Avalanche forecast

Avalanche forecast

Payette Avalanche Center
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Avalanche danger

Sun
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
Out of date — this forecast expired 5 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Dangerous Avalanche Conditions Exist in wind-loaded and even wind-sheltered terrain! Human triggered avalanches are likely! 

Be cautious on all slopes steeper than 30 degrees and Avoid wind-loaded terrain and look for clues of fresh Wind slabs that formed from 30 plus mph wind gusts on Friday.

In wind-sheltered terrain, storm slabs will continue to be sensitive to the weight of a snowmobile and even the weight of a skier.  We have observations from users triggering storm and wind slabs over the last 4 days.

Avalanche problems

  • Storm Slabs

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

    Warmer snow started falling on Wednesday on top of colder light density snow. We knew it could not hold on, and we were able to get results in ski cuts on Wednesday and Thursday in the upper foot of snow.

    Friday, we saw natural avalanches failing on slopes in the 30-35 degree range. Test pit blocks were failing 10inches deep before we could even isolate the column.

    Terrain that is sheltered and steeper than 30 degrees is ripe with this problem and should be avoided. 

    Suttle changes in slope angle are enough to create an area for this problem to arise. Getting pushed by even a small amount of snow can disable you enough to send you out of control and into terrain or trees you were not planning on visiting.

    Stay alert, practice good travel protocols like spreading out and one at a time on slopes steeper than 30 degrees, and always keep your eyes on your partners.

     

     

    (1/7/2022)

    Above Goose Lake road North of Brundage Ski Resort.

    Photo: GH

  • Wind Slabs

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

    While older wind slabs formed a few days ago under variable wind directions and speeds, and maybe stabilizing, Friday a fresh crop of wind slabs formed under strong Southern winds and about 5 inches of new snow. Tamarack ski patrol reported results with explosives producing 5 foot deep crowns in wind slabs and 60-70 mph guts that shut the Summit lift down for the day Friday.

    Leeward terrain above 7,000 feet is going to have the most load and be the most dangerous.

    Look for clues on the snow surface that indicate the direction of loading like etching, drifts, pillows, and or scoured areas where the snow is literally gone. The mountains can influence wind direction or loading so be constantly looking for those directional clues.

     

    A weekly recap of wind at Granite Mtn weather station from Sunday-Friday.

Avalanche Discussion

This information is sponsored by OnXBackcountry...Thank you for supporting the Payette Avalanche Center!

The first thing to take from a considerable danger rating is that Dangerous avalanche conditions exist, and also don't forget that human triggered avalanches are likely...careful snowpack evaluation, cautious route-finding, and conservative decision making are essential...Don't discount danger this weekend as the Sun may inspire bad decisions...the problems are real we have developed a strong over weak set-up in our snowpack that is buried now beneath 4-6 inches of fresh snow from Friday. Early in the week, what was a winter wonderland from the valley floor and above has changed gradually as temps warmed and new warm snow formed a denser, yet soft storm slab in sheltered terrain and strong winds created thick wind slabs in leeward terrain. We have gotten a lot of Observations from various users over the past 4 days of human-triggered wind and storm slabs, and from Tamarack Ski Patrol getting really impressive 5ft crowns from explosives Friday. Friday, we also witnessed a couple of natural storm slab avalanches that were small, but big enough to bury injure or kill a person.

Steeper terrain (30 degrees and steeper) is going to be reactive to the weight of a snowmobile and even the lighter weight of a skier, and steep Southern aspects that start getting Sun on Saturday will shed a little snow and produce point releases avalanches on steep slopes, especially around rocks...if you are seeing red flags like cracking and whoomphing, choose another, safer route and give the snowpack more time to adjust to the warmer temps and this weird stress that is being put on it. 

Winds were strong out of the South last Sunday and Monday which created a brief period of High danger and thick wind slabs and a natural avalanche cycle that most people never witnessed as a lot of evidence was either buried or really hard to see in the fog and snow. Wednesday, we saw a switch in winds and Northwest flow into the light to moderate range. Since Tuesday we picked up about 2 feet of snow that have seen variable winds. 

Saturday and Sunday are going to be days to incorporate extra safety margins into your plan. Avalanche problems are going to be Wind slabs and storm slabs above 6,000 feet. 

*** Check out our Observations Page to see what others are seeing...We are always looking for more Information from snowmobilers and skiers on snow and weather conditions. These observations help our forecasts and they help other users in and outside of the community.

It can be quick with or without a photo…Use the Observations link at the top of the page to submit your observations. If you experience any unfortunate technical issues please email us at [email protected]…Thanks ahead of time.