Date issued

Jan 24, 2018 - 4:00 PM

Valid until

Jan 25, 2018 - 4:00 PM

Prepared by

grant statham

Continual snowfall, cool temps and light winds are making excellent ski conditions. The snowpack is adjusting well to the additional snow and conditions are good - but with three weak layers in the upper snowpack, we are waiting for a tipping point.

Regular season
Thursday - January 25, 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 - January 26, 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.

Saturday - January 27, 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: Wind Slabs

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

With up to 60cm snow over the past 8-days there is plenty of loose snow available to be blown into windslabs which should be anticipated in alpine areas near ridge crests. These windslabs should be easy to trigger on skis.

Travel and Terrain Advice
  • Use caution in lee areas. Recent wind loading have created wind slabs.

Avalanche Problem 2: Persistent Slabs

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

There are 3 weak layers in the upper snowpack: Jan 16, Jan 6, and Dec. 15. All are a mix of sun crust, surface hoar and facets depending on your aspect and elevation. Whumphing is occurring on these layers daily and step down avalanches are possible

Travel and Terrain Advice
  • Use conservative route selection, choose supported terrain with low consequence.
  • Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.

Avalanche Summary

No new avalanches reported or observed, but people continue to get lots of whumphing and settlement cracks - a definite indication of instability. But . . . no significant avalanches.

Snowpack Summary

50cm of snow has fallen in small increments over the past 8-days creating a lot of loose snow on the surface. Alpine winds have distributed this into leeward areas but only at the highest elevations. Three persistent weak layers lurk in the upper half of the snowpack: Jan 16 down 25cm; Jan 6 down 40cm; Dec15 down 55 cm giving easy-mod test results.

Weather Forecast

Continued snowfall expected through Thursday with another 10-15 on the ground by the end of the day Thursday. Temperatures will remain cool and winds moderate from the SW.  Basically the same weather pattern will persist for the next few days.

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.

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