Avalanche forecast

West Slopes South

Northwest Avalanche Center
View on map

Avalanche danger

Mon
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable
Open full map
Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Rain! Bah Humbug! Unstable wet snow will linger in many areas Sunday and maintain potentially dangerous conditions. Give the Grinch (wet snow) a wide berth by staying off of and limiting your time underneath steep open slopes.

Avalanche problems

  • Wet Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1.5–2.5

    Wet snow avalanche problems are notoriously tricky to forecast and manage. They take many different forms (loose wet, wet slab, glide, and cornice), can fail naturally even without more rain, and often result in larger, more powerful slides. So, even though the rainfall will decrease, it’s the uncertainty and consequences of these slides that should have your attention. Give this wet snow hazard space by staying away from and limiting your time under steep open slopes. In some instances, blocks of snow may simply shed from rocky faces. You don’t want to be under one of these slopes if it happens. 

    While we’re used to wet snow avalanches here in Washington, this setup is a bit different. Prior to this storm, the snowpack was very cold, dry, and layered. This is the first real rain the snow has seen in more than a month. Several old weak layers could fail as water percolates deeper. This complexity only adds to the uncertainty around these difficult problems.

    (12/24/2022)

    A large natural avalanche below treeline in Mt Rainier National Park. 

    Photo: NPS Rainier Rangers

Avalanche Discussion

It certainly feels like the Grinch stole our Christmas along with all our soft snow. While the nasty weather severely limited observations, our professional partners came through with a Christmas present in the form of key information. Rain reached well above ridgelines (7000ft)  in most locations. This resulted in loose wet slides at Crystal Mountain and at least one additional larger natural avalanche at Mt Rainier. That’s two days in a row large slides were observed at lower elevations in the Park. The rain affected the snowpack forming rollerballs, runnels, and, at White Pass, breaking down the previously formed freezing rain crust. 

How deep has the rain percolated into the snowpack? How widespread was any avalanche cycle? Is there any dry snow left at upper elevations? We don’t know. 

On Christmas morning you may find a brief break in the weather to enjoy your new toys. However, our stockings are full of coal, and rain will return in the afternoon. Precipitation amounts aren’t very impressive and shouldn’t significantly affect the avalanche danger during the day.

Regions covered