Rainfall
Monthly Rainfall Outlook: August 2022
Issued: 31 Jul 2022
For August 2022, models predict above-normal rainfall over much of the southern ASEAN region.
For August 2022, above-normal rainfall is predicted over much of the southern ASEAN region, with highest likelihood over southern Maritime Continent (Figure 4). The exception is over parts of the western Maritime Continent where no dominant tercile is predicted. The models’ skill is moderate to high for above-normal rainfall over the southern ASEAN region, with the highest skill over the southern Maritime Continent. Over the western Maritime Continent, the models’ skill is low.
For the northern ASEAN region, below-normal rainfall is predicted over much of the band between 10°N to 15°N based on the multi-model ensemble (Figure 4). There is either disagreement between the models or no dominant tercile predicted over the rest of Mainland Southeast Asia and northern half of the Philippines (Figures 1-3). The models’ skill for all three terciles is low for most of the northern ASEAN region, although it is low to moderate for coastal parts of western Mainland Southeast Asia.
For the northern ASEAN region, below-normal rainfall is predicted over much of the band between 10°N to 15°N based on the multi-model ensemble (Figure 4). There is either disagreement between the models or no dominant tercile predicted over the rest of Mainland Southeast Asia and northern half of the Philippines (Figures 1-3). The models’ skill for all three terciles is low for most of the northern ASEAN region, although it is low to moderate for coastal parts of western Mainland Southeast Asia.
Figure 1: Rainfall tercile summary predictions of NCEP model for August 2022 (contains modified Copernicus C3S information).
Figure 2: Rainfall tercile summary predictions of ECMWF model for August 2022 (contains modified Copernicus C3S information).
Figure 3: Rainfall tercile summary predictions of UK Met Office model for August 2022 (contains modified Copernicus C3S information).
Figure 4: Rainfall tercile summary predictions of the multi-model ensemble for August 2022 (contains modified Copernicus C3S information).
Figure 5: Average climatological rainfall's lower tercile boundary for August based on CHIRPS (Reference period: 1991-2020).
Figure 6: Average climatological rainfall's upper tercile boundary for August 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.