Rainfall
Seasonal Rainfall Outlook: September-November 2022 (SON)
Issued: 30 Aug 2022
For SON 2022, above-normal rainfall is predicted for much of the ASEAN region.
For SON 2022, based on the multi-model ensemble (Figure 4), there is an increased chance of above-normal rainfall for much of the ASEAN region. The highest likelihood for all three models is over the southern Maritime Continent, while there is only a relatively small increase in chance over much of Mainland Southeast Asia. Model skill is relatively good for regions with a high likelihood of above-normal rainfall, while low to moderate over Mainland Southeast Asia and the Philippines.
The exception to the wetter conditions is over the western Maritime Continent where below-normal rainfall is predicted. However, model skill is low at this time of year for the western Maritime Continent.
Figure 1: Rainfall tercile summary predictions of NCEP model for SON 2022 (contains modified Copernicus C3S information).
Figure 2: Rainfall tercile summary predictions of ECMWF model for SON 2022 (contains modified Copernicus C3S information).
Figure 3: Rainfall tercile summary predictions of UK Met Office model for SON 2022 (contains modified Copernicus C3S information).
Figure 4: Rainfall tercile summary predictions of the multi-model ensemble for SON 2022 (contains modified Copernicus C3S information).
Figure 5: Average climatological rainfall's lower tercile boundary for SON based on CHIRPS (Reference period: 1991-2020).
Figure 6: Average climatological rainfall's upper tercile boundary for SON 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.