For hundreds of years, scientists have known where to look for the hot water that signals the arrival of El Niño. The western coast of South America, particularly the coasts of Peru and Equador, are El Niño's favorite beaches. Every few years, warmer than usual water splashes onto the beaches, bringing with it the hot air that feeds rainstorms.

In the animation above, the white lines represent the trade winds. The red areas represent the warm water. When the trade winds weaken, the warm water moves eastward. The map is not to scale. The landforms are abstracted for illustrative purposes. The map is not intended to represent real geographic latitudes or longitudes.

When El Niño is not visiting, the warm surface water along the coast of South America is normally blown away, westward toward Asia, by the trade winds. It's a long way to go, but the warm water arrives and gathers near Indonesia, actually causing the Pacific Ocean to be deeper there. Every few years, however, the trade winds stop blowing strongly, allowing the excess warm water near Indonesia to drift back toward South America, evening out the Ocean's depth.

Why do the trade winds stop blowing strongly? Scientists are not sure. The latest scientific instruments that are recording the 1997-1998 El Niño data may suggest some answers.

The extra hot water near South America creates extra hot air, causing extra rain. Meanwhile, on the Indonesian side, the lack of warm water means a lack of warm air, which means no rain. Serious drought conditions result in that region of the world.

So scientists know where to look for the hot water, but we're still not entirely sure where to look for the effects of El Niño. Flooding in Peru and Equador is surely the result of El Niño. Drought in Indonesia is another result. But how about mild winters in Canada? Or excess rain in California? As scientists learn more about El Niño, it looks more as if El Niño's coasts are everywhere.

The following resources offer excellent explorations of the global impact of El Niño.

El Niño: Online Meteorology Guide

This module from the University of Illinois offers a thorough explanation of the location of El Niño.

The Wrath of El Niño

From PBS...an exploration of the global consequences of El Niño.

El Niño and California Precipitation

Preparation for El Niño

These two resources relate specifically to the effects of El Niño in California.