Avalanche Forecast

Low - Wind effect is extremely variable

FRIDAY NIGHT: Flurries, trace to 10 cm snow. Strong southwest wind decreasing to light. Freezing level 1200 m.SATURDAY: Cloudy with isolated flurries, trace to 5 cm accumulation. Light to moderate south- southeast wind. Freezing level 1300 m.SUNDAY: Continued flurries and snow, 10-20 cm snow. Moderate southwest wind. Freezing level dropping to 500m.MONDAY: Cloudy with flurries, snow beginning late Monday night. Light northwest wind. Freezing level below 500 m.

A widespread storm slab avalanche cycle on Thursday was reported in the Sea to Sky region. Storm slabs failing naturally produced very large (size 3) avalanches and skier traffic triggered smaller (size 1-2) avalanches through the day. Most had a depths around 40 cm, representing the total snow accumulated starting Wednesday. Natural avalanche activity is expected to decrease through the weekend, but right now the snowpack is primed for human triggering.

Recent heavy snowfall has accumulated 40-80 cm around the region by Friday afternoon. 75-150 cm total storm snow has accumulated since Jan 1. Above 1850 m, the storm snow remained dry and covered previous wind slabs on south aspects. Extreme alpine winds continue to redistribute snow and develop wind slabs and cornices. At treeline and below, the new storm snow rests on two closely-spaced weak layers (developed Dec 26 and Jan 1), a crust on solar aspects and variable surface hoar found in more sheltered areas. Storm slab avalanche activity on Thursday occurred on this interface between new snow and old, down 50-100 cm in the snowpack.In the lower snowpack, a weak layer of sugary facets is now 150 to 200 cm deep. There have not been reports of avalanches on this layer for over a week, but it may still be reactive to heavy loads in isolated areas.