With no overnight refreeze this week, the entire snowpack is isothermal in most locations and will loose cohesion quickly with daytime warming or rainfall.
Large destructive natural avalanches remain possible. If air temps are warm or it is raining, travel in avalanche terrain is not recommended.
With intense solar radiation and no overnight refreeze, the snowpack is moist and weak. Wet loose avalanches could be triggered in steep terrain. We have observed these loose avalanches stepping down to the basal weakness at Treeline elevations and lower.
Several hot days with no overnight refreeze has warmed and destabilized the snowpack. This early season basal weakness has woken up below 2000m and is producing very destructive avalanches.
Natural activity was ongoing on Friday, with several large wet loose avalanches observed in the highway corridor.
This is capping off a very active week of spring avalanche activity - there was a widespread cycle of natural and controlled, wet loose and deep slab avalanches with numerous sz 3, and isolated sz 4's. Many avalanche paths failed down to ground once the avalanches were in motion.
Warm temps have penetrated the snowpack creating a moist, isothermal snowpack on all aspects into the alpine. Buried crusts in the upper 50 cm are breaking down. Shallow snowpack features have loose, weak snow to ground.
20-40cm above the ground the Nov 17 basal weakness can still be found in many areas.
Warm and dry weather will come to an end Friday, as a trough of low pressure brings light precip and dropping freezing levels (FZL).
Tonight: Cloudy periods, Alpine Low 3°C, FZL 2500m, Moderate E ridgetop wind.
Sat: Isolated showers/wet flurries, High 5°C, FZL 2600m, light S winds.
Sun: Scattered flurries (4cm), Low -1°C, High 1°C. FZL 2200m.
Mon: Isolated flurries, Low -1°C, High 5°C, FZL 2600m.
