Avalanche Forecast

On Friday, a few large natural avalanches to size 3 on south and east aspects in the alpine were reported. Thursday, multiple large explosive controlled avalanches to size 3 were reported in the region that had impressive propagation. Wednesday, avalanche reports documented a natural storm slab cycle averaging size 1-2, with a few size 2.5 avalanches.

Roughly 30-40 cm of new snow fell in the region on Monday and Tuesday. It buried moderately wind-affected snow in exposed areas at higher elevations and otherwise added to about 50 cm of recent storm snow. All this snow overlies a variety of old surfaces, but sheltered terrain where it may overlie preserved surface hoar, is the most concerning. Below 1600m a crust is present beneath the storm snow.

Two additional surface hoar layers in the top 2 m of the snowpack are diminishing in importance. The deeper of the two likely has a robust crust above it, below treeline. The depth of the snowpack varies greatly throughout the region and weak basal facets are present at the base of the snowpack.

Saturday night

Partly cloudy. Variable alpine wind 10-40 km/h. Treeline temperature -34 °C.

Sunday

Mostly sunny. Northwest alpine wind 10-40 km/h. Treeline temperature -28 °C.

Monday

Mix of sun and cloud. Southwest alpine wind 10-60 km/h. Treeline temperature -23 °C.

Tuesday

Mostly cloudy. Southeast alpine wind 10-30 km/h. Treeline temperature -20 °C.

More details can be found in the Mountain Weather Forecast.

• Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
• Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
• Be careful with wind slabs, especially in steep, unsupported and/or convex terrain features.