The “lake effect” is so ballyhooed around Salt Lake City that there’s a restaurant and a beer named after it.
It’s the term for the role the Great Salt Lake plays in creating what has been marketed as “The Greatest Snow on Earth”: the deep, dry powder upon which Utah’s ski resorts, especially those in the Wasatch Mountains, have built their reputations.
But the Great Salt Lake is rapidly shrinking and is soon expected to reach a record low water level. If it disappears, will it take Utah’s revered powder with it?
[Read more: At a record low, what will happen to the Great Salt Lake]
Probably not, experts say.
“The Great Salt Lake effect is not as important as many people think,” Jim Steenburgh, a University of Utah professor of atmospheric sciences and the author of “Secrets of the Greatest Snow on Earth,” wrote in an email to The Tribune.
“But (it) still provides, on average, about 6% of the annual snowfall at the resorts in the Cottonwood Canyons, with amounts greatest in October and November.”
The Alta ski area, located atop Little Cottonwood Canyon, boasts on its website that it is “one of the snowiest places in the country, receiving an average of 547 inches of snow each year.” It credits its frequent storms and fine powder to the lake effect. If Steenburgh’s estimation, taken from a 10-year survey, is correct, however, only about 30-40 inches of Alta’s annual snowfall can actually be attributed to the lake.
The rest of Utah sees even less lake effect. Evan Thayer, a Utah forecaster for OpenSnow, said Park City Mountain Resort and Deer Valley can probably credit the lake for less than 3% of their snow, while that drops to as low as about 1% at resorts like Snowbasin and Sundance.
As for the quality of snow, both Thayer and Steenburgh agreed that the demise of the Great Salt Lake would likely cause only an incremental slip.
“If the lake totally dried up tomorrow,” Thayer said, “we would still get close to our average snowfall.”
The science behind the lake effect
So what does the lake effect actually do then?
Because of its salinity, the Great Salt Lake contributes more lift than moisture to the cold air masses that move across it on their way east. It can destabilize the atmosphere, which in turn can create convection currents and lead to snow. Most often this happens at the tail end of a storm. And because the air masses receive little heat from the lake, and colder storms produce snow with less water content, the precipitation created tends to be a dry powder layer that is an ideal topping over a wetter base.
“Generally, lake effect occurs after a front moves through,” Thayer said. “It leaves light, fluffy snow on top of earlier snow from a warmer front. It’s right-side-up snow.”
That combo is what gives the feeling of “flotation” that many skiers and snowboarders crave.
But, all of that can happen without the lake’s help, too.
Steenburgh attributed Utah’s prized snow to three factors, none of which are dependent upon the Great Salt Lake: 1. The area receives many storms that are neither too big nor too small; 2. The water content of the snow is low (about 8.5% water, on average, compared to an average of about 12% in the Sierra Nevada); and 3. The snow tends to fall “right-side-up” because it starts falling in warmer temperatures, creating a denser layer on the bottom, and continues falling while the temperatures drop for the powder on top.
“Skiing will survive without it,” Steenburgh told The Tribune of the Great Salt Lake, “but it can be helpful for building the early season snowpack, provide some nice dry powder at the end of storms, and sometimes gives the Cottonwood resorts a decent powder day.”
That doesn’t mean the disappearance of the lake wouldn’t be cause for concern for Utah skiers and snowboarders.
The bellwether of water health
On July 24 the Great Salt Lake hit an all-time low in elevation in 160 years of recordings.
Thayer noted that the lake serves as a runway of sorts for the wind to lift an air mass up above the mountains. The smaller the surface area of the Great Salt Lake, the less “fetch,” or runway, the wind will have and the smaller the chance of snow.
Steenburgh added that less lake means more dust. That dust mixes with the snow and eventually works its way atop the snowpack where, because it traps more sunlight than clean snow, it will hasten the melting of the snow in the spring.
Plus, the 30-40 inches the lake contributes is still 30-40 inches, and each morsel of moisture is becoming exponentially more welcome as Utah experiences the effects of climate change, including drought conditions. Any natural snow that falls will reduce the amount resorts have to manufacture, which in turn reduces the amount of water they are pulling from mountain reservoirs that are also shrinking.
Ski Utah, the marketing arm for Utah’s ski industry, isn’t currently taking any action to keep the Great Salt Lake from drying up. But Nathan Rafferty, its CEO, said the way the lake levels are trending is worrisome because of what it could mean for those snowmaking reservoirs.
“We are concerned,” he said. “I’m not a water expert. I’m not a meteorologist. But the lake is a good bellwether for the water health of our region.”
And that water health, and the impact of climate change in general on Utah’s snowfall in the future, isn’t good, Steenburgh said.
“It is one of several things that are changing that we’re going to see in terms of the snow climate changing around here that is going to cause the snowfall around here to decrease over time.”
Thayer said skiers and snowboarders are likely to first notice the loss of the lake effect not under their boards, but in their food bills — perhaps at that very restaurant bearing its name.
“The area that’s maybe most affected, there’s no skiing,” he said. “The Oquirrhs get a much higher percentage of lake effect snow. So it may not affect skiing, but it will affect agriculture in the Tooele Valley.”
