Lawinenlagebericht

Mt Hood

Northwest Avalanche Center
Auf der Karte ansehen

Lawinengefahr

Tue
Hochgebirge
3 · Erheblich
Waldgrenze
2 · Mässig
Unterhalb
2 · Mässig
Open full map
Veraltet — dieser Lagebericht ist 4 years ago abgelaufen. Du siehst vergangene Verhältnisse, nicht den aktuellen Bericht.

Kernpunkte

Winds and warming will build slabs atop previously unconsolidated snow, leading to increasing avalanche danger throughout the day on Monday. Step back your terrain selection as the storm intensifies and avoid steep wind-loaded slopes at upper elevations. Rain on snow may destabilize previously dry snow below treeline to initiate small natural avalanches on steep slopes.

Lawinenprobleme

  • Wind Slabs

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

    Winds began drifting 6-7" of low-density snow from Saturday and Saturday night in some locations above treeline Sunday afternoon. Moderate winds Sunday night increase Monday and may be strong at times in the afternoon, forming fresh slabs as it redistributes recent snow plus 2-5" of fresh snow accumulating during the day above 5000 ft. You'll need to quickly adjust your mindset as conditions will shift rapidly from the right-side-up snow over the weekend. Given the expectation for higher density snowfall on Monday, slabs may become reactive more rapidly than you expect. Look for firm over weak snow structure, shooting cracks, and settlement of the snow as you travel. Any of these confirm instability in your terrain. Above treeline, reactive slabs may be widespread with isolated large avalanches by the afternoon. At lower elevations, most slabs will be smaller and limited to steep, unsupported start zones. Avoid all wind-loaded slopes steeper than 35 degrees by the afternoon.

    (4/17/2022)

    Snow transport, textured snow, and drifting near treeline in the Tilly Jane area on Mt. Hood Sunday afternoon.

    Photo: Andrew Kiefer

  • Loose Wet

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

    Snow levels have been low the past week, maintaining a deep winter-like upper snowpack even below treeline. Lower elevations formed crusts on some aspects and slightly milder conditions helped recent snow to consolidate somewhat at lower elevations. However, rain falling on snow will be a drastic change for the cold snow, particularly on shaded NW-N-NE aspects. On other aspects, crusts may limit the impact of the rain unless the rain breaks through the crust. If you can sink your foot past your ankle into wet slushy snow, natural or human-triggered small wet loose avalanches are possible. It is best to avoid traveling on or under slopes steeper than 35 degrees during periods of more intense rainfall. You can use low-angle slopes and ridges to travel safely while you are below the 4500-5000 ft rain/snow line rather than risking triggering a slow-moving wet avalanche that could entrain enough snow to bury you in a creek or gully.

    Example: Rollerballs and small point release initiating off trees and other vegetation indicate that warming and rainfall have created the conditions for wet loose avalanches.

    Photo: Andrew Kiefer

Avalanche Discussion

Mt Hood received nearly 80 in of snow since April 8th with the most recent 6-7" of snow arriving on Saturday with decreasing winds. Professionals traveling in the Tilly Jane area of Mt. Hood on Sunday found 8 inches of cohesionless, low-density snow sitting on a wind-affected old snow surface. Winds were beginning to drift snow Sunday afternoon. Small, shallow loose-dry avalanches were naturally triggered by sunshine both below treeline and on steep above treeline slopes. Expect widespread breakable crusts when you start your day on Monday except on shaded aspects.

The most recent slab avalanches were large in isolated areas, triggered by Mt Hood Meadows patrol early Thursday in easterly upper elevation terrain.  All the snow since the prominent 4/8 crust has settled to around 4 ft. Recent storms really built up the snowpack and improved low elevation coverage; snow depths on Hood are 106-110% of normal for this time of year.

NWAC is aware of a possible avalanche fatality at Mt. Hood Meadows on 4/5. We are actively working with local authorities to gather more information about the incident. This incident involved a solo snowboarder and a multi-day SAR effort. You can read our initial statement here. We will update the statement early next week (week of April 18th). 

Abgedeckte Regionen