At the higher elevations newly formed and older wind slabs could be human triggered today in steep, wind loaded avalanche starting zones. Shallow, loose snow sloughs are possible on very steep slopes. Large cornices exist and may be unstable. Very large, deep persistent slab avalanches are unlikely except in isolated areas and likely require a larger trigger such as a snowmobile or a cornice drop. At the lower elevations some potential for wet slides may develop on very steep terrain features during the warmest portion of the day. Conduct careful snow stability evaluations, monitor conditions for increasing hazard and avoid steep terrain in areas where the snow structure is poor.
Small pockets of fresh new wind slab formed by southwest winds and older pockets of denser wind slab could be triggered by skiers and riders in steep wind loaded avalanche starting zones. These slabs could be 1 to 2 feet deep.
In isolated areas, a person may be able to trigger a very large, deep persistent slab avalanche if a shallow, weak zone is encountered. Large triggers, such as snowmobiles, the release of a wind slab or a cornice failure may be required to trigger one of these deadly avalanches. Slab depths could vary from four to eight feet at the higher elevations and two to four feet at the lower elevations.
Periods of snow will continue overnight. Additional accumulations of 5 to 10 inches in the mountains and 2 to 4 inches in the valleys are possible. More snowfall and cloudy skies are expected on Thursday. Temperatures will be in the upper teens and 20s in the mountains and upper 20s and 30s in the valleys. Winds will from the southwest at 10 to 20 with gusts to 30 miles per hour.Southwest winds will be forming pockets of fresh wind slab on leeward aspects along the higher ridge crests. These new slabs could build to depths of one to two feet in favored areas. On steep slopes they are likely to be sensitive to human triggers. In areas with poor snow structure dangerous deep persistent slab avalanches continue to be a serious hazard on steep avalanche prone slopes. In these areas dense thick slabs lie upon a base of well-developed faceted snow. The release of these deep slab avalanches are most likely to be initiated by larger triggers such as snowmachines. The general avalanche hazard is expected to be moderate. Conduct careful evaluations of snowpack stability and make conservation terrain choices in areas that have poor snowpack structure.
