Avalanche forecast

Avalanche forecast

Payette Avalanche Center
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Avalanche danger

Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
Out of date — this forecast expired 6 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

The Avalanche Hazard in the West Central Mountains is Moderate.   Natural avalanches are unlikely but human triggered avalanches remain possible.  Expect increasing avalanche hazard as new snow begins to pile up today and over the next few days.  Wind slabs have also been building across our advisory area.  Shallow, sensitive wind slabs should be expected on exposed ridgelines and upper elevation terrain.   New and wind-blown snow will be accumulating and is falling on a variety of old snow surfaces including near-surface facets and our latest crop of surface hoar. 

Multiple human triggered avalanches 2-3 feet deep have occurred in and around our advisory area over the last  2 weeks.  If triggered, these weak layers have the ability to spread out and propagate quickly over large areas. Your best and safest choice in the mountains right now is to AVOID slopes steep enough to slide. 

 

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1

    Erratic winds were the name of the game earlier this week.  While older wind slabs are beginning to stabilize, new wind slabs continue to build throughout our advisory area.  These wind slabs are resting on weak layers below in many places and are surprisingly easy to trigger near ridgelines and on exposed terrain. Telltale signs are easy to see even from a distance, ripple or dune-like deposits across slopes, etched or eroded areas and cornices with pillows below them are obvious and easy to read clues. Changes in the density of the snowpack, cracking, or hollow feeling or sounding snow are also good indicators of wind slab. Winds will be increasing throughout the day today and will continue adding new wind slabs to upper elevation terrain.

     

     

    Cracking and shallow wind slabs were found near ridgetops earlier this week.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–3

    Several weak layers exist within our snowpack.  Surface hoar, near-surface facets, density changes caused by wind and temperature fluctuations, grauple, sun and rain crusts...you name them, we have them. The take-home point is that our snowpack is complex and varied right now.  Not all of these layers are found in all areas, several of them may be found in one area.  ALL of them should give you reason for concern and a healthy suspicion of the snowpack. The buried surface hoar near 65cm/25in is the most dangerous.  This layer is resting just above the rain crust that was buried on 1/26.  This layer is incredibly reactive in some areas and not present in others. Steep slopes in wind-protected or wind-loaded, shady terrain is where you are most likely to find it.  This is the layer that has been producing human triggered avalanches for almost 2 weeks.  Persistent grain types have also formed this week on the snow surface and will increase the avalanche hazard as we add new storm and windblown snow over the next few days. 

    The most repeated message from Avalanche Centers across the Western US right now is "avoid steep slopes", with human triggered avalanches and avalanche fatalities continuing to stack up, pay attention to your slope angles and keep an eye on your partners.  

     

     

     

     

    Reactive layers in the snowpack are the same layers that have been triggered by skiers and snowbikers over the last week producing large avalanches.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    Storms are lined up and primed to drop in excess of 15 inches of snow through the weekend.  Temperatures are rising for the first time in over a week and the new snow will be falling on a variety of old snow surfaces adding another layer of complexity to our snowpack.  Prior to this storm, surface hoar formed in protected areas.  Near-surface facets were fairly widespread as well.   This storm will be building another slab on top of our latest weak layer which is only going to become a bigger problem as we add more snow and more depth over the next few days.

    Snow totals forecasted through Sunday evening.

Avalanche Discussion

Weak layers are fairly widespread across our advisory area right now.  Skiers and motorized users continue to trigger large avalanches in our advisory area and across the region.  The last 2 weeks have produced more recreational avalanche fatalities than ever recorded across the Western U. S.  Statistically speaking we have been very lucky in the PAC advisory area.  Give the snowpack the respect it deserves right now and don't become a statistic.   Check out this article from Avalanche Canada on "Scary Moderate" conditions, it does a great job explaining why we are seeing so many avalanches under Moderate Hazard. 

If you see or trigger avalanche activity, please take the time to snap a picture and note the approximate elevation and aspect, you can submit an observation on our website. Getting your info helps forecasters and other users get a better picture of the conditions throughout our mountains. If you have trouble using our observations page, please email us at: [email protected].,

*Also, Please be mindful of other users, and where you are at. There are closures for motorized travel in and around the local ski areas, Granite Mtn, and other areas throughout our region.

***Check out the Winter Travel Map to find out where you can shred on your sled or moto.