected. Light to moderate southeast ridgetop wind. Treeline temperature around -4 °C.
Sunday
Mostly cloudy. No new snow expected. Light southeast ridgetop wind. Treeline temperature around -3 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
- Choose slopes that are well supported and have limited consequence.
- A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
Problems
Persistent Slabs
Persistent slabs are reactive to human triggers and have been catching people by surprise. They are up to 50 cm deep but show wide propagation across slopes and in convex terrain features, especially where the snow is wind affected.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Wind Slabs
A change in wind direction has formed wind slabs on all aspects. Cracking and whumping below your feet are indicators of wind slab.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 16th, 2024 4:00PM