Regions
Northwest Inland.
Confidence
Fair - Timing or intensity of solar radiation is uncertain
Weather Forecast
Tonight and Friday: Most of the province is under a high pressure system. Moderate to strong wind from the SW will switch from the S. Temperatures will rise as well as freezing levels up to 3000 m (or 2000 m further North) with a mix of sun and clouds during the day.Saturday: A weakening frontal system will reach the coast which should bring light precipitation and strong S winds switching from the SW in the afternoon. Freezing levels are expected to lower to 1400 m. with the arrival of the snow.Sunday: Ridge of high pressure rebuilds over the coast leading to a clearing trend with mild temperatures.
Avalanche Summary
In the far Northern part of the region, there was an avalanche cycle yesterday 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. A couple days ago, a natural avalanche was reported which took place around Smithers. This avalanche occurred on a NE aspects slope at treeline in a wind affected area.
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.