Avalanche forecast

West Slopes South

Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Out of date — this forecast expired 6 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Look to avoid piles of windblown snow on Sunday, particularly on the volcanoes where more snow and wind are expected. New snow may not stick to the surface well and could slide off easily on steep slopes. Continue to prepare yourself for variable travel conditions that could take more time and effort to manage than you are used to.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Observations on Saturday showed that shallow pockets of wind affected snow were already present and reactive near ridgelines in the West South. As we add more snow on Sunday, don’t be surprised to find some shallow Wind Slabs as you ascend in elevation, particularly in areas that receive more snow and wind such as on Mt. Rainier. The new snow should be light and fluffy, easy for the wind to transport, but we are a bit uncertain on how strong the winds will be. Take a look for blowing snow as you travel, and for pockets of wind drifted snow to develop near ridgelines, on the side of gullies, or at the base of cliffs. Shooting cracks were easy indicators of unstable wind-drifted snow on Saturday, and you can look for the same clue on Sunday. Any potential Wind Slab should be small but could be reactive, so steer around terrain features where you suspect wind-loading.

    (1/23/2021) Small and shallow wind pockets were found to be reactive, producing long shooting cracks in the Crystal backcountry on 1/23. Although the depth of these are not concerning at this time, they may thicken over the next few days.

Avalanche Discussion

Mt. Rainier will continue to drive the avalanche danger in the West South zone on Sunday. Compared to other areas of the zone, we are expecting more precipitation and therefore larger and potentially more dangerous slabs, along with more potential snow to run on previously frozen slopes. Look out for these “sluffs” on steep slopes that are holding cold dry snow atop an icy or firm crust formed by the last rain event. These slides can run fast and far, fanning out as they run downhill. You wouldn’t want one to knock you off your feet in consequential terrain.

Although we are once again focusing on Mt. Rainier, that doesn’t mean that hazard doesn’t exist elsewhere in the zone. New snow will be falling and there should be light winds, meaning that avalanche potential will be higher than the past few days. There may not be enough new snow in other parts of the zone to have raised the danger rating, but we often like to mention that there is still avalanche potential even when the map is reading green. All of the travel advice and indicators of potential avalanches we have talked about on Mt. Rainier are applicable regardless of your location on Sunday. With lower snow totals in these areas, you may find shallow areas of weak snow with isolated pockets of wind drifted snow that are reactive, but the amount of snow sliding downhill could be small enough to be inconsequential. 

As we move forward, we will be tracking some weak snow that should get buried on Sunday by this storm. This snow was the culprit for the reactive pockets of wind-deposited snow on Saturday near Crystal. Below this weak snow, you will continue to find a variety of old snow surfaces left by our last atmospheric river event. Firm and icy surfaces are still prevalent in much of the zone and could even be hidden by a dusting of new snow. Continue to travel cautiously as you explore new terrain and enjoy the mountains. Falling on one of these slopes could lead to a long and dangerous slide.

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

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