Rainfall

For August 2024, above-normal rainfall is predicted over much of the equatorial region, with highest likelihood over the eastern region based on the multi-model ensemble (Figure 4). The UK Met Office model (Figure 3) shows the highest confidence for above-normal rainfall over the equatorial region (in particular over the eastern area), and followed by the ECMWF model (Figure 2). The NCEP model (Figure 1) predicts below-normal rainfall over the Malay Peninsula and near-normal over much of Borneo. Elsewhere in the southern ASEAN region, near-normal rainfall is predicted over the southern Maritime Continent. Models’ skill for the southern ASEAN region is moderate to good for predicting above-normal rainfall and low to moderate for predicting near-normal rainfall.

For the northern ASEAN region, a mix of no dominant tercile and above-normal rainfall is predicted, based on the multi-model ensemble (Figure 4). The three models (Figures 1 to 3) predict a slight increase in chance for above-normal rainfall over central Maritime Continent. Elsewhere over the northern ASEAN region, there is either no dominant tercile or disagreement between the models. Models’ skill is generally low for the northern ASEAN region.