South Rockies

Avalanche danger will rise with expected new snow. If more than 20 cm arrives, bump up alpine and treeline danger to high.

Fair

10-20 cm new snow is expected to fall overnight Tuesday and through Wednesday. Ridgetop winds around 60 km/h from the SW overnight Tuesday should become northwest 20-30 by midday Wednesday. Freezing levels are expected to peak around 4am on Wednesday at 1500 m. By 4pm Wednesday, freezing levels are expected to have dropped to around 1000 m. On Thursday, lingering flurries are expected, with generally light west or northwest winds and freezing levels at valley bottom. On Friday, conditions should be dry with some clear spells. Northwest Winds could pick up in speed as colder weather descends from the north.

One size 2 natural avalanche was reported on Sunday. On Monday, no natural avalanche activity was reported, but explosive avalanche control produced avalanches up to size 2.5, initiating in wind slab, then stepping down to the crust. If you have any avalanche observations to report, please send an email to [email protected].

Generally light amounts of snow have fallen in the last few days. In the alpine, winds have been conducive to blowing this snow into wind slabs in exposed lee areas. Around 30 cm below the surface (more in wind affected areas)  you are likely to find a crust that may have surface hoar on top of it. The crust is reported to extend into the alpine to at least 2100 m; the surface hoar was reported to be most reactive on shady aspects around treeline and just below, between around 1600 m and 1900 m. Where the crust exists, it is effectively bridging triggers from penetrating to deeper persistent weaknesses that formed earlier in the season. However, on high alpine slopes above where the rain crust formed, facets, and/or buried surface hoar may be susceptible to triggers.