Avalanche Forecast

Moderate - We are confident the likelihood of avalanche will increase with the arrival of the forecast weather. Uncertainty is due to the timing, track, & intensity of the incoming weather system.

A stalled offshore low continues to push bands of warm air, wind and precipitation our way in the upcoming days with clearing mid-week.

Sunday night: Snow, 10-20 cm, moderate south ridge wind, alpine low temperatures around -3 C. Freezing level 1000 - 1300 m.

Monday: Snow, 10-20 cm, moderate southwest wind gusting strong, alpine high temperatures around -1C. Freezing level 900-1600 m.

Tuesday: Snow, 5 - 20 cm, moderate to strong southwest wind, alpine high temperatures around -4C. Freezing level 900-1500 m.

Wednesday: Cloudy with sunny breaks and isolated flurries, trace to 5 cm new snow, light west ridge wind gusting moderate, alpine high temperatures around -4C. Freezing level 600-900 m.

We anticipate a widespread avalanche cycle is ongoing in zones that received heavy snowfall and wind on Sunday. Early reports from Sunday indicate touchy skier triggered (size 1-1.5) avalanches that failed on surface hoar at treeline and below treeline where temperatures warmed snow into slabs. Explosive triggered small and large (size 1-2) avalanches were widespread on wind loaded lee alpine aspects (NE - NW).

On Thursday, there were reports of touchy conditions and a widespread avalanche cycle including numerous skier triggered small avalanches (size 1-1.5) and a few larger skier triggered and natural avalanches (size 2-2.5). Last week a couple persistent slab avalanche (size 1.5) were triggered in the Valhallas on the early January surface hoar layer on steep north treeline terrain.  

An additional 15-25 cm of snow is forecast overnight Sunday into Monday. This adds to the highly variable previous snowfall amounts of 5-35 cm. It's all coming with warming temperatures and moderate south wind; and it buried a surface hoar layer on Friday night. Expect very touchy avalanche conditions in heavier snowfall zones, particularly where buried surface hoar is present or where wind has transported snow into wind slabs.

There are a series of surface hoar layers in the top meter of the snowpack that could result in surprisingly large avalanches. The first from Friday night (down 20-50 cm), a second more widespread and unstable layer from the long drought (down 30 - 70) and a much deeper layer from early January (down 40 - 130). This last layer was showing only isolated reactivity in shallow snowpacks in the Valhallas and southern Selkirk's.

Deeper in the snowpack, a couple of older persistent weak layers may still be identifiable. The first is from December consisting of decomposing surface hoar and a crust (buried 100-15cm) and the second from early November consisting of a series of crusts with faceted snow (closer to the ground). 

• Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
• Be aware of the potential for large avalanches due to the presence of buried surface hoar.
• Watch for signs of slab formation throughout the day.
• The more the snowpack warms-up and weakens, the more conservative you`ll want to be with your terrain selection.