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 (June – December 2022): Signs of La Niña decay

Updated: June 2022

Recent analyses of sea surface temperature (SST) anomalies over the equatorial Pacific show below average SSTs across the central and eastern tropical Pacific Ocean indicative of La Niña. The international climate outlooks predict that the La Niña is likely to weaken during JJA 2022, although still overall indicate La Niña conditions. After JJA 2022, most models predict the ENSO state to be either cool ENSO neutral or La Niña.

The full ASEANCOF-18 Bulletin can be found here.

 

Latest Model Outlook

Updated: 6 September 2022

Model outlooks from Copernicus C3S (Figure 1), based on the Nino3.4 SST index, show that most models predict the La Niña conditions to persist until the end of the year, although ENSO neutral conditions becoming increasingly likely by January 2023. A few models predict a strengthening of the La Nina conditions in October and November, however, most models predict the La Nina conditions to be weak or moderate during the September to November period. 

c3s_nino34_aug2022

Figure 1: Forecasts of Nino3.4 index’s strength until January 2023 from various seasonal prediction models of international climate centres (image credit: Copernicus C3S).

 

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 September to November (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.

son_rainfall_anomaly_composites_el_nino_la_nina

Figure 2: September to November (SON) 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).