Glacier

New snow continues to slowly build a slab on a dangerous combination of weak surface hoar, facets and a crust.

Approach all avalanche terrain with cation, triggering avalanches is likely.

Moderate

• We are uncertain due to how buried persistent weak layers will react with the forecast weather.
• We are confident that there are persistent slabs in the snowpack, but uncertain about how likely they are to trigger.

There were a few large avalanches in the steep terrain of the highway corridor Friday night. Most notably size 3 slab avalanches were observed in MacDonald Gullies 5 and 11.

A field team was easily able to ski cut size 1-1.5 slabs, about 15cm deep, on the SW aspect of Glacier Crest on Friday.

Operations to the West (with a little more accumulated snow) have been reporting natural and remote triggering of the surface hoar layer, producing avalanches up to size 3.

Wind and warm temps are stiffening up the new snow (20-30cm and counting). This is accumulating over a troubling combination of surface hoar or facets on a crust. The surface hoar is on most aspects and elevations, and is largest (up to 40mm) in sheltered areas below treeline. The crust is firmer on solar aspects, and had been weakening/faceting on polar aspects.

The mid and lower snowpacks are generally well settled and strong.

Ongoing snow flurries are forecast into next week.

Tonight: Flurries (5cm). Alpine low -3 °C. Freezing level (FZL) 1700m. Light SW ridgetop winds.

Sunday: Flurries (5cm). High -2 °C. FZL 1700m. Gusty moderate SW wind.

Mon: Flurries (10cm). Low -6 °C, High -5 °C. FZL 1400m. Moderate SW wind.

Tues: Flurries(5cm). Low -6 °C, High -0 °C. FZL 1700m. Moderate SW wind.

• It's a good day to make conservative terrain choices.
• Avoid areas where the snow feels stiff and/or slabby.
• Avoid terrain traps such as gullies and cliffs where the consequence of any avalanche could be serious.