Lawinenlagebericht

East Slopes Central

Northwest Avalanche Center
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Lawinengefahr

Mon
Hochgebirge
3 · Erheblich
Waldgrenze
2 · Mässig
Unterhalb
1 · Gering
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Kernpunkte

You can trigger avalanches in the recent storm snow at middle and upper elevations. These will mostly be wet loose avalanches, though you may encounter drier recent snow above 6,500ft. Expect temperatures and sun to warm the recent snow, up to 1 foot, that accumulated this weekend.

Lawinenprobleme

  • Loose Wet

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

    You can trigger wet avalanches on slopes steeper than 35 degrees, especially above 5,000ft. It may be easiest to trigger slides on E-S-NW slopes as the surfaces warm from sunshine. Watch for signs of instability, like fresh avalanches and rollerballs, that indicate you could trigger an avalanche. Anticipate the chances of triggering avalanches and move to lower-angle slopes to avoid them.

    If you travel to the highest upper-elevation terrain, you may find that the recent snow is completely dry. Be ready to assess for other new snow instabilities, like storm or wind slabs.

    (3/23/2024)

    A natural loose wet avalanche in 10-12" of new snow near Fortune Peak.

    Photo: Andy Harrington

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    2–3

    Triggering a large 2-4 foot thick persistent slab remains possible on the north side of the compass at upper elevations. We suspect this problem to be most dangerous in areas with fresh wind-drifted snow, especially in locations with a more shallow snowpack. 

    So far, we have received confirmation from the Wenatchee Mountains that cold snow and, unfortunately, a weak snowpack continue to plague northern aspects (NW-N- NE aspects). We have limited information from other parts of the zone, but we suspect the early February crust remains preserved elsewhere on northerlies above 6000 ft. 

    These avalanches can act surprisingly, often propagating widely or being triggered from a distance. You may or may not receive feedback before triggering this type of avalanche. The best way to reduce your risk of triggering persistent slabs is by avoiding leeward sides of ridges and steep, rocky, complex start zones on the north side of the compass. 

    (3/6/2024)

    An example of a persistent slab release from a couple of weeks ago. 

    Photo: Anthony Lubetski

Avalanche Discussion

A spring storm favored east slopes of the Cascades will bring a total of over a foot of snow to the upper Salmon La Sac area with 6-10" in areas further east and north. Precipitation should wind down before dawn on Sunday, giving way to clearing and mostly sunny skies. 

On Saturday, an NWAC forecaster found 10-12" of new snow above 6,000ft near Fortune Peak. He reported natural and human-triggered wet loose avalanches in the new snow. While most slopes may have supportable thick surface crust,  we still have a bit of uncertainty about the reactivity of the Early February Crust.  On 3/22, the Mission Ridge Pro Patrol reported weak snow and propagating test results on the EFC on shaded aspects above 6000 ft. They found this weak layer about 2-3 ft deep. Check out the video in the gallery for more information. On 3/20, an observer on Dirtyface Mountain reported a large whumph on an east aspect at 5700 ft. In this location, the surface snow was moist, but it serves as a reminder that weak layers are still lurking despite the recent warm-up.  During periods with higher uncertainty, the best strategy is to widen your margins. Give slopes that fit the description a wider buffer and carefully assess slopes before skiing, climbing, or riding larger slopes. 

On other aspects, the snowpack has endured a serious beating due to the recent warm-up. Observers have been reporting a variety of wet surfaces, supportable crusts, or even melted-out slopes on windward and steep solar aspects. 

Observations have been sparse. Help create a more accurate forecast by submitting your public observations here. 

 

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