Regions
Northwest Inland.
Confidence
Fair - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
A fast moving front will spread some precipitation Friday night and Saturday before the ridge rebuilds on Sunday..Saturday: up to 5 cm new snow expected with freezing levels around 1000 m. Ridgetop winds 50-70 km/h from the southwest.Sunday and Monday: Dry, with a mix of sun and cloud. Freezing levels around 800 m. Winds light southwesterly.
Avalanche Summary
In the far Northern part of the region, there was an avalanche cycle that ended on 15th Jan at all elevation and on all aspects. Multiple natural releases up to size 3.5. Most of these avalanches would have run on the early January surface hoar layer buried under the storm snow at treeline and below treeline on low angled terrain. In the Southern part, a few small slab avalanches were reported from steep leeward terrain. Around that time, a size 2.5 natural avalanche was reported which took place near Smithers on a SE aspect around 1600 m.
Snowpack Summary
The increased solar radiation and warming trend is keeping avalanche conditions elevated for tomorrow. The intense heat will weaken the surface of the snowpack and most likely increase avalanche activity on all aspects, but especially on S and SE aspects slopes when the sun comes out. There is a possibility that loose wet or slabs could step down to deeper instabilities.The past wind event has created extensive windslabs in the alpine and at treeline. Those settled rapidly with the mild temperatures but could become more sensitive with the forecasted warm temperatures and solar radiation. The buried surface hoar layer at treeline and the basal facets in thin rocky areas at treeline and in the alpine could become more reactive with the forecasted heat shock.
Problems
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.