Avalanche forecast

West Slopes North

Northwest Avalanche Center
View on map

Avalanche danger

Wed
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
Open full map
Out of date — this forecast expired 7 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

The sun will destabilize recent snow, with the potential to produce large avalanches at upper elevations.  Avalanche activity will be confined to areas where 6" of snow exists above the recent crust. Rduce your exposure to steep sun-exposed slopes and smaller pockets of snow drifted to the lee of ridgelines.

Avalanche problems

  • Loose Wet

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

    While Tuesday starts cloudy, recent snow above the 2/7 crust remains susceptible to solar warming if the sun makes its first meaningful appearance since the West North shifted into a stormier pattern on Saturday. Over a foot of snow sits above the crust at 5,500 ft, with approximately 6–8 inches likely at 5,000 ft. Any clearing will expose this snow to the strengthening mid-February sun. Expect an initial volley of rollerballs on sun-exposed aspects, followed by snow shedding from rocks and cliffs and the entrainment of wet, cohesionless snow on slopes below. If solar input is strong enough, wet loose avalanches could entrain all of the snow above the 2/7 crust.

    Once the sun comes out, reduce your exposure to steep slopes, particularly above 5,000 ft. Wet avalanches often start slowly but can quickly gain momentum and become large where they connect to higher elevations or have sufficient vertical relief to build mass. Even at middle elevations, these avalanches may be large enough to bury a person. Move away from steep slopes with dry snow receiving direct sunshine.

    Example: Rollerballs like these serve as your reminder to head to cooler, shaded slopes.

    Photo: Zack McGill - Cascade Mountain Ascents

  • Wind Slabs

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

    By Tuesday morning, you're likely to find 3–6 inches of new snow accumulated in sheltered terrain, with enough wind to form reactive drifts up to 1 ft thick to the lee of ridgelines. These wind slabs will be most reactive early in the day and as you ascend into more wind-exposed terrain.

    The change in new snow depth will increase the size of the problem, while the slab stiffness relative to the underlying snow impacts the reactivity. Fresh, sharp wind lips and lens-shaped deposits are key visual clues; use them to steer around potential problem areas. Test small wind-drifted features before engaging with more consequential steep slopes.

    Example: Extensive cracking on a wind lip feature suggests avalanches are possible on a steep slope nearby.

    Photo: Irene Henninger

Avalanche Discussion

Snow trickled into the West North zone and by late Monday, it looks like the Baker Ski area picked up 2-3" of snow since dawn and have likely improved snow conditions. 10-20 mph SW winds likely formed shallow, fresh slabs near ridgelines. We don't have any fresh information from the zone on Monday.

On Sunday, observers in the Baker Backcountry reported 2–4 inches of new snow at 5000 feet, increasing to around 12 inches of four-finger dry snow in wind-exposed terrain at 5500 feet. A rime or melt-freeze crust was found at the snow surface.  Where present, this rime or melt-freeze crust likely limits the snow available for avalanches and may serve as a bed surface for avalanche activity. In areas where this is not present, avalanche activity may involve snow down to the 2/7 crust. Perhaps thanks to the crusts on the snow surface, steep southerly slopes at mid elevations produced rollerballs under direct sun, but no wet avalanches were observed on Sunday. Breakable surface crust was found at Artist Point (5100 feet) and below. 

The most significant slug of moisture arrived on Saturday with Heather Meadows and Elbow Lake picking up around two inches of precipitation, while many other stations saw only half to a quarter of that. Farther east and colder sites, such as Park Creek Ridge (4610 feet), recorded less precipitation—around 0.75 inches—but more new snow than warmer sites farther west. Elevation also played a role. The Brown Top SNOTEL near the Canadian border (5840 feet) has a base depth well over 100 inches and picked up about five inches of new snow in the last storm, despite typically being drier. 

Regions covered