Avalanche Forecast

THURSDAY NIGHT: Partly cloudy, no precipitation, light wind from the northwest, treeline temperatures cool to -3 C with freezing level dropping below 1200 m.

FRIDAY: Mostly cloudy skies, no precipitation, light wind from the west, treeline and alpine temperatures around -2 C with freezing level around 1000 m.

SATURDAY: Cloudy with isolated flurries, up to 5 cm of new snow, moderate wind from the southwest, treeline temperatures around -2 C with freezing level around 1000 m.

SUNDAY: Mostly sunny skies, no precipitation, moderate wind from the west, treeline temperatures around -4 C.

A widespread avalanche cycle occurred during Wednesday's warm storm. This included numerous size 1-2 avalanches and one size 3 avalanche on Ymir Mountain. These avalanches were 20-40 cm thick, and in many cases were suspected to have failed on a recently buried surface hoar layer (see photos in the MIN post). The storm slabs above this layer were also very reactive to human triggers, and will likely remain possible to trigger in the upcoming days.

We have not heard reports of persistent slab avalanches since last weekend, when we saw several size 2 to 3 avalanches releasing on the early December facet/crust layer. Prior to these avalanches, we were seeing a regular pattern of large destructive avalanches on this layer at the start of the month. These avalanches mostly occurred on thin, wind affected slopes near ridgetops. Although there has been a declining pattern in persistent slab activity, the current warm temperatures could be testing them and warrant some extra caution.

10-30 cm of recent snow is settling with the mild temperatures, but could remain reactive as it sits above a layer of feathery surface hoar and melt-freeze crusts. Lower elevations will likely go through a daily melt-freeze cycle. An accumulated total of 70-100 cm of snow since the beginning of January sits over variable and potentially weak snow surfaces including widespread facets and/or surface hoar up to 5 mm in sheltered areas.

The early December crust/facet layer has been responsible for sporadic but very large, persistent slab avalanches over the past month. The crust is now buried 120-200 cm deep except in thin, wind affected areas near ridgetops where most of the recent avalanches have been triggered.

• The more the snowpack warms-up and weakens, the more conservative you`ll want to be with your terrain selection.
• Continue to make conservative terrain choices while the storm snow settles and stabilizes.
• Storm slabs in motion may step down to deeper layers resulting in large avalanches.
• Avoid shallow, rocky areas where the snowpack transitions from thick to thin.