No snow and 60 in December? It's a La Niña thing

Last year on Dec. 8, the Colorado Springs area was in a deep freeze.

Most of the city was blanketed in about 5 inches of snow, winds gusted above 30 mph and the single-digit temperatures kept the few brave souls who ventured out shivering in the icy blasts.

This year, it’s a different story. The temperature Wednesday was expected to be near the record for the day of 65 degrees set in 1970 and the only blanket of snow in sight was above tree line on Pikes Peak.

It’s all in the difference between El Niño and La Niña, the opposite extremes in the naturally occurring cooling and warming of the equatorial Pacific Ocean off South America’s west coast. Last year was an El Niño, while this year La Niña is in ascendance.

According to the National Oceanic and Atmospheric Administration, Colorado is caught between those extremes:

El Niño, the warming of the tropical waters, typically produces drier and warmer winters in the Northwest and Northern Rockies. El Niño typically brings early and heavy snow to the Southwest and colder winters.

La Niña, the cooling of the tropical Pacific, causes mostly the opposite effects of El Niño. La Niña causes above average precipitation across the northern Midwest, the Northern Rockies, Northern California, and in the Pacific Northwest. Meanwhile, there is below average precipitation in the Southwest and Southeast.

La Niña’s effects tends to be the more predictable of the two, and this year has been no exception, said Nolan Doesken, Colorado’s state climatologist.

“Warmer than average has been dominating our conditions since the fall,” Doesken said. “We’re still in the first few months, so we don’t know how long it will persist.”

Doesken said at this time last year, the Pacific was in the tail end of an El Niño cycle, causing temperatures in Colorado Springs in December to be about 6 degrees below normal. This year, because of La Niña, temperatures this month have been about 7 degrees higher than normal, he said.

Whereas El Niño brought early snowstorms to the region, La Niña has kept rain and snow away. Colorado Springs set a record for days without snow this fall and the past three months have been off nearly an inch and a half from normal precipitation.

It’s not all bad news for the state, though, because Doesken doesn’t expect the dry conditions here to affect the mountain snowpack that determines whether Colorado’s reservoirs are full.

“Most of the mountains have been getting good snow,” he said, noting heavy snows that have blasted ski areas in Summit County and in the north near Steamboat Springs. “So it hasn’t been a grave concern yet.”