Avalanche conditions are dangerous. Very large, natural avalanches occurred yesterday, and more are possible today. The avalanche danger is CONSIDERABLE on all aspects and elevations, and human-triggered avalanches are likely. Avoid travel on and beneath slopes steeper than 30°.
Warm temperatures, rain at the low and mid elevations, and snow and strong winds at the upper elevations are creating tricky conditions. Careful snowpack evaluation, cautious route-finding, and conservative decision-making are essential.
Warm temperatures and significant rain on snow are creating conditions for wet snow avalanches on all aspects and elevations. Yesterday, both wet loose avalanches running on the surface and wet slabs failing on the PWL occurred. Low and mid-elevation north-facing slopes are most suspect.
Wet slab avalanche on north-facing slope at 8000 feet. (Photo: M. Sauer)
Strong wind blowing from the west, combined with dense snow from yesterday are creating thick, stiff slabs along upper elevation ridges. These slabs may be stubborn to trigger and could break above you and pull into lower-angle slopes. Any wind slab triggered today has the potential to step down, resulting in a much deeper and wider avalanche that breaks on the persistent weak layer.
Strong winds were drifting snow along the Park City Ridgeline yesterday. (Photo: Torrey)
The DJL (Dry January Layer) is buried 1-3 feet beneath the surface. This layer is responsible for 3 avalanche fatalities, several accidents, and more than 60 reported avalanches. The situation has recently become more complex, as the overlying slab has grown increasingly strong and hard. The hardness and thickness of the slab allow it to behave as a shield, making it more difficult to impact the weak layer. As the slab has strengthened, it's led to very wide avalanches that connect through and around terrain features across a slope. In this situation, the common ECT snowpack test is unreliable and often provides falsely stable results. Cracking and collapsing are unlikely to be observed. This can lead to a false sense of stability and lure people into avalanche terrain. Discipline and patience are required right now.
Recent avalanche activity is the best indication of current conditions. Both large natural and human-triggered avalanches yesterday point towards the high-consequence nature of this problem.
A large, natural avalanche on a northeast-facing slope at ~10,100 feet failing on PWL. (Photo: Solitude Snow Safety)
If you trigger or see an avalanche adjacent to the road or one of the ski areas and are sure no one was caught in the avalanche, call the nearest mountain dispatch and alert them to the situation. This will allow SAR teams to stand down, preventing them from being subjected to unnecessary hazards.
Salt Lake and Park City – Alta Central- (801-742-2033)
Canyons Resort/PCMR Dispatch- (435 -615-1911)
Brighton Resort Dispatch- (801-891-2339)
Solitude Mountain Dispatch- (801-536-5753)
Several avalanches were reported from the backcountry yesterday. Wet snow avalanches were reported at all elevations, with standout wet slabs reported along PC Ridge. Ski areas reported several very large avalanches breaking on PWL in upper elevation north-facing terrain.
PC Ridgeline- Cinder Chutes from the Saddleback Chairlift at PCMR. Photo: A.L.
Three people were killed in separate avalanche accidents in the past eight days, with a fourth in critical condition.
All of these accidents involved slab avalanches 2-3' thick and up to 500' wide failing on weak faceted snow, our January Dry Layer (JDL). There's something else to point out - in nearly all of these and many other close calls, the individual or party triggered the avalanche from below while in gentle terrain. It's not enough to be on low-angle terrain: you can collapse the slope and pull the avalanche down on top of you.
Yesterday, 1-2 inches of precipitation fell mostly as rain below 9000 feet. Above that, 2-7 inches of dense snow accumulated. Even north-facing slopes up to 10,500 feet saw wet snow and may have a thin surface crust this morning. Strong ridgetop winds blowing from the west were drifting snow, creating stiff wind slabs.
Overnight, skies were cloudy, and temperatures remained warm, with freezing levels around 9000 feet. Winds continued to blow from the west at 10-15 mph with gusts into the 20-30s along the 9000-foot ridges, and 20-40 mph with gusts into the 50-60s along 11000-foot ridges.
Today, lingering light rain and snowshowers this morning will gradually clear out and lead to partly cloudy skies. Temperatures remain warm, climbing into the upper 30s and low 40s °F, though ridgetop temperatures will be much cooler with wind chill. Winds will continue to blow from the west, 10-15mph gusting 20-25 along the 9000 ft. ridges and 25-35 mph with gusts in the 40-50s along 11,000 ft. ridges. Winds decrease through the day.
One needs to understand runout and alpha angles if traveling in the mountain environment. Chris Benson caught this footage of a very close call near Red Mountain Pass in Colorado over the weekend. These are the sort of avalanches that have left three dead and one in the hospital in Utah.
This information does not apply to developed ski areas or highways where avalanche control is normally done. This forecast is from the U.S.D.A. Forest Service, which is solely responsible for its content. This forecast describes general avalanche conditions and local variations always occur.
