Avalanche Forecast
Issued: Feb 1st, 2018 5:33PM
The alpine rating is Persistent Slabs and Storm Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Low - Forecast snowfall amounts are uncertain
Weather Forecast
Friday: Cloudy with flurries bringing 10-20 cm of new snow, increasing overnight. Strong west winds, continuing overnight. Freezing level rising to 1400 metres with alpine high temperatures around -5.Saturday: Cloudy with continuing flurries bringing 5-10 cm of new snow in the morning. Skies clearing over the day. Moderate to strong northwest winds. Freezing level returning to the surface with alpine high temperatures of -12.Sunday: Increasing cloud with isolated flurries and a trace of new snow. Light variable winds. Alpine high temperatures of -10.
Avalanche Summary
Reports from Wednesday included more observations of widespread natural activity that took place over the previous few days. Numerous recent Size 2-3 releases were observed on all aspects at all elevations and several avalanches reached Size 4. Subsequent explosives control yielded storm slab and wind slab releases from Size 2-2.5 and persistent slab results generally from Size 2.5-3. The early January persistent weak layer was named as the primary failure plane for persistent slab releases, although several larger releases stepped down to the mid-December layer. These observations illustrate that dangerous snowpack conditions continue to plague the region and will remain a serious concern for the foreseeable future.On Tuesday natural avalanches to size 2.5 were reported on northwest facing slopes at 2200 m, running on the early January interface. A size 2.5 avalanche on a northeast facing slope at 1920 m resulted in a single fatality in Clemina Creek. More details available here. A natural storm slab avalanche cycle occurred on Monday with heavy snow and temperatures up to +2 C in some tree line locations. See this MIN report for a good example of the avalanche activity.
Snowpack Summary
25-50 cm of storm snow fell between Sunday and Tuesday night. Temperatures reached -2 C at treeline in the south of the region (and +2 C near Barkerville) on Monday afternoon. The new snow sits on an unstable snowpack with three active weak layers we are monitoring:1) Down about 40-80 cm is a crust and/or surface hoar layer that was buried in mid-January. The surface hoar is up to 10 mm in size, found at all elevation bands and has been very reactive on north through east aspects between 1900-2600 m. 2) Deeper in the snowpack, the early-January persistent weak layer is found 50 to 100 cm below the surface. This layer has been reported as the most active persistent weak layer during a recent natural avalanche cycle that took place in the region. It has also been the most reactive to recent explosives control.3) Another weak layer buried mid-December consisting of a facet/surface hoar/crust combination is buried 100 to 150 cm deep. It has been most problematic at and below tree line. Many avalanches that failed at shallower weak layers 'stepped down' to this interface during the recent avalanche cycle and in recent explosives control.See here for some recent snowpack test results.
Problems
Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 2nd, 2018 2:00PM