Avalanche Forecast

South Rockies

Date issued

Mar 28, 2018 - 5:08 PM

Valid until

Mar 29, 2018 - 2:00 PM

Prepared by

cgarritty

Intense winds have blown loose snow into wind slabs on all aspects and elevations. Watch for bouts of sunshine to destabilize slabs on sun-exposed slopes.

Regular season
Wednesday - March 28, 2018
Alpine

2 - Moderate

Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

Natural avalanches unlikely; human-triggered avalanches possible.

Small avalanches in specific areas; or large avalanches in isolated areas.

Treeline

2 - Moderate

Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

Natural avalanches unlikely; human-triggered avalanches possible.

Small avalanches in specific areas; or large avalanches in isolated areas.

Below Treeline

1 - Low

Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Natural and human-triggered avalanches unlikely.

Small avalanches in isolated areas or extreme terrain.

Thursday - March 29, 2018
Alpine

2 - Moderate

Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

Natural avalanches unlikely; human-triggered avalanches possible.

Small avalanches in specific areas; or large avalanches in isolated areas.

Treeline

2 - Moderate

Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

Natural avalanches unlikely; human-triggered avalanches possible.

Small avalanches in specific areas; or large avalanches in isolated areas.

Below Treeline

1 - Low

Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Natural and human-triggered avalanches unlikely.

Small avalanches in isolated areas or extreme terrain.

Friday - March 30, 2018
Alpine

2 - Moderate

Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

Natural avalanches unlikely; human-triggered avalanches possible.

Small avalanches in specific areas; or large avalanches in isolated areas.

Treeline

1 - Low

Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Natural and human-triggered avalanches unlikely.

Small avalanches in isolated areas or extreme terrain.

Below Treeline

1 - Low

Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Natural and human-triggered avalanches unlikely.

Small avalanches in isolated areas or extreme terrain.

Avalanche Problem 1: Wind Slabs

What Elevation?
Which Slopes?
Chances of Avalanches?
Expected Size?

Strong and variable winds have redistributed storm snow into wind slabs on a wide range of aspects and elevations. Newer slabs may become touchy if they see prolonged solar exposure. Intense snow transport from northeast winds was observed Wednesday.

Travel and Terrain Advice
  • Keep your guard up at lower elevations. Wind slab formation has been extensive.
  • Use caution around wind-loaded areas in the alpine and at tree line.
  • Avoid large slopes with thin-to-thick snow coverage and convex features.

Avalanche Summary

Reports from Tuesday included one observation of a recent very large (size 3) wind slab release that appears to have stepped down to the weak layer of sugary facets at the base of the snowpack. This serves as a reminder of the potential consequences of triggering an avalanche in shallow and variable snowpack depth areas. Observations from the past couple of days have otherwise been limited by extreme winds and poor visibility.

Reports from Saturday in the Castle area showed a couple of storm slabs that released to size 1.5 and 2. The smaller avalanche occurred naturally while the size 2 was explosives-triggered.

Snowpack Summary

Up to 35 cm of new snow fell in the region over last weekend. This new snow was initially redistributed by strong easterly winds before winds switched to the southwest. As a result, a mix of old and new wind slabs can now be found on a variety of aspects and at lower elevations as well.

Below the wind effect, the recent snow has buried an old snow surface that consists of crusts up to 2100 metres and dry snow or surface hoar on north aspects above 2100 m. Below this layer the mid-pack is is well consolidated.

Deeper in the snowpack (50-80 cm down) the surface hoar buried in mid-February is now considered dormant.

At the bottom of the snowpack you'll find a combination of crusts and facets that is reportedly widespread.

Weather Forecast

Thursday: Mainly sunny with increasing cloud over the day. Light to moderate west winds. Freezing level to 1600 metres with alpine high temperatures around -5.

Friday: Cloudy with scattered flurries bringing a trace to 5 cm of new snow. Moderate to strong west winds decreasing over the day. Freezing level to 1600 metres with alpine high temperatures around -5.

Saturday: A mix of sun and cloud. Light southwest winds. Freezing level to 1500 metres with alpine high temperatures around -6.

Danger Ratings Explained

1 - Low

Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.

Natural and human-triggered avalanches unlikely.

Small avalanches in isolated areas or extreme terrain.

2 - Moderate

Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.

Natural avalanches unlikely; human-triggered avalanches possible.

Small avalanches in specific areas; or large avalanches in isolated areas.

3 - Considerable

Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential.

Natural avalanches possible; human-triggered avalanches likely.

Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.

4 - High

Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.

Natural avalanches likely; human-triggered avalanches very likely.

Large avalanches in many areas; or very large avalanches in specific areas.

5 - Extreme

Avoid all avalanche terrain.

Natural and human-triggered avalanches certain.

Large to very large avalanches in many areas.

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

  1. South Rockies URL: http://www.avalanche.ca/api/forecasts/south-rockies.rss
  2. Copy the url and paste it into the appropriate field of your RSS aggregator.
  3. Fill in your email address.
  4. 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.