Avalanche Forecast
Issued: Jan 2nd, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
cgarritty,
Avalanche Canada
A strong storm will impact the region over Saturday night through Sunday and an avalanche cycle is expected to occur. Travel in avalanche terrain is not recommended.
Summary
Confidence
Moderate - Forecast snowfall amounts are uncertain.
Weather Forecast
SATURDAY NIGHT: Cloudy with snowfall bringing 15-20 cm of new snow. Strong southwest winds. Freezing level near 1500 metres.
SUNDAY: Cloudy with continuing snowfall bringing 10-15 cm of new snow, easing over the day with possible clearing in the afternoon. Moderate west winds. Alpine high temperatures around -4 with freezing levels near 1500 metres.
MONDAY: Partly cloudy with isolated flurries and a trace of new snow. Light southwest winds. Alpine high temperatures around -4.
TUESDAY: Cloudy with light flurries continuing from the overnight period and 10-15 cm of new snow, including overnight accumulations. Flurries easing over the day. Light southwest winds. Alpine high temperatures around -6.
Avalanche Summary
Saturday was a busy day for avalanches in the Fernie area, where explosives control yielded numerous storm slab releases reaching size 3 (very large). Two size 2.5 (large) natural storm slabs were also observed early in the morning in the same area. These occurred on bed surfaces of previous avalanches that had been reloaded by strong winds redistributing new snow.
Expect similar if not touchier conditions on Sunday as another powerful storm takes aim at the region and continues to build storm slabs with heavy snowfall and strong winds.
Snowpack Summary
Upwards of 30 cm of snow is forecast to accumulate in the region by Sunday afternoon. The snow will be accompanied by elevated freezing levels and strong southwest wind. Storm slabs are expected to build in sheltered terrain and wind slabs in exposed terrain at higher elevations.
In the Lizard Range, a melt-freeze crust has been reported around 20 to 40 cm deep and up to an elevation of 1900 m. A few reports suggest that sugary faceted grains may exist around the crust but others indicate no weakness. It remains to be seen if this layer will become an avalanche problem.
Around 50 to 100 cm deep, weak layers of feathery surface hoar and/or faceted grains may overly a hard melt-freeze crust. This layer appears to be bonding in certain areas of the region but remains suspect where it is well preserved.
Terrain and Travel
- Watch for fresh storm slabs building throughout the day.
- Approach lee and cross-loaded slopes with caution.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Problems
Storm Slabs
Snow will accumulate over Saturday night and over the day on Sunday, building fresh storm slabs in avalanche terrain throughout the region. Expect natural avalanche activity to ramp up as 30 or more cm of new snow accumulates.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
Weak layers of feathery surface hoar and/or sugary faceted grains may be found above a hard melt-freeze crust around 50 to 100 cm deep. Although avalanche activity hasn't been reported on these weak layers for over a week, the likelihood of triggering will be heightened during this stormy period.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 3rd, 2021 4:00PM
