Regions
Northwest Coastal.
Sunshine are warmth are the primary drivers of avalanche hazard. Avoid large sun drenched slopes if the snow is getting moist or wet.
Confidence
Fair - Due to the number of field observations
Weather Forecast
Wednesday: Mainly sunny. The freezing level peaks near 1500 m. Ridge winds are light to moderate from the S-SW. Thursday: Increasing cloud with snow developing late. The freezing level is around 1300-1400 m. Winds increase to strong or extreme from the S-SW. Friday: Moderate snow. The freezing level is near 1000-1200 m and winds are strong from the south.
Avalanche Summary
On Monday there was a report of a size 2 skier triggered slab and a size 1.5 remotely triggered slab in the northern part of region. These were both from alpine terrain and appeared to fail on a buried surface hoar layer. In the same part of the region a size 3.5 cornice triggered slab was reported from steep unskiable terrain. This likely released on a weakness near the base of the snowpack. Besides these two slabs, the only other reports are of small loose wet sluffs from steep sunny slopes.
Snowpack Summary
Recent storm snow accumulations vary across the region, with the greatest amounts near the coast. The storm snow sits on a variety of old snow surfaces including a layer of surface hoar and facets buried on March 25th. This weakness, now down approximately 40 to 60cm has the potential for propagating over large areas. The problem seems more touchy in the northern part of the region, but has been reported throughout the northwest coastal area. The early March facet/crust persistent weakness is now down over a metre and produces hard, sudden planar results in snowpack tests.
Problems
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.
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.