Regions
Northwest Inland.
Confidence
Poor - Due to limited field observations
Weather Forecast
Friday: Light NW wind, changing to moderate SW late in the day. Alpine temperature near -8. 5 cm snow, late in the day.Saturday: Moderate NE wind. Alpine temperature near -7. No snow.Sunday: Light W wind. Alpine temperature near -7. Very light snow.
Avalanche Summary
Snowmobilers witnessed naturally-triggered slabs and loose dry sluffs in the Seaton Basin on Monday. No avalanches have been reported since then.
Snowpack Summary
Up to 25 cm of recent snow is sitting over a weak, faceted old snow surface, which is causing loose dry sluffing in steep terrain. In wind-affected areas, wind slabs have formed behind terrain breaks such as ridges and ribs. A strong mid-pack overlies a weak base layer of facets and the remnants of a crust.
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.