Avalanche forecast

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Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Cold temperatures and plenty of recent low-density snow will keep avalanches possible over the next few days.  Watch for signs of older or recent drifted snow above treeline. At lower elevations, watch for loose avalanches on very steep slopes. 

Avalanche problems

  • Wind Slabs

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

    Travel cautiously along ridgelines, looking for wind-textured snow surfaces, and identifying areas where deeper drifts have formed.  Steer around steep open slopes below ridgelines where you can still trigger a wind slab avalanche.  You're most likely to trigger a slab avalanche just below lee ridges and other wind-loaded terrain features. If you encounter signs of instability like shooting cracks or recent avalanches on similar slopes, step back and choose simpler terrain.  West to southwest winds on the 23rd drifted snow at upper elevations. Since then, winds have been less significant but could've been strong enough to transport the very light snow that blankets many high elevation slopes.

     

    Wind slab avalanche below ridgeline near Cutthroat Pass from a prior season.

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    With cold temperatures and additional light snow, you can trigger loose avalanches in very steep terrain.  Take stock of the terrain where you could trigger a fast running loose dry avalanche or sluff, and avoid slopes where you could be pushed into a terrain trap like trees or over a cliff band.  

    (12/23/2021)

    You may trigger loose dry avalanches like this one seen in the L. Wentachee area Thursday.

    Photo: Nate Hough-Snee

Avalanche Discussion

New snow has incrementally piled up since the Winter Solstice, with storm totals of over 2' in the Hwy 20 corridor.  Several reports from Thursday and Friday found the recent snow unreactive to quick tests and was generally loose and lacking a slab structure.  Earlier this week observers reported finding surface hoar on Delancey Ridge and in the Hairpin Valley.  They also noted steeper S-SW slopes had formed a thin sun crust.  So far, these layers haven't been involved with any reported avalanches.    

A widespread avalanche cycle occurred on Saturday, Dec 18th (up to size D2.5) in the Washington Pass area.  A crust buried in early December can now be found roughly 4-5 feet below the surface, especially on slopes near and above 6000 ft.  We haven't seen recent avalanche activity on the crust.  If you're in the mountains, you can contribute to the forecast by submitting an observation.

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