Avalanche Forecast
South Rockies
Fresh wind slabs are set to form over a new weak layer on Thursday. Natural wind slab releases could provide ample triggers for deeper persistent weak layers.
Avalanche Problem 1: Persistent Slabs
What Elevation?
Which Slopes?
Chances of Avalanches?
Expected Size?
Travel and Terrain Advice
- Stick to simple terrain and be aware of what is above you at all times.
- Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
- Avoid open slopes and convex rolls where buried weak layers may be preserved.
Avalanche Problem 2: Wind Slabs
What Elevation?
Which Slopes?
Chances of Avalanches?
Expected Size?
New snow and wind will build fresh wind slabs over a new weak layer on Thursday, and older wind slabs already exist on a range of aspects at higher elevations. A wind slab release may have the force needed to trigger a deeper persistent weak layer.
Travel and Terrain Advice
- Use ridges or ribs to avoid pockets of wind loaded snow.
- Be extra cautious as you transition into wind affected terrain.
Avalanche Summary
Large persistent slab avalanches were observed north of Sparwood (see the report here), which likely occurred over the weekend. Otherwise, limited reports suggest wet loose avalanches have been running in steep solar terrain and small thin wind slabs (size 1-1.5) releasing in alpine terrain.
Snowpack Summary
Light new snow amounts forecast for Wednesday night will begin to cover both a new layer of feathery surface hoar that has been developing in sheltered areas as well as sun crust on solar aspects. Recent warm temperatures formed this crust and also worked to settled the upper snowpack. Strong winds from the past few days have scoured windward slopes and formed new wind slabs in lee terrain at higher elevations. Wind direction has been variable but predominantly from the southwest.
An unstable weak layer from mid-December (predominantly feathery surface hoar crystals and/or a sun crust) is found at treeline and below treeline elevations. Slabs can fail easily on this layer, either naturally or with the weight of a person or machine. Deeper in the snowpack, an early-season rain crust and sugary facets exist. An avalanche in motion could step down to these deeper layers, creating a large and destructive avalanche. Although the snowpack structure is variable across the region, these persistent slab problems are generally widespread. Snowpack depths are across the region are similarly variable, but typically shallower in the east.
Weather Forecast
Wednesday night: Scattered flurries bringing 2-4 cm of new snow. Strong to extreme southwest winds.
Thursday: Cloudy with continuing flurries bringing 5-7 cm of new snow. Strong to extreme southwest winds. Freezing level to 1700 metres with alpine high temperatures around -2.
Friday: A mix of sun and cloud. Moderate to strong southwest winds. Freezing level returning to near surface with alpine high temperatures of -6.
Saturday: Mainly cloudy. Moderate west winds. Alpine high temperatures of -7.
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
- South Rockies URL:
http://www.avalanche.ca/api/forecasts/south-rockies.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.
Large avalanches may be triggered on a number of buried weak layers, even in fairly dense trees and shallow slope angles. Stress on deep weak layers will increase as new snow and wind load the snowpack on Thursday.