Avalanche Forecast
Northwest Coastal
Natural activity will likely taper off on Friday, however expect the new storm slabs to remain primed for human triggering especially in wind-loaded areas. Choose conservative terrain and be aware of overhead hazard especially on sunny aspects.
Avalanche Problem 1: Storm Slabs
What Elevation?
Which Slopes?
Chances of Avalanches?
Expected Size?
Travel and Terrain Advice
- Be careful with wind loaded areas, especially near ridge crests and roll-overs.
- Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Use conservative route selection, choose moderate angled and supported terrain with low consequence.
Avalanche Problem 2: Persistent Slabs
What Elevation?
Which Slopes?
Chances of Avalanches?
Expected Size?
A weak layer exists 120-150 cm below the surface. It may still be possible for humans to trigger persistent slab avalanches on this layer, or for a storm slab release to step down to this layer resulting in a very large avalanche.
Travel and Terrain Advice
- Caution around convexities or areas with a thin or variable snowpack.
- Minimize overhead exposure during periods of heavy loading from new snow, wind.
- Avoid lingering in runout zones. Large avalanches may run long distances.
Avalanche Summary
A widespread natural avalanche cycle occurred in the Terrace and Shames areas during Wednesday's storm with reports of numerous storm slab avalanches up to size 2 running far and fast in the new snow at all elevations.
Tuesday there were reports of two skier triggered size 1 wind slab releases just northwest of Terrace, where a soft slab up to 35 cm deep had formed on wind-loaded features.
Monday evidence of a natural avalanche cycle from size 2.5 - 3.5 was reported on north to south aspects between 1000-1700 m, west of Terrace, with several persistent slabs suspected to have failed on the mid or early January layers during the height of the weekend's storm.
On the weekend persistent slab activity was reported north of Meziadin Junction where a natural size 4 and a natural size 3.5 were observed on a southwest and northeast aspect at 1800-2000 m and are suspected to have failed on the mid-January layer.
Snowpack Summary
Wednesday's storm delivered another 30-50 cm of new snow, and a mix of rain and freezing rain for areas west of Terrace, bringing storm snow totals of over 100 cm in the last 10 or 12 days for the Terrace area. Northern areas have seen about 50-70 cm of recent storm snow.
Beneath the storm snow lies a 5-20 cm thick crust that was buried early February and can be found 60-110 cm below the surface on all aspects up to 1400 m.
A weak layer buried in mid-January is 120-150 cm below the surface and remains a concern. In most areas this layer is a crust, but it may also be surface hoar in sheltered areas at treeline and below. This layer produced a few human triggered avalanches throughout the region over the past week, and may remain reactive as it adjusts to the weight of the new snow.
In thinner snowpack areas (north and inland), deeper crust / surface hoar layers that were buried in December and early January may still be a concern as well. They are buried over 150 cm below the surface, but may still be triggerable from shallow spots.
Weather Forecast
FRIDAY: Mostly sunny. Ridge wind light to moderate, northeast. Temperature -10. Freezing level valley bottom.
SATURDAY: Mostly sunny. Ridge wind light, southwest. Temperature near 0. Freezing level 1600 m.
SUNDAY: Mostly sunny. Ridge wind light, north. Temperature -6. Freezing level valley bottom.
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.
Wednesday's storm event has formed reactive storm slabs at all elevations but especially in wind-exposed areas at treeline and above. Be aware that these slabs overlie a crust from early-February and may also step down to a deeper weak layer.