Rainfall

For October 2024, above-normal rainfall is predicted over the eastern equatorial region, based on the multi-model ensemble (Figure 4). The UK Met Office model (Figure 3) shows the highest confidence of above-normal rainfall for this region, followed by the ECMWF model (Figure 2). The NCEP model (Figure 1) predicts a mix of near- and above-normal rainfall over this region. Elsewhere in the southern ASEAN region, the models disagree on the dominant tercile for the western equatorial region and southern Maritime Continent. While the NCEP and ECMWF models predict mostly near-normal rainfall, the UK Met Office model overall predicts above-normal rainfall for these regions. The 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, no-dominant tercile is predicted over Mainland Southeast Asia and above-normal rainfall is predicted the Philippines based on the multi-model ensemble. However, there is some disagreement between the individual models (Figure 4) over Mainland Southeast Asia. The UK Met Office model (Figure 3) predicts the highest chance of above-normal rainfall over much of the region, apart from much of Myanmar and northern Lao PDR, where below- to near-normal rainfall is predicted. In contrast, the NCEP model (Figure 1) shows no dominant tercile over most of the region, and the ECMWF model (Figure 3) predicts a small increase in chance of near- to above-normal rainfall for much of the northern ASEAN region. Over the Philippines, all models agree on above-normal rainfall. model skill is generally low for the northern ASEAN region at this time of the year.