Avalanche Forecast

Kootenay Boundary

Date issued

Apr 9, 2018 - 4:10 PM

Valid until

Apr 10, 2018 - 2:00 PM

Prepared by

mconlan

Warm air and rain are forecasted for Tuesday. This warming will weaken the snow surface and increase the likelihood of triggering avalanches. Travel in avalanche terrain is not recommended at high elevations and make sure to avoid overhead exposure.

Regular season
Monday - April 9, 2018
Alpine

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.

Treeline

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.

Below Treeline

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.

Tuesday - April 10, 2018
Alpine

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.

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

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.

Wednesday - April 11, 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.

Avalanche Problem 1: Storm Slabs

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

Warm air is expected well above the mountain tops, which will weaken storm slabs that formed over the weekend. Natural and human triggering will become more likely because of this.

Travel and Terrain Advice
  • Observe for the bond of new snow with the old surface before committing into avalanche terrain.
  • It is a good day to avoid avalanche terrain due to the likelihood of triggering avalanches.
  • Avoid overhead exposure, as avalanches may run full-path.

Avalanche Problem 2: Loose Wet

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

Recent wet avalanches have been large and destructive. Be cautious if you find moist or wet snow, which may be found to the mountain tops on Tuesday. Watch out in steep and gullied terrain, where even small avalanches can have severe consequences.

Travel and Terrain Advice
  • Use caution above cliffs and terrain traps where small avalanches may have severe consequences.
  • Avoid steep slopes when air temperatures are warm, it is raining, or the solar radiation is strong.

Avalanche Summary

Storm slabs from the weekend's storm snow were reactive to humans, explosives, and natural triggers on Sunday. The slabs were small to large (size 1.5 to 2.5), 20 to 30 cm deep, generally on east to south to southwest aspects, and from 1700 to 2200 m.

Loose wet avalanches were also reactive. A natural cycle occurred in the south of the region on Sunday, with small to large (size 1.5 to 2.5) avalanches on all aspects up to 2050 m.

Snowpack Summary

Warm air temperatures have moistened the snow surface at all elevations and on all aspects. Forecasted snow on Tuesday will fall on this. Around 20 to 40 cm of storm snow that fell on the weekend with associated strong winds overlies numerous melt-freeze crusts formed over the past few weeks.

The mid and lower snowpack is generally well-settled and strong.

Weather Forecast

TUESDAY: Cloudy with light precipitation, accumulation 5 to 10 mm water equivalent, light to moderate southwest winds, alpine temperature 2 C, freezing level 3000 m dropping to 2000 m over the day.

WEDNESDAY: A mix of sun and cloud, light south winds, alpine temperature -2 C, freezing level 1700 m.

THURSDAY: Cloudy with snowfall, accumulation 5 to 10 cm, light southwest winds, alpine temperature -3 C, freezing level 1500 m.

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. Kootenay Boundary URL: http://www.avalanche.ca/api/forecasts/kootenay-boundary.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.