We are in a heavy storm cycle. Expect permit area closures until things settle out.
Weather Forecast
An unstable airmass will linger over the area today, bringing clouds and flurries. Things will dry out overnight, but another front is due to arrive on Friday, bringing another 13+mm of precipitation to the area tomorrow. The weekend promises to be unsettled as well, with improving weather for Monday.
Snowpack Summary
35 cm of storm snow overnight with moderate to strong South winds have created a storm slab in the alpine and treeline. These slabs overly crusts on solar aspects and facets or surface hoar on north aspects. The SH is best preserved above 2400m. Below treeline, the snowpack has become isothermal, frozen in the mornings, mush by afternoon.
Avalanche Summary
A widespread natural avalanche cycle occurred late yesterday and over night with the addition of heavy wet storm snow, up to size 3, running to valley bottom. Glide cracks and cornices are growing larger, and are failing unpredictably. Heavy loading overnight will make things touchy today.
Confidence
Timing, track, or intensity of incoming weather system is uncertain on Friday
Problems
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.
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.
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.