Avalanche Forecast
Issued: Apr 11th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Wet, Cornices and Wind Slabs.
cgarritty,
Avalanche Canada
Tune in and anticipate the effects of warming as you travel. It will affect increasingly high elevations and shaded aspects over the coming days. Be especially wary of slopes with cornices above them.
Summary
Confidence
High -
Weather Forecast
Sunday night: Clear. Light north winds, increasing into the morning.
Monday: Sunny. Moderate northeast winds, becoming strong overnight. Alpine high temperatures around -4 with freezing levels to 1600 metres.
Tuesday: Sunny. Light northeast winds. Alpine high temperatures around 0 with freezing levels to 2100 metres, continuing to rise overnight
Wednesday: Sunny. Light to moderate northeast winds, potentially strong in the alpine. Alpine high temperatures around +4 with freezing levels to 2500 metres.
Avalanche Summary
Saturday's MIN was active! Many users in the Sea to Sky and in adjacent regions encountered unstable snow conditions. Avalanche activity appears to have been limited to the depth of our latest storm snow, which was substantial in southern parts of the region. Wind loaded features were (unsurprisingly) especially reactive.
Looking forward, Monday's concerns should be limited to lingering wind slabs and predictable wet loose activity connected to daytime warming. Tuesday ushers in the start of a dramatic warming trend that will begin to expand the extent of wet loose concerns to higher elevation, more shaded aspects and may eventually test deeper snowpack layers.
Snowpack Summary
New surface melt-freeze crusts formed on solar aspects by the end of the day Saturday atop 10-30 cm of new snow, tapering with elevation and toward the north of the region, that accumulated through Friday night. Strong to extreme south and east winds have left behind varying levels of wind effect on many aspects in open terrain. Whistler Peak saw gusts of up to 140 km/h during the storm.Â
Overall the new snow is likely to have now established a solid bond with the previous surfaces of crust, wind effect, and settled storm snow, however isolated slabs in steep, wind loaded features may remain reactive to human triggering.Â
Solar warming will break down surface crusts and encourage wet loose releases -both natural and human triggered- each day on solar aspects and increasingly toward shaded alpine terrain as freezing levels march upward over the coming days.
Cornices are large and looming along ridgelines and formed fragile new growth during Friday's storm. Their release is unpredictable, requiring a large berth if you're travelling above or below them. Forecast rising freezing levels will increase the chances of cornice releases.
Terrain and Travel
- Loose avalanches may start small but they can grow and push you into dangerous terrain.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Small avalanches can have serious consequences in extreme terrain. Carefully evaluate your line for wind slab hazard before you commit to it.
Problems
Loose Wet
Surface snow will lose cohesion and become unstable with solar warming during the day. Avoid exposing yourself to terrain where a small wet loose release could have big consequences.
Aspects: South East, South, South West, West.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Cornices are large and looming along many ridgelines, and have grown with recent fresh snow and wind. They become increasingly unstable during periods of warming.
Aspects: North, North East, East, West, North West.
Elevations: Alpine.
Likelihood
Expected Size
Wind Slabs
Isolated wind slabs may still react to human triggering in steep features at ridgecrest.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 12th, 2021 4:00PM
