Backcountry skiers and riders could trigger dense wind slabs up to four feet deep. Deep persistent slabs, which lie upon weak faceted snow, still warrant concern. As the day progresses, warming temperatures and the additional weight of dense snow will make these slides more likely. These conditions mandate a conservative approach to terrain choices. With above freezing temperatures and rain in the forecast, natural wet slides will be possible at the lower elevations.
Soft surface slabs up to 30 inches in depth could be triggered by humans who venture onto avalanche prone slopes. These slabs could step down and trigger dangerous persistent deep slabs in areas with poor snowpack structure.
Dangerous hard slabs, with depths to six feet, could be triggered on steep slopes where persistent layers of weak faceted snow exist within the snowpack. These dangerous slabs could be triggered on slopes that have been crossed multiple times by other riders or skiers.
At the lower elevations, where overnight lows remained above freezing, wet slabs could release naturally. Rain and warming temperatures will increase the likelihood of these slides as the day progresses.
( Discussion is generated from the previous day's afternoon forecast. )The next storm system will begin to impact the region tonight and continue through Thursday. Up to a foot of new snow is possible by Thursday night. Southwesterly to westerly ridgetop winds at 25 to 35 miles per hour will accompany this snowfall. Overnight lows in the mountains will be in the mid 20s before rising to near freezing during the day. Valley temperatures could dip below freezing during the night before rising into the low 40s, and rain at the lower elevations is likely.Similar slides to today's events are likely on Thursday, and the general avalanche hazard is expected to be CONSIDERABLE. Deep persistent slabs, with depths up to eight feet, could also be triggered by skiers and riders, or step down from the failure of surface slabs. New snow and strong westerly ridgetop winds will increase the likelihood of triggering these slabs. These conditions mandate a conservative approach to terrain choices. The potential for one or more fatalities is very real, and possibly imminent. With overnight temperatures near freezing and valley rain in the forecast, wet slides will remain possible at the lower elevations.
