Avalanche Forecast

A strong ridge of high pressure will keep the region dry and cold, with the potential for lingering valley clouds. The next round of snow is expected late Sunday night as a shift in the weather pattern will occur.

Friday night: Mostly clear skies. Lingering valley clouds. Freezing level rising to 500 m. Alpine temperatures around -15 C. Light to moderate westerly winds.

Saturday: Increasing cloudiness. Flurries. Freezing level rising to 800 m. Alpine temperatures around -8 C. Moderate to strong southwesterly winds.

Sunday: Snow 5-10 cm. Freezing level rising to 1200 m. Alpine temperatures around -6 C. Moderate to strong southwesterly winds.

Monday: Snow 10-15 cm. Freezing level rising to 1400 m. Alpine temperatures around -2 C. Strong to extreme southwesterly winds.

Wind slabs are still showing signs of instability on isolated features as human-triggered and natural avalanches have been reported thought out the region. 

Convex rolls in open areas at treeline remain features of concern, as skiers were able to easily triggered wind small slab avalanches (size 1). Several natural slab avalanches were reported, probably induced by the strong solar warming of Thursday.

In the neighbouring region of South Columbia, two large persistent slab avalanches (size 3) were reported, one near London Ridge, and one from the Valhallas. They both occurred naturally on a south-westerly alpine slopes. These evidences are showing that, with added load to the snowpack from the last weekend’s storm, the mid-January weak layer began to "wake up". 

Recent cold temperatures and northerly winds have modified and transported the last storm snow (30-100 cm), creating heavily wind-affected surfaces in exposed areas and wind slabs in lee areas. Below ~1200 m, 10-20 cm of snow is now overlying a thick melt-freeze crust. 

Up to 120 cm now overlies a weak layer formed in mid-February. This layer consists of surface hoar in sheltered areas, a melt-freeze crust at lower elevations, a sun-crust on steep solar aspects, and hard wind-affected snow in the alpine and exposed treeline. Reports suggest that in many areas, the recent snow is bonding poorly to this firm layer.

The mid-January surface hoar/crust layer is now down 50-150 cm in the snowpack. Although reactivity of this layer has tapered off after the last storm this week, isolated observations are still been reported.

• Recent wind has varied in direction so watch for wind slabs on all aspects.
• Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.
• Shooting cracks, whumphs and recent avalanches are strong indicators of an unstable snowpack.
• Be aware of the potential for large avalanches due to the presence of buried persistent weak layers.