Authors: Trent Ford*, Illinois State Water Survey, Liang Chen, Illinois State Water Survey, Justin T Schoof, Southern Illinois University-Carbondale
Topics: Climatology and Meteorology, Hazards, Risks, and Disasters
Keywords: extreme precipitation, climate change, Midwest
Session Type: Virtual Paper
Start / End Time: 9:35 AM / 10:50 AM
Room: Virtual 40
Presentation File: No File Uploaded
Monthly to seasonal precipitation extremes, both flood and drought, are important components of regional climates worldwide, and are the subjects of numerous investigations. However, the transition between precipitation extremes, and associated impacts are the subject of far fewer studies. Recent such events in the Midwest region of the United States, such as the 2011-12 flood to drought transition in the upper Mississippi River Basin and the 2019 flood to drought transition experienced in parts of Kentucky, Ohio, Indiana, and Illinois in 2019 have sparked concerns of rapid transitions between precipitation extremes and compounded economic and environmental impacts. In response to these concerns, this study focuses on characterizing variability and change in Midwest precipitation extremes and transitions between extremes over the last 70 years. Overall we find that the Midwest as a region has gotten wetter over the last seven decades, and that in general the annual maximum and median wetness, defined using the Standardized Precipitation Index (SPI), have increased at a larger magnitude than the annual minimum. We find large areas of the southern Midwest have experienced a significant increase in the annual SPI range and associated magnitude of transition between annual maximum and minimum SPI. We additionally find wet to dry transitions between extremes have largely increased in speed (i.e., less time between extremes), while long-term changes in transition frequency are more regional within the Midwest.