Today's heavy snowfall and strong winds will create very dangerous avalanche conditions. Large to very large slab avalanches are likely to release naturally and may run full path into lower elevation avalanche run out zones. A forecasted increase in the winds will cause conditions to become more dangerous as the day progresses. Travel in avalanche terrain is not recommended during periods of high avalanche hazard. In the United States nine people have died in avalanche accidents since February 1.
Strong west-southwest winds will be rapidly loading avalanche starting zones and could trigger the release of large natural avalanche events. These dangerous slab avalanches could be one to four feet deep. Once released they could dig down to buried weak layers and become very large and run full path into lower elevation run out zones.
At the higher elevations very large persistent slab avalanches with depths from 3 to 5 feet may release naturally or be human triggered on a variety of aspects. If triggered these destructive slides could run full path into lower elevation avalanche run out zones. At the lower elevations smaller persistent slab avalanches up to two feet in depth could be human triggered on steep wind loaded avalanche prone slopes.
( Discussion is generated from the previous day's afternoon forecast. )The next pulse of moisture will bring moderate snowfall to the area that will start this evening and continue until tomorrow afternoon. New snowfall amounts of 6 to 12 inches are likely in the mountains with 3 to 6 inches in the valleys. Temperatures will be mostly in the single digits and teens. Winds will be from the west-northwest with gusts for 40 to 50 miles per hour along the higher ridge crests and cause areas of blowing and drifting snow.The general avalanche hazard is expected to be considerable at the higher elevations. Strong winds will build wind slabs on leeward aspects and increase the load on persistent weak layers. Skiers and riders could easily trigger wind slabs 1 to 3 feet deep in steep wind loaded avalanche starting zones. Dangerous persistent slab avalanches 2 to 5 feet could also be triggered on avalanche prone slopes. A careful evaluation of the snowpack and terrain and conservative terrain choices are warranted.
