Continued precipitation overnight may create fresh wind slabs in the alpine and loose wet avalanches in the alpine and treeline. Approach avalanche terrain cautiously as we assess the impacts of several large storms.
Heavy precipitation on Wednesday night may turn to snow up high and create a wind slab problem in the alpine. If dry snow exists in the alpine, watch out for cracking, whoomphing and wind transportation.
Wednesday's storm brought significant rainfall that saturated the snowpack. Cooling temperatures will help to decrease the likelihood of loose wet avalanches, but steep slopes will remain likely places for wet loose avalanches to occur - especially with a human trigger.
Wednesday overnight: 2500m freezing levels will begin to descend reaching ~1800m by morning. Another 20-40mm can be expected, initially falling as rain, and eventually falling as snow at higher elevations. Winds will continue to be strong to extreme from the southwest.
Thursday: A clearing trend! Up to 10mm of mixed precipitation can be expected in the early morning, with freezing levels sitting around 1700m. Throughout the day we will see clearing skies, gradually lowering freezing levels and winds steadily decreasing into the moderate to strong range from the west.
Friday: A brief period of high pressure prevails. A mainly sunny day with light winds from the southwest and freezing levels at valley bottom. High cloud may develop in the afternoon with another front approaching.
Saturday: Another system is upon us. 10-30cm of snow is expected throughout the day accompanied by strong westerly ridgetop winds. Freezing levels starting the day at near valley bottom rising up to 1300m.
There have been very few reports in the past 24 hours. On Wednesday, Island Lake Lodge reported several size 1.5 wet loose avalanches out of steep alpine terrain and a Size 2 Natural Storm Slab on at NE aspect at 1900m. I suspect a widespread natural avalanche cycle has occurred in the region in conjunction with Wednesday's storm.
Reports in the region remain limited. If you go out in the mountains, please share your observations and/or photos on the Mountain Information Network!
Heavy rain has soaked the snowpack to mountaintop in most areas. In the high alpine (above 2300m) up to 50cm of wet snow accumulation is possible. Until temperatures cool, this will result in a wet, heavy, and unstable upper snowpack.
Below 40cm of saturated storm snow lies a thick mid-November rain crust which has been the suspected bed surface of a few recent step-down avalanches. Moist snow is still found below the crust and to the ground.
Snowpack depths range from 20-50cm at treeline elevations. Expect to find a deeper snowpack at higher elevations and in previously wind-loaded areas. Snowpack decreases rapidly below 1900m.
