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Out of date — this forecast expired 2 years ago.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

Today it is still possible to trigger a wind slab avalanche in leeward terrain and loose dry snow avalanches in the upper 1-2' of the snowpack are likely in steep terrain. Persistent slab avalanches 1-4' are becoming less likely, yet still possible.

We have had multiple reports of snowmobilers and skiers triggering avalanches over the weekend. Southwest winds upwards of 40mph built slabs 1-2' thick mostly on SE, E, and North aspects.

Slopes steeper than 30 degrees should be treated with careful evaluation and safe travel protocols.

Avoid wind-loaded terrain. Use extra caution near overhanging cornices and treewells that are growing more dangerous.

Avalanche problems

  • Loose Dry

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

    More than a foot of snow in the mountains in the last 12 hours the whiteroom vibe is on.  If the slope you are on is steeper than 38 degrees and it is sustained, it is possible to get the upper snowpack (1-2') moving with you.

    Slough management skills are going to have to be utilized... Use extra caution around terrain traps (like cliffs and gullies) that would expose you to being carried into bad places by loose dry snow.

     

  • Wind Slabs

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

    Winds calmed last night yet have gusted into the 40+ mph range out of the Southwest and done a good job of moving snow and forming slabs on mostly East through North aspects in the mountains as well as down to the valley floor most of this week. We have had many reports of people triggering avalanches in wind-loaded terrain over the weekend.

    Avoiding wind-loaded slopes is going to be your best bet today as these slabs take time to heal. Look for indicators of wind direction as some terrain has an effect on the wind, and may load a slope on a different aspect than what you may be expecting. If you are seeing cracking and or hearing or feeling collapsing, find another slope to travel on.

    (3/3/2024) Cornice drop remotely triggered slide on SE wind loaded aspect. Photo: Brian Peters

  • Persistent Slabs

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

    Dry clear periods of weather this last week formed layers of surface hoar that were easily triggered Monday and reported being triggered by skiers and snowmobilers Friday and Saturday. Saturday by a snowmobiler. Depth ranged from 1-3' deep. Sunday we had skier reports of remote triggering slabs. Test scores have improved but still indicate the potential for propagation, or producing a large avalanche.

    With a trend of wind and snow and poor visibility, it is believed that a lot of natural avalanche activity early last week happened mid-storms and was erased by subsequent snowfall.

    Pinning down the exact location where this problem exists is going to be somewhat difficult, but you are most likely to trigger this persistent weak layer in areas where the Sun and wind have not been able to break it down. 

    Throughout the week we have been getting easy to hard propagating results on multiple layers of graupel and surface hoar which has been confirmed by observations from skiers and sledders.

    If you approach slopes steeper than 30 degrees that are sheltered, do so with caution and use good travel protocols like watching your partner from a great safe spot well out of avalanche terrain.

    (3/3/2024) Extended column test results with ECTP 12 SC Photo: Josh Joyner

Avalanche Discussion

Committing to big consequential terrain is going to require good travel protocols and good slope assessments. Buried weak layers are gaining strength and have slid in many places mid-storm. Some people are pushing into big terrrain and getting away with close calls this past weekend with red flags going off.

Keep the odds in your favor by doing simple things like digging a pit, wearing a transceiver with fresh batteries, checking your partners for transceiver function, Shovel and probes on your back, traveling one at a time through terrain steeper than 30 degrees, and watching your partners from a safe spot are going to be prudent to success in the mountains.  

Check out all of the great observations from sliders and riders who have reported triggering avalanches throughout the week. They will be entered in our monthly drawing for submitting an observation, and you can too!

Today's advisory is sponsored by Brundage Mountain Resort.