Wetter winters may be ahead for parts of the U.S.

New computer model research from the University of Illinois at Chicago (UIC) indicates that wetter winters and extreme weather events will become increasingly common across large portions of the United States.

"Very wet" winters, which are defined in this report as those that rank at least in the top 5 percent historically, would happen as often as once every four years in some regions of the United States.

“We found that, unlike summer and other seasons where projected changes in precipitation is highly uncertain, there will be a robust future intensification of winter precipitation,” said lead author Akintomide Akinsanola. “It will accelerate well past what we have seen in historic data.” (from UIC Today).

The study, utilizing 19 earth climate models, compared projected precipitation at the end of the 21st century (2070-2099) to the most recent period (1985-2014).

The researchers found that there would be a general 2 to 5 percent in U.S. mean winter precipitation per degree of warming by the end of this century. The largest increases in winter precipitation are projected to be over the Northeast and Northwest regions of the U.S.

Six of the seven U.S. regions would experience more frequent "very wet" winters. The one exception was the South Central region, which is predicted to see more extreme "dry" events vs. "wet" events by the end of the 21st century.

The mix of precipitation will also likely change in many areas. Previous studies have projected that as temperatures rise, more precipitation will fall as rain rather than snow, resulting in lower snow depth. This reduced snowpack plus higher rain will stress existing systems, according to the UIC Today report.