Avalanche Forecast

Moderate - We are confident a natural avalanche cycle will begin shortly after the arrival of the incoming weather. Uncertainty is due to how buried persistent weak layers will react with the forecast incoming weather.

A warm wet storm will peak in intensity overnight Saturday then gradually taper off as the day progresses on Sunday. Rising freezing levels will mean the bulk of the precipitation will fall as rain but the highest peak elevations. The storm looks to focus on the south of the region, with lighter amounts in the north.

Saturday night: Snow and rain mixed heavy, at times 40-60 cm. Extreme southwest winds. Treeline low temperatures reach +2. Snow levels rising to 2000 meters.

Sunday: Rain and heavy snow 15-30 cm. Strong southwest winds. Treeline high temperatures reach +2. Snow levels 2000 meters lowering to 1500 meters.

Monday: Flurries. Moderate southwest winds. Treeline high temperatures around -1. Snow levels around 1500 m.

Tuesday: Heavy snow or rain. Moderate to strong southwest winds. Treeline high temperatures around +2. Freezing level around 2500 m.

Friday, numerous large slab avalanches (size 2 and 2.5) were artificially triggered near Whistler and Blackcomb. While the majority of them occurred within the last storm's snow, some were released on a deeply buried crust/facets combo. Several natural cornices falls were also reported in the same area. 

With the incoming precipitations and warming, a large natural avalanche cycle (size 3) is very likely to happen overnight Saturday.

Friday, reactive storm slabs have been observed at treeline and in the alpine on all elevations. Recent strong southerly winds have also created wind slabs in leeward alpine and treeline features. 

The recent snow buried mainly wind-affected surfaces, however, surface hoar was observed in the Whistler area earlier this week between 1800 and 2100 meters. As a result, storm slab reactivity may persist in places where new snow buried these weak grains. A combo of thick crust/ facets has been observed up to 2200 meters. This weak layer is now likely to become reactive with the increased load and warming from the current storm.

Average snow depths at treeline are now likely closer to 120-190 cm; 250+ cm in the alpine. Snowpack depths decrease dramatically below treeline and may still be below threshold for avalanches in some areas. This is changing with each storm pulse we see. Early season hazards such as rocks, stumps, and creeks are still a concern at these lower elevations.

• Avoid exposure to overhead avalanche terrain during periods of heavy loading from new snow, wind or rain.
• If triggered, storm slabs in-motion may step down to deeper layers and result in very large avalanches.
• Stick to simple terrain and be aware of what is above you at all times.