Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Sun
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
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Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Welcome back as we embark on another winter together! As we incrementally build our snowpack at Snoqualmie Pass, be prepared for early-season conditions and potentially difficult travel in the mountains. Not a lot is known about the higher elevations, but there could be unstable pockets of snow to avoid.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    As you ascend in elevation, be prepared for an increase in snowpack depth and more avalanche potential. You could find that some small Wind Slabs have formed on the leeward side of ridgelines or near rocky features such as the base of cliffs. You can feel for differences in the stiffness of the snow or look for textured surfaces as your travel to help you identify wind-loaded pockets to avoid. Cracking of the snow surface or other red flags of instability such as whumpfs shouldn’t be ignored. Use them as an indication to head toward more simple terrain. 

    (11/25/2020) Example: Wind can often drift snow to the base of cliffs creating sensitive pockets. This shallow Wind Slab was triggered by a skier in November a few seasons ago in a closed ski resort and knocked travelers off their feet.  Photo: Charlotte Guard

Avalanche Discussion

The season is just getting underway at Snoqualmie Pass and as you might expect, observations and information about the current snowpack structure are currently limited. A storm on Friday brought a fair amount of rain followed by a few inches of snow to much of the zone. At most trailheads, this storm likely didn’t result in much avalanche concern. You may find that some of the biggest hazards you encounter are early-season conditions such as open creeks or shallowly buried rocks, stumps, and bushes. You can expect to find a deeper and more layered snowpack as you ascend in elevation, resulting in a higher likelihood of avalanches. As we get into Saturday night and Sunday, a more significant storm is set to impact the zone and should further increase avalanche potential.

Earlier this week, a storm dropped up to 9” of snow at the pass, creating the 11/22 interface. This interface could harbor some weak (faceted) snow in sheltered locations, but we do not yet have a handle on its distribution. A public observation from 11/23 indicated that skiers in the Alpental Valley experienced cracking snow surfaces and localized whumpfing. In the neighboring Stevens Pass zone, preserved faceted snow has been found by NWAC forecasters. 

As we continue to ramp up for the season, please help us out by submitting observations and sending us pictures about what you’re seeing out there. Thanks in advance and we're looking forward to another great season together!

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