Clouds developing over a wide region under broader atmospheric conditions. While rainfall may appear uneven at the local scale, it is often influenced by larger-scale patterns that transport moisture and shape where and when precipitation occurs. Credit: Jie Chen. A new study led by the University of Oxford and ETH Zurich reveals that a key part of the climate system—the large-scale wind patterns that determine where rain falls—can be underestimated by current climate models, helping explain why forecasts of regional rainfall remain uncertain. Ultimately, this insight could enable more confident projections of future rainfall patterns, supporting better preparation for floods and droughts. The findings, published in Nature , are based on an analysis of winter rainfall patterns across the Northern Hemisphere from 1950 to 2022.…