Avalanche Forecast

Over the past week we have seen a pattern of human and remotely triggered size 1 to 1.5 wind slab avalanches with a few being up to size 2.  Natural avalanches have been triggered on leeward slopes by wind transport but human-triggered avalanches have occurred on a range of aspects. Slabs have been averaging 20 - 30 cm thick, with some failing on buried surface hoar.

Surface conditions are highly variable. Wind effect can be found on all exposed slopes. A new crust exists on the surface at lower elevations and likely up to mountain tops on south aspects. In sheltered  terrain soft snow can still be found. In the afternoon the snow surface could become moist as the freezing level rises.

15 to 30 cm of snow sits above a widespread crust. Many areas have reported a weak surface hoar layer above this crust, which is very problematic in areas where wind has formed a slab above the layer.

Snowpack depths decrease rapidly below treeline.

Sunday Night

A mix of cloud and clear skies. 5 to 10 km/h southeast alpine wind. Treeline temperature around -3°C.

Monday

A mix of sun and cloud. 5 to 10 km/h southeast alpine wind.  Freezing level rising to 1800 m.

Tuesday

Mostly cloudy with trace amounts of new snow possible in the alpine. 10 to 20 km/h southwest alpine wind. Freezing level rising to 1600 m.

Wednesday

A mix of sun and cloud with trace amounts of new snow possible. 5 to 15 km/h west alpine wind. Freezing level around 1700 m.

More details can be found in the Mountain Weather Forecast.

• Avoid freshly wind loaded terrain features.
• Wind slabs may be poorly bonded to the underlying crust.
• Surface hoar distribution is highly variable. Avoid generalizing your observations.
• Keep in mind that human triggering potential persists as natural avalanching tapers off.
• Back off slopes as the surface becomes moist or wet with rising temperatures.