Avalanche Forecast

Moderate - Intensity of incoming weather systems is uncertain on Tuesday

An Arctic air mass keeps things cold and dry until Tuesday, when moderate snow is expected, with milder temperatures and strong south-westerly winds.More details can be found in the Mountain Weather Forecast.

A very large, widespread avalanche cycle was observed on Thursday and Friday. Slopes of all aspects and elevations ran full path and reached valley floor. In some cases, mature trees were smashed. Many of these failed on persistent weak layers, while some involved only the recent storm snow. The natural cycle is winding down, but human-triggering remains a real concern. You might be surprised by how large an avalanche can be triggered and how far it could run.

Strong north to north-westerly winds have loaded lee slopes with 30-40 cm recent storm snow. This adds to an existing storm slab up to 1m deep from the last couple of weeks accumulation. Several persistent weak layers make up a troublesome snowpack which is not tolerating the recent load. In the top 1-1.5 m of the snowpack, two surface hoar layers buried in January can be found. The shallower of the two has been particularly reactive on north to east aspects above 1900 m, but expect to find one or other of these on all aspects and elevations.Deeper in the snowpack (120-200 cm deep) is a facet/crust/surface hoar layer from December, most prevalent at and below treeline.Near the base of the snowpack is a crust/facet combo, most likely to be triggered from thin spots in the alpine.All of these layers have produced large avalanches recently. The wide distribution and ongoing reactivity of these layers suggests that avoidance through choosing simple terrain is the best strategy.