Avalanche Forecast
Issued: Dec 13th, 2018 4:42PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
cgarritty,
Avalanche Canada
Wind has likely been a key factor in building slabs with each pulse of new snow we've seen over the week. Reports from the region have been limited so be sure to supplement this forecast with your own observations.
Summary
Confidence
Low - Due to the number of field observations
Weather Forecast
Thursday night: Increasing cloud with isolated flurries as the next storm pulse moves into the region. Light to moderate west winds. Friday: Cloudy with flurries bringing about 10 cm of new snow, clearing in the evening. Light to moderate southeast winds. Alpine high temperatures around -10.Saturday: A mix of sun and cloud with cloud increasing over the day and light flurries beginning in the afternoon and increasing overnight. Light southeast winds. Alpine high temperatures around -8 with freezing levels beginning a rise to 1300 metres overnight.Sunday: Cloudy with continuing flurries bringing 10-15 cm of new snow, including overnight accumulations. Strong southeast winds. Alpine high temperatures around -4 with freezing levels peaking at about 1500 metres.
Avalanche Summary
A MIN report from Ashman (west of Smithers) describes two avalanches in north-facing gullies at lower treeline elevations see here. We have very limited reports from this region so it is import to supplement this forecast with your own observations. If you have been out, please submit any observations to the Mountain Information Network (MIN).
Snowpack Summary
20-30 cm of new snow has covered the region so far this week, the product of an ongoing series of storms. Areas like Howsons in the far southwest may see storm totals closer to 60 cm. The combination of new snow and forecast strong south winds is likely forming thicker, more sensitive wind deposits at higher elevations. Even below the wind, the new snow will need a bit more time to form a good bond with the weak surface hoar and facets that were sitting on the surface prior to the storms. (see this MIN report).A hard crust was reported 10-20 cm below the previous snow surface (so now closer to 30-50 cm deep) and in some locations there is an early season crust with facets near the bottom of the snowpack.Expect an average snow depth of 70-110 cm in the alpine, however this decreases dramatically at lower elevations. The ongoing storms are gradually bringing lower elevations to threshold depths for avalanches, replacing the rocks, stumps, and open creeks lurking beneath thin snow cover that have been the primary hazards thus far.
Problems
Storm Slabs
Continuing snowfall is adding to the depth of storm slabs and burying the wind slabs that are likely now quite widespread on lee (northeast facing) slopes at higher elevations. Expect deeper, touchier new slabs in the southwest of the region.
Approach steep lee and cross-loaded slopes with caution.Be alert to conditions that change with elevation, aspect, and exposure to wind.Field observations have been limited. Supplement this forecast with your own observations.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 14th, 2018 2:00PM
