Avalanche Forecast

Moderate - Uncertainty is due to the timing of the incoming weather system.

MONDAY NIGHT: Cloudy, moderate wind from the southwest, alpine temperatures around -8 C.

TUESDAY: Periods of snow starting midday with 5-15 cm by the evening, strong wind from the southwest, alpine high temperatures around -4 C.

WEDNESDAY: Another 10-20 cm of snow by Wednesday morning then cloudy in the afternoon, light wind from the southwest with moderate gusts, snow level up to 1000 m, alpine high temperatures around -3 C.

THURSDAY: Another system brings 5-10 cm of snow, light wind from the west, alpine temperatures drop to -12 C.

New avalanche problems will develop with the arrival of new snow and strong wind on Tuesday afternoon. Over the past week a few small (size 1) human triggered wind slab and dry loose avalanches have been reported. 

A widespread cycle of very large deep persistent slab avalanches occurred prior to Christmas (up to size 3.5). The likelihood of triggering a deep persistent slab avalanche has declined since then, but the consequences are severe. Triggering could be more likely if significant snow accumulates this week. A MIN report from Friday north of Fernie (in the South Rockies forecast region) shows the possibility of triggering large avalanches from thin spots in rocky alpine terrain.

A series of frontal systems are bringing new snow and strong wind Tuesday afternoon into Wednesday morning. Sheltered terrain currently has 10-30 cm of soft snow, while thin wind slabs have formed at higher elevations. Below 1700 m a hard rain crust makes for difficult travel. Hard snow sits above weak snow and crusts near the bottom of the snowpack (80-150 cm deep).This weak snowpack structure resulted in very large avalanches prior to Christmas. The likelihood of triggering a deep persistent slab avalanche has declined since then, but could still be possible from thin spots in steep terrain that did not avalanche in the last storm.

• Fresh wind slabs will likely form throughout the day, diligently watch for changing conditions.
• Avoid convexities, steep unsupported terrain and rocky outcroppings.
• Be aware of the potential for large avalanches due to the presence of a deep persistent slab.
• Don't let the desire for deep powder pull you into high consequence terrain.