According to Tony Barnston at the International Research Institute for Climate and Society, El Niño conditions are now evolving in the tropical Pacific. El Niño is the name given to sustained sea surface temperature (SST) anomalies greater than 0.5°C across the central tropical Pacific Ocean; it is the warm phase of the El Niño Southern Oscillation (ENSO), a global coupled ocean-atmosphere phenomenon involving the tropical eastern and western Pacific Ocean.
El Niño also has important consequences for weather around the globe. Because El Niño’s warm pool feeds thunderstorms, for instance, it frequently leads to increased rainfall across the central and eastern Pacific Ocean. At the same time, El Niño episodes are usually accompanied by a decrease in the strength of the Pacific trade winds and a reduction in rainfall over eastern and northern Australia. El Niño events are also associated with drier and hotter conditions in Southeast Asia and Northern Australia, a milder hurricane season in the Caribbean and North Atlantic, and warmer winters in the United States northern plains and Midwestern states.
But while El Niño has been linked to an increase in natural disasters in the public imagination, global climate-related socioeconomic losses are not necessarily larger during El Niño years. Rather, strong ENSO events lead to greater predictability of the climate and, potentially, to socioeconomic outcomes. As a result, effective use of climate forecasts could mitigate negative impacts and transform El Niño years into the least costly in terms of life and property.
It’s still too early to say, however, whether this year will be one of the extremes. Models currently indicate a 56% probability that El Niño conditions will continue for the June-July-August season in progress. Moving forward, probabilities increase to 60-65% until the end of the year after which time they drop back below 50%. Because the climate is a dynamic system, however, these predictions may change. Keep up to date by checking out the IRI Technical ENSO Update, found here.