Northwest Coastal

Good - Timing, track, or intensity of incoming weather is uncertain on Thursday

A few more cm of new snow is expected on Monday night for Coastal and Interior regions. Temperatures are expected to drop to about -15 in the alpine by Tuesday morning as a ridge of high pressure moves into the region. Wednesday is expected to be mostly clear, but not as cold as Tuesday. The next system should be on the coast by Wednesday night or Thursday morning.

Widespread avalanche activity along the highway corridors during Saturday night and Sunday morning. Size was limited due to storm and avalanche cycle earlier in the week. Size 4.0 natural on Mt Rainey ran to valley bottom adjacent to Stewart Town site on Sunday morning. Widespread natural activity in the Shames area, possibly up to size 3.0 in the "Valley of Doom". Due to poor visibility we do not have any observations from alpine terrain.

Another 10-20 cm of snow has added to the storm snow from Saturday night. The storm slab is now about 50-80 cm depending on elevation. Very strong southwest winds have probably transported this new storm snow into thick windslabs and storm slabs. This new storm layer is sitting on top of a storm layer from earlier in the week that did not have a lot of time to settle and strengthen. A relatively thin layer of surface hoar or facets was reportedly buried New Year's day - this may have been the focus of some of the storm snow releases during the current storm; however, I suspect this layer will settle out quite rapidly. Lower down, it is still possible to find a surface hoar/crust/facet combo from mid-December. I suspect it would take a very heavy trigger such as a cornice fall to trigger this layer now, although if you are traveling in an unusually shallow snowpack area I'd still be cautious of it. The lower snowpack is generally well settled and strong.