Corn Belt groundwater and irrigation boost thunderstorm complexes by 24–35%, simulations show

An international team of researchers has illustrated how intense thunderstorm complexes over the U.S. Corn Belt are augmented by moisture rising from the region’s fertile soils and subsurface sources. These findings pave the way for enhanced weather forecasts for this vital agricultural area while also providing scientists with critical insights into refining computer models that contribute to the understanding of atmospheric dynamics.

The study, spearheaded by scientists at the U.S. National Science Foundation National Center for Atmospheric Research (NSF NCAR), concentrates on mesoscale convective systems (MCSs). These systems, which are composed of thunderstorms that extend over 60 miles and can last for several hours, exhibit increased frequency due to natural reservoirs of shallow groundwater combined with irrigation practices and the extensive agricultural landscape of the Corn Belt. The research indicates that these factors boost the occurrence of such storm systems by 24–35% and extend their duration by approximately 10%.

MCSs play a vital role in the Corn Belt’s weather pattern, accounting for about 40–60% of precipitation during the growing season. While these powerful storms are essential for delivering moisture to a region responsible for over a third of the global corn production, they can also result in significant hazards, such as flooding, hail, strong winds, and tornadoes.

"Our findings present a comprehensive perspective on how interactions between groundwater, crops, and irrigation influence the local atmosphere, subsequently enhancing thunderstorms," stated Zhe Zhang, an NSF NCAR scientist and lead author. "This information is crucial for improving severe weather forecasts in a major agricultural sector and offers a foundation for long-term storm prediction models that could extend weeks or even months ahead."

Zhang and his team utilized advanced computational simulations along with a specialized algorithm to uncover the processes driving thunderstorms in the region. The Corn Belt, which spans a dozen states from Ohio in the east to Nebraska in the west, served as the focal point of their analysis.

The research is detailed in the journal Communications Earth & Environment. This collaborative effort included co-authors from the Institute for Atmospheric and Climate Science (ETH Zürich) in Switzerland, the Universidade de Santiago de Compostela in Galicia, Spain, and the Hong Kong University of Science and Technology.

Land use and the weather

Prior studies have indicated that the Corn Belt has experienced increased humidity and rainfall, yet the underlying reasons for this change have only recently been discerned through advanced computational modeling techniques.

Zhang previously examined the impact of extensive land-use changes and irrigation in the U.S. Corn Belt, alongside the influence of shallow groundwater remnants from Ice Age glaciers, on local precipitation trends. Employing a unique algorithm to track water vapor dynamics within simulation models, he and his team demonstrated the role of groundwater in contributing moisture to the surface and how crops and irrigation contribute to atmospheric moisture.

In this more recent study, Zhang and several co-authors refocused on the Corn Belt to investigate the effects of groundwater and agricultural practices on MCSs.

The scientists utilized a dual set of sophisticated NSF NCAR-based computer models to replicate storm conditions across the Corn Belt during the growing season, which spans from April to August. To gain a clearer understanding of how land surface conditions affect the atmosphere, they conducted two scenarios: one that included the effects of groundwater, crop growth, and irrigation, and another that excluded these components.

The simulations were processed at the NSF NCAR–Wyoming Supercomputing Center. A previously used algorithm was implemented to trace water vapor movements in the simulations.

Upon comparing the simulated outputs to actual weather patterns documented in the Corn Belt over three years—2010 (wet), 2011 (normal), and 2012 (dry)—it was evident that only simulations factoring in groundwater, crops, and irrigation accurately replicated real-world storm conditions, consistent with data from rain gauges and satellite observations. The algorithm revealed how groundwater and agricultural activities amplified water vapor levels, bolstering updrafts, enhancing atmospheric instability, and generating conditions conducive to more intense and longer-lasting MCSs.

Zhang emphasized that this research presents a valuable perspective on the Earth system, aiming to refine computer models further. Whereas many studies primarily examine the horizontal movement of weather patterns, this study highlights the vertical dynamics of water vapor from subterranean sources to the upper atmosphere.

Such exploration, combined with Zhang's earlier investigations into local precipitation mechanisms, illuminates the relative impacts of agricultural activities and other factors—such as moisture-laden air from the Gulf and groundwater extraction during varying climatic conditions—on rainfall in the Corn Belt. Understanding the nuances of these influences, which fluctuate yearly, can aid in shaping agricultural strategies and optimizing water resource management.

"It is crucial to enhance our understanding of how land use changes influence local weather, particularly in a highly agricultural zone that is essential for our food supply," Zhang remarked. "Our findings are aimed at informing the next generation of models, as well as guiding water management practices and the agricultural community."

Publication details

Zhe Zhang et al, Moisture from US Corn Belt fuels more intense convective storms, Communications Earth & Environment (2025). DOI: 10.1038/s43247-025-03089-0