Avalanche Forecast
Issued: Mar 16th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Storm Slabs.
zryan,
Avalanche Canada
Practice good travel habits and choose conservative, low consequence lines. A buried weak layer has been reactive in recent days, creating large and surprising avalanches.
Make sure to read the Avalanche Problems section.
Summary
Confidence
Moderate - Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.
Weather Forecast
A series of frontal systems coming in off the coast will bring light precipitation throughout the week.
Wednesday Overnight: Partially cloudy, light snowfall, up to 5 cm of accumulation. Freezing level dropping to 500 m. Moderate to strong southwest winds.Â
Thursday: Cloudy with snowfall, 5-15 cm of accumulation. Freezing level rising to 1500 m. Moderate to strong southwesterly winds.Â
Friday: Partially cloudy, light flurries. Freezing level rising to 1500 m in the afternoon. Light to moderate southwesterly winds.
Saturday: Mainly cloudy, light flurries. Freezing level around 1000 m. Light to moderate southwesterly winds.Â
Avalanche Summary
On Tuesday, numerous natural and skier-triggered storm slabs were reported throughout the region. The larger and more consequential avalanches occurred in wind-loaded terrain or on the weak layer of surface hoar or crust below.Â
A natural avalanche cycle up to size 3 occurred on Monday afternoon with heavy snowfall, wind and warm temperatures.
Snowpack Summary
Continued light precipitation will add to 30-60 cm of recent settling storm snow at treeline and above. Storm snow tapers rapidly below treeline, where moist snow or a melt-freeze crust can be expected from rain and warm temperatures.
This new snow is sitting on various surfaces, including hard wind-affected snow, sun crusts on southerly slopes, facetted snow, and isolated pockets of surface hoar. The new snow is bonding poorly to this old surface, especially where a facet/crust layer or surface hoar is present below.
The late February persistent weak layer combination of crust, facets and surface hoar is down 30-40 cm. Reports suggest this layer is not a problem in most areas. Two persistent weak layers from mid-February and late January are buried 50-120cm deep. No recent avalanches have been reported on these layers.
Terrain and Travel
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Be especially cautious as you transition into wind affected terrain.
- Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
- Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
Problems
Persistent Slabs
Over the past week, 40-80 cm of new snow buried a weak layer of facet/crust and surface hoar. This layer is most concerning on south-facing aspects, where a sun crust and facets may be buried, or in open areas at treeline and below, where surface hoar may be preserved.
The most reactivity has been seen around Malakwa (e.g., Queest/Gorge).
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Storm Slabs
40-80 cm of recent storm snow, warm temperatures, and moderate southwest winds have formed storm slabs that have been most reactive in wind-affected terrain, or where slabs are sitting on a weak layer of surface hoar or a sun crust.
In steep sheltered terrain, small dry-loose sluffs may be reactive to human-triggering. Avoid terrain traps, such as gullies, where the consequences of a small avalanche could be serious.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 17th, 2022 4:00PM
