Avalanche Forecast
Purcells
Danger ratings are based on 5-10 cm of new snow on Saturday. If you see more than 25cm of new snow (possible in the south of the region) consider the danger to be HIGH . Buried weak layers increase the potential size of avalanches.
Avalanche Problem 1: Wind Slabs
What Elevation?
Which Slopes?
Chances of Avalanches?
Expected Size?
Travel and Terrain Advice
- Be cautious as you transition into wind affected terrain.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
- Avoid travelling in areas that have been reverse loaded by winds.
Avalanche Problem 2: Persistent Slabs
What Elevation?
Which Slopes?
Chances of Avalanches?
Expected Size?
Several troublesome layers exist in the snowpack and may be reactive to large triggers such as a cornice or storm slab release. Human triggering may also be possible in shallow or thin, rocky areas.
Travel and Terrain Advice
- Avoid the runout zones of avalanche paths. Very large avalanches have been running full path.
- Pay attention to overhead hazards like cornices which could easily trigger persistent slabs.
- Avoid steep convexities or areas with a thin or variable snowpack.
Avalanche Summary
On Friday, skiers were able to intentionally trigger small (size 1) wind slab avalanches in immediate down wind (lee) features near ridge crests. See here for an update on conditions near Golden.
On Wednesday, a few small avalanches, including one involving a skier, were reported in recent storm snow with crowns approximately 30 cm deep.
A week ago, explosive control work continued to produce large, deep avalanches up to size 3 on north to southeast aspects above 2200m. On the same day, a skier is believed to have remotely (from a distance) triggered a size 1.5 avalanche on a northwest aspect at 2800m that failed on the early January layer.
Although deeper, persistent avalanche activity is becoming less frequent, these avalanches point to the continued reactivity and destructive potential of these layers.
Snowpack Summary
Recent storm snow totals are 10-20cm. I suspect moderate south west through north west winds shifted these accumulations into deeper, reactive slabs in wind-exposed terrain. These accumulations overlie a mix of older wind slabs in exposed higher elevation terrain, a sun crust on steep solar aspects and surface hoar on sheltered slopes.
Below the snow surface several persistent weak layers make up a troublesome snowpack which is not tolerating recent storm loads. In the top 1-2 m of the snowpack, two surface hoar/ crust layers buried in January can be found. Expect to find one or other of these on all aspects and elevations.
Deeper in the snowpack (around 200 cm deep) is a facet/crust/surface hoar layer from December, most prevalent at and below treeline.
Near the base of the snowpack is a crust/facet combo, most likely to be triggered from thin spots in the alpine.
All of these layers have produced large avalanches recently. The wide distribution and ongoing reactivity of these layers suggests that avoidance through choosing simple terrain is the best strategy.
Weather Forecast
The south of this region will see significantly more snow from the storm on Saturday (15-20cm possible). Clearing and becoming cold on Sunday as frigid arctic air moves in
SATURDAY: Snow (15-20 cm possible in the far south with 5-10cm more likely near Golden). Tree line temperature around -12C. Winds southwesterly 30km/h.
SUNDAY: Clearing, but lingering flurries possible. Tree line temperatures around -20C. Winds light northeasterly.
MONDAY: Sunny but cold. Alpine temperatures near -18 Celsius. Winds light northerly.
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
- Purcells URL:
http://www.avalanche.ca/api/forecasts/purcells.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.
New wind slabs may be especially reactive and slow to gain strength due to a mix of underlying weak surfaces. Watch for new wind slab development and reverse loading due to strong northwest through southwest winds.