New snow and strong west winds have increased the possibility for skiers and riders to trigger pockets of soft slabs at the mid and high elevations today. These slabs are most prevalent in very steep wind loaded terrain. Also above 7500 feet, the possibility persists for backcountry travelers to trigger deeper slabs that formed during the mid-January storm cycle. Avalanches below 7500 feet are unlikely. Careful snowpack and terrain evaluation is essential today.
Recently developed soft wind slabs six to eighteen inches deep lie in steep, wind-loaded avalanche terrain above 7,500 feet. These slabs will increase in sensitivity today as they are weakened by warming temperatures and direct sunlight this morning and as they are rapidly loaded by new snow late this afternoon.
Slabs lie upon persistent weak snow types and crusts that formed during the dry period between Christmas and early January. These slabs could have depths to three feet and could be soft or hard. Although they have become less likely to initiate, in certain steep terrain features such as steep cliff areas, a slight chance exists for them to be triggered by the weight of a single person.
( Discussion is generated from the previous day's afternoon forecast. )The first in a series of disturbances is to bring snow to the area tonight through Friday morning. This relatively weak system is to bring two to six inches of snow by noon. Following a brief respite, a stronger system is impact the area late Friday afternoon. Temperatures are to remain warm on Friday, with highs in the upper twenties at higher elevations in the afternoon. These warm temperatures could allow for rain in the valleys Friday afternoon. Winds are to average 20-30 mph from the southwest.The general avalanche hazard will Moderate above 7500 feet and Low below that elevation. New snow will slowly increase the size and sensitivity of existing wind slabs and create new shallow ones. The snow will also further load persistent weak layers that although unlikely to trigger may still fail to the presence of humans, particularly larger loads such as groups or snowmachines.
