Warming temperatures, strong ridge crest winds and more snow are increasing the avalanche hazard at the mid and upper elevations. At the upper elevations and on northerly aspects at the mid elevations persistent weak layers and firm snow surfaces exists below the recent new snow. Conservative terrain choices and a careful evaluation of the stability of buried weak layers is warranted. More snow means today’s avalanches will be larger and more dangerous. Avalanches are unlikely in areas where the snow that has fallen since Sunday has accumulated on mostly bare ground. In these areas the general avalanche hazard will be low.
On steep slopes at the mid and upper elevations where old snow from earlier in the fall persists beneath the recent new snow, dangerous slab avalanches could release naturally or be triggered by humans. These slabs could be one to three feet deep.
Snowfall intensity was picking up just before sunset to rates of 1 to 2 inches per hour. Winds were beginning to veer to the west-northwest. Heavy snowfall is likely to continue until midnight before decreasing in intensity by sunrise. Light snowfall will linger over the area in the morning before it diminishes in the afternoon. Temperatures will drop into the single digits overnight and rise into the teens in the mountains on Saturday. Winds will be westerly at 15 to 25 with gusts to 40 miles per hour. Avalanche conditions are dangerous at the upper elevations and on steep north facing terrain down to an elevation of 8,000 feet. In these areas new snow that has fallen since Sunday lies upon weak layers of surface hoar and faceted snow. Large slab avalanches could release naturally or be triggered by skiers and riders on these persistent weak layers. These slabs could be up to three feet deep and once released could gouge down into older layers of faceted snow. More snow tonight means tomorrow’s avalanches will be larger and more dangerous. The general avalanche hazard is expected to be considerable at the upper elevations (9,000 to 10,500 feet) and moderate at the mid elevations (7,500 to 8,000 feet).Avalanches are unlikely in areas where the snow that has fallen since Sunday has accumulated on mostly bare ground. In these areas the general avalanche hazard will be low.
