Avalanche Forecast
Issued: Mar 31st, 2021 5:56PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Loose Wet and Cornices.
Mark Herbison,
Alpine hazard has been elevated due to forecasted high winds and the potential for rapid wind slab development. The below tree line hazard is rated as Moderate for the possibility of loose wet avalanches late in the afternoon.
Summary
Weather Forecast
Thursday will see clear skies in the morning with increasing cloudiness into the afternoon, with 1-5 cm of snow accumulation. Winds are forecasted to be 30-80km/hr from the South West. Freezing level will rise to ~2000m. Another pulse of snow is expected on the weekend.
Snowpack Summary
15-35cm of recent storm snow, with the most around Sunshine and Bow Summit, will be available for transport by the forecasted strong winds on Thursday to build wind slab. The March 19 interface is down 20-50cm and consists of crust on solar aspects and facets on north aspects. Basal facets exist in shallow areas east of the divide.
Avalanche Summary
A size 2, human triggered avalanche occurred on Tuesday in the Bow Summit area, one person caught, no injuries.
Reports of natural cornice activity in the Sherbrooke Lake area, cornice debris did not triggered the slope. Some loose dry sluffing was also observed out of steep alpine terrain.
Confidence
Problems
Wind Slabs
Strong winds from the South West on Thursday will likely build wind slab in the alpine and down into tree line. Use caution in steep or loaded terrain until you have a sense for how reactive the new slab is.
- Use caution in lee areas. Recent wind loading have created wind slabs.
- Be careful with wind loaded pockets, especially in steep confined alpine terrain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Wet
Sun and warm temperatures will weaken the snowpack at lower elevations, especially on steep, rocky, solar terrain. Avoid these areas if the snow is moist or punchy.
- Avoid ice climbs that are exposed to steep rocky terrain on solar aspects.
- Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.
Aspects: South East, South, South West, West.
Elevations: Below Treeline.
Likelihood
Expected Size
Cornices
Cornices are big and the springtime is when they fall off more frequently. Strong winds combined with the forecasted warmup may make them more likely to fall. Don't be nearby when they do!
- Minimize exposure to overhead hazard from cornices.
- Cornices become weak with daytime heating, so travel early on exposed slopes.
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 1st, 2021 4:00PM
