Rainfall
Seasonal Rainfall Outlook: April-June 2024 (AMJ)
Issued: 31 Mar 2024
For AMJ 2024, above-normal rainfall is predicted for the southern ASEAN region with below-normal rainfall for the northern ASEAN region.
For AMJ 2024, above-normal rainfall is predicted for the southern ASEAN region based on the multi-model ensemble (Figure 4). While the ECMWF and UK Met Office models (Figure 2 and 3) show high confidence of above-normal rainfall over the southern ASEAN region, the NCEP model (Figure 1) has low likelihood of above-normal rainfall for the region. 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). All three models are in agreement with the below-normal rainfall over much of Mainland Southeast Asia. Over the Philippines, both the ECMWF and UK Met Office models (Figure 2 and 3) show high confidence for below-normal rainfall, followed by the NCEP model (Figure 1) showing moderate confidence over the region. The models’ skill for below-normal rainfall is relatively good over Philippines and moderate to good over Mainland Southeast Asia.
Figure 1: Rainfall tercile summary predictions of NCEP model for AMJ 2024 (contains modified Copernicus C3S information).
Figure 2: Rainfall tercile summary predictions of ECMWF model for AMJ 2024 (contains modified Copernicus C3S information).
Figure 3: Rainfall tercile summary predictions of UK Met Office model for AMJ 2024 (contains modified Copernicus C3S information).
Figure 4: Rainfall tercile summary predictions of the multi-model ensemble for AMJ 2024 (contains modified Copernicus C3S information).
Figure 5: Average climatological rainfall's lower tercile boundary for AMJ based on CHIRPS (Reference period: 1991-2020).
Figure 6: Average climatological rainfall's upper tercile boundary for AMJ 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.