Regions
Vancouver Island.
Confidence: High , Daily terrain and snowpack observation during the past forecast period.
A well documented (view our Instagram page) natural avalanche was filmed on a North aspect , this wind slab was large size 2 .
During both Saturday and Sunday, many solar induces Natural loose wet avalanches on steep solar aspects where observed. Most where size 1 with a few size 2. One very large loose wet was observed on a large south aspect feature Mount Kusum and was size 2.5 or greater.
During travel in wests aspect terrain between 1600 meters and 1100m , the forecast team experience settlement and cracking around ski, this was below the 1300 meter elevation mark.
Past Weather
Previous warm weather has been followed by cooling temperatures with freezing levels nearing seas level and moderate North west wind. The norther region of the forecast area ( north of sitika river) received 20 cms of new snow and this was found at 300m and above. During Saturday and Sunday, ridgetop wind transport was evident as available snow was at times being transported to south east aspects. Sun was in full effect during periods of clear skies, direct solar aspects became warm and numerous Loose dry avalanches ran naturally.
Weather Forecast
A strengthening artic high pressure is entering the region bringing to the forecast areas, cool temperatures, clearing sky , and moderate to strong North West wind. The possibility of power flurries delivering daily light amounts to isolated areas exists, this seems to be focused to the southern areas of our region.Monday: No new precipitation, Winds Light to Moderate from the North West, Freezing levels at sea level with a day time a high of 500 meters.Tuesday: 0-5 cm, Winds light from the South East, Freezing levels at sea level with a day time high of 600 meters.Wednesday: 0-5 cm, Winds Moderate from the North East, Freezing levels at seas level with a daytime a high of 500 meters.
Terrain Advice
Be cautious when route-finding and avoid convex roll features.Seek low angle terrain that is well supported. Avoid travel on South aspect terrain during the period of warming and direct sun exposure.
Snowpack Summary
Snowpack depths vary from 350 cm in norther regions to 500cm plus in the mid and southerly region of the forecast area. They do all have one similar characteristic and that is the January 23, 2021 PWL. This layer can be found between 60 and 100 cm deep and has been reactive to extensive testing. Moderate compression testing produces sudden planar results. This problematic condition, will continue to linger and should be monitored and observed prior to committing to entering terrain. Currently a well bonded layer dense snow is "bridging the upper snowpack" and protecting this layer from triggering in all but thin areas and unsupported features. Expect this to begin to loose some strengthen with the coming cool weather.
Snowpack Details
- Surface: variety of surfaces, new low density snow, wind scoured at upper ridge tops and wind loaded on southerly aspects.
- Upper: A dense and strong layer of poly crystals overlies rounds.
- Mid: An eroding crust with facets at its base.
- Lower: Well settled.
Problems
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
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.
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.