"These are conditions that will produce a lot of avalanches," said Utah Avalanche Center director Bruce Tremper. "This is the first major, big warm-up of the season."
Though the avalanche danger was only moderate Thursday, a dozen soft, wind slab avalanches were triggered by backcountry enthusiasts. Most were less than a foot deep and 10 to 70 feet wide.
"They were fairly manageable, but a lot of people got surprised," Tremper said.
The avalanche danger today also was moderate.
Now, with mountain temperatures expected to skyrocket from last week's teens to the upper 50s, forecasters are weary of problems arising.
"By Monday it is suppose to be 57 degrees on ridge tops, which is extremely warm," Tremper said. "The snowpack doesn't like rapid change."
Because northern Utah has experienced cold, snowy conditions for such a long time, the dramatic shift is expected to cause natural avalanches.
"It is the equivalent of a human taking a cold shower," Tremper said. "It's quite a shock to the system."
Wet avalanches at lower elevations could begin occurring Saturday on south facing slopes before expanding higher and further up slopes, Tremper said.
"I think Sunday and Monday will be the worst days," he said.
The new advisories will be issued for all Utah mountains but especially those near Salt Lake City because of heavy snowfall earlier this week. The danger is highest in the backcountry and not at ski resorts or on highways, Tremper said.
