After a powerful Monday storm delivered more than 21 inches of snow along the Park City ridgeline, the Utah Avalanche Center warned that avalanche conditions are now highly dangerous and could worsen further this week.
In a forecast issued Tuesday morning, forecaster Nikki Champion said avalanche danger is now rated “considerable” at upper elevations and on mid-elevation slopes above 8,000 feet, where human-triggered avalanches are likely and natural avalanches remain possible.
Champion said avalanches in these areas may break anywhere from 1 to 6 feet deep, either within 1 to 3 feet of recent storm snow and wind drifts, or much deeper on buried weak layers on northerly aspects.
The storm that moved through northern Utah early this week brought heavy, dense snowfall with a snow water equivalent of between 1.7 and 3.8 inches. With sustained winds up to 20 miles per hour, and some gusts reaching into the 50s along high ridgelines, the storm created prime conditions for wind loading and slab formation in the snowpack.
“Clear skies and soft snow may tempt riders, but the snowpack remains dangerous,” said Champion. “Most accidents and fatalities occur after peak instability — today has accident written all over it. Avalanche terrain can be avoided, and excellent riding exists on lower-angle slopes under 30 degrees.”
On Monday alone, six avalanches were reported in the Salt Lake area with two of those involving deep slabs that failed into older layers, compounding the impact and danger of the avalanche.
In Hidden Canyon, a skier was caught, carried and partly buried in an avalanche that released 30 feet above him, failing as deep as 15 feet in places after breaking into older layers in the snowpack. No injuries were reported.
It was the fourth significant avalanche reported in Hidden Canyon in the past week. On Friday, two teenagers were caught, carried and buried after ducking a rope out of bounds at Brighton Ski Area. They were both carried 500 feet down. One was fully buried head first. The other, who was partially buried and able to dig himself out, helped to recover his friend. Neither skied with any avalanche rescue gear. They did not sustain lasting injuries and walked out from the area safely.
Another large avalanche occurred Monday in the First Cornice area, where a snowmobiler was caught and carried in a slide estimated to be 4 feet deep and 800 feet wide. Additional avalanche reports from Monday included natural slides of smaller slabs and loose snow at Twin Lakes Pass, Two Trees, God’s Lawnmower and Mount Superior.
In a special avalanche bulletin issued Monday, forecasters warned that dangerous avalanche conditions were widespread across northern Utah and southeastern Idaho, including the Wasatch Range and the Uinta Mountains.
“Large and unsurvivable tree snapping avalanches 4-6 feet deep have already occurred, multiple riders have been critically buried in an avalanche in the Brighton backcountry since Friday, and more human-triggered avalanches are expected, with natural avalanches possible,” wrote the Utah Avalanche Center.
Avalanches are most likely on slopes steeper than 30 degrees and may be triggered remotely, from below, or from adjacent lower-angle terrain. While lower-angle slopes under 30 degrees continue to offer safer travel options, forecasters said avoiding avalanche terrain entirely is the most reliable way to reduce risk during the current cycle.
Another storm is expected to move into the region later Wednesday, bringing colder temperatures and additional snowfall. Forecast projections range from 8 to 24 inches of snow, said Champion.
For now, forecasters said backcountry users around Park City should expect dangerous avalanche conditions to persist and should plan accordingly as winter storms continue to build on an unstable foundation. Check the daily forecast at utahavalanchecenter.org.