Regions
Northwest Coastal.
The forecast hazard may go higher on specific terrain features, especially in the afternoon with daytime heating
Confidence
Fair - Timing or intensity of solar radiation is uncertain
Weather Forecast
Clear and sunny for the next few days with the next Pacific frontal system forecast to arrive on the coast late Wednesday. Freezing levels will rise with daytime heating to 1300m and drop overnight to near valley bottoms. Winds should be mostly light from the south
Avalanche Summary
Several large natural avalanches have been reported recently, with one of them being a cornice failure. Solar aspects are becoming active with daytime warming and producing point releases that grow up to size 2, and in one case triggered a slab on a weak layers to size 2.5
Snowpack Summary
Recent storm snow varies across the forecast area, with the biggest accumulations near the coast. With warm temperatures the storm snow is bonding to the 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 problems seems more touchy in the northern part of the region, but has been reported throughout the northwest coastal area. Weaknesses have also been found within the recent storm snow with tests producing easy to moderate sudden results in the top 20 to 40cm. 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.