Avalanche danger in the ALPINE is expected to increase from CONSIDERABLE to HIGH as storm slabs develop through the day
Confidence
Low - Forecast snowfall amounts are uncertain
Weather Forecast
The bulk of the forecast storm looks like it is going to scrape just along the 49th parallel. Depending on the actual track some areas may see substantially more or less snow than forecast. Moderate to heavy snows are expected to continue overnight and through Tuesday. Snowfall amounts vary quite a bit across the region and between forecast models. Up to 20cm is forecast for the Coquihalla, with 40cm for the Duffy, and 30 in the Hurley. Winds are expected to be mainly light from the southwest with a freezing level around 1500m. The next pulse of the storm bringing another 10 to 15cm on Wednesday, with light southeast winds and a freezing level of 1000m. Thursday will see flurries, moderate westerly winds and a freezing level of 1000m.
Avalanche Summary
No new avalanche have been reported as of publishing Monday evening.
Snowpack Summary
The forecast snowfall will fall on a sun crust on steep solar aspects, or a layer of surface hoar on sheltered and shady slopes at all elevations. 10 to 15 cm below this is a second buried weak layer again consisting of a melt-freeze crust on solar aspects in the alpine or well-developed surface hoar in sheltered areas at treeline and lower elevations. Deeper still, the mid and lower snowpack is generally strong, with the exception of shallow snowpack areas that may be more faceted.
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.