Finally a decent winter storm rolled through Rogers Pass, modifying the snowpack and landscape.
Let the mountains settle into their new blanket of snow peacefully. Stick to supported, low-angled slopes with limited overhead exposure.
Anticipate dry loose avalanches in steep, sheltered terrain where it hasn't settled into a slab. If you decide to enter the backcountry, manage your group appropriately and be aware of terrain traps around you.
The recent storm brought another 30cm of storm snow, which was accompanied by strong winds. The storm slab is reactive at all elevations and deeper in wind-loaded areas.
This layer has been mainly dormant for the last few weeks but has the potential to 'wake up' with the additional snow load from the storm. Steep, thin, unsupported areas are where this deep layer may be triggered, and the resulting avalanches would be VERY LARGE!
A natural avalanche cycle is currently underway Tues afternoon in Rogers Pass. Artillery control has been productive in the highway corridor, with average sz 2.5-3 avalanches from explosive triggers.
70-85cm of storm snow from the last 6 days, strong SW winds, and mild temps have created reactive surface slabs.
The mid-snowpack is mainly rounded grains.
The basal Nov 17 deep persistent weak layer is mostly faceted with a decomposing crust in various locations.
The tail-end of the atmospheric river leaves the area tonight, with unsettled flurries, gusty winds, and dropping freezing levels in its wake.
Tonight: flurries, 5-10cm, Alp low -12*C, mod/gusting strong W'ly, 400m FZL
Wed: isolated flurries, trace snow, Alp high -11*C, light SW winds, 700m FZL
