Northwest Coastal

Fair - Timing, track, or intensity of incoming weather system is uncertain

On Tuesday, the next Pacific frontal system tracks across the South Coast. The edge of this system should affect the southern portions of the NW regions. Generally unsettled conditions are expected for Wednesday before another weak system impacts the central coast on Wednesday night or Thursday morning.Tuesday: Snowfall 10-15cm in the south, 2-5cm in the north, afternoon freezing levels around 400m, ridgetop winds 40-60km/h SWWednesday: Mostly cloudy, light intermittent snowfall 1-3cm, afternoon freezing levels around 400m, ridgetop winds 20-30km/h SW-WThursday: Snowfall 5-10cm, afternoon freezing levels around 300m, ridgetop winds 30-50km/h W-NW

On Sunday, natural slab avalanches up to size 2 were reported to be triggered by solar radiation. Two skier-triggered remote avalanches were reported (from 10-20m away), size 1.5 and 2, occurring down around 40cm with the storm snow overlying the Feb 10 weak layer.On Saturday, natural slab avalanches up to size 2 occurred, additionally some larger size 2.5 were triggered with explosives control. Numerous size 1-2 skier remote (up to 50 m away) slab avalanches released down 60 cm all on the old buried surfaces mentioned above in the snowpack summary.

Over the past week the parts of the region have received over 1.5m of cumulative snowfall which has settled into a slab with a typical thickness of 60-90cm. This storm slab overlies a variety of facets, surface hoar, crusts, hard wind press, or any combination of these. Widespread whumpfing, cracking, avalanche activity and remote triggering at all elevations indicate there is a poor bond between the new snow and these old surfaces. Snowpack tests show easy, sudden planar results good propagation propensity.Recent Strong to extreme SE winds have built thick, touchy wind slabs on leeward terrain features and slopes.The mid and lower snowpack is generally strong and well-settled. Basal facets and depth hoar still sit dormant at the bottom of the snowpack in some parts of the region but triggering this layer is generally unlikely.