Avalanche forecast

West Slopes North

Northwest Avalanche Center
View on map

Avalanche danger

Wed
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
Open full map
Out of date — this forecast expired 5 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Expect another warm sunny day with freezing levels rising to 6500ft. The likelihood of wet loose avalanches will increase throughout the day. Stay alert to changing conditions and move off steep sun-exposed slopes by the time snow surfaces become wet and weak. 

Avalanche problems

  • Loose Wet

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

    Tuesday will be the third day in a slow and ongoing wet loose avalanche cycle. Only the most northerly and shaded slopes will escape the effects of the strong April sun. The day will start out cold, but expect snow to begin melting off trees and rocks by mid-morning. Falling snow on slopes below may be first to initiate loose wet avalanches. The sun will work around the compass E-S-W as the day progresses, and wet loose avalanches could occur on any steep slopes in direct sun. 

    Pay attention to rapid changes in the snow surface and watch for rollerballs and avalanches on similar slopes. It's time to move to shady slopes or head home early when you start noticing these indicators. Keep your return routes in mind as well - slopes you crossed safely early in the day may become wet, weak, and dangerous by afternoon.  

    (4/11/2021) Small wet loose avalanche (D1) on the east aspect of Catherdral Crag near 5000ft in the Mt. Baker NRA

  • Wind Slabs

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

    Snow from recent storms (4/7-8 and 4/9-10) continues to settle and is generally well bonded to an underlying crust (4/7 interface). Evidence of wind-affected snow is easy to find in the alpine. Some concern for wind slabs lingers, but these slabs are a few days old and gaining strength. You may still find unstable areas of wind drifted snow above treeline, primarily on north and east aspects above 5000ft. The most likely places to trigger an avalanche would be on rollovers 35 degrees and steeper, and on slopes below cornices and cliff bands. Use visual clues to identify and avoid wind-loaded snow in consequential terrain. Seek out wind-sheltered slopes or terrain less than 35 degrees if you find recent avalanches, cracking, or collapsing. 

    (4/10/2021) A skier-triggered wind slab avalanche (D2) on a NE aspect at 5500ft in the Canyon Creek area. The avalanche broke up to 18in deep. No one was caught in the avalanche. Photo: Greyson Herdman

Avalanche Discussion

More sun-exposed slopes will shed snow Tuesday, and a significant spring thaw will continue through the week. Freezing levels are on the rise (6500ft) and will climb each coming day. The wet loose cycle is underway, and plenty more slopes have yet to flush out. Expect a mix of wet and dry snow avalanche problems and big variations between aspects, elevations, and time of day. 

Over the weekend, observers throughout the West North zone reported numerous small wet loose avalanches and a handful of small human-triggered wind slabs. Wind slabs are becoming harder to trigger, but stay alert as you climb up in elevation and transition into wind-affected terrain. Isolated large glide avalanches also occurred recently, and we will likely see more with continued warming and sun. Keep your eyes peeled for crevasse-like cracks in the snowpack and avoid travel on or below slopes where they exist. Cornices grew large throughout the winter and continue to be tested by sun and warming. Stand far back from these features along ridges, and avoid travel on slopes below.

On Saturday, a skier triggered an avalanche in the Snoqualmie Pass zone and was caught, carried, and fully buried. Fortunately, the skier was rescued by their partner and survived, but sustained injuries during the event. You can read the Accident Summary or watch this Video for more information.

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

Regions covered