Bulletin d’avalanche

Mt Hood

Northwest Avalanche Center
Voir sur la carte

Danger d’avalanche

Sun
Alpin
1 · Faible
Limite forestière
1 · Faible
Sous la limite
1 · Faible
Open full map
Périmé — ce bulletin a expiré 4 years ago. Vous consultez des conditions passées, pas le bulletin en cours.

Points saillants

Forecast updated 7:24 AM to add a wind slab problem.

Winds redistributed shallow snowfall early Saturday. You can trigger an isolated wind drift 6" or deeper on a steep or unsupported lee slope at upper elevations. Below treeline, the snowpack has become summer-like with discontinuous coverage.

Problèmes avalancheux

  • Wind Slabs

    • Alpin
    • Limite forestière
    • Sous la limite forestière
    Probabilité
    Possible
    Taille
    1

    Mt. Hood picked up 2-4" of snow early Saturday. Moderate W winds and strong gusts drifted the recent snow into shallow slabs you can trigger near or particularly above treeline. Shallow cracking snow surfaces can help identify the transition into wind-affected terrain. The depth of the new snow over a crust will tell you a lot. Anticipate areas of deeper drifts using clues from wind-textured snow and swales around rocks. Steer around lee slopes in steep avalanche start zones, particularly where they might push you into a terrain trap such as rocks or a gulley.

    Example: Wind textured snow, scoured ridgelines, and thick wind drifts on leeward slopes.

    Photo: Andrew Kiefer

Avalanche Discussion

Mt. Hood experienced another warm day with temperatures quickly rising into the 30s and 40s and featuring mostly sunny skies. Warm temperatures, rainfall, and sunshine over the last several months have significantly impacted the lower elevation snowpack at Mt. Hood. NWAC forecasters traveling in White River Drainage on Friday found generally stable avalanche conditions. Snow conditions below 5500-6000 ft had deteriorated and become dirty with discontinuous snow coverage in a summer-like state and open stream crossings. Many ridgelines and sun-exposed slopes are melted out. Fortunately, snow conditions improve quickly above 6000 ft. In the transition zone, snow surfaces appear scabby with old wind drifts in a dry to wet transition and very visible on top of the dirty older snow. Above treeline, Wednesday's 1-3" of snow becomes more continuous with the potential for very isolated wind slabs above 7500 ft.  Given the warm temperatures, wet loose potential increased as the recent transitional snow became more continuous, but the risk remains limited. No new avalanches have been reported since 3/24.

In less wind-affected terrain, the new snow will form rollerballs and very shallow wet loose avalanches once sunshine makes an appearance by the afternoon. Expect a rapid destabilization of the fresh, cold snow. These avalanches could pick up steam and push you into undesirable terrain traps if you're at the bottom of a long steep slope at the wrong time. Use the rollerballs and sticky snow as a clue to adjust your aspect and reduce your exposure.

Régions couvertes