Avalanche officials are preparing for ongoing challenges this winter as early season snow combined with dry weather and inconsistent storms have impacted Utah’s snowpack.
Record snowfall in October made skiers and snowboarders optimistic. Over time, though, the sun melted away the early season snow on the southern slopes and weakened what remained on the other aspects. A dry November failed to replenish the snowpack, and a stormy December formed slabs — which occur when a strong layer of snow sits on top of a weak layer. It’s the right combination to trigger an avalanche as the snowpack becomes overwhelmed, according to Nikki Champion, a Utah Avalanche Center forecaster.
Officials saw several avalanches in late 2021 but conditions in the backcountry began improving when the snow ceased for nearly six weeks in January and February. Avalanches are less likely to occur when there are prolonged periods of dry weather, which means the avalanche danger has been relatively low for much of the winter. But new snowfall, like the storms in recent days, can change the situation.
The Utah Avalanche Center rated the risk of avalanches in the central Wasatch Range, which includes the Park City ridgeline, as considerable as of Friday morning, while the risk in the Uintas was moderate.
“The entire snowpack has been weakening over the last two months and now moving forward, we are entering a more active period where we’ve started seeing avalanches again,” Champion said. “And we’re probably going to see more as we start to put a slab on top of those weak (snow) grains from January and February.”
The situation is similar to the winter of 2020-2021 when most of the west experienced early season snow in October and November with dry conditions in December and January. This caused the snowpack to become faceted, which is when the snow has become “sugary” with larger grains that form weak connections. Most of the snow covering Utah’s mountain ranges fell into this category, according to Champion.
“We often deal with these persistent weak layers, but we tend to bury them pretty deeply and lose them midseason,” she said. “We have a very similar setup this year but we got enough snow in January that we kind of put those layers to rest.”
But last year, a dry start meant that the weak base persisted for months at the time until a larger storm buried it. Officials often have to deal with those lasting layers, but it’s uncommon for them to last as long as they did last winter.
Long, persistent weak layers can cause avalanches to occur later in the season and they are often easier to trigger.
Avalanches do not occur randomly and are triggered naturally or by people skiing, snowboarding or riding snowmobiles. They occur on slopes steeper than 30 degrees and require a weak or buried base layer to be topped by a slab.
Dangerous conditions, combined with skiers overlooking the risks as the problem persisted,
contributed to one of the deadliest winters in the state’s history last season, according to Champion. There were six avalanche fatalities in the backcountry in 2021 with another death close by in southeast Idaho.
“People began to push the bounds to see if they could outsmart the problem, and it’s just not a problem that people can really outsmart,” Champion said. “So we were seeing unfamiliar avalanches for a longer period of time.”
This season, she expects that avalanche conditions will continue “for the foreseeable future.” Southern slopes that receive more sun are not at the same risk as other slopes, however, which provides more skiing and riding options.
“If avalanches are ever in the question, slope angle and aspect are the answer,” Champion said. “Look for areas where that problem doesn’t exist.”
Champion urges users to pay attention to the avalanche forecast, which is updated every day, to receive travel advice and danger ratings and to make sure they have the appropriate training and equipment if traveling into the backcountry.
The avalanche forecast and additional information can be found at the Utah Avalanche Center website, utahavalanchecenter.org.