Reports

ENSO Outlook

This page considers the ENSO outlook for the next three to six months, and the typical impact of El Niño and La Niña events on rainfall in Southeast Asia.

Current SST conditions are shown on the climate monitoring node website: sst - SEA Climate Monitoring

 

Latest Climate Outlook (December 2022 – May 2023): La Niña likely to weaken and gradually return to neutral

Updated: November 2022

Recent analysis of sea surface temperature (SST) anomalies over the equatorial Pacific shows below-average SSTs across the central and eastern equatorial Pacific Ocean indicative of La Niña. The international climate outlook predicts that the La Niña is likely to weaken during DJF 2022/2023, although overall still indicates La Niña conditions. After DJF 2022/2023, most models predict the ENSO state to gradually return to neutral.

The full ASEANCOF-19 Outlook Bulletin (DJF 2022/2023) can be found here.

 

Latest Model Outlook

Updated: 6 January 2023

Model outlooks from Copernicus C3S (Figure 1),  bbased on the Nino3.4 SST index, show that models predict the La Niña conditions to weaken during the start of 2023, although La Niña conditions are still more likely than ENSO neutral conditions for January and February 2023. ENSO neutral conditions become more likely for March and April.

c3s_nino34_dec2022

Figure 1:Forecasts of Nino3.4 index’s strength until May 2023 from various seasonal prediction models from international climate centres (grey lines). The blue and yellow lines note the La Niña and El Niño thresholds, respectively, used by various centres.

 

Impact of El Niño/La Niña on Southeast Asia

The typical impact of El Niño on Southeast Asia is drier-than-average rainfall conditions, including for much of the Maritime Continent during December to February (Figure 2, left). Warmer temperature conditions typically follow drier periods. The opposite conditions for rainfall (and consequently temperature) are observed during La Niña years (Figure 2, right).

The impact on the region’s rainfall and temperature from ENSO events is more significantly felt during strong or moderate-intensity events. Also, no two El Niño events or two La Niña events are exactly alike in terms of their impact on the region.

djf_rainfall_anomaly_composities_el_nino_la_nina

Figure 2: December to February (DJF) season rainfall anomaly composites (mm/day) for El Niño (left) and La Niña (right) years. Brown (green) shades show regions of drier (wetter) conditions. Note that this anomaly composite was generated using a limited number of El Niño and La Niña occurrences between 1979 and 2017 and therefore should be interpreted with caution (data: NOAA CPC CAMS_OPI).