Avalanche forecast

West Slopes North

Northwest Avalanche Center
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Avalanche danger

Sat
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Out of date — this forecast expired last year. You’re viewing past conditions, not the current bulletin.

Highlights

Heavy snowfall is expected overnight and into the early morning. Start your day in lower-angle terrain and assess for instability before moving into anything steeper or more exposed. If snowfall exceeds forecast amounts and lasts longer into the day, then avalanche danger will approach HIGH.

   

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2.5

    Another morning of new snow and strong but decreasing winds will greet backcountry users on Friday. It could be a repeat of the day before with stable snow and minimal avalanche activity. It’s just as likely that we will see more avalanches as the new snow starts to stack up. Also, small variations in temperature, wind, and snowfall can make for big changes when it comes to the likelihood of triggering an avalanche.

    You're most likely to trigger a slab on steep, wind-loaded slopes, but the abundance of new snow means even sheltered spots can be unstable. Quick tests - like hand shears, stomping on wind drifted features, or small slope tests - can show the bond of new snow layers. Marginal visibility might keep you out of big terrain no matter what kind of results you get. When in doubt, stick with simple, low-angle slopes.

    (3/25/2023)

    A slab avalanche that released in layers of new snow in the Baker Backcountry.  Photo from a prior winter.

    Photo: Jason Speer

Avalanche Discussion

The sun should stay in check on Friday, but if it does make it out, start looking for wet avalanches. Higher-than-expected snow levels and warm low-elevation temperatures could also cause some wet snow to move down the hill. Tree bombs and rollerballs are the first signs that the snow is warming. Sluffing will also likely be a thing if you do head into steeper terrain.

Snowfall amounts and avalanche activity from the latest storm were notably less than expected. Areas that received the most came in at around 12”. The only reported avalanches were small slabs with limited propagation in wind loaded terrain, and also some dry loose. What new snow we did get was observed as right side up and well bonded. Warming temperatures - and a bit of sun and greenhousing at Schriebers/Baker NRA - moistened up snow surfaces but didn’t facilitate wet avalanches. 

There are a few points of uncertainty for Friday. One is the amount of new snow in the forecast, but this uncertainty is nearly a given with every storm. The difference tomorrow is that areas east of Baker Lake could see convergence zone-enhanced snowfall. If it sets up a little more to the west, then heavily traveled areas could see some serious snow all day long.

Timing is another uncertainty. There will be a big difference in observed instability if the storm peaks and snowfall backs off in the early morning hours compared to midday. Finally, the new snow will add additional load to seemingly inactive crust-facet layers that formed and were buried earlier in the month. A much bigger load with coming storms should give any lingering weakness one final test and possibly produce some very large avalanches.

 

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