A winter storm showed up yesterday afternoon. So far the storm has dropped a wintery mix in the mountains and will continue for the next 24 hours. Weather models show rain in the valleys and snow in the mountains today. The rain snow line is currently at about 4000 ft in the Selkirk/Cabinets and about 5000 ft in the Silver Valley. Strong SW winds could transport snow, increasing snowloads on leeward slopes (N-E-SE). It was nice seeing the snowpack heal over the past weak, but now the concern will be a new one, after this storm is done. I don't expect epic pow conditions out there right now. More than likely the new snow will be touchy until it cools off on Wednesday evening. I'd give the new snow a couple days to adhere to the old snow surface before venturing out.
The snow falling in the mountains now is pretty heavy and wet. Between the weight added to the snowpack and the creation of a new slab of snow on the surface, expect to see the avalanche danger increase over the next 24 hours. Heavy wet avalanches also have the ability to trigger deeper instabilities deep in the snowpack.
Deep instabilities are still a concern. Even though the snowpack has been healing nicely over the past week, there are still some deep buried layers that could wake up. The best way to wake up deep layers is to add a bunch of weight to the snowpack, like what's happening now. We won't know what this added weight does until we can get out and check conditions after the storm or wait until it freezes.
Expect to see rain, snow and SW wind throughout the day. The precipitation and wind are forecast to increasing this evening into tonight. Tonight, snow levels could creep as high as 7300 ft and then come back down to 6000' after midnight. SW winds will increase tonight to 20-29 mph (gusts to 41 mph). Snow accumulations will depend on the rain/snow line, but upper elevations could see over 12'' of snow by Wednesday. Temperatures look to get cold (14 degrees F) on Wednesday night as this storm moves out.
