Lawinenlagebericht

Selkirk Mountains

Idaho Panhandle Avalanche Center
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Lawinengefahr

Sat
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
2 · Mässig
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Veraltet — dieser Lagebericht ist 4 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

You could still trigger an avalanche on several buried weak layers or wind drifted snow at upper elevations. These now persistent slabs formed on weak snow above the prominent early March rain crust and vary across the Selkirks & Cabinets forecast zone. Carefully evaluate terrain on all aspects at upper elevations, digging quick pits often to look for weak layers in the 15-20” of snow above this crust. Lower elevations are in a melt/freeze cycle, and wet loose avalanches will become possible as the day goes on and temperatures rise. 

Lawinenprobleme

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–2

    Multiple persistent weak layers exist in the approximately 15-20” of snow above the stout early March crust. While variable in strength across our terrain, we’re seeing weak layers both immediately above this crust and also 6-10” above it near the interface of last week’s snow and this week’s snow. Watch for these weak layers on all aspects. It’s easy to dig down to the early March crust to look for these layers, and their variability means it’s worth digging to test them often. You might find these layers more prominent in the Cabinets than Selkirks. Either way, the large avalanches they could produce should motivate you to evaluate them carefully rather then blindly rolling the dice on a steep slope. Avoiding terrain steeper than 30 degrees is your best option for truly avoiding persistent slabs near and above treeline.

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Unlikely
    Größe
    1–2

    Winds slabs can be found at upper elevations on northerly aspects. Avoid steep open wind loaded slopes, knowing that even a small wind slab might step down to larger persistent slab below.

    Wind slab avalanches

    North face, 5800'

    Selkirk Mountains

  • Loose Wet

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–1.5

    Wet loose avalanches continue to become possible at the warmest time of day on most aspects at low elevations and on sun-warmed slopes at upper elevations. Watch for roller balls and snow falling out of trees as signs that you could initiate these relatively small but heavy sluffs in steep terrain.

Avalanche Discussion

Upper Elevation (at and above tree line)The storm that moved through last Monday left 8-15’’ of new snow in the Selkirks and Cabinets and had enough southwest winds to transport snow onto northerly slopes. A spike in snow levels on Tuesday turned snow to rain up to at least 6,000’ for some of our terrain, especially in the Selkirks near Schweitzer. You may find breakable rain crust with a little snow on top in the upper portions of the new snow from Monday. Persistent weak layers can be found near the interface of this somewhat recent snow and last week’s snow as well as a little deeper, above the robust early March rain crust. These weak layers vary, and we lack certainty on exactly where you’ll find them. For example, we’re seeing extended column test results with full propagation on west and south aspects where we less commonly see persistent slab problems. A healthy suspicion of these weak layers should keep you on your toes, carefully evaluating the snowpack on any steep slope you consider, and choosing low consequence terrain.

Lower Elevation (in the forest)Spring is here! I was surprised to see how much snow melt was up the Pack river! At lower elevations the snowpack is going through a melt / freeze process. It’s been pretty firm riding up in the mornings but soften as the day goes on. Slopes that warm up throughout the day or sit in the sun become increasingly unstable as the day goes on. This is an avalanche problem that’s easier to manage than others.  You can manage your risk by going early in the day.

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