Northwest Coastal

Another round of heavy snowfall and strong to extreme wind is expected to maintain a natural avalanche cycle through the day on Thursday. Travel in avalanche terrain is not recommended.

Wednesday night: Cloudy with periods of snow bringing 20-30 cm of new snow. Extreme southwest winds.

Thursday: Cloudy with continuing periods of snow bringing 15-20 cm of new snow, easing overnight. Moderate to strong southwest winds shifting west. Alpine high temperatures around -7.

Friday: Cloudy with flurries bringing about 5 cm of new snow, increasing overnight. Moderate southwest winds, increasing overnight. Alpine temperatures around -7.

Saturday: Mainly cloudy with easing flurries and about 5 cm of new snow. Moderate southwest winds, easing over the day. Alpine high temperatures around -6

Reports from Tuesday included a few observations of small (size 1) new wind slabs reacting to skier traffic as well as failing naturally on steeper north aspects. Many loose wet avalanches, up to size 2 (large) were observed running naturally on steep, sun-exposed slopes.

Over the weekend wind slabs were widespread to size 2 with an average depth of 30 cm.

Natural cornice failures have featured regularly in reports from the last week, with some cornices failing to produce avalanches when they impact slopes below, and others producing small wind slabs. 

We recently received a report of a very large (size 3.5) persistent slab avalanche that likely ran on February 5th. It ran naturally on a north/northwest facing feature at 1850 m, this avalanche failed on the January facets mentioned in our snowpack summary.

It's also worth noting that glide slabs continue to release sporadically. a size 2.5 natural glide slab avalanche was reported from an east facing feature at 700 m near the Basalt Creek Rest Area east of Prince Rupert On Friday February 7th. It's always a good idea to avoid slopes with glide cracks.

35-50 cm of new snow is expected to accumulate in the region by end of day on Thursday, under the influence of strong to extreme southwest winds. The new snow will mainly bury widespread wind-affected surfaces and recent wind slabs in exposed areas as well as sun crust on sun-exposed slopes at lower elevations. 

The new snow adds to 15 to 20 cm of snow from Monday night, which overlies an aspect and elevation-dependant mix of melt-freeze crust (lower elevations), sun crust (sun-exposed slopes), faceted snow and/or surface hoar (shaded aspects).

A thin layer of facets that formed during the January cold snap is now 100-150 cm below the surface and an early season crust exists at the base of the snowpack. These layers produced a few large naturally triggered avalanches in early February but have more recently been nonreactive.

• Avoid all avalanche terrain during periods of heavy loading from new snow and wind.
• Storm slab size and sensitivity to triggering will likely increase through the day.
• Recent new snow may be hiding windslabs that were easily visible before the snow fell.
• Avoid exposure to slopes that have cornices overhead.