Editor’s note: This story has been updated to correct how balloons are used to forecast the weather.

Summit County’s rainy summer may have some folks excited about a snowy winter. However, according to Water Commissioner Troy Wineland, larger climate factors that come into play often debunk that correlation. 

Wineland works for the Colorado Division of Water Resources, and each month, he measures snowfall in Summit County. While Summit County did have a rainy summer, Wineland said climate patterns like La Niña and El Niño, wind direction, elevation and temperature could change the amount of snowfall Summit County receives. 

“A storm coming in from the west with a certain topography may be favorable for certain slopes and certain conditions,” Stark said. “Whereas a storm coming from the southeast — same moisture content and wind speeds and all that — could give you something completely different.” 

As of now, Wineland said Summit County snowpack is between 97% to 104% in comparison to the 20-year average, meaning the county has gotten an appropriate amount of snowfall for this time of year.

Future snowfall predictions are less cut and dry, however. Wineland said temperatures from January to February are predicted to be warmer than average, but whether the area gets more precipitation than normal is still 50/50. 

Five automated snowfall sites placed throughout Summit County automatically measure the amount of snow accumulation. The sites use air-filled “balloons,” that measure the pressure of snow that lands on them. 

The amount of water in the snow accumulation could vary, however. According to Wineland, 10 inches of snowfall does not always mean 10 inches of rain. Since snow doesn’t condense like water does, 10 inches of snow could actually contain only 10% to 35% of water. Therefore, the sites help to measure snow accumulation and water density. 

Wineland also does manual tests. With a metal tube, Wineland collects a chunk of snow from a designated site. Much like the balloon method, Wineland then weighs the snow to check for accumulation and water density. 

Wineland said water density is especially important for determining avalanche predictions. He explained that a water-dense snowfall that collects on a less-dense snow accumulation below could cause the snow to fall through, which could kick-start an avalanche. 

Snow measurements are also important when determining the condition of snowpack for a winter season. For example, it helps with year-to-year comparisons as well as reservoir levels and spring runoff. 

Jennifer Stark, the meteorologist in charge at the Boulder Weather Service, said the snowfall measurements will help to predict fire weather, drought and river forecasts. 

“That’s primarily what we’re monitoring for — how are we doing as far as percent of normal, what does the runoff potential look like, are we in for critical fire weather conditions because we don’t have the snowpack that we would normally expect?” Stark said as she gave examples.  

Both Wineland and Stark said that the biggest determinant of snowfall is La Niña, a weather pattern caused when colder temperatures come off of the eastern Pacific Ocean. It often means more snowfall for southern Colorado and less snowfall for central to northern Colorado. 

While La Niña may mean less snow fall, Stark said this summer’s rains were good for Summit County’s moisture levels. 

“The precipitation of the summer months was really driven by the southwest monsoon season, and we actually did have a monsoon rainfall, which we’re very, very happy about,” Stark said. “We’re not going into the winter months quite as dry, especially with it being a La Niña winter.”

Wineland also explained this summer’s rains may help to spur spring runoff. He added that a dry summer season, soil is more likely to soak in winter runoff. However, if the soil is moist like it was after this summer’s monsoonal rains, spring runoff continues onto springs, rivers and reservoirs.

Many ski resorts are reporting better early season conditions than recent years, allowing them to open more terrain ahead of schedule than previously anticipated, and long-term forecasts that called for dry conditions have been upended by winter storms and surprise snowfall.

For all of these reasons, Wineland said it’s extremely important to monitor, measure and keep track of snowfall. 

More information about Colorado’s snowpack levels can be found at the Natural Resource Conservation Service Snow Survey Program or at Colorado Division of Water Resources, at DWR.State.CO under Climate Stations.