La Nina weather predictions for Chicago this winter are trending towards volatile temperature changes and more precipitation, which may lead to flooding.
For the second year running, La Nina returns to the northern hemisphere bringing volatile weather patterns for parts of the U.S. and Canada. La Nina is not a storm, but a weather pattern that occurs when there are cooler than average water temperatures near the equator west of South America in the eastern Pacific Ocean. While the norm is for La Nina to occur every three to five years, sometimes it can occur in successive years. The effects of La Nina are generally most felt during the winter months when there is a strong jet stream over the U.S. and parts of Canada.
The Midwest region including Chicago, needs to watch out for heavy rains and flooding. However, estimates suggest only a 34 percent probability that the Chicago region will suffer from significantly greater amounts of precipitation this winter. Chicago also appears to trend toward above-average temperatures. While snow is difficult to predict with great accuracy, experts believe that La Niña could bring increased snowfall over various areas of the upper U.S. including the Midwest Great Lakes region.
If last year’s La Nina event is repeated in Chicago, we could have both extremely war and extremely cold temperatures with large snowstorms which is not an unusual La Niña pattern for Chicago. Last year, the most extreme winter weather occurred from the last week of January to the third week of February, when 34.1 inches of snow was recorded at O’Hare International Airport and 41.3 inches near Midway Airport.
Forecasters emphasize that while La Nina weather patterns result in predictable outcomes in different areas of the U.S. and Canada, the actual weather that occurs is a matter of probability not certainty. Each event is different so until it is occurring forecasters can’t be certain exactly what will happen weatherwise in different areas or how long the event will go on for.
So, Chicagoans, if you are curious about whether La Niña will affect the area this winter, NOAA scientists offer this answer:
"Maybe. Probably. Probably not. The answer depends on many factors, including where you live, how strong the event continues to be, and other climate patterns that develop and influence the seasonal outcome."
If you’re looking for a comparison to a standard trusted source of long range weather prediction, the Farmers' Almanac predicts that this year Chicago and the surrounding area will see an "icky, flaky" and cold winter. Time to take stock of your winter wardrobe and outer wear, Chicago!