Avalanche forecast

West Slopes North

Northwest Avalanche Center
View on map

Avalanche danger

Fri
Alpine
4 · High
Treeline
3 · Considerable
Below
3 · Considerable
Open full map
Out of date — this forecast expired 2 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Very large and dangerous avalanches, natural and human-triggered, are likely on Thursday. Stability may improve as snowfall rates slow and strong winds back off, but we just received several feet of snow with intense wind, and this isn't the time to thread the needle. Avoid all avalanche terrain, including lower-angle surfaces beneath steep slopes  as you work your way up in elevation and start encountering thick deposits of new snow.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    2–3

    The storm is tapering off on Thursday, but with recent intense snowfall and extreme wind, remain on alert. Avoid all steep slopes and lower-angle terrain beneath steep slopes, especially at higher elevations. If you see or trigger any new avalanches, see any long shooting cracks or experience any whumphing, avoid all avalanche terrain. 

    Stability may improve throughout the day, but it will be difficult to actually identify any changes. Weaknesses will likely stay hidden, as the slab of highly wind-affected new snow is very thick. You may not notice anything is wrong until you get out onto a steep slope and trigger a large, unsurvivable avalanche. Some avalanches may fail within the new snow layer, only a foot or two deep, and others may be several feet deep. Don't push it into steep areas as the day progresses - we need to give this several-foot snowstorm time to settle and stabilize. 

Avalanche Discussion

We've seen photos of very large avalanches in the Canyon Creek area from Monday and Tuesday (media gallery). They likely failed on a weak layer of facets above the Early February Crust. We've investigated many areas in the zone, and we've gotten mixed results, with weakness still existing in this location in some spots and not in others. Especially if you're in the Canyon Creek area there's a chance you could trigger a very large avalanche that could fail all the way down to the crust, which is now over 5 feet below the surface. The avalanche would likely span very wide. There are a few other layers buried beneath the new snow, over 3 feet deep, where weaknesses are present, but they are inconsistent with coverage throughout the zone. 

I went to the Baker backcountry on Wednesday in the heavy snowfall and extreme wind. Weather was intense: our tracks filled in almost immediately. The snow was heavy on top and lighter about a foot down, making travel difficult. This indicates an "upside down snowpack", or a slab sitting over a softer layer, which might indicate weakness that could lead to avalanches. The heavy surface snow was stubborn and it was tough to trigger any small avalanches on test slopes or find any signs of weakness. That being said, there was still no way we wanted to enter any avalanche terrain, considering the recent snowfall and wind. In a pit we saw propagating test results (ECTP11) about 50cm down, beneath the last 24 hour's new snow, in an extended column test.

Mount Baker's total snow stake has gone up 39 inches since Saturday, Feb 24th. It will likely surpass 100 inches Wednesday night. Other locations in the zone, mainly further west, have received closer to 5 feet of snow in the last 4 days.  On top of this, almost 2 feet of snow is forecasted to fall Wednesday night before snowfall backs off, and then we'll probably get about 6 inches during the day Thursday. Winds will transition from extreme to moderate. This doesn't mean it's a free for all on Thursday, as the snowpack needs time to adjust. 

With 4 to 6+ feet of new snow throughout the zone by the time this storm winds down, make sure you're aware of tree well and snow immersion suffocation (SIS). Aside from trees, creeks and other holes are sneakily buried up to at least 5000ft and there's a high risk of falling into them. 

If you make it into the backcountry, please share with us what you saw by submitting an observation. 

Regions covered