Changing conditions: snow and strong winds are making a good recipe for avalanches.
Confidence
Fair - Due to the number of field observations
Weather Forecast
A series of low pressure systems is forecast to bring heavy precipitation, strong southerly winds and rising freezing levels. On Tuesday, around 10 cm snow is expected (locally 20 cm around the Coquihalla). Overnight, another 15-30 cm is forecast, before a lull on Wednesday. On Wednesday night and Thursday, a possible atmospheric river is expected to bring 10-30 mm of precipitation with the freezing level rising to around 1900 m. Winds are strong to gale from the south. For more details check out avalanche.ca/weather
Avalanche Summary
No recent avalanches have been reported.
Snowpack Summary
Forecast storm snow is likely to build slabs, which may bond poorly to the current cornucopia of surfaces including hard slabs, crusts, facets and large surface hoar crystals. The snowpack is highly variable across different aspects and elevations. There is anywhere from 30-150 cm on the ground. Previous northerly outflow winds scoured upwind slopes back to a firm crust, and created wind slabs on lee aspects, which are gradually gaining strength. Shallow snowpack areas may be rotten (facetted).
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.