Rainfall
Monthly Rainfall Outlook: May 2022
Issued: 27 Apr 2022
For May 2022, models predict above-normal rainfall over much of the northern ASEAN region and the southern Maritime Continent.
For May 2022, above-normal rainfall is predicted for much of the northern ASEAN region, including central and southern parts of the Philippines, as seen in the multi-model ensemble (Figure 4). Over Mainland Southeast Asia, all three models predict an increased chance of above-normal rainfall over central and eastern parts, with the NCEP model (Figure 1) predicting below- to near-normal rainfall over western Mainland Southeast Asia while the ECMWF and UK Met Office models (Figure 2 and Figure 3) predicting an increased chance in above-normal rainfall. The models’ skill is moderate to relatively good for the Philippines, and southern Mainland Southeast Asia, with low to moderate skill for northern Mainland Southeast Asia.
For the southern ASEAN region, all models predicted an increased chance of above-normal rainfall over southern parts of the Maritime Continent (Figures 1 – 3). However, there is some disagreement between models for the equatorial region, as well as the models’ skill is only low to moderate for this region. The models’ skill is moderate to relatively good for the southern Maritime Continent.
For the southern ASEAN region, all models predicted an increased chance of above-normal rainfall over southern parts of the Maritime Continent (Figures 1 – 3). However, there is some disagreement between models for the equatorial region, as well as the models’ skill is only low to moderate for this region. The models’ skill is moderate to relatively good for the southern Maritime Continent.
Figure 1: Rainfall tercile summary predictions of NCEP model for May 2022.
Figure 2: Rainfall tercile summary predictions of ECMWF model for May 2022 (contains modified Copernicus C3S information).
Figure 3: Rainfall tercile summary predictions of UK Met Office model for May 2022 (contains modified Copernicus C3S information).
Figure 4: Rainfall tercile summary predictions of the multi-model ensemble for May 2022 (contains modified Copernicus C3S information).
Figure 5: Average climatological rainfall's lower tercile boundary for May based on CHIRPS (Reference period: 1991-2020).
Figure 6: Average climatological rainfall's upper tercile boundary for May 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.