Date issued

Feb 7, 2018 - 4:00 PM

Valid until

Feb 8, 2018 - 4:00 PM

Prepared by

stephen holeczi

Yet another storm system will continue to overload the highly sensitive snowpack. Avoid all avalanche terrain. This includes the runout zones of any avalanche path as we have seen avalanches run to valley bottom.

Regular season
Thursday - February 8, 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

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.

Below Treeline

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.

Friday - February 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

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.

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.

Saturday - February 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

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.

Avalanche Problem 1: Persistent Slabs

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

Three weak layers exist in the mid snowpack: Jan 16, Jan 6, and Dec 15. All are a mix of sun crust, surface hoar and facets depending on the aspect and elevation. The recent and forecasted snow will continue to overload these layers.

Travel and Terrain Advice
  • Avoid all avalanche terrain.
  • Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.

Avalanche Problem 2: Storm Slabs

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

Look for storm slab formation with warmer temps and forecasted snow amounts. Winds will be variable in direction through the storm period which may result in widespread slab distribution. These new slabs may also be sitting on previous wind slabs.

Avalanche Summary

There have been large avalanches every day this week, mainly to size 3 with some larger. Most of these avalanches have been failing on the persistent layers mentioned above, with the odd avalanche going on the ground. Many close calls have been associated with these events.

Snowpack Summary

Storms from the last 7 days have deposited up to 70cm of snow. The main concern continues to be the 3 persistent weak layers of surface hoar and/or facets that are found between 50 and 150cm down in the snowpack. We continue to observe sudden test results, whumphing and large propagations on these layers.

Weather Forecast

Another storm should track through our region starting Wed night and will continue into Thursday. With this we can expect up to 20-30cm along the divide, strong W winds, and warming alpine temperatures (-5C ).  As the storm ends tomorrow, winds will shift to the East and diminish with a cooling trend.

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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