The snowpack will tighten up and improve as the cold returns. The warmth has penetrated deep into the snowpack at treeline and below. Remember that it may take some time for the cold to sink into the snow.
Weather Forecast
A cooling trend will start tonight. Expected afternoon highs will be around -9 in the alpine. The winds will also drop and settle to 30-40km/hr from the west. No snow is expected for the next few days.
Avalanche Summary
Nothing new was noted today, however the light was poor.
Snowpack Summary
The warm weather has had a significant impact on the snowpack. Long term this will help, but for the time being the snowpack quality is marginal. Below treeline almost the entire snowpack is moist snow. The basal layers are still the dry facets that we've seen all year. Near treeline the snow has settled into a moist, dense layer that sits on the weak Feb 18th facets or hardslab from past wind events. Some whumphing and cracking was noted today, but the wet slab had more of a collapsing feel to it. The warm air hasn't reached the upper elevations yet. In upper treeline areas and alpine areas the surface snow has remained cool. Some wind transport was noted today, but not enough to create wind slabs.
Problems
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.