Warm temperatures and sunshine are expected to increase natural and human triggered avalanche activity.
Avoid exposure to sunny slopes especially as things heat up in the afternoon.
Above freezing temperatures are expected to increase the reactivity of the persistent slab problem which sits over a widespread weak layer. If triggered, a failure on this layer could propagate wider than expected.
No significant precip but a big warm up will raise freezing levels (FZL) to near mountain top on Thursday.
Tonight: Flurries trace new snow. Alpine low -2°C. Moderate SW wind. (FZL) 1700m.
Wed: Cloudy. Low 0°C, high 3°C. Moderate SW wind. FZL 1900m. Weak inversion.
Thurs: Sun & cloud. Low 3°C, high 6°C. Light gusting moderate SW wind. FZL 3000m.
Fri: Sun & cloud. Low -4°C, high 5°C. Moderate SW wind. FZL 3000m.
Human triggering continues on the late Jan surface hoar. Over the past few days field teams have been able to trigger several size 1 slab avalanches at and below treeline.
Regionally there have been numerous natural, skier and remotely triggered avalanches also failing on the surface hoar layer.
Forecast significant warming will turn the snow surface heavy and wet increasing slab cohesion. Roughly 30cm beneath the surface is the late Jan weak layer of surface hoar, facets and a crust. This layer is found on all aspects and elevations with largest surface hoar (up to 40mm) in sheltered areas below treeline. The crust is firmer on solar aspects.
The mid and lower snowpack is generally well settled and strong.
