Northwest Coastal

Fair - Forecast snowfall amounts are uncertain on Tuesday

Synopsis: A low pressure system in the north Pacific continues to feed moisture onto the BC coast.Tonight: Cloudy with flurries, possible 10 to 20cm of precipitation,, freezing level around 300 metres winds from the south light occasionally gusting to strong.Wednesday: Cloudy with flurries, 5 to 10cm of precipitation expected, freezing level around 500 metres, ridge top winds light from the west, gusting to moderate.Thursday: Cloudy with sunny periods and possible flurries, trace amounts of precipitation, freezing level around 600 metres, winds light, from the west, occasionally gusting to moderate.Friday: Cloudy with flurries, 5 to 10cm of precipitation. Freezing level around 600 metres, light ridge top winds, occasionally gusting to moderate.

Reports of large natural avalanche cycle during and after Mondays precipitation and wind event. Avalanches up to size 3, running on the early March and Feb. 10th persistent weak layers. With continued loading and wind, rider triggering is definitely possible at this time.

10 to 25cm of recent precipitation and strong winds continue to build wind slabs in lee terrain and increase the depth of the storm slab that overlies the March persistent weak layer. This persistent weak layer is now buried well over a metre in most parts of the region. The recent storm snow has fallen on a melt freeze and/or rain crusts exist in most parts of the region below 1200 metres. This could become reactive on solar aspects when the sun finally comes out.The March weak layer is a combination of hard wind-scoured slab surfaces in exposed terrain, facets and/or surface hoar in sheltered and north aspects, and sun crust on steep solar aspects and is widespread throughout the forecast region.A late January/early February crust/facet/surface hoar combo is still showing up in snowpack tests with moderate to hard shear tests. This layer will be with us for a long time, and a slide triggered on this layer would be very large and destructive. Recent warming temperatures will be good for bonding on this layer, but a sudden increase in load, or a large rainfall event could "wake up" this layer and result in very large avalanches.