Avoid all avalanche terrain as avalanches can run to valley bottom.
Weather Forecast
Winter Storm Warning in effect for Waterton on Thursday. Forecasts models regarding precipitation amounts range from 20cm-50cm. This snow is accompanied with cold temperatures (-15C) and light NE winds. Snow will taper off into Friday, temperatures will warm-up and skies will clear into the weekend.
Snowpack Summary
There is a weak facet layer deep in the snowpack that has been producing large avalanches to the West of Waterton. We are concerned that the new snow on Thursday might cause this weak layer to fail producing large avalanches.
Avalanche Summary
There have been large avalanches to the West of Waterton, in the Lizard Range, in the last week.
Confidence
Timing, track, or intensity of incoming weather system is uncertain on Thursday
Problems
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.
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.