Avalanche Forecast
South Rockies
Yet another pulse of snow and wind Monday will create dangerous conditions at higher elevations. Stick to small supported terrain features and avoid overhead hazards.
Avalanche Problem 1: Storm Slabs
What Elevation?
Which Slopes?
Chances of Avalanches?
Expected Size?
Travel and Terrain Advice
- Avoid avalanche terrain during periods of heavy loading from new snow and wind.
- If triggered the storm slabs may step down to deeper layers resulting in large avalanches.
- Stick to simple terrain and be aware of what is above you at all times.
Avalanche Problem 2: Deep Persistent Slabs
What Elevation?
Which Slopes?
Chances of Avalanches?
Expected Size?
Several deeply buried weak layers have the potential to produce large avalanches reaching run out zones. Cornices have been a common trigger.
Travel and Terrain Advice
- Be aware of the potential for large, deep avalanches.
- Minimize exposure to overhead avalanche terrain, large avalanches may reach run out zones.
- Extra caution needed around cornices with current conditions.
Avalanche Summary
In the neighboring Lizard Range the east facing Mt. Corrigan slide path produced a very large natural avalanche Saturday. The avalanche is estimated to be a size 4.0, and it took out mature timber in the path as it overran the Flathead FSR south of Corbin. Photos here.
Reports are limited, but there was one explosive triggered wind slab avalanche east of the divide on Saturday. There was likely natural wind slab activity in the northeast part of the region where the heaviest accumulations occurred.
On Friday, a snowmobiler was partially buried by a size 2 avalanche in the Alexander Creek drainage. The avalanche occurred on a north aspect around 2000 m and failed on weak snow near the ground. See report here. A few small wind slabs were triggered by skiers in lee terrain on Thursday and Friday.
A few large persistent slab avalanches that released during last weekend's storm were observed last week as well. These avalanches failed on deep weak layers from November and December, resulting in large avalanches (size 3). Most were triggered by cornices falling on north and east facing slopes.
Snowpack Summary
An upslope storm has delivered lots of cold low density snow east of the divide on Saturday and Sunday (20-40 cm). The distribution of new snow is highly variable, and so are the surface snow conditions. The western parts of the region in BC were relatively warm with less snow, while areas in Alberta and around the divide were much colder and windier which likely formed touchy wind slabs in open terrain.
The lower snowpack in this region is weak, with a number of concerning weak layers. A layer buried mid-January is composed of surface hoar on sheltered aspects and a sun crust on solar aspects is now 30-50 cm deep. Another surface hoar layer from early-January is buried 40-60 cm deep. A widespread weak layer from mid-December composed of facets, crusts, and surface hoar is 60-80 cm deep. Finally, a rain crust with sugary facets buried in late-November is near the bottom of the snowpack. Although the snowpack structure is variable across the region, these persistent weak layers are generally widespread.
Weather Forecast
A modified Arctic air mass combined with some upslope snowfall should shake up the South Rockies snow globe on Monday while keeping temperatures cool. A drying trend takes hold on Tuesday that is expected to last through Wednesday before the promise of yet another storm on Thursday. Stay tuned for more details.
MONDAY: Overcast, with a chance for some clearing late in the day, freezing level at valley bottom, moderate variable winds out of the west in the morning shifting to the east before returning to the west late in the day, 10 to 15 cm of snow.
TUESDAY: Broken cloud cover initially, clearing throughout the day, freezing level at valley bottom, light variable winds at treeline, strong northwest wind at ridge top, no significant snowfall expected.
WEDNESDAY: Clear skies in the morning, cloud cover steadily increasing though the day, freezing level at valley bottom, strong west wind, no snow expected until Wednesday night.
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.
Continued new snow and strong wind will add to the established touchy slabs, especially at higher elevations and in wind-affected terrain. Weather forecasts are handling the situation poorly, so some areas may have extra thick and touchy storm slabs.