Happy New Years! This new year has brought with it a tricky-moderate danger rating as a result of our shallow, weak, and atypical coastal snowpack.
Avoid wind-loaded areas at upper elevations where wind slabs may remain reactive to human triggering. Concern for buried weak layers in the mid to lower snowpack should have you sticking to conservative, low-consequence terrain and practicing good travel habits.
Strong southerly winds have redistributed 15 - 30 cm of new snow into deep deposits of wind slabs at higher elevations. These wind slabs may remain reactive to human triggering, particularly where they overlie a slick crust.
Keep in mind that wind slab avalanches have the potential to step down to deeper weak layers creating large avalanches.
A weak layer of surface hoar has been reported down 60 - 100 cm. This layer is of greatest concern on shaded, northerly aspects and in thinner snowpack areas where human-triggering is most likely.
Keep in mind that this layer has the potential to create large and destructive avalanches on it's own, but also has the potential to step down to the weak facets at the base of the snowpack.
The winter snowpack is not as deep as usual, and along with a cold and dry early winter, the lower snowpack consists of weak, unconsolidated facets and depth hoar crystals. With weak basal layers, a cautious approach to large open terrain features is required especially around rocky or thin areas.
This week, 10-20 cm of storm snow was accompanied by strong southwest winds, creating hard wind-affected surfaces in open areas, and wind slabs in lee terrain features. This new snow overlies a rain crust formed earlier in the week. This crust is thin at higher elevations and up 2 cm thick below treeline.
In the mid-snowpack, a weak layer of surface hoar has been observed down 80-100 cm, this layer is most prevalent in shaded and sheltered areas.
The lower snowpack consists of weak, sugary crystals of facets and depth hoar.
Snowpack depths remain highly variable, roughly 50 to 200 cm at treeline.
On Wednesday, a large, size 3 avalanche was remotely triggered by skiers roughly 100 m away. The avalanche was on a northeast aspect at 2050 m. It ran on a weak layer of surface hoar (80 to 100 cm deep), before scrubbing down to the ground in steep terrain.
Observations remain limited, and no reports of new avalanches have been made since Wednesday.
Please continue to post your observations and photos to the Mountain Information Network.
Saturday night
Clear periods. Alpine temperatures reach a low of -8 °C. Mostly light southwest ridge wind occasionally gusting to 25 km/h. Freezing level at valley bottom.
Sunday
Sunny with cloudy periods. Alpine temperatures reach a high of -5 °C. Ridge wind light to 15 km/h from the southwest. Freezing level at valley bottom.
MondayA mix of sun and cloud. Alpine temperatures reach a high of -3 °C. Mostly light ridge wind occasionally gusting to 30 km/h from the south. Freezing level at valley bottom.
TuesdayCloudy with sunny periods. Alpine temperatures reach a high of -5 °C. 25 km/h ridge wind occasionally gusting to 50 km/h from the southwest. Freezing level at valley bottom.
More details can be found in the Mountain Weather Forecast.
