Weather Forecast
We will see increasing cloud today as a frontal system enters the region. Expect light flurries, alpine temps just below -10, and moderate westerly winds. On Tuesday we expect 5-10cm of snow with strong westerly winds intensifying loading. On Wednesday, the clouds should start to clear again with temperatures dropping to -20 in the alpine.
Snowpack Summary
A new sun crust will have formed on steep solar aspects yesterday. In the upper snowpack, layers down 40 (crust) and 80 (crust on solar and large stellars/ pockets of surface hoar elsewhere) have been reactive to ski cutting on steep unsupported features in Rogers Pass, and in the surrounding region caused several human triggered size 2 avalanches.
Avalanche Summary
Yesterday, there was a widespread avalanche cycle. They were loose avalanches size 1.5 to 2.5, on solar aspects, triggered by strong sunshine. On Saturday, skiers triggered size 1.5 slab avalanches on the SE face of 8812. Recent natural avalanches on N and E aspects have been size 2-2.5 and triggered by loading due to steady moderate SW winds.
Problems
Wind Slabs
Wind Slab avalanches are the 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.
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.