Avalanche forecast

East Slopes Central

Northwest Avalanche Center
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Avalanche danger

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

Warming temperatures may lead to moistening snow surfaces, and loose avalanches may run on steep slopes in the sun. You could still get surprised by triggering a persistent slab 2-3ft deep at mid and upper elevations.  Look for simpler, less steep, and more supported terrain while these dragons linger.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3

    Faceted snow over the Early February Crust (EFC) is the weak layer responsible for numerous close calls throughout the eastern Cascades and a fatal avalanche accident near Darland Mountain on Friday.  Most recently a skier took a ride and was partially buried in a large slab on a NW aspect of Jim Hill in the Stevens Pass zone. These avalanches are failing 2-4ft deep, propagating widely, and being remotely triggered from low-angle terrain below or adjacent to steep slopes. A smaller avalanche could also step down to this layer. Signs of instability can be inconsistent, creating a tricky problem that is essentially 'unmanageable'. You might not receive signs of instability before the whole slope fails. It could be the 2nd, 3rd, or 8th person on the slope that triggers it. 

    Consider avoiding slopes steeper than 30 degrees, and stay well out from underneath slopes of that angle. Give larger terrain features wider safety margins than you normally would. At lower elevations, we don't have enough slab over the weak layer for this to be a consistent problem. 

    (3/2/2024)

    You can trigger large avalanches like this on Sunday. This avalanche would easily be large enough to bury or kill you. 

    6600 ft, NE aspect in the East- South zone.

    Photo: Katie Warren

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    Direct sun and slightly warmer temperatures may create wet loose instability on steep slopes. You can anticipate this problem by considering your aspect vs. timing of when you might be on any given slope. Look for signs of instability, like small rollers falling out of trees or small fan shaped slides. Feel for moistening snow surfaces on slopes in the sun. You can use test slopes to check and see how any given area might react. These slides should remain small, but may be able to entrain more than you'd think, especially in larger terrain features. 

    (3/5/2024)

    Numerous wet loose slides on steep south facing terrain.

    Photo: Willie Webster

Avalanche Discussion

Wednesday should be another beautiful day in the mountains with mostly sunny skies that may cloud up later. Strengthening March sun is starting to have more of an affect on snow surfaces by the day. Surface conditions are still excellent powder. Steeper SE-SW aspects may hold a crust that'll melt down early in the day and might become moist and heavy by afternoon.

A skier triggered a large deep slab on a NW aspect at 6,500ft on Jim Hill on Tuesday. The skier took a ride and was partially buried but luckily ended up with only minor injuries. Our snowpack is complicated due to the intermittent dry spells in February. Besides the early February Crust, there are also potential layers of surface hoar and faceted grains from the 14th, 18th, and 24th. Widely propagating avalanches could fail on any of these layers. Approach the mountains cautiously and enjoy some low-angle powder until these weak layers gain strength. But be patient, as it could be a while before we see improved snow stability. 

This pattern of persistent slab problems can be challenging for backcountry decision-making. It takes conservative terrain management and patience. The structure is especially apparent in the eastern Cascades, where the snowpack is generally more shallow than at the crest. So, if you're venturing into these eastern zones, be prepared to take a step back in your typical terrain selection and understanding of the snowpack.

Thanks to everyone who submitted observations over the weekend. It really helps us track the snowpack and avalanches during these active periods. 

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