The higher elevations have received five feet of snow with over six inches of moisture since January 1. The snowfall has been accompanied by strong and gusty winds. Last night was no exception as heavy snowfall and sustained winds continue to increase the hazard at all elevations today. Human triggered slab and loose snow avalanches are likely. Natural avalanche releases are possible. Expert terrain evaluation skills and conservative decisions are essential for safe travel in avalanche terrain today.
Strong west to southwest winds have transported snow onto leeward aspects. These slabs will be further loaded today by new snow and southwest winds. At mid and upper elevations, backcountry travelers could trigger these slabs with depths up to three feet. Pockets of wind slab up to two feet in depth can also be triggered on steep, wind loaded terrain features at the lower elevations.
Weak snow near the base of the snowpack continues to be a concern. These slabs could be up to six feet in depth. This layer has been further stressed by recent snow and an avalanche could be triggered by a wind slab, a single person, or group of people. This layer has been most active on northwest to northeast slopes above 8,000 feet but can be found on other aspects as well. Being caught in one of these large hard slabs is likely to have severe consequences.
Periods of light snowfall are possible this evening and are expected to be over by sunrise. Skies will clear during the day. Temperatures will fall into the single digits above and below zero overnight. Daytime highs will rise into the teens in the mountains and into the 20’s in the valleys. Winds will be light at 15 to 20 miles per hour on the peaks. These winds will be from the west to northwest before they begin to back to the southwest ahead of the next storm system.Avalanche conditions are dangerous. On Friday the snowpack will still be struggling to adjust to the new load. Large to very large avalanches are likely to be human triggered on steep slopes at the mid and upper elevations where the general avalanche hazard is expected to be considerable. Natural avalanche releases are possible. These dangerous slab avalanches could be 2 to 6 feet deep. At the lower elevations, below an elevation of 7,500 feet, the general avalanche hazard is expected to be moderate. Small to large slab avalanches up to 2 feet in depth could be human triggered on steep wind-loaded terrain features.
