Upwelling is a process by which deep, colder, higher-nutrient waters are brought to the sea surface. In the tropics, an indicator that an upwelling event has occurred is lowering of sea surface temperatures (SSTs) to 25°–27°C from a mean of ~28°C. Based on more than one year of in situ data, we observed an unusual extreme upwelling event (EUE) when the near-surface temperature (NST) dropped by 10°C within one hour during the s...