Spring is a dynamic time of year; conditions can vary widely and change rapidly. Localized periods of heavy snowfall may form fresh, reactive storm slabs, while even short periods of strong sun can rapidly destabilize the upper snowpack.
Carefully assess your local conditions and pay attention to how the weather is affecting the snowpack.
In areas where the recent storm snow has not formed a cohesive slab, dry loose avalanches may initiate easily in steep terrain, particularly where they overlie a slick crust.
Avoid exposure to steep slopes during periods of strong sun. Even brief windows of strong sunshine could rapidly initiate natural dry loose avalanches.
10 to 20 cm of new snow accompanied by strong southwest wind has built wind slabs in lee areas.
It is possible that convective flurries may deliver up to 20 cm of new snow to localized areas on Sunday, which could form fresh, reactive storm slabs throughout the day.
Prior to this weekend's storm, avalanche activity has mainly consisted of small (size 1) natural and skier-triggered wind slabs on north-facing aspects and a few wet loose avalanches (size 1-2) from steep rocky terrain.
At the time of publishing on Saturday, no new avalanches have been reported.
10 to 20 cm of new snow arrived in the past 2 days, accompanied by strong southeast, shifting southwest winds. Below the new snow, a melt-freeze crust exists on all aspects at treeline and below, and on solar aspects to the mountain top. On high north aspects dry snow remains.
The mid-snowpack is generally strong but the lower snowpack is a different story.
A weak layer of sugary facets is still prominent at the base of the snowpack. Small surface avalanches and cornice falls are the most likely things to trigger this layer. However, there remains a concern for human triggering in rocky, shallow, or thin-to-thick snowpack areas at treeline and above.
Saturday night
Clear periods with isolated flurries. Alpine temperatures drop to a low of -11 °C. Ridge wind southwest 10 to 35 km/h. Freezing level at valley bottom.
Sunday
A mix of sun and cloud with convective flurries, localized accumulation up to 15 cm. Alpine temperatures reach a high of -6 °C. Ridge wind light from the southeast. Freezing level rises to 1200 metres.
Monday
A mix of sun and cloud with isolated flurries. Alpine temperatures reach a high of -5 °C. Ridge wind to light from the north. Freezing level rises to 1400 metres.
Tuesday
A mix of sun and cloud with isolated flurries. Alpine temperatures reach a high of -5 °C. Ridge wind light from the northeast. Freezing level rises to 1300 metres.
More details can be found in the Mountain Weather Forecast.
