Avalanche forecast

Avalanche forecast

Payette Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 2 years ago.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

Highlights

Wind slabs 1-2 feet thick will become sensitive to human triggering today. Conditions will be most dangerous above 7000', on east-facing slopes, near or below ridgelines. New snow has built a slab over a weak upper snowpack. Watch for obvious signs of instability like shooting cracks or whumpfing and dial back your terrain choices if you're seeing obvious red flags.

Avalanche problems

  • Wind Slabs

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

    6-12" of recent snowfall along with strong SW winds have created sensitive wind slabs. SW winds will continue drifting and blowing snow throughout the day. An additional 3-6" of snowfall is expected by the end of day.  You are most likely to find wind slabs on east-facing terrain, above 7000', especially near or below ridgelines. On solar aspects, there is a 1-2 cm thick melt-freeze crust. New snow will not bond well to slick surfaces like crusts. Local terrain features can influence the prevailing wind direction and load slopes around the compass. Pay attention to obvious clues like shooting cracks from your skis, sled, or board. Look at the snow surface for drifts, dunes, or pillows to indicate wind slabs might be present. Given the fact that new snow fell over a weak upper snowpack, you may get audible feedback such as whumpfing.

    Additional Discussion: Wind slabs building over a weak upper snowpack may be extraordinarily sensitive today. Wind slab avalanches could behave more like persistent slabs, propagating farther distances than you may expect. Below 7000', you are more likely to encounter softer slabs of new snow. These slabs will be more of the storm slab flavor and slightly less affected by the wind. Storm slabs below 7000', may not be as thick or sensitive as upper elevation wind slabs, but they will have the same strong over weak setup as upper elevations.

    (1/31/2025)

    Active wind loading onto east-facing slopes

    Photo: Kevin Studley

Avalanche Discussion

After nearly three straight weeks of dry weather, the January dry spell has officially come to a close. After two weeks of high pressure in early December, the avalanche forecast ushered these words, "Today marks a temporary end to an era. The past few weeks, people have been getting after some steep, aggressive terrain. It's time to dial back that confidence we've been enjoying the past few weeks." Those same words apply today. This weekend is a good time for a shift in mindset and to take a big step back from the terrain that people have been recreating in over the past several weeks. The mountains could see totals of 12-18" by the end of day Saturday. All of this new snow is stacking up on top of a variety of snow surfaces that formed during the dry spell, which may include: crusts on solar aspects, weak, faceted snow on shaded north-facing slopes, and stiff wind-hardened surfaces from weeks of north winds. The takeaway is that the upper snowpack is weak. We are now building a slab atop this weak, upper snowpack. The only other ingredients needed for an avalanche are a trigger and slopes steep enough to slide. You can avoid this avalanche stew by giving yourself a wide margin around slopes steeper than 30 degrees, where the wind has been at work.

Let us know what you're seeing out there. Submit an observation this weekend. Submitting an observation helps improve avalanche forecasts.