Avalanche forecast

Avalanche forecast

Payette Avalanche Center
View on map

Avalanche danger

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Out of date — this forecast expired 2 years ago.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

Highlights

SW-North winds upwards of 20mph have made triggering a 1-3' thick wind slab possible in leeward terrain. Avoid wind-loaded terrain and use extra caution near cornices that are overhanging.

Triggering a persistent slab avalanche up to 1 foot deep is a possibility in Sun and wind-sheltered terrain where the slope angle is 30-45 degrees.

Use cautious travel protocols for slopes steeper than 30 degrees and only expose a single person in your group to avalanche terrain at a time. 

 

Avalanche problems

  • Wind Slabs

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

    Winds have gusted upwards of 20mph out of the SW and were sending snow into leeward terrain, mostly North and East aspects until Wednesday when northern winds sent snow onto W and SW aspects. Plumes of snow were visible off of the peaks and ridges. Slabs that formed previously have likely healed but be prepared for the possibility of triggering a 1-3 foot deep wind slab in upper elevation leeward terrain.

    If you are seeing cracking or hearing whumphs find another route...Look for signs of wind loading as different terrain may load different aspects. Extreme terrain or consequential terrain like exposure or terrain traps like cliffs are going to compound the consequences of this problem. 

    (3/13/2024) Winds from the NNW filling in tracks almost within the hour Photo: George Halcom

  • Persistent Slabs

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

    Tuesday3/12- Wednesday 3/13 Snow came in on top of graupel and surface hoar crystals that formed on the surface during the last week while we were loving the few sunny days.

    This snow, now around 10-12" does not have a great connection and was running on steep slopes with ski cuts on Monday. This new snow is getting harder as it settles and we may see some elevated activity on this layer. Observed activity shows that these avalanches are not running far, or full track---they tend to be in random pockets where the weak layer stayed better preserved.

    Use extra caution on slopes that are steeper than 35 degrees and that are sheltered and where there are potential hazards of terrain traps like gullies or cliffs. This problem is most likely found where the Sun and wind have not broken down weak snow that formed on the old surface. Expect 1-2' deep soft slab avalanche potential.

    Sluff management techniques are going to be prudent for big exposed lines as the upper 10-12" will be moving and may push you where you would rather not go.

    (3/12/2024)

    Public Observation: ENE aspect Granite Mtn, N-D1.5 very similar to multiple others observed on 3/13 on Nothern aspects.

Avalanche Discussion

We had manageable sluff while skiing northern sheltered terrain Wednesday. Dry loose sluffs could push you around if you were skiing real slow and near terrain traps this would pose a problem that should diminish in the coming days a a warm trend will likely speed up snowpack settlement. As the Sun dominates the sky and temps climb in the afternoon, Crusts are going to begin to form and we will likely see Wet-loose avalanches on Sothern aspects , while small and harmless in the D-1 range. If you are seeing wet loose evidence like rollerballs and point releases find a cooler aspect to play on. North winds should help keep activity cool, but protected solar slopes will be first to shed soft snow especially rocky solar terrain

We have a deep persistent layer buried about 3-4 feet deep now that has some dense and strong snow above it: February 25th we buried a layer of surface hoar that was responsible for a human and natural avalanche cycle a week ago. We have not seen or heard of any activity on this layer and Recent saw tests (PST 47/100 end on March 11th) on this layer show a very hard-to-trigger slab with a remaining small potential to propagate a crack over a distance. ***Riders on snowmachines are more likely to trigger these layers, especially in areas where the slab or the snow is thin or shallow and rocky or near trees or other areas.

With temps climbing and the uncertainty of triggering persistent weak layers that can propagate, Increase your margin of error in case you find the sweet or trigger spot by doing things like 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.  

You can help us and others by reading and submitting a quick observation to our website. Click on Submit Observations and feel good about yourself as you are entered into our FPAC monthly drawing for great gear prizes.

Today's Advisory is sponsored by Skidoo.