Island Climate Update 266 - December 2022

The NINO3.4 Index anomaly (in the central equatorial Pacific) over the last month was 0.92˚C (climatology: 1991 2020), showing a cooling trend compared to October.

The SOI was +0.3 during November and +1.3 over the September November period (climatology: 1991 2020), the latter within the La Niña range.

Trade winds were stronger than normal during November, sustaining oceanic La Niña conditions.

In the subsurface central equatorial Pacific, anomalies of 3˚C to 5˚C were located at 50 100 m depth in the east. This strong sub surface expression will likely allow oceanic La Niña to continue through February. However, the West Pacific Warm Pool began an eastward progression with warm anomalies now occurring in the central Pacific at 150 200 m depth. Any substantial relaxation or reversal in trade winds over the next three months could move the system toward ENSO neutral. 

Our analysis indicates that a mature La Niña event is ongoing and is expected to last through to February (75% chance). An easing toward ENSO neutral is likely from March May 2023 (80% chance). Beyond this, the long term outlook for El Niño developing have risen to over 40% for winter 2023. 

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• Island Climate Update - December 2022 (PDF 2.7 MB)