Weather data analysis is now uncovering the secrets of El Nino. ENSO events - 'El Nino Southern Oscillation' is now understood better, at least in terms of the data. Predicting these events is still elusive.
As Physicsworld.com describes it:
"El Niño, meaning "the Christ child", is so-called because the first signs of its appearance are marked by a warm current off the coast of Ecuador just after Christmas. These rising sea temperatures are related to a weakening of the trade winds that usually transport warm surface waters to the western margin of the Pacific. During an ENSO phase – which occur every 2–7 years – these warmer waters accumulate in the eastern tropical Pacific.
Individual ENSO episodes can last up to two years and lead to severe flooding in Latin America and droughts in South East Asia. One extreme cycle in 1997–1998 had far-reaching consequences, including extensive fires in the Indonesian rainforests and mudslides in California. Another impact of El Niño is that the accumulated warm water acts to block cold-water currents, which usually transport nutrients from the deep ocean to ecosystems along the Latin American coast. This can have a devastating effect on the fish stocks that form an important part of the economy in countries such as Peru and Colombia. "
Full story at http://physicsworld.com/cws/article/news/47268