Island Climate Update 268 - February 2023

The NINO3.4 Index anomaly (in the central equatorial Pacific) over the last month was -0.69˚C, close to La Niña thresholds.

The SOI was +1.0 during January and +1.0 over the November-January period, both at the La Niña threshold.

Trade winds were stronger than normal during January in the central and western Pacific.

In the subsurface central equatorial Pacific, warmer than average water has developed in the far eastern equatorial Pacific around 50 m depth. A remnant cool water anomaly was located near the surface in the central Pacific, which will likely allow a La Niña-like ocean signature to persist for another month or two. Any substantial relaxation or reversal in trade winds over the next three months will move the system toward ENSO-neutral. 

NIWA’s analysis indicates that La Niña conditions will most likely transition to ENSO-neutral during February-April, most likely by the end of March (80% chance). During May-July, ENSO-neutral is favoured at around a 50% chance. The chance for El Niño increases to around 55% from August-October 2023. The last time El Niño conditions occurred during winter and spring was in 2015.

A pulse of the Madden-Julian Oscillation (MJO) will move from the Maritime Continent into the Pacific Ocean region during the first half of February. These MJO pulses will increase the potential for tropical cyclone (TC) formation during this period, with a TC expected to from imminently in the Coral Sea. Keep up-to-date with forecasts from your local met service. 

Download

• Island Climate Update - February 2023 (PDF 5.8 MB)