Conditions change drastically with elevation. Expect wind slab development in the alpine and challenging travel down low.
Recent heavy snowfall arrived with warm temps and strong winds creating a widespread slab problem. Be cautious near ridge top and in any alpine terrain that has not already avalanched.
A crust layer from early March is the most likely failure plain for a persistent slab at the moment. This layer is buried 50- 140cm deep. Deeper in the snowpack, two dormant persistent weak layers are buried down ~ 180 and 210 cm.
Avalanche activity has slowed down with no notable new observations on the weekend.
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.
Storm arriving Tuesday.
Tonight Mainly cloudy, no precipitation. Alpine high -9°C. Winds SW 20 to 40km/h. Freezing level (FZL) 600m.
Mon Mainly cloudy. No precipitation. Alpine high -4°C. Wind SW 20 gusting 55km/h. FZL 1600m.
Tues Snow, 17cm. Alpine high -3°C. Wind S 15 gusting to 85km/h. FZL 1600m.
Wed Flurries , 6cm. Alpine high -5°C. Wind SW 20-gusting to 90km/h. FZL 1300m.
