Rainfall

For MAM 2025, above-normal rainfall is predicted over much of the eastern Maritime Continent, based on the multi-model ensemble (Figure 4), with below- to near-normal rainfall predicted elsewhere in the Maritime Continent. The ECMWF and UK Met Office models (Figures 2 and 3) predict above-normal rainfall for much of the eastern Maritime Continent, while the NCEP model predicts above-normal rainfall only over the northeastern Maritime Continent. The NCEP model predicts the largest extent of below-normal rainfall over the central Maritime Continent, followed by the UK Met Office model and the ECMWF model. Skill over the northeastern Maritime Continent is relatively good, and low to moderate elsewhere.

For Mainland Southeast Asia, above-normal rainfall is predicted over most of the region, based on the multi-model ensemble (Figure 4). The UK Met Office model predicts an increased chance of above-normal rainfall over most of Mainland Southeast Asia, while the ECMWF predicts above-normal rainfall over the central and southern regions, and the NCEP model predicts above-normal rainfall over parts of western and northern Mainland Southeast Asia. Model skill for above-normal rainfall is relatively good for the southern half of Mainland Southeast Asia and low to moderate elsewhere.