La Niña Confirmed For A Second Year, Northern States Brace For Wet Weather

WISCONSIN — The National Ocean and Atmospheric Administration announced Thursday that La Niña has developed and will continue for a second year.

The phenomenon occurs when water near the equator in the Pacific Ocean is cooler than average, and its effects on the climate in North America are more evident in the winter.

Strong La Niña winters typically bring colder, wetter, snowier weather to northern states such as Wisconsin, while the South tends to see warmer and drier conditions.

La Niña will last through early spring, climate forecasters said. There is an 87 percent chance of La Niña from December through February.

It’s back! Today, NOAA declared that #LaNina conditions have emerged for the second winter in a row. Read more at https://t.co/d6txR1BOO5 pic.twitter.com/i0l8aJTlVJ
— National Weather Service (@NWS) October 14, 2021

Two La Niñas aren't exactly the same, but they share some common themes. The administration explains it this way.

"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," associate scientist Emily Becker said in a blog post. "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."

It was a factor in the stronger hurricane season in the Atlantic, Climate Prediction Center deputy director Mike Halpert said.

Previous La Niñas occurred between the winter of 2020-2021 and 2017-2018, climate forecasters said. El Niño developed in 2018-2019.

Milwaukee declared a snow emergency in December after 9 inches of snow dropped across southern Wisconsin, the Milwaukee Journal Sentinel reported.

Lucas Combos, Patch staff, contributed to this article.

See Also: Cold, Wet Winter Hits Wisconsin Early This Year: Forecasters