Long-term projections from the National Oceanic and Atmospheric Administration and National Weather Service have already suggested that the Midwest could potentially see a snowier-than-average winter, but could La Niña increase those odds even more?
La Niña, an oceanic and atmospheric phenomenon that causes significant weather changes around the world, could once again occur for a third-straight winter in the Northern Hemisphere, according to the latest NOAA projections, and that could mean some big changes for Illinois residents.
According to the National Oceanic and Atmospheric Administration, during a La Niña event, trade winds in the Pacific Ocean are stronger than usual, pushing more warm water toward Asia. Off the west coast of the United States, a process called “upwelling” increases, bringing cold and nutrient-rich water to the surface.
That cold water then pushes the jet stream northward, leading to stronger droughts in the southern United States and more precipitation in the Pacific Northwest and in the Midwest.
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More importantly for Midwest residents, the change in jet stream also allows cold air to flood into the region, making winter temperatures colder-than-normal.
According to the latest forecasts released by the NOAA, La Niña is expected to continue through the winter months, with a 91% chance of the event occurring through November and a 54% chance of those trade winds remaining accelerated through March of 2023.
If that occurs, the Midwest could potentially see a colder, wetter winter, but forecasts remain unclear on that front, as the NOAA says there is still “large uncertainty” for the long-term outlook.
The NOAA’s long-range precipitation predictions are calling for a higher-than-average amount of precipitation in the Midwest during meteorological winter, which runs from December through February.
That pattern is expected to continue through the early part of the spring, according to officials.
After above-average temperatures during the fall, NOAA long-term forecasts indicate average temperatures during the winter.