NBC Chicago meteorologist Kevin Jeanes explains that after the warmest September in 64 years, Chicagoans might be in for a colder and wetter winter.
Get ready for a wetter, snowier winter, Chicago -- and a colder one, too...maybe.
That's according to the National Oceanic Atmospheric Administration's latest winter weather outlook for 2024-25, which says a "La Niña" winter is expected, which would ultimately result in a "wetter than normal" winter in the Great Lakes, especially in parts of Wisconsin, Illinois and Indiana.
According to Kevin Jeanes, the predictions are a far cry from the Chicago winter of 2023-24 -- an El Niño winter -- which wound up to be the fourth warmest winter on record.
Wetter winter
The winter precipitation outlook for the Chicago area is expected to be above average, Jeanes said.
"That would be beneficial because we have been in a sort of moderate drought," Jeanes said. "We need that."
According to the National Weather Service, 18.5 inches of snow were recorded during 2023-24 meteorological winter, which was 11.1 inches below normal.
Local
For 2024-25, the big question will be whether or not temperatures will cause that precipitation to fall in the form of rain or snow
Will it be colder?
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It depends.
It could be, Jeanes said, but that's only compared to such warm temperatures recorded in 2023-24.
"It was so warm last winter," Jeanes said. "If temperatures are closer to average, its going to feel colder than what we had last year."
According to Jeanes, NOAA predicts "equal chances" of temperatures being above or below average.
"Not sure it's going to be a colder winter," Jeanes said. "There are equal chances it may be above average, or may be below average."
Across the Northwest however, a much colder winter is expected, Jeanes noted.
La Niña winter predictions for Chicago
According to the NOAA, they’ve implemented a series of upgrades to forecasting tools, including an experimental model called the “Probabilistic Winter Storm Severity Index.” That data was used to help with this year's projections after it was first implemented in late 2023, according to officials.
According to the University of Illinois, stronger La Niña patterns can produce winters that are typically “warmer and wetter than average,” with more snow and winter storms during those seasons. A La Niña also typically leads to cooler springs if the pattern persists.
In a La Niña event, trade winds are stronger than usual, and they push warm water away from the Americas and toward Asia. This allows a process known as “upwelling,” which brings cold water to the ocean’s surface.
Those cold waters then cause the Polar Jetstream further north, leading to drought in the southern United States and more precipitation in the Midwest and in the Pacific Northwest.
According to the latest updates from the Climate Prediction Center, La Niña is favored to emerge between the months of September and November, and is expected to persist at least through the winter months.
