Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
View on map

Avalanche danger

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Out of date — this forecast expired 3 years ago.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

Highlights

You can still trigger an avalanche in the storm snow at Snoqualmie Pass on Monday. Focus your attention on steep unsupported slopes, chutes, convexities, or wind-loaded terrain where you’re more likely to do so. Dynamic springtime weather may change conditions throughout the day, so pay attention to how the snowpack is reacting and alter your travel plans if necessary. 

Avalanche problems

  • Storm Slabs

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

    Signs point toward a settling but still grumpy upper snowpack at Snoqualmie Pass. Numerous avalanches triggered by backcountry travelers over the weekend have failed within or at the base of the recent storm snow. So take the time to investigate everything above the 3/31 crust for potential weak points before committing to a slope. You can do this by digging with your hand or shovel, using test slopes, or uptrack tests as you travel. Slab depth will increase as you ascend in elevation or in wind-loaded terrain. Be leery of steep unsupported slopes, confined chutes/gullies, or convexities where triggering one of these avalanches may be more likely. 

    Loose avalanches will also be a concern on slopes over 35 degrees. While often thought of as a manageable problem by some backcountry travelers, don’t get surprised or tripped up by one in consequential terrain. They could run far distances on the underlying crust.

    (4/2/2023)

    Multiple avalanches resulting in overlapping debris piles were triggered by skiers on Bryant Peak on 4/2.

    Photo: Pubic Observation

Avalanche Discussion

Expect a few additional inches of snow on Monday to add to the almost 20 inches we’ve received at Snoqualmie Pass since Friday. All of this snow is sitting above a crust (3/31 interface) that should be an easily identifiable snowpack marker for your assessments. We do not anticipate any avalanche activity below this interface.

Throughout the weekend, we received multiple reports from backcountry travelers, avalanche professionals, and NWAC forecasters about sensitive Storm Slabs being triggered on steeper slopes.  Additionally, many reports indicated that loose avalanches failed easily due to human-triggers. The general thought is that most of these avalanches are failing a few inches above the 3/31 crust on an interface identified by NWAC forecasters on both Saturday and Sunday. Don't ignore these red-flag signs of instability. If someone triggered an avalanche in similar terrain to where you're thinking of traveling, odds are that you will too. You can catch up on the public observations and recent avalanches submitted over the weekend here.

We’re anticipating interspersed periods of sunshine and convective snow showers on Monday at the Pass. Generally speaking, less snow and more sun breaks are expected than what we experienced on Sunday. We may also see an uptick in winds. This springtime weather could manifest in multiple changes to the snowpack throughout the day. Solar input could help the upper snowpack gain cohesion and “slab up” a bit. It could also help snow shed from trees and rocks, triggering loose avalanches or even slabs on the slopes below. If the sun is out for an extended period of time, you may start to see Wet Loose avalanche activity develop. With cold dry snow in place, you may even see some shallow Wind Slabs forming on leeward features.

Regions covered