Rainfall

For OND 2023, below-normal rainfall is predicted for most of the Maritime Continent, based on the multi-model ensemble (Figure 4). The ECMWF model (Figure 2) shows the highest confidence for below-normal rainfall for regions south of the equator, while the NCEP and the UKMO (Figures 1 and 3) models show high confidence over relatively smaller parts in the Maritime Continent. However, all three models predict an increase in chance of above-normal rainfall over the northwestern Maritime Continent. Models’ skill is moderate to good skill for below-normal rainfall over the Maritime Continent, and low to moderate for above-normal rainfall over the northwestern Maritime Continent.

For Mainland Southeast Asia, there is a small increase in chance of above-normal rainfall over much of the region, apart from over the where no dominant tercile is predicted, based on the multi-model ensemble (Figure 4). The NCEP model (Figure 1) predicts above-normal rainfall over much of Myanmar, much of Thailand and northern parts of Lao PDR and Viet Nam, while the ECMWF and UKMO models (Figures 2 and 3) predict a mix of near- to above-normal rainfall over these regions. The models’ skill is generally low to moderate over Mainland Southeast Asia for all three tercile categories.