Ann Arbor Times

The University of Michigan has released new research indicating that winter storms in the Great Lakes region are likely to become warmer and rainier in the future. The study, titled "Historical Trends in Cold-Season Mid-Latitude Cyclones in the Great Lakes Region," analyzed decades of data on midlatitude cyclones, also known as extratropical cyclones.

These storm systems are significant drivers of winter weather in the area, but their connection to the region's fluctuating climate patterns has been underexplored, according to U-M researcher Ayumi Fujisaki-Manome. "We’ve been noticing a lot of changes in wintertime climate. Sometimes there’s warming, other times you have extreme cold," said Fujisaki-Manome, an associate research scientist at the Cooperative Institute for Great Lakes Research (CIGLR). She added that it was natural to question the impact of these cyclones on observed climatic changes and fluctuations.

The findings were published in Geophysical Research Letters. The analysis highlighted that while the day-to-day weather remains highly variable, a significant trend has emerged: air masses carried by these storms are warming faster than the general climate warming level in the Great Lakes region. Additionally, these storms are carrying more moisture, which is more likely to fall as rain in southern parts of the region.

"The year-to-year variability—the strength of the storms, their location, their frequency—is wild. It’s all over the place," said Abby Hutson, corresponding author of the report and assistant research scientist at CIGLR. "But according to historical data sets, the midlatitude storms rolling through the area are getting warmer and wetter, and their tracks are shifting northward."

This shift implies that storm centers with high winds and a mix of snow and rain will become more common in northern areas, potentially creating hazardous conditions for travel and shipping. It also increases the likelihood that winters will feature more liquid water from rain rather than snow or ice melt, leading to higher risks of flooding, particularly along coastal regions.

The study tracked average characteristics of winter cyclones traveling through Michigan, Wisconsin, Minnesota, Illinois, Indiana, Ohio, Pennsylvania, New York and Ontario from 1959 to 2021. While this allowed researchers to identify trends within these cyclones over time, Hutson and Fujisaki-Manome emphasized that further work is needed to understand how these average trends affect individual weather events.

Although an increase in storm moisture was noted over time, no corresponding rise in average precipitation as either rain or snow was found. "On average we’re not seeing that," Hutson explained. "But our potential for extreme precipitation is certainly going up."

Ryan Glassman contributed to this project as an undergraduate research fellow from Valparaiso University. The study received funding from the National Oceanic and Atmospheric Administration.