But on Tuesday, heavy thunderstorms delivered 0.96 inches of rain in one day to parts of the Atacama Desert, which led the Copiapo River to swell far beyond its banks — though it typically doesn’t have any water in it at all.
It seems likely that the rainfall was enhanced by the current El Nino event, which increases water temperature off the coast of Chile. “The heavy rains were from a cold front that hit the Andes Mountains,” writes Jeff Masters at Weather Underground. “Unusually warm ocean temperatures approximately [1.8 degrees] above average off of the coast meant that high amounts of water vapor were available to fuel the storm and generate exceptionally heavy rains.”
At least nine people have died in the floods, and Chile declared a state of emergency on Wednesday, the AP reports:
The flooding is “the worst rain disaster to fall on the north in 80 years,” Deputy Interior Minister Mahmud Aleuy said Thursday.TV images showed brown, muddy waters flooding the streets and reaching a hospital in Copiapo city. Some people living along the river had to be rescued by helicopter because roads were blocked by water and mud. TV footage showed several families waiting on the roofs of their homes, including a man who had punched a hole through his roof to save his toddler.