One of the reasons why we’re getting more heavy rains and more devastating floods these past decades in the United States is because the air temperature has been getting warmer. As the air gets warmer it holds more moisture, and when it meets with cool air it causes heavier precipitation. An example of the same principle can be observed when we boil water: the moisture condenses into very small drops of liquid floating in the air and when the drops get bigger, they precipitate.
According to the article, historically large storms that used to occur every 20 years in the Midwest and Northeast will be expected to occur every 4 to 6 years by the end of the 21st century. The article featured a video by Dr. Amanda Staudt, a climate scientist for the National Wildlife Federation. I have to admit that I agree 100% with Dr. Amanda Staudt because records show that these events have already become more frequent over time.