Avalanche Forecast
Issued: Mar 8th, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
JH,
Avalanche Canada
We haven't had significant snowfall in awhile, but it is not time to start stepping out yet.
Skiers/riders could still trigger large avalanches on the persistent weak layer.
Make plans to ski conservative slopes with limited overhead exposure, and stick to them.
Summary
Confidence
Avalanche Summary
On Thursday, we observed fresh naturally triggered size 3 slab avalanches from Catamount Mtn SE face and Mt. Leda NE face. These were both deep slabs, suspected to have failed on the Feb 3rd crust.
On Monday, a field crew remote-triggered a sz 1 on the Feb 3 crust while approaching a snow profile site.
We continue to see daily reports in the region of human triggered avalanches on the Feb 3rd layer.
Snowpack Summary
Intense spring sun has created a thin surface crust on South & West aspects.
Variable winds have created soft wind slabs at ridgetop on most aspects. Expect significant wind effect below glaciers due to strong downflow winds.
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
A cold front moving inland gives modest snowfall amounts and increasing winds Saturday afternoon into Sunday.
Tonight: Clear periods. Alpine low -6°C. Light Southerly ridgetop winds.
Sat: Cloudy, pm flurries (5-10cm). Alpine high -1°C. Freezing level (FZL) 1800m. Increasing SW winds (extreme gusts by the PM).
Sun: Flurries (5-10cm). Low -9°C, High -5°C. Gusty mod SW winds.
Mon: Flurries (~5cm).
Terrain and Travel Advice
- 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
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Problems
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
Wind Slabs
Just as old windslabs are becoming less reactive, increasing winds Saturday into Sunday will refresh this problem. Expect increasing reactivity in the immediate lees of alpine ridges or cross loaded areas.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 9th, 2024 4:00PM
