Northwest Coastal

The effect of recent warming is uncertain, and buried weak layers exist in the snowpack. Conservative terrain selection remains critical.

Moderate - Intensity of incoming weather systems is uncertain on Wednesday

Wednesday: 5-15cm of new snow / Strong southwest winds / Freezing level at about 1100mThursday: 4-8cm / Light and variable winds / Freezing level at about 1100mFriday: Light flurries / Light and variable winds / Freezing level at about 800m

Over the past few days a natural avalanche cycle up to size 3 occurred in response to heavy snow and wind. The peak of the natural avalanche activity occurred a few days ago; however, human triggered slab avalanches to size 1.5 were observed failing on recently buried surface hoar as recently as Monday. Recent naturally triggered wind slabs were also observed.Ongoing storm slab activity is expected in response to new snow and wind on Tuesday and Wednesday. New snow will also add stress and destructive potential to deeper weak layers. Loose wet avalanches are expected to continue at lower elevations where precipitation falls as rain.

Anywhere from 40-80 cm of recent snowfall has fallen. Precipitation has been falling as wet snow or rain at lower elevations. The new snow overlies a variety of old surfaces which include wind slabs, facets, sun crusts on steep solar aspects and well-developed surface hoar in sheltered locations. Deeper in the snowpack, the mid-January surface hoar/facet layer is now down roughly 80-120 cm. Recent observations suggest the layer has generally stabilized but isolated weaknesses may still exist, mainly where buried surface hoar is still intact. Below this layer, the snowpack is generally strong and well settled. The exceptions are areas around Bear Pass and Ningunsaw where basal facets remain an ongoing concern, especially in shallow snowpack areas.