Avalanche Forecast

Moderate - Forecast snowfall amounts are uncertain.

A weather system will approach the BC coast today. Tonight, the system will pivot towards the southern half of BC. The system will stall over southern BC tonight through the weekend resulting in persistent rain showers and alpine snow. The convective nature associated with this system could bring higher localized precipitation amounts.

Friday Night: Snow 3-10 cm. Winds light from the southeast. Alpine temperatures near -1 C and freezing levels 1500 m.

Saturday: Snow 5-10 cm at upper elevations. Wind light from the South. Alpine temperatures near -! and freezing levels 1600 m. 

Sunday: Snow 10-15 cm at upper elevations. Light wind from the South. Alpine temperatures -2 and freezing levels 1500 m. 

Monday: Snow 5 cm. Light-moderate wind from the southwest. Alpine temperatures near -4 and freezing levels 1500 m. 

At treeline and in the alpine, the new snow combined with light to moderate wind may build fresh and reactive storm slabs. The new snow may have a poor bond to the old snow surfaces which are mostly crusts. Below treeline will see rain that will keep snow surfaces wet and weak. Loose wet avalanches are possible. 

Cornices remain weak and fragile. They require a large berth from above and below as they are very unpredictable.

Over the past week, the region saw intense warming and sunshine. This resulted in a widespread natural avalanche cycle up to size 4. Many of these involved the full depth of the snowpack, running to the valley bottom. Last weekend, multiple large to very large wet slab avalanches were observed near Whistler, size 2-4. Many of these involved the full depth of the snowpack, running to the valley bottom.

 

New snow will accumulate at treeline and in the alpine through the weekend building fresh and reactive storm slabs. Below treeline elevations will likely see rain. The new snow will be landing on a melt-freeze crust that extends to the alpine on solar slopes and 2100 m on polar slopes. It may bond poorly. Rain below treeline will likely keep the snow surfaces wet and weak.

Cornices are large and looming along ridgelines. They are weak and very unpredictable. 

• Watch for fresh storm slabs building throughout the day.
• Storm slab size and sensitivity to triggering will likely increase through the day.
• Be alert to conditions that change with elevation and wind exposure.
• A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
• Pay attention to cornices and give them a wide berth when traveling on or below ridges.