Prepare for a wet and stormy day. Avoid avalanche terrain during periods of heavy loading from rain, snow or wind.
If you see signs of a rapidly warming snowpack, like snow that feels like a slurpy, or clumps up and pinwheels down a slope, retreat to mellower terrain.
On the highest alpine peaks, the temperature may be cold enough for it to snow, building storm slabs through the day. Strong to extreme southwest wind could be stripping ridges down to rock, or rapidly loading leeward terrain.
The alpine is likely to be an unpleasant and unpredictable place to be on Monday.
With moderate rainfall up to 2500 m, loose wet avalanches will become likely.
Watch for signs of a rapidly warming snowpack, like snow pinwheeling or snowballing down the slope, or surface snow that starts to look and feel like a slurpy. Loose wet avalanches will become larger and more likely as this slushy snow gets deeper.
No new avalanches were reported before 4pm on Sunday.
On Saturday in the Loop ridge area, right on the border with this forecast area, some whumpfing and shooting cracks were reported on a wind-loaded road cut, in terrain not steep enough to avalanche. See more details on the Mountain Information Network (MIN) here.
If you have any observations from this region, let us know what you are seeing by submitting a report to the Mountain Information Network.
Rain is soaking the snow surface up to mountain tops. Previously, dry snow remained on shaded (northerly) slopes, and thin crusts on slopes that face the sun and all aspects below ~2000 m.
A buried melt-freeze crust exists in the mid-snowpack, down 50 to 120 cm from the surface.
A weak layer of sugary crystals at the base of the snowpack persists. This layer has not produced recent avalanche activity in this area, but professionals continue to monitor for signs of it becoming active.
Snow/Rain amounts for the incoming storm are uncertain. Weather models are not agreeing on how widespread or intense the precipitation will be. Prepare to continually evaluate the conditions, and change plans as necessary.
Sunday Night
Clear, becoming cloudy through the night. 0-2 cm of snow expected in the alpine. Rain below 2100 m. Moderate southwest ridgetop wind, trending to Extreme at high elevations.
Monday
Cloudy. Moderate rainfall expected. 5-15 mm. Snow/rain line rising to 2500 m. Moderate southwest ridgetop wind, trending to extreme at high elevations.
Tuesday
Mostly cloudy. 2-5 cm of snow expected. Snow/rain line starts the morning around 2000 m and falls to valley bottom through the day. Moderate southwest ridgetop wind, trending to strong at high elevations.
Wednesday
Partly cloudy. 2-5 cm of snow expected. Treeline temperatures around -5°C. Light southwest ridgetop wind.
More details can be found in the Mountain Weather Forecast.
