Avalanche Forecast

A widespread avalanche cycle occurred during the storm on Friday and Saturday, producing large avalanches at all elevations and aspects on multiple persistent weak layers. Most of the activity was on the two surface hoar layers from January, but there was also activity on the November facets near the bottom of the snowpack. Avalanches ranged in size from 1.5 to 3.5.

Human triggered avalanche activity continued on Sunday, with numerous reports of remote, accidental, and controlled avalanches. These avalanches were generally up to size 2 and were triggered on one of the two surface hoar layers buried in January.

Looking forward, there may be a slight decline in the reactivity of these weak layers, but the snowpack is inherently weak and large human triggered avalanches remain likely.

A recent layer of surface hoar and a crust on south facing slopes can be found under 20 to 60 cm of new dense storm snow at treeline and above. Wind slabs exist on north, west, and east facing terrain at treeline and above. A surface crust will form below 1800 m as the freezing level drops.

There are four additional weak layers in the snowpack. The most reactive in recent days have been the layer mentioned above and another surface hoar layer from early January. The bottom of the snowpack is made up of large facets buried in late November. This layer remains a concern.

In general, this year's snowpack is complicated, weak, and shallow. Keep this in mind as you move through the mountains.

Monday night

Cloudy with flurries bringing trace amounts of snow, 20 km/h southwest wind, freezing level drops to valley bottom with treeline temperatures cooling to -7 °C.

Tuesday

Mostly cloudy with the possibility of light flurries bringing trace amounts of snow, 20 km/h southwest wind, freezing level around 1000 m with treeline temperatures around -5 °C.

Mostly cloudy with light flurries bringing trace amounts of snow, 20 to 40 km/h southwest wind, treeline temperatures around -6 °C.

Cloudy with scattered flurries bringing 5 to 10 cm of snow, 40 km/h southwest wind, treeline temperatures around -6 °C.

More details can be found in the Mountain Weather Forecast.

• Be mindful that deep instabilities are still present and have produced recent large avalanches.
• Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
• Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
• Uncertainty is best managed through conservative terrain choices at this time.