Boletín de aludes

Boletín de aludes

Payette Avalanche Center
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Peligro de aludes

Alta montaña
4 · Fuerte
Límite del bosque
4 · Fuerte
Bajo el límite
4 · Fuerte
Desactualizado: este boletín caducó 5 years ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

Travel in Avalanche Terrain is Not Recommended Today! Gusty, Strong winds and warmer, heavier snow will stress the cold snowpack in wind-loaded and wind-sheltered terrain.

Slopes that are steeper than 30 degrees, or connected to slopes steeper than 30 degrees should be avoided.

A large, cautious distance should be given to potential run-out zones of steep terrain.

Problemas de aludes

  • Wind Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Certain
    Tamaño
    1–3

    Southern winds have been dominating our mountains over the last 24 hours, sending plumes of snow into the air that was able to be seen 10 miles away both Sunday and Monday. Variations in the mountain terrain can influence wind direction enough to make all aspects suspect. Clues on the surface can indicate true local wind loading patterns.

    Heavier, denser snow is forecasted along with strong Southern winds gusting into the 30 plus mph range. Large drifts, growing cornices, and scoured rocky areas are already making up the surface of the ridgelines. 

    Wind-affected snow is widespread which is making travel on most slopes dangerous, impossible, or not preferable.

    Avoid slopes steeper than 30 degrees and that have been wind-loaded. If you are seeing red flags like shooting cracks, fresh avalanches, or hearing hollow or whoomphing noises, find a different, safer route.

    (1/4/2022)

    Gusty SW winds at the Granite Weatherstation Monday-Tuesday Morning at 7,700 FT,

    Photo: GH

  • Storm Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Very Likely
    Tamaño
    1–2

    Strong over weak is a basic bad recipe for a snowpack, and that is what we are going to get according to the weather forecast and the trend over the last 24 hours. Heavier denser snow is going to overly colder lighter density snow that everyone has been loving and is going to form a storm slab that may fail naturally on steeper slopes, but on those 30-38 degree slopes it may just take your weight to set it off and make it fail.

    Slopes steeper than 30 degrees should be avoided.

Avalanche Discussion

This information is sponsored by Franklin Building Supply in McCall, Idaho. Thank You for supporting the Payette Avalanche Center!

If you did not read the bottom line, travel in avalanche terrain is not recommended! High Avalanche danger exists on slopes steeper than 30 degrees. 

The snowpack is changing as the winds and temperatures have steadily risen. The Cold dry powder that we love has taken a beating from gusty winds since Sunday. We have seen winds in excess of 30 mph. Plumes of snow flying off of the peaks were visible from across the valley on both Sunday and Monday. Snow and wind will be an ongoing theme throughout the week.

Cold temperatures had previously laid down soft light density snow that is not going to be able to hold onto the stronger, denser snow that is forecasted to stack up in sheltered areas and go full send under strong southern winds. Amongst the colder previous snow that makes up the upper 2 feet of the snowpack, are facets that formed on the surface as well as surface hoar. It is likely that a lot of weaker layers at the surface got destroyed under such wind, but there could be areas that were protected enough to preserve them more, but even without the weaker crystals in the mix, the heavy/strong over weak snow is going to naturally avalanche on Tuesday. 

Wind loaded slopes are going to be likely spots to trigger a wind slab, but be cautious in protected areas as this new snow will become a slab, and if it hasn't already slid it might just be waiting for a trigger like you to make it slide.

Watch out for the edges of cornices breaking off. The winds have formed some massive cornices with lips that are rapidly growing. They may break off and start an avalanche if not just hurt you...If you get too close to the edge they can break and send you falling with them. Give the edges of cornices some distance as it really might be hard to tell where the edge is hanging over, and it may let you get out there and break back way further than you thought.

Make sure you have room for errors and use extra caution this week as we get heavier and heavier snow stressing our mountain snowpack. Use good travel protocols and make sure everyone in your group has a transceiver, shovel, and probe in a pack, on their back so that they have it if they are caught in an avalanche, and it is not buried with their sled.

 

Don't forget to send in an observation! Pictures are really good as well as all of the information, but we will take what you got either way.  Use the observations tab above to submit your own.

Thanks ahead of time!