Bollettino valanghe

Bollettino valanghe

Payette Avalanche Center
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Pericolo valanghe

Wed
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
3 · Marcato
Non aggiornato — questo bollettino è scaduto 4 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Dangerous avalanche conditions exist! Careful snowpack evaluation, cautious route-finding, and conservative decision making are going to be essential today as sustained warm temperatures (rain up to 7,000 feet), up to a foot of new snow in the upper elevations in the last 24 hours, and moderate winds have easily created sensitive storm slabs on all aspects that are failing from just the weight of a skier as reported from users.  20 MPH Southern winds have formed dense wind slabs that are also sensitive to the weight of a skier or rider. Any slope that is steep enough to slide (30 degrees +) should be approached with caution...Human triggered avalanches are likely that may range in size from small to medium (D2-D2+).

Below 7,000 feet, rain on snow may produce small to medium wet loose avalanches!

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–1.5

    20 MPH + Southern winds have formed dense wind slabs that are also sensitive to the weight of a skier or rider.  These slabs could range in size from 6 inches to 2 feet deep. Most wind slabs have likely formed on Northern aspects, but be cautious and on the lookout for clues on the snow surface that indicate which way the particular slope is being loaded as the terrain can influence loading or cross-loading direction.

    Winds over the week at the Granite weather station. 

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2.5

    Just about a foot of new snow has fallen in the upper elevations over the last 2 days. The new snow is much warmer, heavier, and denser than the snow below it creating a basic bad recipe for a snowpack (strong over weak). Many surfaces that the new snow has fallen on were firm and or harboring weak facets on or near the surface which could make them easier to fail. Steep slopes, if approached, should be done so with caution...red flags like cracking or whumping should turn you around to find another safer, maybe lower angle route to travel. 

    (2/28/2022)

    The warmer temps with the new snow were building storm slabs on all aspects

    Photo: GH

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!

The warming trend has arrived and warm temps will be the theme over the next couple of days. Winds ramped up into the 20 MPH range Monday and did a good job of forming wind slabs while storm slabs formed on all aspects. Buried crusts and weak layers as well as the denser, now stronger snow above have helped to elevate the avalanche danger. Monday we observed these sensitive slabs and got 2 observations from skiers of slabs that were sensitive to their weight, and one that triggered a 5-8" slab  (D2) above Pearl Lake. It is going to take a few days for the temps to come back down and for the danger to calm down also.

Prior to this warmup, we were finding pockets of buried surface hoar that were propagating in extended column tests. We believe that this is isolated, and preserved in areas that were protected and cold...well things have changed and the warm temps, and yes rain may help our stability over the long term?

Be patient, and careful in the next coming days, watch for red flags in the snowpack, carry all of your rescue gear, and keep your eyes on your partners only exposing one person ever to slopes steeper than 30 degrees. This thicker snow may force you to find steeper terrain to slide on which is exactly where you wanna be careful.

 

****One of our sponsors, OnXBackcountry has partnered with the Payette Avalanche Center. For each membership purchased with promo codePAYETTE20 for onX Backcountry or PAYETTESLEDS20 for onX Offroad you get a 20% discount. Plus, a 20% donation goes back to the Payette Avalanche Center upon purchase, so you’ll be directly supporting avalanche forecasts. 

Go to 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. 

Sledders and Snowbikers, please be aware that there are some areas of the Payette National Forest that are closed to motorized use, some of these closures are to protect wildlife and some are to protect other recreators.  If you are using Gaia or OnX you can download a layer called snowmobile trails that shows groomed routes and motorized closures.  Check out the Winter Travel Map below for details.

https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fseprd891395.pdf