Seek out soft snow in sheltered areas at lower elevations to avoid wind slabs hidden by the new snow up high. A wind slab in motion could be just the trigger for a large step down avalanche on the persistent weak layer we're tracking.
Snowfall and southwest winds formed reactive wind slabs over the stormy early part of the week. North through east aspects in exposed areas will be the most likely places to trigger one.
A number of buried weak layers remain possible to trigger. These layers appear to be most problematic in upper treeline and alpine elevations, in shallow, variable, rocky start zones. A sensitive wind slab overlying this problem could serve as the perfect trigger for a destructive step-down avalanche.
Observations from Monday in the snowier southwestern part of the region show our recent storm snow reacting to ski cutting, which produced numerous small (up to size 1.5) storm slabs on steep slopes at treeline and below with crowns up to 40cm. Isolated natural releases were also observed in the alpine.
Although post-storm observations in the region remain limited, these occurrences give an indication of some of the human triggering potential that could persist in the near term. Similarly little is known yet about the effects of the increased load on our buried persistent weak layers.
If you are out in the backcountry, please share your observations to the Mountain Information Network!
Recent snowfall and southwest winds have accumulated around 50-60 cm of storm snow that is continuously being blown into wind slabs. This growing storm total sits on a crust from the warming event on January 25th and will need time to form a solid bond.
The mid and lower snowpack continues to bond and stabilize. A few concerning weak layers can still be found in the top meter of the snowpack including a surface hoar layer from early January and a crust from late December.
Tuesday night
Becoming cloudy with scattered flurries and a trace of new snow. Light southeast winds shifting southwest. Treeline high temperatures around -8.
Wednesday
Mainly cloudy with flurries bringing up to 5 cm of new snow in the morning. Light to moderate southwest winds. Treeline high temperatures around -8.
Thursday
Cloudy with continuing flurries bringing 5-15 cm of new snow, including overnight amounts. Strong south winds easing a bit over the day. Treeline high temperatures around -2 with freezing levels rising to 1200 m.
Friday
Diminishing cloud and flurries finishing with up to 5 cm of new snow. Storm totals of 15-30 cm. Strong southwest winds shifting west. Treeline high temperatures around -5 and falling over the day.
More details can be found in the Mountain Weather Forecast.
