The general avalanche hazard will be increasing at all elevations today. Strong winds are rapidly loading avalanche starting zones and will be creating very dangerous avalanche conditions above an elevation of 9,000 feet and dangerous avalanche conditions below that elevation. Increasing winds, heavy snowfall and rising air temperatures will result in unstable conditions on steep slopes. Warmer snow will be falling on top of colder snow that is not expected to bond well to existing snow surfaces. Large slab avalanches are likely to become easily triggered by humans. Natural releases may impact highways in the river canyons. Travel in avalanche terrain is not recommended during periods of high avalanche hazard.
At the higher elevations large to very large slab avalanches are very likely to be human triggered and likely to release naturally. At the mid and lower elevations small to large slab avalanches are likely to become sensitive to human triggers and may release naturally. These new wind slabs may grow to depths of two feet and are expected to become large and dangerous.
Today's strong winds and new snow are increasing the load on buried weak layers of faceted snow. This loading will be increasing the likelihood for large to very large deep slab avalanches to be human triggered or release naturally on these persistent weak layers. If triggered these dangerous deep slabs could be 3 to 8 feet deep.
( Discussion is generated from the previous day's afternoon forecast. )The next storm cycle has begun and is expected to favor the western and northern portions of our forecast region. Periods of moderate to heavy snowfall will occur in a fast-moving northwest flow. Accumulations of 4 to 8 inches in the mountains and 1 to 3 inches in the valleys are expected by morning. After that steady to moderate snowfall will continue into Friday. On Thursday temperatures will be rising as this snow falls. Westerly winds will also be increasing. Forecast speeds are 20 to 30 with gusts to 40 miles per hour on the higher ridge crest.The avalanche hazard will be increasing at all elevations. During the next 24 hours warmer snow will be accumulating on top of colder snow. Snowfall rates and winds will also be increasing. This scenario is expected to create increasingly unstable conditions on steep slopes. The cold snow that falls at the beginning of this storm cycle is not likely to bond well to slick and firm old snow surfaces. The general avalanche hazard is expected to rise to considerable. Wind slab avalanches are likely to be triggered by humans and may release naturally. New slabs could build to depths of two feet and are likely to become large and dangerous. Evaluate the snowpack and terrain carefully. Expert route selection and conservative terrain decisions will be essential for safe travel in avalanche terrain.
