Rainfall

For ASO 2025, above-normal rainfall is predicted for much of the Maritime Continent, based on the multi-model ensemble (Figure 1). The highest probability of above-normal rainfall is over the southern Maritime Continent. Most models agree on above-normal rainfall as the most likely tercile for much of the southern, central and eastern parts of the region (more than six models, Figure 2). Below-normal rainfall is predicted over the northwestern Maritime Continent with low skill and moderate agreement between the models. Model skill for predicting above-normal rainfall is good for the southern, central and southeastern Maritime Continent and low to moderate elsewhere.

For Mainland Southeast Asia, above-normal rainfall is predicted over the eastern half and no dominant tercile is predicted over the western half. There is moderate agreement (4-6 models) for the above-normal rainfall and little agreement (less than 3 models) for the no dominant tercile over the western half (Figure 2). Model skill is low to moderate for Mainland Southeast Asia.