This problem is most prevalent at and below treeline, and will become easier to trigger with the warm temperatures. An avalanche on this layer will have heavy consequences with a burial depth of 20-50cm and the potential for wide propagation.
Rising freezing levels will make wet loose avalanches a major concern. Be mindful of your overhead hazard be aware that warm temperatures may cause cornices to fail.
Older wind slabs will become more reactive throughout the day as temperatures increase. Be especially wary of sunny lee slopes.
Deep persistent slabs are best managed by:
Cornices are best managed by:
Thursday: Sunny. Alpine temperature: High 3 C. Ridge wind southwest: 20-40 km/h. Freezing level: 2600 meters dropping to 1300m overnight with a weak inversion.
Friday: Repeat of Thursday with a little more cloud cover.
Saturday: Flurries. Ridge wind southwest: 30 km/h gusting to 60 km/h. Freezing level: 2500 metres.
Surface snow will quickly become moist as the sun beats down and freezing levels rise to ridge top. 20-50cm wind slab sits on top of the weak February 14 facet layer which is above a melt freeze crust at treeline and below. The remainder of the midpack is made up of dense facets and decomposing crusts, with early season ice crusts forming the base.
Several natural wind slab and loose wet avalanches were observed on Wednesday on SE through NE aspects from 1800-2200m with rising freezing levels. Expect this trend of natural avalanches to continue until temperatures drop.