Avalanche Forecast
Purcells
Storm slabs on steep slopes, wind slabs on lee slopes, and a persistent slab that seems to be "waking up" on southerly slopes. There's lots to think about, and manage!
Avalanche Problem 1: Wind Slabs
What Elevation?
Which Slopes?
Chances of Avalanches?
Expected Size?
Travel and Terrain Advice
- Stay off recent wind loaded areas until the slope has had a chance to stabilize.
- Be cautious as you transition into wind affected terrain.
- Use caution on steep open slopes and convex rolls
Avalanche Problem 2: Persistent Slabs
What Elevation?
Which Slopes?
Chances of Avalanches?
Expected Size?
An interface buried up to 70cm deep has "woken-up". This problem seems most reactive in south-facing terrain where buried crusts exist.
Travel and Terrain Advice
- Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.
- Carefully assess and consider avoiding southerly facing slopes
- Watch convoluted terrain with variable snowpack depth and multiple trigger points.
Avalanche Summary
Recent avalanche activity has consisted of mainly wind slabs (skier triggered and skier remote) in the size 1-1.5 range. However, we've also received reports of persistent slab avalanches (to size 3) where recent accumulations have been the highest. These avalanches, were skier-triggered or remotely triggered (from a distance) on Monday and naturally occurring on Tuesday with wind loading on cross-loaded slopes. We suspect the buried sun crust buried mid-February.
Deep persistent avalanche activity has become less frequent over the past week.
Snowpack Summary
Around 30 cm of recent storm snow is being redistributed into deeper, reactive slabs in wind-exposed terrain. Up to 60cm below the surface there's a layer buried mid-February that's a sun crust on solar aspects, and spotty surface hoar on sheltered slopes. This layer looks most concerning on on solar aspects where it's associated with with small facets or surface hoar above.
There are several deeper layers that have shown signs of improving but still remain suspect as low probability - high consequence avalanche problems. I'm talking about surface hoar layer buried back in December and January. Near the base of the snowpack is a November crust combined with loose sugary snow. These layers may "wake-up" with strong inputs such as sustained warming, sustained snowfall, large triggers (e.g. cornice fall, smaller avalanches coming down from above); human triggering is also possible in shallow snowpack areas with convoluted terrain.
Weather Forecast
An approaching Low and weak front should only bring light snow Wednesday afternoon and overnight with winds backing to the south.
THURSDAY: light snow with moderate to strong southeast winds during the day. Treeline temperatures around -10 C
FRIDAY: more snow overnight Thursday and possibly into Friday with up to 10 or even 15 cm possible. However, there's significant uncertainty about the just how much new snow will fall. Having said that, highest amounts will be in the south, less towards Golden. Light to moderate South winds.
SATURDAY: trace to a few centimetres of snow, light and variable winds, continued treeline temperatures of around -10 C.
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 snow and ongoing strong winds will continue to promote wind slab formation in wind-loaded areas on the leeward side of ridges and on cross-loaded slopes and gulleys. Storm slabs may also be found in sheltered area on steeper slopes and rolls.