Island Climate Update 236 - May 2020

El Niño Southern Oscillation (ENSO) neutral conditions continued during April 2020. The Southern Oscillation Index (SOI) was +0.1.

The NINO3.4 Index anomaly (in the central Pacific) for April was +0.54˚C (on the El Niño side of neutral). During April 2020, upper oceanic heat content continued to decrease across the equatorial Pacific. This is the first time in at least a year that heat content was below average in the vicinity of the International Dateline. Heat content was slightly above average in the eastern part of the basin, closer to South America.

Trade winds during April were slightly stronger than normal along the equator. This pattern is expected to continue over the next 1 2 months, most likely leading to continued cooling in the west central Pacific.

In the subsurface ocean, cooler than average temperatures extended across the Pacific below 50m depth and were buffered by a slightly warmer layer above. While there is no immediate indication that these cooler seas will surface, it lends credence to the idea that oceanic La Niña conditions might arrive later in 2020 as some models suggest.

According to the consensus from international models, ENSO neutral conditions are very likely (76% chance) for the May July period. For the August October and November January periods respectively, the probability for ENSO neutral conditions is 50% and 40% with the probability for La Niña increasing to 30% by late 2020.

Download the full report: Island Climate Update - May 2020