Avalanche Forecast
Regions: Mt Hood.
Avoid steep slopes at higher elevations suspected of wind deposited snow. Wind slab avalanches should be shallow in nature, but remain possible to trigger on specific terrain features.
Detailed Forecast
Cloudy conditions with periods of light snow are expected Saturday. Only light to moderate Ridgetop winds are expected and this should not cause a significant increase in danger. Some new shallow isolated wind slabs may form on steep lee slopes, so watch for active wind transport.Â
Snowpack Discussion
About a week of fair weather was centered around the New Year. This allowed the significant snow that fell during a strong storm cycle, that ended about Christmas, to settle and stabilize.
By New Years Eve through the weekend moderate to strong east-northeast winds had significantly scoured most of the available surface snow, mainly in the near and above treeline elevation bands.
Surface snow sculpted by recent wind and active wind transport. Photo: Laura Green
On Monday the Mt Hood Meadows pro patrol reported warming and a widespread 1 cm freezing rain crust up to 7000 feet.
Laura was out again near the Mt Hood Meadows ski area on Tuesday and Wednesday and reported 5 inches of storm snow had formed small slabs, non-reactive to ski cuts, but some explosive triggered slides up to 10 inches were seen on steep slopes of varied aspects. These shallow slabs were becoming less sensitive by Wednesday as a result of warming temperatures.
No avalanches have been reported over the past several days on Mt Hood.
Avalanche Problems
Wind Slabs
Release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Wind Slabs form in specific areas, and are confined to lee and cross-loaded terrain features. They can be avoided by sticking to sheltered or wind-scoured areas..
Wind Slab avalanche. Winds blew from left to right. The area above the ridge has been scoured, and the snow drifted into a wind slab on the slope below.
Wind slabs can take up to a week to stabilize. They are confined to lee and cross-loaded terrain features and can be avoided by sticking to sheltered or wind scoured areas.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 1