Avalanche Forecast
Regions: South Rockies.
Recent reverse loading from northeast winds have formed wind slabs in unusual places. There is uncertainty about how quickly slabs will bond to old surfaces like melt-freeze crusts and hard wind-pressed snow.
Confidence
Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.
Weather Forecast
TUESDAY NIGHT: Mostly clear, light northeast winds at treeline, alpine lows -27.
WEDNESDAY: Mostly sunny, increasing clouds later in day, light northeast winds at treeline, high alpine could see moderate to strong winds, especially later in the afternoon. Alpine high of -15.Â
THURSDAY: Light flurries overnight. Partly cloudy with light northwest winds. Alpine high of -10.
FRIDAY: Mostly sunny, light southwest winds and alpine highs of -10.
Avalanche Summary
On Tuesday the field team reported evidence of a natural wind-driven avalanche cycle (likely from Monday), with avalanches in the size 1-2 range in the northern Elk Valley. On the east slope of the divide dry loose avalanches and small wind slabs have been reported.
Snowpack Summary
The 10-20 cm of most recent snow has been redistributed by moderate to strong northeast winds and has formed wind slabs in unusual places. Depending on wind loading and where you are in the region you could find approximately 20-50 cm over melt-freeze crusts on solar aspects at all elevations, and over firm wind-affected snow in other exposed terrain.Â
The snowpack below is generally well consolidated, with a crust/facet layer found near the bottom of the snowpack. It is currently considered dormant but could become active later this season. Check out the forecaster blog for more information.Â
Terrain and Travel
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Be alert to conditions that change with elevation and wind exposure.
Avalanche Problems
Wind Slabs
Watch for pockets of wind slab on various aspects in exposed terrain and around ridgelines. These slabs have formed on top of old crusts and hard wind-pressed snow and there is uncertainty about how quickly they will bond to old surfaces.
The storm initially came in with southwest winds, but with the intrusion of arctic air, winds switched to the northeast potentially building slabs in less common locations.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2