Northwest Coastal

Another powerful storm will affect the region on Tuesday and a natural avalanche cycle is expected. This will be a good day to avoid avalanche terrain.

• Storm slabs in motion may step down to deeply buried weak layers resulting in very large avalanches.
• Minimize exposure during periods of heavy loading from new snow and wind.
• Storm slab size and sensitivity to triggering will likely increase through the day.
• Avoid exposure to overhead avalanche terrain during periods of heavy loading from new snow, wind or rain.

Monday night: Cloudy with increasing snowfall bringing about 20 cm of new snow by morning. Strong southwest winds.

Tuesday: Cloudy with continuing snowfall bringing about 20 more cm of new snow and new snow totals to about 40-45 cm. Easing precipitation in the afternoon with a possible transition to light rain below 1000 metres. Precipitation increasing again overnight. Moderate to strong southwest or west winds easing over the day and picking up again overnight. Alpine high temperatures reaching about -1 as freezing levels climb to near 1500 metres by afternoon.

Wednesday: Cloudy with easing flurries bringing up to 5 cm of new snow, about 30 cm with overnight accumulations. Light southwest winds. Alpine high temperatures around -4 with freezing levels to 1000 metres.

Thursday: Cloudy with isolated flurries. Light west or southwest winds. Alpine high temperatures around -6.

Observations were limited by weather on Saturday, but we have preliminary reports of the recent storm and associated natural avalanche cycle producing storm slabs to size 3. (very large) in the Terrace area. 

So far, avalanche activity appears to have mostly been limited to storm snow and only involving deeply buried layers in isolated instances. With that said, a few crown fractures were noted at up to a metre in depth. Ski cutting of small features on Saturday produced small releases up to 30 cm deep.

Looking forward, heavy snowfall and strong winds forecast for Monday night through Tuesday are likely to initiate another natural avalanche cycle on Tuesday. This will be a good time to step back from avalanche terrain.

About 40 cm of new snow is expected to accumulate over the region by the end of the day on Tuesday, with the greatest amounts closest to the coast. The new snow will mainly bury wind-affected snow on all aspects at higher elevations and add to 60-80 cm of recent storm snow.

90-150 cm of snow from the second half of January overlies a thin layer of facets that formed during the mid-January cold snap. Recent avalanche activity in the Bear Pass area and snowpack tests results have indicated that this layer remains a concern (check out this MIN report).

A crust from mid November exists at the base of the snowpack. So far, we have only one observation from Saturday in the far north of the region showing this layer waking up during the storm. Previously, the last avalanche reported on this layer was on January 17. Potential still exists for large avalanches in surface layers to step down to this layer.