The ongoing storm will continue to develop touchy storm slabs on Monday. Large, natural avalanches should be expected and extremely conservative terrain selection is essential including avoiding exposure to overhead hazards.
Heavy snowfall is expected to continue to build touchy storm slabs on Monday and a natural avalanche cycle is expected. The storm snow may be failing on a hard, underlying melt-freeze crust or on interfaces within the storm snow.
Rain at lower elevations will destabilize the upper snowpack. Loose wet avalanches are most likely at elevations where rain soaks recent snowfall overlying a hard melt-freeze crust, or the crust completely breaks down.
A major storm system is expected to continue to impact the region until Monday night and may end up lingering into Tuesday morning. Snow amounts are uncertain and may be highly variable across the region.
Sunday Night: Snowfall 20-40 cm, strong to extreme SW wind, freezing level low around 800 m.
Monday: Snowfall 20-40 cm, strong to extreme SW wind, freezing level high around 1000 m.
Tuesday: A mix of sun and cloud with lingering flurries in the morning, strong NW wind easing through the day, freezing level high around 1200 m.
Wednesday: A mix of sun and cloud, moderate to strong SW wind, freezing level high around 1500 m.
No new avalanches have been reported in the past few days but observations have been very limited.
If you are getting out in the backcountry, please consider sharing your observations to the Mountain Information Network.
As of Sunday afternoon, many weather stations were showing 40-50 cm of new storm snow accumulation. This storm snow has buried a widespread, supportive melt-freeze crust. Strong southwest wind will be redistributing this new snow in exposed high elevation terrain forming touchy wind slabs. Lower elevations are expected to continue to see wet snow or rainfall, and wet loose avalanche should be expected.
The middle and lower snowpack are generally strong and well bonded.
