A strong El Niño already underway has been confirmed by specialists. It could bring relief to the drought-stricken farmers of California.
El Niño occurs when the warm ocean waters in the equatorial areas of the Pacific move east toward South America. This then alters the weather patterns, such as tropical storms shifting eastward.
It is likely to be one of the strongest every recorded, according to forecasters, and should continue through late autumn or early winter. Other forecasters believe it could stretch into next spring.
With it will come more precipitation that normal, but much depends on where the rains fall. The US Climate Prediction Center believes it will be of help to the south-western US which has been blighted to drought for some four years.
The Center said, however, that water temperatures were still lower than 1987 and 1997 when some of the strongest El Niños occurred.
Warmer than average temperatures are expected in Alaska, Canada, and western parts of the US.
Scientists do not know what triggers an El Niño cycle. El Niños are not identical as atmosphere and ocean patterns can vary.
El Niño, a Spanish reference for the Christ child, was originally named El Niño de Navidad by Peruvian fishermen in the 1600s because the phenomenon often started around Christmas. Climate records of El Niño date back millions of years, with evidence of the cycle found in ice cores, deep sea muds, coral, caves and tree rings.
