Avalanche Forecast
Issued: Jan 14th, 2025 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs.
Parks Canada,
Avalanche Canada
Take the time to dig into the snowpack. See if the surface hoar/suncrust exists underfoot. If it's there and the snow feels firm above, there's the potential for a human-triggered slab avalanche.
Summary
Confidence
Moderate
Avalanche Summary
Skier triggered sz 3 in Lone Pine yesterday, ran ~1000m and accumulated significant mass.
The natural cycle has slowed. Several natural avalanches to sz 2.5 were observed Monday afternoon, triggered by solar input on S through W slopes.
There have been several reports of rider triggered avalanches up to size 1 in terrain adjacent to Glacier National Park.
Snowpack Summary
30-40cm of settled snow overlies a weak interface of widespread surface hoar on all aspects into the high alpine, and a thin suncrust on steep S to W aspects. Open Alpine and Treeline slopes exposed to S'ly winds, and their adjacent lee features, hold pockets of wind slab. Where present, stiff surface slabs have been reactive in tests, indicating propagation potential.
Overall the mid and lower snowpack is strong and well settled.
Weather Summary
Mild temps until Thurs, then a small pulse of snow and plummeting temps.
Tonight Mainly cloudy. Alpine low -4°C. Wind SW 30-40km/hr. Freezing level (FZL) at valley bottom.
Wed Cloudy, isolated flurries. Alpine high -1°C. Wind SW 30-40km/hr. FZL 1700m.
Thurs Flurries. 10cm. Alp high -5°C. Winds W 30 gusting to 90km/h. FZL 1100m.
Fri Sun/cloud/isolated flurries. Alp high -12°C. Winds N 15-35km/h. FZL valley bottom
Terrain and Travel Advice
- Be especially cautious as you transition into wind-affected terrain.
- Avoid areas where the snow feels stiff and/or slabby.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks, or recent avalanches.
Problems
Persistent Slabs
Up to 50cm of new snow this week is settling into a slab. This slab is reactive in tests at Treeline and above, and shows a potential for significant propagation. It was likely the culprit in the skier-triggered, size 3 avalanche on Lone Pine Monday.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 15th, 2025 4:00PM
