Avalanche Forecast
Issued: Mar 15th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
zryan,
Avalanche Canada
Storm slabs are expected to remain reactive to human-triggering in wind-loaded terrain or where slabs are sitting on a weak layer of surface hoar or a sun crust.
Start on smaller terrain features and gather information before committing to bigger terrain.
Summary
Confidence
Moderate - Forecast precipitation (either snow or rain) amounts are uncertain.
Weather Forecast
A series of frontal systems coming in off the coast will bring light precipitation throughout the week.
Tuesday Overnight: Mainly cloudy, light precipitation. Localized areas up to 10 cm accumulation. Moderate to strong westerly winds. Freezing level dropping to 900 m.Â
Wednesday: Partially cloudy, light precipitation. Moderate westerly winds. Freezing level rising to 1500 m.
Thursday: Mainly cloudy, light precipitation. Localized areas up to 10 cm accumulation. Moderate to strong southwesterly winds. Freezing level 1500 m.
Friday: Partially cloudy, light precipitation. Moderate to strong southwesterly winds. Freezing level rising to 1500 m.
Avalanche Summary
On Monday, limited alpine observations were made with stormy conditions. Several natural storm slabs were observed at treeline and below. These storm slabs where mainly failing on a weak layer of surface hoar or a crust below the storm snow.
Numerous naturally triggered storm slab avalanches up to size 2 were reported at treeline and above over the weekend. They occurred primarily on wind-loaded north-east aspects.
Riders may get surprised by widely propagating storm slabs that are sitting on a weak layer of surface hoar at treeline and below.
Snowpack Summary
Continued light precipitation will add to 20-50 cm of recent settling storm snow. In the alpine and treeline, southwest winds have created deeper deposits of slab in lee areas. Storm snow tapers rapidly below treeline, where moist snow or a melt-freeze crust can be expected from rain and warm temperatures.
The recent storm snow is sitting on various surfaces, including hard wind-affected snow, sun crusts on southerly slopes, and surface hoar on shady or sheltered slopes.Â
The lower snowpack is generally well-settled and strong in most areas, with prominent crust layers 50 to 100 cm deep. No recent persistent slab avalanches have been reported on these layers.
Terrain and Travel
- 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.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
Problems
Storm Slabs
20-50 cm of recent snow and moderate southwest winds formed fresh storm slabs that have been most reactive in wind-affected terrain; especially where slabs are sitting on a weak layer of surface hoar or a sun crust.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 16th, 2022 4:00PM
