Northwest Coastal

The newest wind slabs are likely to be small, but are just as likely to be reactive to human triggering. Keep your brain turned on as stability improves.

Moderate -

Friday night: Clear. Strong northeast winds, possibly to extreme in coastal areas.Saturday: Sunny. Moderate to strong northeast winds easing over the day. Alpine high temperatures around -11.Sunday: Sunny with cloudy periods. Strong northeast winds. Alpine high temperatures around -15.Monday: Sunny. Moderate to strong northeast winds, easing over the day. Alpine high temperatures around -10.

A small (size 1) storm slab was triggered by a skier in the southeast of the region on Thursday. This occurred on a steeper (38 degree), convex, north-facing slope at 1300 metres. Although small, it highlights the potential for smaller, older storm slabs to react to skier triggering on suspect features.Reports from Wednesday showed explosives control yielding mainly small (size 1) wind slab releases in the Shames area. Several other recent small (size 1.5) natural wind slab releases were observed in alpine features in the Legate Peak area.Tuesday's reports showed more limited wind slab reactivity, with one smaller (size 1.5) wind slab triggered with a ski cut.Reports from Monday included several small (size 1.5) remote triggered (triggered by a skier at a distance) wind slabs on north aspects at around 1500 metres. Slab depths were 20-25 cm and they had failed on the crust buried beneath our recent storm snow.

In most areas, the upper snowpack is composed of successive layers of aging, wind affected storm snow layers. The top layer of this snow has been faceting (becoming sugary) under the influence of recent cold temperatures at all elevations. More recent, thin wind slabs may be found directly in the lee of ridgecrests and other wind exposed features impacted by recent southeast and northeast winds.Sheltered areas at lower elevations may still hold pockets of around 40 cm of low density snow which will overlie a thick melt-freeze crust at and below treeline.In the south of the region, the remainder of the snowpack is well-settled.Around Bear Pass and in the north of the region, there is a weak layer of feathery surface hoar crystals about 50 cm deep. This layer is likely most prominent in sheltered and shaded areas. Also in the north, a few weak layers may still exist within the middle and lower half of the snowpack. These include another layer of surface hoar around 70 to 100 cm deep and a layer of sugary faceted snow around 200 cm deep. These layers are a concern in thinner snowpack areas at higher elevations, where thicker, bridging layers of old storm snow and crust may be absent.