Avalanche Forecast
Northwest Coastal
Strong southerly winds have amplified wind slab problems and sustained warming is testing a deeper weak layer. Play it conservative until temperatures cool off.
Avalanche Problem 1: Wind Slabs
What Elevation?
Which Slopes?
Chances of Avalanches?
Expected Size?
Travel and Terrain Advice
- Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.
- Be increasingly cautious as you transition into wind affected terrain.
Avalanche Problem 2: Persistent Slabs
What Elevation?
Which Slopes?
Chances of Avalanches?
Expected Size?
A weak layer buried about 60-80 cm may become reactive with warming temperatures. Shallower slabs may step down to it and form large, destructive avalanches. This layer may have been involved in several large avalanches in Bear Pass area on Saturday.
Travel and Terrain Advice
- Avoid convexities or areas with a thin or variable snowpack.
- Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
Avalanche Problem 3: Loose Wet
What Elevation?
Which Slopes?
Chances of Avalanches?
Expected Size?
Warm temperatures will persist on Monday. Small loose wet avalanches may still run naturally or with a human trigger in steep terrain - especially in areas that have new snow on the surface.
Travel and Terrain Advice
- Use extra caution on solar slopes or if the snow is moist or wet.
Avalanche Summary
Reports from the Bear Pass area on Sunday included observations of a few naturally triggered Size 2-3 slabs releasing from northeast-facing alpine terrain. It hasn't been confirmed, but these may have run on the mid-December crust/facet interface described in the snowpack discussion. Size 1-2 wind slabs were also observed releasing naturally from crossloaded gully features below treeline. No avalanches were reported from elsewhere in the region.
Snowpack Summary
Precipitation combined with variable freezing levels delivered a mix of around 5-10 cm of new snow and freezing rain to the region on Saturday. Where the new snow exists, strong southerly winds have been blowing it into fresh wind slabs in lee terrain. Beneath the new snow, recent strong northerly outflow winds formed wind slabs on southerly and southwesterly features, so a mix of old and new wind slabs can now likely be found on all aspects in wind affected areas.
Below the most recent precipitation, up to 45 cm recent snow overlies several layers of interest in the upper snowpack. These include crusts, surface hoar and facets. A hard crust with associated facets from mid-December sits deeper in the snowpack, about 60 cm down. Any of these layers could create a persistent slab problem as wind-loading and warming change the properties of the slab above.
The lower snowpack is generally strong, with the exception of areas around Stewart and further north where a basal crust and facets exist.
Weather Forecast
Monday: A mix of sun and cloud with low valley cloud due to a lingering temperature inversion. Light southeast winds. Freezing level to around 1500 metres with alpine high temperatures around +2. Cooler at lower elevations.
Tuesday: Mainly cloudy with scattered flurries bringing 1-4 cm of new snow, continuing overnight. Moderate to strong south winds. Freezing level returning to about 700 metres as the temperature inversion dissipates. Alpine high temperature to -2.
Wednesday: Cloudy with flurries bringing approximately 5 cm of new snow with light flurries continuing overnight. Moderate to strong east winds. Freezing level to 600 metres with alpine high temperatures of -4
Avalanche Forecasts in your Inbox
Avalanche Canada has switched to an RSS feed for its daily forecasts. This is a much more flexible method that allows automatic delivery to your email inbox, or to an RSS reader of your choice.
What are RSS feeds?
RSS (Really Simple Syndication) is a popular standardized file format allowing up-to-date delivery of web-based content. RSS feeds enable you to receive content updates from websites, delivered to your email through an RSS aggregator (such as blogtrottr.com) or viewed through applications called RSS readers (such as feedly.com).
Set up an RSS feed for your email:
Select a RSS aggregator
- Northwest Coastal URL:
http://www.avalanche.ca/api/forecasts/northwest-coastal.rss - Copy the url and paste it into the appropriate field of your RSS aggregator.
- Fill in your email address.
- Voila! Watch the Avalanche Canada forecast roll into your inbox.
Forecast Disclaimer
Avalanche Canada's Public Avalanche Bulletin, and other information and services provided by Avalanche Canada, are intended for personal and recreational purposes only.
**THIS INFORMATION IS PROVIDED "AS IS" AND IN NO EVENT SHALL THE PROVIDERS BE LIABLE FOR ANY DAMAGES, INCLUDING, WITHOUT LIMITATION, DAMAGES RESULTING FROM DISCOMFORT, INJURY, OR DEATH, CLAIMS BY THIRD PARTIES OR FOR OTHER SIMILAR COSTS, OR ANY SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, ARISING OUT OF THE USE OF THE INFORMATION.**
The user acknowledges that it is impossible to accurately predict natural events such as avalanches in every instance, and uses the data in this bulletin with this always foremost in mind. The accuracy or reliability of the data is not guaranteed or warranted in any way and the Providers disclaim liability of any kind whatsoever, including, without limitation, liability for quality, performance, merchantability and fitness for a particular purpose arising out of the use, or inability to use the data.
Strong southerly winds have been blowing new snow into wind slabs in lee terrain. Older, more stubborn windslabs from recent outflow winds may still be reactive around ridgecrests and on crossloaded features at lower elevations.