Town flooded by less than an inch of rain
Living through a drought is hard, but abrupt interruptions droughts can lead to their own problems as well. The dry, hardened earth can be so compacted it can’t sponge up water when it arrives, leading to flash-flooding. This is what happened recently in Arica, Chile, when the driest place on earth received the equivalent of 14 years worth of rain in a single day.
Rainfall is relative
That’s not to say that they got as much rain as Boston might get in a single large storm. But the 0.96 inches of rain delivered last week was dangerously above the usual 0.07 inches the Atacama desert normally gets in a whole year. As a result, the Copiapo River (which is normally a dry riverbed), immediately overflowed, leading to nine deaths.
The relatively-torrential rainfall is probably due to the current El Nino event in the Pacific Ocean. Warm ocean temperatures and a cold front of air hitting the Andes Mountains combined to bring extra moisture to the desert that once went 14 years without any rain at all.
Source: 14 years worth of rain in one day triggers deadly flooding in driest place on Earth by Angela Fritz, The Washington Post