Avalanche Forecast
Issued: Mar 28th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Cornices.
kdevine,
Avalanche Canada
Recent new snow with strong wind has formed storm slabs that are likely still reactive at upper elevations, especially in wind loaded areas.
Keep in mind that the sun can quickly initiate natural avalanche activity and weaken cornices, especially at this time of the year.
Summary
Confidence
Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.
Weather Forecast
SUNDAY NIGHT - Cloudy with clear periods and isolated flurries / moderate to strong northwest wind / alpine low temperature near -12
MONDAY - Mainly sunny / moderate to strong north wind / alpine high temperature near -7 / freezing level 1300 m
TUESDAY - Mainly cloudy / moderate west wind / alpine high temperature near -3 / freezing level 1100 m
WEDNESDAY - A mix of sun and cloud / moderate southwest wind / alpine high temperature near -1 / freezing level 2000 m
Avalanche Summary
The likelihood of triggering avalanches will decrease somewhat in the wake of Sunday's storm, however, human triggering remains likely, especially in wind loaded areas at upper elevations. With so much new snow, even short periods of direct sun can trigger natural avalanches. Cornices are large and should be given a wide berth, especially when the sun comes out.
It is likely that a natural avalanche cycle occurred during the day on Sunday.
Snowpack Summary
20-40 cm of new snow fell throughout the region since Saturday night. This sits above a widespread melt-freeze crust, with the exception of high north-facing terrain. It may also be sitting on small surface hoar crystals reported on north and east aspects in the alpine. This recent precipitation likely fell as rain in many areas below treeline. The snow surface has likely frozen into a crust at lower elevations.
Cornices along ridgelines are large, and the likelihood of them failing will increase when the sun comes out.
Terrain and Travel
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Brief periods of sun could quickly initiate natural avalanche activity.
- Be aware of highly variable recent wind loading patterns.
- Cornices become weak with daytime heating or solar exposure.
Problems
Storm Slabs
Recent fresh snow and strong winds have formed widespread storm slabs that are likely still easy to trigger, especially in wind loaded areas. A change in wind direction on Monday means that wind loading may be found on many aspects.
With all of this new snow, even brief periods of sun can quickly trigger natural avalanches.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Cornices are large and looming along many ridgelines, and have likely grown with the recent snow and wind. Direct sun can weaken cornices significantly.
Aspects: North, North East, East, West, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 29th, 2021 4:00PM
