Avalanche Forecast

Moderate - Uncertainty is due to how the snowpack will react to the forecast weather.

WEDNESDAY NIGHT: Clear skies, 20 to 40 km/h southwest wind, alpine temperature -0 C, above-freezing layer around 2000 m.

THURSDAY: Clear skies, 30 to 50 km/h southwest wind, alpine temperature -1 C, above-freezing layer dissipating near noon.

FRIDAY: Cloudy with snowfall, accumulation 5 cm, 30 km/h south wind, alpine temperature -4 C.

SATURDAY: Cloudy with snowfall, accumulation 5 cm, 20 km/h south wind, alpine temperature -5 C.

Many wind slab avalanches were triggered naturally and by riders on Tuesday. They mostly occurred on southerly aspects due to recent north wind. They most occurred at alpine and treeline elevations. Check out these MINs for a few examples: here, here, and here.

A few large avalanches have been observed on the weak layers described in the snowpack summary within the past week and they were triggered triggered by riders, explosives, and naturally. They occurred on northerly aspects between 1900 and 2100 m and were generally 30 to 50 cm deep.

Warm air is forecast for the alpine, which could mean that recent wind slabs will remain easy to trigger. The wind slabs may be found on all aspects due to variable wind directions.

Two potential concerning weak layers may be present in the snowpack: 

• The shallower layer, being around 50 to 80 cm deep, includes feathery surface hoar crystals. This layer may be found in sheltered terrain features at treeline and lower alpine elevations but has been reported as spotty across the region. 
• The more widespread weak layer includes sugary faceted grains that overlies a hard melt-freeze crust. This layer ranges in depth from 10 cm to 100 cm due to the wind blowing and loading the snow in different terrain features over the past two weeks. The layer has been reported as being widespread up to around 2000 to 2200 m. 

To date we have mostly seen sporadic avalanche activity on these layers, but they remain possible to trigger where they exist in the mountains.

The remainder of the snowpack is well-settled.

• Be careful as you transition into wind affected terrain.
• Avoid steep slopes when air temperatures are warm, or solar radiation is strong.
• Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
• If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
• Pay attention to cornices and give them a wide berth when traveling on or below ridges.