Copious amounts of warm, heavy, and wet snow is falling on top of yesterday’s cold, light, and fluffy surface snow. Add in strong wind with extreme gusts and this is a recipe for avalanches. Today will see avalanche danger rise dramatically. Slides on greater than 35° slopes will be large to very large and may run long distances. Be aware of terrain traps and do not venture onto or below big, exposed terrain today. Stick to low angle, low consequence terrain and give this agitated storm snow time and space to settle in. Travel in avalanche terrain at all elevations is not recommended.
New warm, heavy, and wet snow falling on top of our previous cold, light, and dry surface snow will create a dangerous upside-down upper snowpack. The light, dry surface snow will likely lack cohesive strength to bear the new load and may fail. Soft slab avalanches of one foot or greater are likely on steeper slopes and may entrain significant amounts of snow and debris.
Steady southwest winds at or above 20mph, with gusts to 40mph or higher, means even our dense storm snow will be transported. Wind loaded terrain will see deeper than normal stiff slabs that might be sensitive to skier/rider weight.
NOAA has called this storm an “Atmospheric River. ” By the time it passes, new snow accumulation will be measured in feet rather than inches. With low temperatures last night at or above freezing, todays highs in the mid 30’s , and potential for wind gusts in excess of 50mph; we will have most, if not all, Avalanche Red Flags today. We’re receiving heavy snowfall or rain, natural avalanches are likely, as are shooting cracks and whoomphing, wind loading will continue through the day, and temperatures have been rising since last night.
Avalanche danger will likely peak today, but elevated danger may linger for days to come. This storm will need time to settle and bond to the existing snowpack. Choose low consequence terrain today and avoid avalanche terrain at all elevations. Be aware that avalanches can be triggered above you on steep and convex slopes.
If you are seeing signs of instability, be ready to turn around and head home. It might be a great resort day!
