Sorry to be a buzzkill, but skiers and snowboarders who were spoiled last winter and spring with bountiful snow probably won’t be as fortunate this season.
One of the factors that influences our winter weather suggests we could have slightly below-normal snow in the mountains this year, said Colorado State Climatologist Russ Schumacher. That’s because neither of the phenomenons known as El Niño and La Niña are at play.
There are many factors that influence our mountain snowfall, but a big one is the swing in Pacific Ocean temperatures that produces El Niño and La Niña. El Niño occurs when surface temperatures in the equatorial Pacific are above-average, usually resulting in wet and cool conditions across the southern tier of states, with good snow for Colorado’s southern resorts. La Niña years, when those ocean temperatures are cooler than normal, tend to produce dry, warm conditions in the south, while the Pacific Northwest is wet and cool. That can favor our northern resorts.
Why the science lesson? Because the U.S. Climate Prediction Center says readings in the equatorial Pacific are near average, producing “neutral” conditions in the El Niño-La Niña cycle. And that may not be good for our snowfall outlook.
“It’s probably a safe bet that we’re not going to see another epic snow season like we saw last year,” said Schumacher, director of the Colorado Climate Center at Colorado State University. “Most locations in the mountains tend to be on average a little bit lower than normal snowfall during neutral conditions. There’s a handful of neutral years where you get a lot of snow and a handful where it’s quite dry. In the record that we have, there is more of those dry years than the snowy years in the neutral phase.”
Neutral years also make it harder to predict our winter weather than when El Niño or La Niña influencing it.
“That takes away one of our tools for making these seasonal outlooks,” Schumacher said. “The connection between El Niño and snow in the mountains here in Colorado is not super strong anyway. It’s something we can use, but during neutral conditions, what ends up playing out is often a little bit less certain.”
The Climate Prediction Center is predicting neutral conditions will persist through next spring.
“There’s no sign that we’re going into La Nina, so I’m hopeful that we don’t have a repeat of the terrible snow drought of two winters ago,” Schumacher said. “That was La Nina conditions, which, especially for the southern mountains, historically tends to be very dry.”
Climatologists are still trying to figure out why Colorado had such great snow last winter, extending well into spring.
“It was a big year pretty much everywhere in Colorado, as well as in California and a lot of other places,” Schumacher said. “Usually, when we think of atmospheric rivers, we think about California, the Sierra Nevada. What ended up happening, especially in February and March, we had a series of atmospheric rivers bringing moisture from the Pacific, and there was just so much of it that a lot of it ended up making it into western Colorado as well. We had storm after storm, especially in the San Juans and into the central mountains. February and March were huge months. April and May stayed cool and continued snowy. Steamboat had snow on June 22, the latest they ever had measurable snow in town there.”