Avalanche Forecast

MONDAY NIGHT: Partly cloudy, light wind from the west, alpine temperatures drop to -12 C.

TUESDAY: Increasing cloud with light flurries starting in the afternoon and up to 5 cm of snow, light to moderate southwest wind, alpine high temperature around -8 C.

WEDNESDAY: Cloudy with scattered flurries, 5-15 cm of new snow, light to moderate southwest wind, alpine high temperature around -4 C with freezing level climbing to 1200 m.

THURSDAY: Cloudy with light flurries, light southwest wind, alpine high temperatures around -2 C with freezing level climbing to 1500 m.

The new snow on Sunday was very reactive to human triggering, as there were numerous small (size 1) dry loose and soft slab avalanches. 10-30 cm thick slabs were triggered on all aspects at and below treeline, some of which ran relatively long distances on the recently buried surface hoar layer. Storm slabs above this weak layer will continue to be reactive this week, but the avalanches will be relatively small. The snowpack is setup to be dangerous when the next significant storm arrives.

15-30 cm of recent snow has buried a widespread layer of surface hoar (size 10-20 mm). This layer exists at all elevations. This same layer of surface hoar has been reported as sitting on a thin sun crust on solar aspects which is a particularly nasty combination. The new snow will likely become increasingly reactive to human triggers as it stacks up and settles into a cohesive slab. The early February rain crust down 50-100 cm is another prominent layer in the upper snowpack that requires monitoring at lower elevations. The mid and lower snowpack is generally well settled and strong.

• Choose slopes that are well supported and have limited consequence.
• Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
• Be aware of the potential for human triggerable storm slabs at lower elevations, even on small features.
• Avoid terrain traps such as gullies and cliffs where the consequence of any avalanche could be serious.