How La Niña Is Expected To Impact Colorado

COLORADO — North America is poised to get another La Niña winter — a weather phenomenon that occurs when the water near the equator of the Pacific Ocean is cooler than average. La Niña's effects on the climate are most pronounced in the winter months.

The weather event is expected to bring dry, windy weather to Colorado — particularly to our state's southern regions. Denver's metro area saw record-breaking snowfall last season — which was also a La Niña winter — but this year average snowfall is expected in the metro, according to predictions by the National Oceanic and Atmospheric Administration. Colorado's mountains, however, could see higher-than-average snowfall — a boon for skiers who hit a lot of icy slopes last season.

If the uncertainty is too much to bear, fear not: NOAA is set to share its official winter predictions on Oct. 21, providing a final, comprehensive overview of what forecasters expect for the colder months.

Climatologists with the agency began spreading the word for a potential "double-dip" La Niña back in July, and forecasts since have only strengthened. On Thursday, NOAA's Climate Prediction Center confirmed La Niña's highly-anticipated arrival and predicted it would last into next spring.

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Nationally, strong La Niña winters typically bring colder, wetter, snowier weather to the Pacific Northwest and other northern states, while the South tends to see warmer and drier conditions.

Having consecutive La Niña winters is far from uncommon, and NOAA notes the phenomenon has earned "frequent-flier" status recently, having been present in 2016, 2017, 2020, and now, 2021.

"Our scientists have been tracking the potential development of a La Niña since this summer, and it was a factor in the above-normal hurricane season forecast, which we have seen unfold," said Mike Halpert, the center's deputy director. "La Niña also influences weather across the country during the winter, and it will influence our upcoming temperature and precipitation outlooks."

While no two La Niñas are exactly the same, they do share a few things in common.

NOAA explains:

"We've already seen one likely effect of La Niña this year—a more active Atlantic hurricane season, with nearly twice as many storms as average so far this year. But the most substantial La Niña effect on North American rain, snow, and temperature happens during winter. In summary, La Niña winters tend to be drier and warmer across the southern third of the U.S., and cooler in the northern U.S. and Canada. The Pacific Northwest, the Tennessee/Ohio Valleys, and parts of the Midwest tend to see more rain and snow than average."

Here is a look at the differences in snowfall patterns during weak and strong La Niña years:

Learn more about La Niña's arrival on NOAA's Climate Blog.