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Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Human-triggered wind slab avalanches 1-3 feet deep are most likely in terrain that has been loaded by recent SSW winds ---You will find these slabs mainly on Northern aspects, however, pay attention to signs of loading as patterns change around terrain features.

Deeper weak layers are difficult to trigger yet still have the potential to propagate if triggered---use your best travel protocols and avoid or use extra caution on wind-loaded, steep rocky, and shaded terrain.

Avalanche problems

  • Wind Slabs

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

    Yesterday we got an observation from a local professional that remotely triggered a 1-3 foot deep wind slab avalanche that was large enough to bury a person (D2) on a Northern aspect above 8,000 feet, that released on a rain crust that formed last Friday 1/19.

    South to Southwest Winds over the last few days have been just strong enough, gusting to about 20mph, with light snow accumulations. This has formed thick slabs 1-3 feet in leeward terrain that are sensitive to the weight of a person.

    Local terrrain can influence wind loading in unusual ways. Watch for red flags like cracking in the snow surface and collapsing or whumphing noises both indicating unstable snow. Signs of drifting can indicate which direction the wind has loaded a slope. Most caution is necessary on northern aspects steeper than 30 degrees, where we have seen evidence of loading by windward globs on tree trunks and witnessed active loading and dune formation. 

     

    (1/22/2024) Cracking in the upper 4-6 inches of the new snow while skinning.

  • Persistent Slabs

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

    Our persistent slab problem that formed in late December ran a Natural avalanche cycle and has not been reported as being triggered in the last week. Our stability tests have indicated hard to trigger yet still sending or propagating a crack (PST 40/100 end). Our Southern end of the advisory area, West Mountain, has been the most sensitive and slow to heal.

    Thin, rocky, and shady areas are going to be the most suspect locations where you may still trigger buried weak layers like surface hoar and or crust facet combinations in the lower snowpack. While we think it may be trending less likely the minor possibility could have major consequences. Use extra cautious protocols if not avoidance of steep consequential terrain, especially in start zones where the snowpack is thin around rocks and trees where triggering an avalanche is most likely.

    (1/22/2024)

    Monday, we spotted this hard slab avalanche that failed sometime this past weekend naturally on rocks above the road just before Fall Creek TH in the Lick Cr drainage.

    HS-N-R1-D2 estimated 5768’ SE aspect 250’ wide

Avalanche Discussion

Temps have been warm, hovering just below freezing in upper elevations. Temps above freezing, and light to moderate rain have dominated terrain below 6,000 feet... snow at these lower elevations may be challenged to stay on rocks and steep slopes and may melt altogether in the coming days. Use extra caution on all steep slopes right now.

We have a snowpack with facet layers that formed in November that is now moist and is slowly trending stable, however, this past weekend the upper foot of new snow and wind and rain have formed a slab in the upper snowpack and buried crusts and likely a weak layer of facets that are sensitive to the weight of a person.

Check out a first-hand account of triggering an avalanche yesterday, our observation, and other observations, or submit your own to spread the word---you could save a life and will be entered into our FPAC monthly drawing where you could win some nice gear!