Last weeks snowfall needs time to settle. Human triggering remains likely in the Alpine.
Travel at lower elevations is very challenging!
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.
Recent heavy snowfall arrived with warm temps and strong winds creating a widespread storm slab problem. Dropping freezing levels will strengthen the snowpack, but the ~140cm of recent snow will need time to settle.
Avalanche activity has slowed down.
A widespread, natural avalanche cycle occurred up to size 3.5 in Rogers Pass Thursday and Friday. Explosive avalanche testing also produced results up to size 4 on Friday afternoon.
Many storm slab avalanches stepped down to persistent weak layers resulting in large avalanches, running full path.
Check out some of the excellent MIN Reports with pics from the recent avalanche cycle.
In the alpine, up to 140cm of recent snow has been redistributed by strong winds. At tree line and below, a thick crust has formed on the surface.
Below the recent storm snow, a crust from early March is buried 60-140 cm deep.
The Feb 9 and Jan 26 surface hoar layers are now buried 150-210 cm deep. These problems have become less active with the colder temperatures but the persistent weak layer will need time to adjust to the recent snow load.
Drying trend.
Tonight Isolated flurries, trace precipitation. Alpine low -12°C. Winds SW 25 to 45km/h. Freezing level (FZL) valley bottom.
Sun Cloudy, isolated flurries. Trace precipitation. Alpine high -9°C. Wind SW 25-45km/h. FZL 1100m.
Mon Mainly cloudy. No precipitation. Alpine high -5°C. Wind SW 15 gusting 45km/h. FZL 1500m.
Tues Snow, 11cm. Alpine high -4°C. Wind S 10-30km/h. FZL 1500m.
