New snow and wind are increasing the avalanche danger. New storm slabs are developing that may be easy to trigger from light additional loads like skiers/riders.
Confidence
Poor - Due to the number of field observations
Weather Forecast
Overnight and Monday: 15-30 cm of snow overnight as the cold arctic air from the North meets the warm moist Pacific air crossing from the West. The South of the region may see more snow than the North. Snow ending by the afternoon, and then cooling temperatures and winds becoming Northeast.Tuesday: Cold and dry with light Northerly winds.Wednesday: Sunny, dry and cold.
Avalanche Summary
The new storm snow is expected to slide easily on the old surface weak layers. Expect easy triggering with light additional loads applied.
Snowpack Summary
Forecast new snow and strong Westerly winds are expected to develop a new storm slab above the existing shallow weak snowpack. The new storm slab may not bond well to the old surface weak layers of crusts, wind slabs, and surface hoar. We expect new storm snow amounts to vary across the region due to the fast moving nature of the system from West to East.
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.