The Exceedingly Low Odds of Vermont’s Flooding Disaster

The rainfall that hit parts of Vermont on Monday had less than a 1-in-100 chance of occurring in any given year, according to federal flood data. And yet, for some residents, it brought a sense of déjà vu -- it rivaled the devastation of another so-called 100-year storm, Hurricane Irene, from a dozen years ago.

The chances of two such deluges hitting the Green Mountain State in such a short span? Just 0.6 percent, said Art DeGaetano, a professor at Cornell University and director of the National Oceanic and Atmospheric Administration’s Northeast Regional Climate Center.

There was more than chance at play, though, as the planet’s steady warming increases how much moisture the air can hold. Climate scientists have for decades predicted that would translate to extreme bursts of rain in places like New England.