Island Climate Update

A monthly summary of the climate in the tropical South Pacific islands, with an outlook for the coming months. This bulletin is a multi-national project with collaboration from a number of Pacific nations and support from various organisations.

You can follow the Island Climate Update on Facebook and Twitter.

During June, the NINO3.4 Index anomaly (in the central Pacific) was 0.12˚C. Upper oceanic heat content decreased notably across the east central equatorial Pacific. Anomalies were below average east of the International Dateline, suggestive of an ocean system that is moving towards La Niña. 

In the subsurface ocean, cooler than average conditions pushed eastward during June with widespread anomalies of 0.5˚C to 2.0˚C. Warmth increased slightly at depth in the western Pacific. At this stage, the anomalies are consistent with developing oceanic La Niña conditions. 

Rainfall and convection was below normal across the equatorial Pacific during June, consistent with the cooling trend in the ocean. 

Trade winds during June were stronger than normal in the east central Pacific. This is expected to continue over the next 1 3 months and could lead to more cooling in the eastern and/or central Pacific. 

According to the consensus from international models, ENSO neutral and La Nina conditions are about equally likely (51% and 47% chance, respectively) for the July September period. For the October December and January March 2021 periods respectively, the probability for ENSO neutral conditions is 42% and 53%. The probability for La Niña is 45% during October December and 34% in January March. 

Based on the observations and forecast guidance, a La Niña watch is in place as of June 2020.

Download

Subscribe to the Island Climate Update email newsletter

* indicates required

Issues

El Niño –Southern Oscillation (ENSO) neutral conditions continued across the tropical Pacific during June 2018. Sea surface temperatures (SSTs) in the central equatorial Pacific warmed for the third consecutive month and are currently slightly above average. The NINO3.4 is currently weakly positive with a value of + 0.27°C for June 2018.
ENSO-neutral conditions persisted in the tropical Pacific during May 2018. Sea surface temperatures (SSTs) in the central and eastern equatorial Pacific Ocean continued to warm during May and are now near or slightly above average. The NINO3.4 is currently close to zero (+0.01°C for May 2018).
Weak La Niña conditions transitioned to ENSO-neutral in the tropical Pacific during April 2018. Sea surface temperatures (SSTs) in the central and eastern equatorial Pacific Ocean remained below normal during April 2018, but continued to weaken relative to March values.
Weak La Niña conditions continued in the tropical Pacific during March 2018, but trends in low-level winds and in sub-surface ocean temperatures during the month indicate that the event is coming to an end.
Weak La Niña conditions continued in the tropical Pacific during February 2018, but the current state of the Ocean-Atmosphere system in the Equatorial Pacific indicates that it is now reaching its decay phase.
Weak La Niña conditions continued in the tropical Pacific during January 2018. Below average sea surface temperatures (SSTs) remained present in the central and eastern equatorial Pacific Ocean but warmed slightly compared to December 2017.
Weak La Niña conditions persisted in the tropical Pacific during December 2017
The tropical Pacific is still officially in a ENSO (El Niño Southern Oscillation) neutral state, but some indicators have leaned more towards La Niña conditions during the course of October 2017.
The tropical Pacific is still officially in a ENSO (El Niño Southern Oscillation) neutral state, but some indicators have leaned more towards La Niña conditions during the course of October 2017.
La Niña-like signals in the ocean–atmosphere system in the tropical Pacific Ocean have become more prominent and coherent in September 2017, although have not yet reached the thresholds required for a La Niña event to be declared.
ENSO (El Niño –Southern Oscillation) neutral conditions (neither El Niño nor La Niña) continued in the tropical Pacific during July 2017, mixed signals were again present this month. Some atmospheric patterns have been recently leaning more towards weak La Niña conditions.
ENSO (El Niño –Southern Oscillation) neutral conditions (neither El Niño nor La Niña) continued in the tropical Pacific during July 2017, mixed signals were again present this month.
The tropical Pacific remained in an ENSO (El Niño –Southern Oscillation) neutral state (neither El Niño nor La Niña) during June 2017, but oceanic and atmospheric anomalies were mixed, with some indicators leaning towards El Niño and others towards La Niña.

International guidance still suggests that a transition toward El Niño conditions over the next three month period (June –August 2017) is more likely than not.

The tropical Pacific overall remained in an ENSO (El Niño –Southern Oscillation) neutral state (neither El Niño nor La Niña) during April 2017. 

The tropical Pacific is currently in an ENSO (El Niño – Southern Oscillation) neutral state, although some of the indices are indicative of La Niña conditions.

An overview of the present climate in the tropical South Pacific Islands, with an outlook for the coming months, to assist in dissemination of climate information in the Pacific region.

An overview of the present climate in the tropical South Pacific Islands, with an outlook for the coming months, to assist in dissemination of climate information in the Pacific region.
An overview of the present climate in the tropical South Pacific Islands, with an outlook for the coming months, to assist in dissemination of climate information in the Pacific region.
An overview of the present climate in the tropical South Pacific Islands, with an outlook for the coming months, to assist in dissemination of climate information in the Pacific region.
An overview of the present climate in the tropical South Pacific Islands, with an outlook for the coming months, to assist in dissemination of climate information in the Pacific region.
An overview of the present climate in the tropical South Pacific Islands, with an outlook for the coming months, to assist in dissemination of climate information in the Pacific region.
An overview of the present climate in the tropical South Pacific Islands, with an outlook for the coming months, to assist in dissemination of climate information in the Pacific region.
An overview of the present climate in the tropical South Pacific Islands, with an outlook for the coming months, to assist in dissemination of climate information in the Pacific region.

Pages