Wind, snow and warming temperatures may increase the avalanche hazard on Sunday. Stay tuned!
Weather Forecast
Moderate SW winds can be expected at tree line and above building to strong on Sunday. Temperatures will be mild with 10 cm possible on Sunday (rain showers in valley bottom). Expecting clearing, winds easing and temperatures cooling beginning of next week.
Snowpack Summary
The snowpack is unpredictable. Shallow wind slabs have been failing on solar aspects in the alpine. In sheltered areas, approximately 10-15 cm of settled snow is sitting on a weak and faceted mid-pack with depth hoar to ground. The November crust exists sporadically and is hard to find in the southern forecast area.
Avalanche Summary
Large slab avalanches to size 3 have been reported recently on open solar aspects in the alpine.
Confidence
Timing, track, or intensity of incoming weather system is uncertain on Sunday
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.