Utah avalanche season ramps up with new snow
With up to 1.5 feet of new snow in the Wasatch Back and four feet of powder reported in Little Cottonwood Canyon, the conditions are ripe for avalanches.
The Utah Avalanche Forecast Center says avalanches are happening now. On Sunday Forecaster Drew Hardesty reported that in addition to the heavy, dense snow, strong winds have created a dangerous situation.
“A couple of those were triggered down to the ground,” Hardesty said. “And I suspect that it's the snowpack is just going to be raising the white flag and we are seeing avalanches as we speak, you know, both natural and human-triggered avalanches in the backcountry and at the ski areas right now. High danger. It's a pretty easy avalanche forecast for me, right now. I rarely tell people to hide under the bed. But that's what the travel advice is to avoid all avalanche terrain for today and let things settle out.”
It was a blockbuster storm that forced the avalanche center to ramp up in a hurry.
“We started off with lower density snow on Friday and this atmospheric river, decaying atmospheric river, is still delivering a punch to the mountains and the avalanche danger has risen to high overnight. You know, in some areas, we're just seeing, one, two, three inches of snow an hour and combined with moderate to strong winds out of the west-northwest. Part of it really, is that's coming in upside down - that the temperatures are rising with the storm. It's upside down and cakey, very slabby. And all this is stressing those old weak layers that we formed back in October, November.”
“Upside-down" describes higher density snow falling on lower density snow and Hardesty says it's a recipe for trouble. Shooting cracks in the snow he says are a clear sign of instability.
On Saturday, a long-time avalanche observer triggered a large avalanche along the Park City ridgeline from 150 feet away. The avalanche was estimated to be 2 to 3 feet deep and 300 feet wide, running on the weak, sugary snow from October and November.
Another new snow slide was reported off of 10-4-20 at about 9,400 feet with a northeast aspect. It was reported about 6 inches deep and 30 feet wide.
The forecast is calling for diminished snowfall rates with clear skies by Monday afternoon with a warming trend that will push temperatures into the upper 40s by Tuesday. A weak system follows for Thursday.