Avalanche forecast

Snoqualmie Pass

Northwest Avalanche Center
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Avalanche danger

Fri
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Expect easterly winds to drift new snow into slabs on Thursday. They could exist in unusual spots or be easier to trigger than you’re used to. Use visual clues such as textured surfaces or fresh drifts to identify wind-loaded slopes to avoid.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    New snowfall and strong east winds could form fresh slabs on leeward ridgelines, convexities, or near rocky terrain. Easterly winds often result in more cross-loading and mid-slope loading than you might be used to. They also load different aspects than our typical storms. Look for actively blowing snow, fresh cornices, or new drifts to identify wind-loaded features to avoid. Using small test slopes or uptrack tests as you travel can give you insight into how the new snow is reacting to your weight as a traveler.

    Weak snow was reported on or near the surface in recent days. This could result in slabs breaking widely or in surprising ways.

    (2/13/2024)

    A small skier-triggered wind slab in a confined/rocky chute. It failed on the Early February Crust. 

    Photo: Andy Harrington

Avalanche Discussion

A prolonged east wind event began on Wednesday and should continue through Friday at Snoqualmie Pass. The peak winds will coincide with new snowfall on Wednesday night and Thursday morning. We’re expecting somewhere in the 4-6 inch range with moderate winds.

New snow will fall on a variety of surfaces, most of which are some variation of temperature crust. The exception is on shaded and wind-sheltered slopes where you could still find well-settled dry snow from Monday’s storm. As alluded to above, weak snow has been observed on the surface and could become a buried weak layer for the new snow to fail on, particularly in wind-sheltered terrain. 

To complicate matters, numerous crusts interspersed with weak snow exist over the sout and easily identifiable Early February Crust (EFC). During recent field days, NWAC forecasters have found weak facets just above the EFC. Although this isn’t a big storm by PNW standards, it could start to test some of these layers as slabs develop. Smaller avalanches could step down to older crusts or even the EFC. Look at all of the snow above the EFC for points of failure and default to lower-angled terrain if you have any suspicions. We do not have any concerns below this burly snowpack marker at this time.

This storm will help start to rebuild our thin snowpack at lower elevations. You could still see drifting or isolated cracking, but we don’t believe there will be enough new snow to create consequential avalanches during this event. There will still be travel hazards such as open holes/creeks or shallowly buried rocks/bushes/avalanche debris.

Regions covered