Rainfall
Seasonal Rainfall Outlook: March-May 2024 (MAM)
Issued: 29 Feb 2024
For MAM 2024, above-normal rainfall is predicted for the southern ASEAN region with below-normal rainfall for the northern ASEAN region.
For MAM 2024, above-normal rainfall is predicted for the southern ASEAN region based on the multi-model ensemble (Figure 4). The ECMWF model (Figure 2) shows the highest confidence of above-normal rainfall over the southern ASEAN region, followed by the NCEP model (Figure 1) and then the UK Met Office model (Figure 3). Models’ skill is moderate to good for above-normal rainfall over the southern ASEAN region.
Below-normal rainfall is predicted over the northern ASEAN region, based on the multi-model ensemble (Figure 4). Over the Philippines, the ECMWF (Figure 2) model shows high confidence for below-normal rainfall, followed by the UK Met Office Model (Figure 2), and then the NCEP model (Figure 1) showing below- to near-normal rainfall over the region. Over Mainland Southeast Asia, the NCEP and ECMWF models show below-normal rainfall over much of the region, while the UK Met Office model shows near-normal rainfall. The models’ skill for below-normal rainfall is relatively good over Philippines and moderate to good over Mainland Southeast Asia.
Figure1: Rainfall tercile summary predictions of NCEP model for MAM 2024 (contains modified Copernicus C3S information).
Figure 2: Rainfall tercile summary predictions of ECMWF model for MAM 2024 (contains modified Copernicus C3S information).
Figure 3: Rainfall tercile summary predictions of UK Met Office model for MAM 2024 (contains modified Copernicus C3S information).
Figure 4: Rainfall tercile summary predictions of the multi-model ensemble for MAM 2024 (contains modified Copernicus C3S information).
Figure 5: Average climatological rainfall's lower tercile boundary for MAM based on CHIRPS (Reference period: 1991-2020).
Figure 6: Average climatological rainfall's upper tercile boundary for MAM 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.