Some areas in the West of the region may have received more new snow recently. If your area has more than 30 cms of new snow in the alpine, then consider these ratings a little low.
Confidence
Fair - Due to limited field observations on Sunday
Weather Forecast
Overnight and Sunday: Light precipitation overnight should become very light by morning. Alpine temperatures should be about -8.0 and the freezing level should be down to the valleys. Winds should lighten and back to the SE. Expect broken skies in the East of the region.Monday: Overcast with light drizzle or wet flurries in the valleys. Alpine temperatures around -8.0 with strong SW winds at higher elevations. Tuesday: Western areas should get another warm pulse of moisture, maybe up to 15 mm. The East of the region may get considerably less moisture, and more wind.
Avalanche Summary
No new avalanche observations. No signs of whumphing or cracking were observed in the Harvey Pass area.
Snowpack Summary
A report from near Harvey Pass tells us that there is about 25 cms of storm snow that is "damp" at treeline and the ski penetration is only about 20 cms. The November crust was found to be buried down about 60 cms and was associated with a layer of facets either directly above or below. Light winds were not transporting much snow in this area. Alpine elevations may be quite different, as most of the recent precipitation has fallen as snow. We are hoping that the storm snow will bond well as temperatures cool, this may still take a day or two.
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.
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.