Avalanche Forecast
Regions: North Columbia.
Moderate winds shifting northwest overnight will continue to redistribute recent storm snow into deep slabs. Give the new snow time to settle and stabilize before pushing into bigger terrain. Crusty surfaces below treeline will make for low hazard but difficult travel conditions.
Confidence
Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.
Weather Forecast
Sunday night: Flurries bringing around 5 cm. Moderate northwest wind. Freezing level drops to valley bottom. Alpine temperature -13.
Monday: Mix of sun and cloud. Moderate northwest wind. Freezing level valley bottom. Alpine temperature -15
Tuesday: Mostly cloudy. Light westerly wind. Freezing level 1400 m. Alpine temperature -7.
Wednesday: Sunny. Light southwest wind. Freezing level 2000 m. Alpine temperature -1.
Avalanche Summary
We are still awaiting reports of avalanche activity from the weekend's storm. A widespread natural cycle is likely to have occurred Sunday.
Recent avalanche activity has primarily been small (size 1-1.5) wind slab and dry loose, with a few reaching the 2-2.5 size range. One notable size 3 slab avalanche was observed northeast of Revelstoke on Wednesday. The avalanche failed on the ground on a south aspect at 1600 m. In neighboring Glacier National Park and South Columbia regions, several natural cornice falls triggered deep slab avalanches size 2-3. As temperatures rise mid week, keep in mind that the springtime heat penetrates down to layers buried deep in the snowpack
Snowpack Summary
The weekend's storm dropped 20-40 cm over the southern Selkirk mountains and 5-10 cm elsewhere. This snow has likely been redistributed by strong wind, switching from southwest to northwest Sunday night. Crusty surfaces exist below treeline.
At alpine and treeline elevations, a widespread crust exists (except on north-facing slopes above 1800 m) buried 50-100 cm deep. Overall the snow seems to be bonding well at this interface, although there have been a few isolated avalanches running on crust layers over the past few week.
Terrain and Travel
- Be careful to keep storm day fever from luring you out into bigger terrain features.
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Seek out sheltered terrain where new snow hasn't been wind-affected.
- Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
Avalanche Problems
Storm Slabs
Storm slabs are most likely to remain reactive in wind loaded terrain features. Wind direction has varied from southwest to northwest so watch for these deep pockets on a variety of aspects.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2
Cornices
Cornices are likely fragile due to rapid growth with recent snow and wind.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood: Possible
Expected Size: 2 - 3