Avalanche Forecast
Issued: Mar 10th, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
CG,
Avalanche Canada
Gusty winds and steady, light snowfall will build reactive storm slabs in the Alpine and at Tree-line. Once moving, these new slabs may have enough mass to trigger the deeper instabilities, resulting in large avalanches.
Stick to smaller, supported features with limited overhead exposure.
Summary
Confidence
Avalanche Summary
Numerous natural avalanches in the storm snow were observed from Tupper, Macdonald, Mannix, and Cougar Corner today, from sz 1.5 to 2.5, ending on the fans.
Thursday, we observed naturally-triggered size 3 slab avalanches from Catamount Mtn SE face and Mt. Leda NE face. These were both deep, likely failing on the Feb 3rd crust.
We continue to see daily reports in the region of human triggered avalanches on the Feb 3rd layer.
Snowpack Summary
New snow and gusty winds are depositing a storm slab atop variable old surfaces: a thin suncrust on South & West aspects; previous wind effect from variable winds in open terrain; and settled powder in sheltered areas.
80-140cm of settled snow sits atop a sugary facet layer. These facets are not bonding well to the widespread, very firm crust from Feb 3rd. This crust is a significant persistent weak layer and will be the main layer of concern for the foreseeable future.
Weather Summary
Weak cold fronts will pepper the Rogers Pass region over the next 2-3 days. Light snowfall and gusty winds with each passage should be expected.
Tonight: Flurries, 5cm, low -7°C, mod SW winds, FZL 1000m.
Mon: Flurries, 5cm, Alp high -6°C, light/mod SW winds, FLZ 1400m
Tues: Flurries, 5-10cm, Alp high -6°C, light/mod SW winds, FZL 1500m
Wed: Mix of sun/cloud, Alp high -8°C, light W winds, FZL 1300m.
Terrain and Travel Advice
- Watch for fresh storm slabs building throughout the day.
- Use conservative route selection. Choose simple, low-angle, well-supported terrain with no overhead hazard.
- Remote triggering is a concern, avoid terrain where triggering slopes from below is possible
Problems
Storm Slabs
Storm snow is slowly piling up, accompanied by gusty SW winds. This will build soft slabs in lee-specific areas and they'll likely become more reactive as snowfall amounts and winds increase. If triggered, these slabs may also provide enough mass to trigger the deeper Persistent Weak Layer.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
This crust-facet combo (Feb 3rd) was created by a rain event followed by an extended cold, clear period without snow earlier this month. 80-140cm now sits on the persistent weak layer. Human triggered avalanches on this layer remain possible, and resulting avalanches could be very large in size.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 11th, 2024 4:00PM
