Rainfall

For December 2024, above-normal rainfall is predicted over the northern and southern Maritime Continent, and below-normal rainfall is predicted over parts of the central equatorial region based on the multi-model ensemble (Figure 4). The NCEP and UK Met Office models (Figures 1 and 3) show higher confidence for below-normal rainfall over Sumatra and Borneo, followed by the ECMWF model (Figure 2) with below-normal rainfall predicted for Sumatra and near-normal rainfall over Borneo. In contrast, the ECMWF model has higher confidence for the above-normal rainfall for much of the rest of the Maritime Continent, followed by the UK Met Office and NCEP models. Models’ skill is moderate to good for both above- and below-normal rainfall over the Maritime Continent, except over the Malay Peninsula where model skill is low.

Above-normal rainfall is predicted over most of Mainland Southeast Asia based on the multi-model ensemble (Figure 4) except the northeastern region. However, it is the dry season for Mainland Southeast Asia. The NCEP model (Figure 1) has the largest extent and confidence of above-normal rainfall, followed by the ECMWF model (Figure 2) and the UK Met Office model (Figure 3).  Models’ skill for above-normal rainfall is generally low for the mentioned regions.