Avalanche forecast

Avalanche forecast

Payette Avalanche Center
View on map

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Out of date — this forecast expired 2 years ago.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

You are likely to trigger an un-survivable slab avalanche 4 feet deep on slopes 35-45 degrees, especially on terrain tipped away from the Sun. Buried persistent weak layers, if triggered, will propagate, and could produce a 4-foot-deep slab avalanche.

Wind slabs may be sensitive and could break deep, 4-6 feet deep. Stay out of steep wind loaded terrain, if you are seeing cracking or other red flags choose another, lower angle slope to travel on.

Survival requires careful travel protocols and snowpack evaluation that challenges even experienced professionals. Increase your margin of error by checking your slope angle, and choosing simple terrain without consequences like terrain traps. Keep your eyes on your partners and make sure you are re-grouping far away from steep slopes. 

Avalanche problems

  • Persistent Slabs

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

    A 4+ foot slab avalanche could be triggered. Triggering is getting harder, but if you do trigger this weak layer, it could propagate far and wide and swallow you fast. Some slopes have slid naturally and it's likely that slopes 35-45 degrees, especially those tipped to the North are going to have more danger lingering, and potential to fail. 

    Riders on machines are going to have more chance of triggering this weak layer, and likely trigger points for all would be thin spots in the slab where rocks or trees are.

    Choose simple terrain with slope angles of less than 30-35 degrees and give steeper slopes a good distance or buffer and stay out of their runout.

  • Wind Slabs

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

    4-6' deep wind slab avalanches are possible. Winds have moved snow and formed slabs in leeward terrain which can be strange or in new places.

    The terrain will influence where the slabs form. Look for clues as to which way the snow has been sent and avoid it, especially near ridges and cornices. If you see cracks or hear whoomph’s, turn around a find a slope with less angle.

    Winds have calmed down and should not be forming any new slabs through the day. It may take a few more days for the wind-blown snow to solidify.

Avalanche Discussion

Dry loose avalanches and sensitive cornice edges are possible in steep terrain if that is where you insist on going? You could break off with an overhanging cornice or get enough snow, or sluff  moving with you and push you into a bad place, but the larger issue begs respect, and that is that we have a poor structured snowpack with persistent weak layers 4 or more feet below the snow surface.

We have been in an active storm cycle that has laid down around 4 feet of snow (7-8" of SWE) in the last 8 days. This started on Friday, 1/31....now we have a 4–5-foot slab resting on weak layers of facets and buried surface hoar that could step down even a foot deeper beneath 1/3 rain crust on facets---this was likely responsible for the majority of whoomphing noises people have been reporting. Avalanches and loud thunderous whoomphing noises of collapses in the snowpack have been the theme. Saturday through Tuesday remote triggering was reported. No New avalanche activity has been reported since Tuesday, But Don't rule out triggering a 4-foot-deep slab avalanche. This scenario is high consequence and becoming harder to trigger as the snow above gains strength. Discipline and or abstinence from steep terrain is your best choice. Choosing simple terrain, practicing companion rescue with you buddies, Nordic and resort skiing...all of these are great options to keep you safe for the coming week as big lines and consequential terrain like gullies and cliffs remain off the table.

This is a great time to dig and look at the weak layers of the snowpack. Weak layers from 1/31 and 1/3 are getting deep to where only a propagation saw test is going to be accurate.

Stay safe and look at the great observations people have been submitting. Throw in one of your own observations by clicking on Submit. We would love to see your photos too...Thanks!

Today's Forecast is sponsored by Carl’s Cycle in Boise. Thank You for supporting the PAC with Polaris RMK Pro 650's!