The National Oceanic and Atmospheric Administration released their winter outlook for the winter season nationally. Their main takeaway for Wisconsin is above-average expected precipitation. The NOAA pointed toward a later-developing and weaker La Niña, which drives much of their modeling.
La Niña is an extended climate pattern that increases winds which push warm water off the coast of South America toward Asia. This leads to more cold water moving toward the surface on the Pacific coast and driving weather patterns across the United States. The colder ocean conditions push the polar jet stream further north across the U.S. and Canada and typically lead to colder and wetter conditions across the northern U.S.
A weaker La Niña creates less certainty in the NOAA’s forecast and could lead to more variation in the predicted conditions. The prediction for temperature is an even chance for either warmer or cooler than average for Wisconsin and much of the Midwest. After Madison’s warmest winter on record, we may see a brief return to the winters of yesteryear. But, it may also continue the worrying trend of wetter winters and drier summers for Wisconsin as a whole.
Madison averaged 51.8 inches of snowfall from 1991-2020, with the 2023-2024 winter coming in at 43.3 inches. The NOAA believes increased precipitations will improve drought conditions in Madison and southeastern Wisconsin, which persisted for much of the summer.
More precipitation does not necessarily mean more snow. In the winter of 2022-23, during the last weak La Niña winter for the U.S., Milwaukee saw only 26.4 inches of snow, 10.7 inches below the average from 1990-2020. But, the equivalent precipitation during the winter was 8.61 inches, 3.18 inches above average. This is because snowfall contains less water than rainfall and precipitation is measured using rainfall and a ratio of snowfall.
Madison received 71.8 inches of snow during 2022-23, showing the high variability of snowfall as a result of local weather. The NOAA predictions are regional and do not account for local weather events, nor intend to predict them.
