Avalanche forecast

Avalanche forecast

Payette Avalanche Center
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Avalanche danger

Wed
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Today's avalanche hazard is complex and offers a wide variety of problems from the upper to the lower elevations. Expect to encounter storm slabs in the middle and upper elevations. Snow is piling up on a weak layer above the rain crust and was failing easily yesterday. Fresh wind slabs will also be building with today's new snow and strong winds. Pay attention to wind slabs at ridgetops and on leeward terrain features. Keeping you on your toes will be a wet loose avalanche hazard below 6000'. Rain is falling within this elevation and will be saturating the snow and easily producing avalanches.

Avalanche problems

  • Storm Slabs

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

    Yesterday, I triggered this small avalanche in the West Mountain zone that was 10 inches deep and about 150' across, it ran several hundred feet and had enough destructive force to bury or kill a person. This avalanche released on a layer of facets above the rain crust from early March. These weaker layers are now being buried under additional snowfall and more heavy winds today. Expect these weak layers to become more reactive throughout the day as we are anticipated to add another 1" of water weight to our snowpack today through tomorrow.

    The rain crust from early March is farily widepsread on all aspects up to about 7800' in elevation. In most locations, the snow grains have been faceting (weakening) above and below the rain crust. These avalanches will be growing in destructive size. If you notice signs of instability (i.e. cracking, collapsing, or recent avalanches) find a safe route away from slopes steeper than 30 degrees.

    (3/14/2022) Avalanche remotely triggered yesterday (03/14/22)

  • Wind Slabs

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

    Yesterday, I found wind-deposited snow was confined to specific terrain features that faced east, northeast, and north. These wind slabs were reactive on steep slopes where the rain crust is present (most slopes below 7800'). Today, expect to encounter new wind-deposited slabs from snowfall occurring this morning. Currently, winds are gusting between 30-45 M.P.H. on ridgetops throughout our advisory area. Heavy snow and strong winds can build wind slabs rapidly.

    Pay attention to wind slab development on ridgetops and leeward terrain features. As this storm progresses, expect wind slab hazard to increase in the likelihood and destructive size. You may be able to trigger wind slabs in areas near ridgetops, in natural depressions, or gullies. Tune into the snow as you travel into upper elevation terrain and dial back terrain selection if you encounter evidence of wind slab (punchy, slabby, or hollow feeling). Look for signs of drifiting and wind blown snow to indicate evidence of wind slabs on leeward slopes. 

    (3/14/2022) Evidence of wind-deposited snow from windward to leeward terrain.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    Currently, rain is falling below 6000' throughout our advisory area. Rain on snow can create wet loose avalanches in a short period of time. Pay attention to snow becoming saturated in lower elevations. Stay out from underneath steep slopes, large rocks, and cliffs. Rain that produces wet loose avalanches can be heavy. Even if there's not a lot of volume, these small avalanches can pack a punch and easily push a snowmachine (and especially a person) around. 

Avalanche Discussion

Today's Advisory is sponsored by Franklin Building Supply just South of McCall on Highway 55. Thank You For Supporting the Payette Avalanche Center!

Your snow and avalanches senses should be on high alert today in the mountains. Top to bottom our avalanche hazard today is complex and should keep even the most experienced professionals alert to changing conditions. We have three distinct avalanche problems that each offer a different hazard within a different elevation. 

  • Storm slab: Snow that has fallen since Sunday is adding weight and stress to a buried weak layer on the rain crust from early March. I triggered an avalanche yesterday on this weak layer while traveling in the West Mountain zone (see photos below). Expect these storm slabs to grow with more snow and weight today. The likelihood and triggering one of these avalanches will be increasing along with their size.
  • Wind slab: Fresh wind slabs will be building on leeward terrain features. Winds have been gusting between 30-45 M.P.H.  this morning and four inches of snow has fallen since 4 AM. Watch for clues of wind slabs developing (drifted snow, pillows, slabby or hollow feeling). Stay clear of steep slopes harboring recent wind slabs.
  • Wet loose: Rain is falling below 6000' this morning. Rain on snow can produce avalanches almost immediately in steeper terrain. If you are traveling into these lower elevations pay attention to the snow becoming saturated and stay off of (and out from underneath) steep slopes and runout zones.