Rainfall
Seasonal Rainfall Outlook: December 2024 - February 2025 (DJF)
Issued: 29 Nov 2024
For DJF 2024/2025, models predict an increased chance of above-normal rainfall over much of the Maritime Continent, and below-normal rainfall over the western equatorial region.
For DJF 2024/2025, above-normal rainfall is predicted over much of the Maritime Continent, based on the multi-model ensemble (Figure 4) except over the western equatorial region where below-normal rainfall is predicted. The ECMWF model (Figure 2) shows the highest confidence for above-normal rainfall over the region, followed by the UK Met Office model (Figure 3) and then the NCEP model (Figure 1). Models’ skill is low to moderate for both below-normal and above-normal rainfall for much of the Maritime Continent, except for over the Philippines where the models’ skill is relatively good.
For Mainland Southeast Asia, all three models (Figures 1 – 3) agree on above-normal rainfall over the southeastern region and a mix of near- to above-normal or no dominant tercile elsewhere. However, it is the dry season for the region and the models’ skill is generally low.
Figure 1: Rainfall tercile summary predictions of NCEP model for DJF 2024/2025 (contains modified Copernicus C3S information).
Figure 2: Rainfall tercile summary predictions of ECMWF model for DJF 2024/2025 (contains modified Copernicus C3S information).
Figure 3: Rainfall tercile summary predictions of UK Met Office model for DJF 2024/2025 (contains modified Copernicus C3S information).
Figure 4: Rainfall tercile summary predictions of the multi-model ensemble for DJF 2024/2025 (contains modified Copernicus C3S information).
Figure 5: Average climatological rainfall's lower tercile boundary for DJF based on CHIRPS (Reference period: 1991-2020).
Figure 6: Average climatological rainfall's upper tercile boundary for DJF based on CHIRPS (Reference period: 1991-2020).
The qualitative outlook is assessed for the region in general. For specific updates on the national scale, the relevant ASEAN National Meteorological and Hydrological Services should be consulted.