“I believe the Midwest is going to enter a state of neutrality — neither extremely wet nor extremely dry — this summer rather than experiencing cooler weather,” says Tony Lupo, professor and chair of the Department of Soil, Environmental and Atmospheric Sciences at MU. “While the La Niña weather pattern has faded, it hasn’t been fully replaced by the much cooler and wetter weather pattern of El Niño.”
La Niña is a weather pattern that directs the jet stream from the Pacific on a northeastern path over Canada. Rain-producing storms follow the jet stream, leaving states in the central and south-central U.S. dry.
El Niño is a weather pattern that not only brings moisture to the Midwest, but also brings cooler and wetter weather. The weather pattern helps steer the jet stream toward the Midwest, bringing cooler temperatures from the Pacific Ocean. While La Niña has faded, the majority of the Midwestern population can’t expect to see a huge increase in precipitation this summer, Lupo says.
“This state of neutrality will bring more moisture to much of the Midwest, but at below-normal levels,” Lupo says. “A late summer pickup in normal rain will be too late for much of the growing season.”
Even if a neutral or El Niño weather pattern cools the warmer weather throughout the Midwest, the dry soil left from multiple years of drought will result in higher than average summer temperatures.
“Soil moisture influences air temperature,” Lupo says. “High soil moisture produces high evaporation which produces evaporative cooling. Without this cooling, daytime temperatures could be as much as 10 F higher than average.”
This combination of high temperatures and few rain showers means farmers should prepare for another tough summer.
“This drought we have had for the past two years has left some of the soil in prime growing areas dry to a depth of at least 5 feet,” says Randall Miles, associate professor of soil science at MU. “The slight increase of rain won’t help this summer either because it will take a consistent period of rain for the soil to replenish fully.”
La Niña and El Niño are regularly occurring climatic features, often alternating every few years.