Several days of light accumulations have resulted in the possibility to trigger soft surface slabs and sluffs in very steep terrain at the high and mid elevations.Also, in isolated areas above 9000', although very unlikely, a chance persists to trigger large slides involving weak snow near the base of the snowpack.
Winds from varying directions over the last week have formed soft surface slabs in steep terrain, particularly near ridges crests and in areas prone to wind loading. These slabs could be human triggered today in pockets with depths to eighteen inches at the high elevations and in smaller isolated pockets at the mid elevations.
In isolated areas at the high elevations, a layer of crusts and facets persists at the base of the snowpack. It is unlikely that backcountry travelers would trigger such a slide. However if triggered, these hard slabs are likely to carry severe consequences.
The first of two storm systems will move in tonight bringing four to eight inches of new snow to the higher elevations by Sunday evening. Westerly ridgetop winds will increase to 20 to 25 miles per hour. Overnight lows in the mountains will be in the single digits before rising into the mid-teens during the day.The low probability/high consequence persistent deep slab problem keeps the General Avalanche Hazard at MODERATE on Sunday. While backcountry travelers are very unlikely to be able to impact these deeper layers, the result of being caught in one of these slides would be severe. In very steep and extreme terrain, skiers and riders might also be able to trigger isolated pockets of wind slab six to eighteen inches in depth.
