The higher elevations have received up to a foot of dense new snow since early Wednesday morning. At the mid and upper elevations skiers and riders who venture into steep avalanche prone terrain could trigger soft slab avalanches. Large cornices exist and may be unstable. Deep persistent slab avalanches are unlikely; however they could be a serious concern in isolated areas. At the lower elevations wet slides may become a hazard 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.
At the mid and upper elevations soft slab avalanches could be triggered by humans on steep avalanche prone slopes. These slabs could be one to two feet deep and may run long distances in steep chutes and couloirs. New snow during the day may contribute to an increase in this type of hazard.
It is unlikely, but possible that a person could trigger a very large destructive deep slab avalanche in isolated areas. Large triggers like a large cornice failure or a snowmachine that crosses a shallow, weak zone may be necessary to initiate the failure of one of these slides. If triggered these dangerous slides could be 4 to 8 feet deep and run long distances.
Zonal flow aloft will develop with the jet stream to the south over Utah on Saturday. Light to moderate snow showers will continue tonight before decreasing in intensity on Saturday. Overnight lows in the mountains will be in the single digits before rising into the upper teens in the afternoon. Nighttime lows in the valleys will be near 10 before climbing into the mid-20s during the day. Southwesterly to westerly ridgetop winds will range from 15 to 25 miles per hour.Above 7,500 feet, new snow and wind will add a little depth and volume to the existing wind slabs. In very steep avalanche terrain, skiers and riders could trigger these slabs with depths ranging from one to two feet. Persistent deep slab avalanches remain a threat in the Togwotee Pass and Southwest Trails forecast zones. Snowmobilers are more likely than skiers to impact the weak layers of faceted snow that reside three to six feet down. With these persistent deep slabs, previous tracks are not an indication of stability. The snowpack below 7,500 feet has gone through several melt-freeze cycles. After an expected hard freeze overnight, avalanche activity will be unlikely on Sunday.
