Great Lakes winters are trending warmer and the storm systems are wetter, according to research at the University of Michigan
Abby Hutson, assistant research scientist at the Cooperative Institute for Great Lakes Research at the University of Michigan's School for Environment and Sustainability, is an author of a new report published in the journal Geophysical Research Letters.
Hutson looked at six decades' worth of winter weather in the Great Lakes region. That’s a lot of data, so researchers took it a year at a time, looking at the huge storm systems the scientists call midlatitude cyclones.
“If all the storms were smushed together, averaged together for one season, and we looked at each season as time went on, that’s where we saw our statistically significant increasing trends in temperature and moisture,” Hutson said.
That does not mean we’re seeing more snow or more rain in a single year, but the huge systems are carrying more moisture. In the future that could mean more precipitation, likely lake effect snow in the north and more sleet, rain, and drizzle in the south.
Hutson said it also could mean more of those big winter weather variabilities where its freezing one week and in the 40s or 50s the next week, among other big swings.
“You know, sometimes we’re getting a ton of rain. Sometimes it’s pure blizzard coming out of the north. So, when we are able to average them all in one season and looking at the larger numbers, and taking a step back, that’s where we’re able to make sense of these trends.”
These large storm systems are not well understood, but looking at these big data sets do reveal some of the trends noted above.