Island Climate Update 233 - February 2020

El Niño-Southern Oscillation (ENSO) neutral conditions continued during January 2020. The Southern Oscillation Index (SOI) was +0.2, the first positive monthly value since December 2018.

The NINO3.4 Index anomaly (in the central Pacific) for January was +0.45 ̊C, slightly warmer than December. The warmest ocean waters with respect to average continued to be located in the west- central Pacific. Upper-oceanic heat content remained above average near the Dateline, as it has for much of the past year. Overall, this was indicative of oceanic ENSO neutral conditions that leaned toward El Niño Modoki.

Across the global tropics, rainfall patterns indicated a decay of the strongly positive Indian Ocean Dipole pattern during January, with abundant rainfall and convection north of Australia. Rainfall and convection was also prominent in the vicinity of the International Dateline due to the warm pool of water there. This warm water is likely to result in an increase in SW Pacific tropical cyclone activity during February.

Trade winds were weaker than normal near and west of the Dateline during January, allowing the west-central Pacific warm pool of ocean water to persist. During February, stronger than normal trade winds are forecast to develop in the eastern and central Pacific, which may lead to cooling of SSTs in that region.

According to the consensus from international models, ENSO-neutral conditions are most likely (68% chance) for the February – April period. For the May – July period, the probability for ENSO-neutral conditions is 64%. The probability of La Niña increases to 30% in August-October although ENSO-neutral remains the most likely outcome.

Download the full report: Island Climate Update - February 2020 [PDF 1.5MB]