Avalanche Watch Issued: Monday, February 19, 2018 at 7:00 AM
Expires: Tuesday, February 20, 2018 at 12:00 PM

A winter storm is expected to impact our forecast area throughout the day on Monday. The avalanche danger is expected to rise to HIGH (Level 4) by early evening. Large dangerous human triggered avalanches are likely today and will become very likely as the snow adds up. If you trigger one of these avalanches it will most likely break at the ground and will entrain the entire season’s snowpack. Watch for rapidly changing conditions and the increasing threat of natural avalanches during the day on Monday as new snow adds up.

Mon, Feb 19, 2018 at 6:57 AM
Issued by: CBAC

Today

 

Tomorrow

Considerable (3) Dangerous avalanche conditions. Cautious route-finding and conservative decision-making essential.   High (4) Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
Considerable (3) Dangerous avalanche conditions. Cautious route-finding and conservative decision-making essential.   High (4) Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
Considerable (3) Dangerous avalanche conditions. Cautious route-finding and conservative decision-making essential.   Considerable (3) Dangerous avalanche conditions. Cautious route-finding and conservative decision-making essential.
  Danger Scale

  • No Rating
  • 1
    Low
  • 2
    Moderate
  • 3
    Considerable
  • 4
    High
  • 5
    Extreme

Summary

There is no new snow to report this morning, but the next large winter storm is literally trying to blow your house down. With extreme southwest winds in the forecast and incoming snow, the avalanche danger will rise quickly today. We are forecasted to reach HIGH avalanche danger shortly after dark, with very dangerous avalanche conditions developing. As the snow piles up this afternoon, natural avalanche activity will increase with the threat of some very large and destructive avalanches late in the day. 

The last round of natural avalanches was just last Friday night, such as this destructive avalanche off of Gothic Mountain hitting the valley bottom. Winds and new snow will be straining start zones on northerly and easterly facing slopes. Stay aware of avalanche paths above you and don’t linger below alpine start zones. Both persistent slab avalanches and windslab avalanches will be large and potentially destructive. These avalanche problems will become very sensitive to human triggering. Keep your slope angels near or below 30 degrees with cautious route-finding and conservative decision making.

You can go ski or ride the fresh snow today, but awareness of your surroundings and changing conditions will be key. Discuss your route with partners in a warm and dry location this morning and note where you will be exposed to potential overhead hazards. If you are finding 10” or more of new snow, then snowfall in your area is exceeding forecasts and the avalanche danger is rising quicker then expected. Planning to return home in the early afternoon will help avoid the most dangers part of the day. 

 

Avalanche Problem

 
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Above Treeline
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Problem Type Aspect/Elevation Likelihood Size

What You Need to Know About These Avalanches


Persistent slabs can be triggered by light loads and weeks after the last storm. You can trigger them remotely and they often propagate across and beyond terrain features that would otherwise confine wind and storm slabs. Give yourself a wide safety buffer to handle the uncertainty.

Avalanche Problem

 
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N
S
E
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NW
NE
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Above Treeline
Near Treeline
Below Treeline
Certain
Very Likely
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Historic
Very Large
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Problem Type Aspect/Elevation Likelihood Size

What You Need to Know About These Avalanches


Wind slabs can take up to a week to stabilize. They are confined to lee and cross-loaded terrain features and can be avoided by sticking to sheltered or wind scoured areas.

Avalanche Problem

 
problem icon
N
S
E
W
NW
NE
SE
SW
Above Treeline
Near Treeline
Below Treeline
Certain
Very Likely
Likely
Possible
Unlikely
Historic
Very Large
Large
Small
Problem Type Aspect/Elevation Likelihood Size

What You Need to Know About These Avalanches


Loose wet avalanches occur where water is running through the snowpack, and release at or below the trigger point. Avoid terrain traps such as cliffs, gullies, or tree wells. Exit avalanche terrain when you see pinwheels, roller balls, a slushy surface, or during rain-on-snow events.

Archived Forecasts

  • Select Forecast: 2018 Valid 2018/02/19 6:57 AM