The National Oceanic and Atmospheric Administration has released its winter weather outlook for 2024-2025, and Chicagoans will likely need to get boots and shovels ready.

That’s because the dominant weather pattern across the Great Lakes is likely to be strengthened by a “slowly developing” La Niña event in the Pacific Ocean, NOAA officials said.

That would ultimately result in a “wetter than normal” winter in the Great Lakes, especially parts of Wisconsin, Illinois and Indiana.

This La Niña pattern is expected to strengthen during meteorological winter, which runs from December 1 to February 28, and will likely send the prevailing Jetstream further north, causing more storm systems to impact the Chicago area.

The big question will be whether temperatures will cause precipitation to fall in the form of rain or snow. Right now, NOAA says there is an “equal chance” of above or below average temperatures, which could obviously have a significant impact on whether it’s rain or snow that falls in the region.

According to NOAA, they have implemented a series of upgrades to forecast 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 continues.

During a La Niña event, the trade winds are stronger than normal and push warm water away from the Americas and toward Asia. This enables a process known as ‘upwelling’, which brings cold water to the ocean’s surface.

That cold water then triggers the Polar Jetstream further north, leading to drought in the southern United States and increased precipitation in the Midwest and Pacific Northwest.

According to the latest updates from the Climate Prediction Center, La Niña is favored to develop between the months of September and November, and is expected to last at least through the winter months.