50-60% chance of El Niño later in 2017
2017-05-08 (IPMA)
There is a 50-60% chance of an El Niño event forming in middle to late 2017, according to a new Update from the World Meteorological Organization.
The El Niño/Southern Oscillation (ENSO) is a naturally occurring phenomenon involving fluctuating ocean temperatures in the central and eastern equatorial Pacific, coupled with changes in the atmosphere. It has a major influence on weather patterns in many parts of the world and has a warming impact on global air temperatures.
Following borderline weak La Niña/cool-neutral conditions during the second half of 2016, sea surface temperatures and most atmospheric fields returned to more ENSO-neutral levels in January 2017 that continued to the present.
However, sea surface temperatures in the far eastern tropical Pacific Ocean increased to 2.0° Celsius or more above average during February and March, creating very heavy rainfall and a trade wind collapse from the Galapagos Islands to the coasts of Ecuador and Peru. This localized warming – known in Peru as a “coastal El Niño” - is different from the more broadly known El Niño warming pattern, but its impacts on the affected areas were just as big.
Many of the climate models surveyed indicate that basin-wide neutral conditions will persist through to June 2017. The subsequent development of an El Niño during the second half of 2017 is more likely than the continuation of neutral conditions. The emergence of La Niña appears very unlikely, according to the Update, which is a consensus-based product, based on contributions from leading centres around the world that monitor and predict this phenomenon, and expert assessment of the results of climate models.
It should be kept in mind that predictions of ENSO made before May or June for the second half of the year typically have less certainty than outlooks made later in the year.
