Lawinenlagebericht

East Slopes Central

Northwest Avalanche Center
Auf der Karte ansehen

Lawinengefahr

Thu
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
1 · Gering
Veraltet — dieser Lagebericht ist last year abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

As Winter turns into Spring, don't let yourself be lulled into a false sense of security. Avalanche conditions are still dynamic. As you increase in elevation, expect the likelihood of triggering an avalanche large enough to bury you in wind-affected snow to increase, too. Signs of wind transport, such as uneven snow surfaces, blowing snow, or shooting cracks from your equipment in exposed terrain are good reasons to pause and reassess your terrain choices.

Lawinenprobleme

  • Wind Slabs

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

    It is possible to trigger an avalanche 1-2 ft deep in previously wind-loaded snow. The higher in elevation you travel, the more likely it will be to find terrain that a wind slab will have formed in. The likelihood of triggering these aging slabs is decreasing; however, on Wednesday afternoon, new snow begins to fall with increasing wind speeds from the east. This will build fresh, small slabs in atypical locations that could be reactive. This could also increase the sensitivity of older slabs by adding load. Expect higher snow totals the closer you are to the Cascade Crest. 

    Gather information from several data points before committing to bigger, exposed terrain. You can do this by jumping on safe test slopes representative of your objective and looking for signs that the wind has worked the snowpack in the alpine. In addition to the signs laid out in the bottom line, look for changes in how the snow feels underneath you, dune-like drifts, and recent cornice formation. Wind slabs typically form just below ridgelines and in terrain features that are gully or chute shaped, but sometimes slabs can form in "sneakier" terrain, such as in burn areas or lower down on slopes than you might expect. Long shooting cracks or audible collapses are obvious signs you found an unstable slab.

    Additional Discussion:

    It's unlikely, but lingering storm slab instabilities may exist in steep or unsupported terrain closer to the Cascade Crest. If you plan on traveling in these western parts of the zone, approach steep, open terrain with some suspicion. You can use a small test slope or simple hand pits to help you gauge the reactivity of the recent storm snow. 

    (3/12/2025)

    I triggered wind slabs on both sides of this ridgeline. I had anticipated this because of visual clues that showed the wind had recently blown in both directions. The slab on the right is a bit deeper.

    Photo: Payton Schiff

Avalanche Discussion

This wintery pattern continues as the official start of Spring approaches. The southern end of East Central saw an additional couple of inches Monday night, bringing snow totals to over 1 foot for the past few days. We will have a break in the action Tuesday night and Wednesday morning before a warm front moves in. This system will ultimately be the build-up to a larger storm that will begin impacting the forecast region Wednesday night. 

The past few days have been a busy avalanche period. There have been a number of avalanche involvements with skiers and snowmobilers in the East Central zone as recently as Tuesday, two of which included catch and carry's. In the nearby Snoqualmie zone, another skier was also caught and carried on Tuesday. All of these slides were wind slab avalanches. Fortunately, all parties were uninjured and skied out under their own power.

The most notable detail from many of these occurrences is that the involved parties were surprised that they triggered a slide. This serves as a good reminder that we must ease into terrain after stormy periods, regardless of the time of year or however powder hungry you feel. The snowpack is still layered, the sun creates complicated slab properties, and the wind is blowing from various directions. It's exciting to get out and have fun in the sun while also getting excellent powder turns in, but we are not out of the weeds yet. Obvious signs of instability don't always jump out at you as you travel up to your objective, so use all the tools in your toolbox to reduce your risk.

Persistent slabs continue to be an issue in the adjacent zone to the north. While we’ve put this problem to bed in the East Central, it’s worth considering in very northern portions or more far-flung parts of the zone. To reduce your risk, you can default to simpler terrain that is planar and short.

You can help us gather more data by submitting an observation HERE or via the Avy App.

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