Approximately 140mm of precipitation was delivered by the recent Atmospheric river with freezing levels around 2000m. Give the new snow time to settle before stepping out into consequential terrain.
Travel at lower elevations will be treacherous!
Two persistent weak layers are buried down ~ 180 and 210 cm. These layers were reactive during the recent avalanche cycle but the drop in temperature will likely strengthen the snowpack. More time is required before we can take this problem off the board.
Heavy snowfall with warm temps and strong winds has created a widespread storm slab problem. Dropping freezing levels will strengthen the snowpack, but the ~140cm of recent snow will need time to settle.
A widespread, natural avalanche cycle up to size 3.5 in Rogers Pass Thursday and Friday. Explosive Avalanche testing also produced results up to size 4.
Many storm slab avalanches stepped down to persistant weak layers resulting in large avalanches, running full path.
In the alpine, up to 140cm of recent snow has been redistributed by strong winds. At tree line and below (approx. 2000m) heavy rain has saturated the upper snowpack. This moist snow will refreeze on Friday morning.
The Feb 9 and Jan 26 surface hoar layers are now buried 150-210 cm deep. These layers will become less active with the cooling temperature but the persistent weak layer will need time to adjust to the recent snow load.
Freezing levels are dropping.
Tonight Isolated flurries, trace precipitation. Alpine low -7°C. Winds SW 30 gusting to 90km/h. Freezing level (FZL) 1100m.
Sat Cloudy, sunny periods. Alpine high -8°C. Wind W 20-30km/h. FZL 1100m.
Sun Sunny periods, isolated flurries. Trace precipitation. Alpine high -9°C. Wind SW 20-40km/h. FZL 1000m.
Mon Cloudy, sunny periods. Alpine high -4°C. Wind SW 15-30km/h. FZL 1500m.
