Sunny-day flooding, also known as high tide flooding, is happening more often due to rising sea levels.
By 2050, high tide flooding on a national scale is expected to be between 45 and 70 days per year on average. Major and moderate high tide flood events will occur as frequently as moderate and minor high tide flood events occur today. The Northeast Atlantic, Western Gulf, Southeast Atlantic and Eastern Gulf coasts may see some of the highest levels of high tide flooding if the planet continues to get warmer.
The U.S. annual high tide flooding frequency is more than twice that in the year 2000 due to rising relative sea levels.
Higher global temperatures increase the chances of higher sea level by the end of the century and beyond.
National Oceanic and Atmospheric Administration: Flooding on a Sunny Day? Here's How. (1-Minute Watch)