The prolific flooding that inundated portions of New York’s Hudson Valley and Vermont on Sunday and Monday after about two months’ worth of rain fell in two days wasn’t triggered by a tropical storm or hurricane, but rather by low pressure and a cold front associated with a more typical summertime weather system that encountered a powder keg of atmospheric conditions.
Rainfall that saturated the ground ahead of the storm, double the normal amount of moisture, an atmospheric traffic jam and Vermont’s flood-prone terrain were among the elements that contributed to the catastrophic flooding. On top of that, scientists suspect that human-caused climate change boosted the intensity of the rainfall.
Here are five key ingredients that came together to create a historic flood event.
Ground was already saturated
Plenty of rain had already fallen across the region during the previous month, especially in the two weeks immediately preceding the flooding. Many locations had received 4 to 8 inches of rain since the last week of June, or about 150 to 300 percent of what they normally get during that time.
