Avalanche Forecast
Northwest Coastal
Strong winds have littered exposed areas with wind slabs of varying age and reactivity. Keep your guard up in sheltered terrain - recently buried surface hoar continues to demand conservative terrain selection.
Avalanche Problem 1: Wind Slabs
What Elevation?
Which Slopes?
Chances of Avalanches?
Expected Size?
Travel and Terrain Advice
- Use caution in lee areas. Recent wind loading has created deep slabs.
Avalanche Problem 2: Persistent Slabs
What Elevation?
Which Slopes?
Chances of Avalanches?
Expected Size?
Two weak layers are being monitored in the upper snowpack, surface hoar found about 25 cm deep as well as a crust at the base of our recent storm snow. These layers were active during the storm and remain an ongoing concern.
Travel and Terrain Advice
- Be cautious around convex rolls at and below treeline where buried surface hoar may be preserved.
- Use conservative route selection, choose moderate angled and supported terrain with low consequence.
Avalanche Summary
Reports from Friday included more extensive observations of a recent natural avalanche cycle that produced numerous storm slab avalanches to size 3. Another round of explosives control southeast of Terrace yielded mostly size 1 loose dry and slab releases, with one size 2 wind slab. An explosives-controlled cornice also triggered a size 2.5 slab down to the base of the snowpack on a confined feature in a thin snowpack area.
Explosive control work on Thursday produced very large destructive storm slab results from size 3-4+ on north and south aspects the Skeena corridor, as well as a remotely (from a distance) triggered size 2 storm slab at treeline in the Shames area.
On Wednesday and Tuesday we received a reports of a large (size 3-3.5) natural cycle as well as two very large (size 4 and 4.5) natural avalanches that failed in deeply wind-loaded areas. The larger of these occurred near Snowbound Creek west of Terrace on a south aspect at 1400 m and ran full path from ridge top to valley bottom, destroying a significant amount of mature forest beyond its historical trimlines.
Snowpack Summary
Strong outflow winds have been scouring and redistributing recent storm snow accumulations of 50-100 cm into deep wind slabs on a variety of aspects in wind-exposed terrain.
In sheltered areas at treeline and below, 20-30 cm of settling snow sits over a layer of surface hoar that was recently reported as reactive to skier traffic. Below this, the interface at the base of the storm snow consists of heavily wind affected surfaces at higher elevations as well as sun crusts or dry facets in sheltered terrain. These two layers are the concerns identified in our persistent slab problem.
Another interface composed of sun crust, facets, and more isolated surface hoar can be found about 100-150 cm deep.
Deeper in the snowpack, around 150-200 cm down, you'll find a crust/surface hoar layer from January which still has the potential to be triggered from a thin snowpack spot, or with a large trigger like cornice fall.
Basal facets may be found near the bottom of the snowpack in colder and drier parts of the region, such as in the far north.
Weather Forecast
Sunday: Mainly sunny. Some valley cloud due to a weak temperature inversion. Light variable winds. Alpine high temperatures of -8. Slightly cooler at lower elevations.
Monday: Mainly cloudy with isolated flurries and a trace of new snow. Light southwest winds. Alpine high temperatures of -10.
Tuesday: Cloudy with flurries bringing about 3 cm of new snow, increasing overnight. Light to moderate south winds.
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 winds have been redistributing storm snow into a mix of old and new wind slabs on all aspects. Depending on their age, wind slabs may range from stubborn to touchy.