Regions
Northwest Coastal.
Confidence
Fair - Forecast snowfall amounts are uncertain
Weather Forecast
Tuesday evening: A Pacific frontal system tracking mostly across the South Coast will affect southern portions of the NW regions. Generally unsettled conditions are expected for Wednesday before another weak system impacts the central coast on Wednesday night or Thursday morning. Possibility of 10 to 209 cm in the Mtns. just east of the coast.Wednesday: Mostly cloudy, light locally moderate snowfall, some parts of the forecast area may receive 10-15cm of snow, freezing levels around 400m, ridge top winds 20-30km/h SW-WThursday: Freezing level at or near valley bottom. Snowfall amounts, 5-10cm, ridge top winds from the W-NW 30-50km/h Friday: Freezing level around 100m. Light to locally moderate precipitation, some parts of the area may receive 10 to 15cm of snow, ridge top winds light to moderate from the south.
Avalanche Summary
Numerous reports of size 1.5 to 2.5 natural avalanches, as well as skier remote avalanches up to size 2
Snowpack Summary
Parts of the forecast region have received over 1.5m of cumulative storm snow which has now settled into a slab with a typical thickness of 60-90cm. This storm slab overlies a variety of facets, surface hoar, crusts, hard wind press, or any combination of these. Widespread whumpfing, cracking, natural avalanche activity and remote triggering at all elevations are a strong indication of poor bond between the new snow and these old surfaces. Snowpack tests show easy, sudden planar results with good propagation propensity.
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.