Avalanche Forecast

Moderate -

3-6 cm of new snow is forecast for Sunday overnight with moderate southwest wind in the alpine. Another 2-4 cm is expected on Monday morning with light alpine wind. Sunny breaks are forecast for the afternoon with freezing levels reaching around 1700 m. Tuesday is expected to be mainly cloudy with sunny breaks in the morning and light snow in the afternoon. Alpine wind is forecast to be moderate from the southwest and freezing levels are expected to reach around 1700 m. Similar unsettled conditions are currently forecast for Wednesday with sunny breaks and light snowfall both possible.

On Saturday, a few natural size 2.5 avalanches were observed in gulley features on a northwest aspect. A natural size 3 persistent slab was observed on a southeast aspect at 2500 m which failed down 60 cm and was 600 m wide wrapping around a feature. On Friday, explosives trigger two cornices on a northeast ridge.  A natural size 1 wind slab and cracking under skies was reported in the central part of the region. A few larger avalanches were reported midweek, including a natural size 3 avalanche on a northeast aspect at 2500 m, an explosive triggered avalanche that failed on the ground down 100 cm, and a natural size 4 deep persistent slab that failed on a broad ridge feature on south through north aspects.On Monday, the recent storm snow is expected to be reactive at higher elevations, especially in wind loaded terrain and on steep convex features. Cornices are large and may become weak with daytime warming or during stormy periods. We are in a low probability, high consequence scenario for persistent slab avalanches failing on deep buried weak layers. Click here for more details. Click here for photos the avalanche cycle last week.

20-40 cm of snow has now accumulated over the past week which overlies a widespread crust below around 2100 m and higher on solar aspects. On steep solar aspects, a new sun crust is also being reported.  Alpine wind has recently been strong mainly from south through west aspects and has loaded leeward slopes in exposed terrain at treeline and in the alpine. Large cornices are also reported in the alpine. At lower elevations, there may be multiple crust layers in the upper snowpack which are now generally well bonded and stable. At higher elevations, the February crust/facet layer is now down around 90-150 cm and has been reactive with several avalanches recently releasing on it. It is expected to be most reactive in the alpine where the snowpack remains dry. The deep mid-December facet layer and November rain crust both still linger near the bottom of the snowpack and a few avalanches and cornice falls have stepped down to these layers recently resulting in very large avalanches.  Heavy triggers like cornices and explosives continue to sporadically trigger deep weaknesses in the snowpack as recently as Saturday.