Summary
Confidence
Good
Weather Forecast
As the low off the Oregon coast moves inland and South, light-moderate snowfall amounts are expected through Thursday. The low deteriorates by Friday morning and is being replaced by a ridge, bringing dry, sunny conditions with very little wind. Overnight into Thursday: Light-moderate snow accumulations. Ridgetop winds will blow light from the East. Alpine temperatures near -6 and freezing levels at 1300 m.Friday and Saturday: Ridgetop winds will remain light from the NW-N. Alpine temperatures near -5 and freezing levels rising to 1500 m in the afternoon then falling to valley bottom overnight.
Avalanche Summary
No new natural avalanche activity reported. On Tuesday, many operators in the region did control work using explosives and triggered slab avalanches size 1-3 on N-SW aspects generally above 2200 m.
Snowpack Summary
Up to 80 cm of snow fell over the past week and continues to settle. Moderate ridgetop winds have built winds slabs on lee slopes and terrain features. Wind slabs and storm slab instabilities remain, particularly on the west side of the region where accumulations have been highest.Buried beneath (60-100 cm) exists a surface hoar and a sun crust layer, which continue to be lingering concerns. On solar aspects, the sun crust seems to be more reactive. Large looming cornices exist on ridgelines. Cornice fall could trigger a large slab avalanche on the slope below, especially when the sun comes out on Friday.Below treeline exists a melt-freeze crust with moist snow beneath it. The crust may be bridging instabilities deeper in the snowpack. If temperatures warm at lower elevations, you'll notice the crust breaking down and the snowpack becoming weaker.
swerner,
Avalanche Canada
