Avalanche forecast

Northwest Mountains

Crested Butte Avalanche Center
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Avalanche danger

Wed
Alpine
4 · High
Treeline
4 · High
Below
3 · Considerable
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Highlights

An AVALANCHE WARNING is in effect.  The avalanche danger could rise to HIGH today as a powerful cold front delivers heavy snowfall and continued strong winds.  Avalanches will break in the new snow, and some could be very large and destructive, releasing on weak layers deeper in the snowpack.  Travel in or below avalanche terrain is not recommended as storm totals increase through the day. 

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2–3

    Intense wind and snowfall loading today could overload weak layers in the upper few feet of the snowpack, causing easily triggered or natural avalanches that are large and dangerous.  The most prominent and active weak layer is buried surface hoar several feet deep on the north half of the compass. There is also potential for avalanches to break on faceted crust layers on some higher, southerly aspects, or depth hoar layers near the ground.  Give steep terrain a wide berth today and be careful of runout zones. Slope angles consistently less than 30 degrees without overhead hazards offer the safest travel options today.   

    A broad avalanche on the north side of Crystal Peak that ran during last week's storm.  

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    Consistent strong to extreme winds over the past 24 hours have formed thick drifts at all elevations.   Slabs will grow in size and distribution through the day with heavy snowfall and continued wind loading.  Some slopes will be scoured, other slopes will be wind loaded, and if we see the high end of snow forecasts, storm slabs will also start to form in wind-protected areas. Cracking, collapsing, and blowing snow are all signs of instability.  Consider slab size and terrain consequences before crossing on or below slopes steeper than 30 degrees.  Avoid avalanche terrain where the problem overlaps with larger persistent slab issues; smaller slabs in the new snow can step down and produce much larger avalanches.  

    A wind slab photo from the archives.  

Avalanche Discussion

The first phase of the storm has underdelivered on snowfall, and our confidence that we are barrelling toward a major avalanche cycle has significantly diminished.   The second, and more potent phase of the storm is still heading our way today.  A late-morning cold front is forecasted to bring intense snowfall rates and continued strong winds.  We've already gotten plenty of wind, but we need to add more fuel for transport to bring the danger up to High.  This morning, the avalanche danger is Considerable.  An Avalanche Warning is in effect with the potential for the danger to rise to High today if the cold front over delivers, or at least reaches the high end of the forecasted amounts.  If we see more than a foot of snow today, that will put us near the threshold of High danger.   Regardless, we are in a dynamic weather pattern and our buried weak layers don't like rapid change.  The combination of wind loading overnight and intense snowfall today onto productive weak layers are two reasons to give avalanche terrain a wide buffer today.  This video describes the situation; although projected storm totals are now about half of what they were when we created it, so natural avalanche activity isn't expected to be as significant as advertised.  

Events: The CBAC Fireside Chat Series presents legendary American alpine climber George Lowe on Sunday, March 3 at the Mallardi Cabaret Theatre in downtown Crested Butte at 6 p.m. Best of all, it’s free!

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