Rainfall
Seasonal Rainfall Outlook: June-August 2022 (JJA)
Issued: 31 May 2022
For JJA 2022, models predict above-normal rainfall for much of the southern ASEAN region and below-normal rainfall over western Mainland Southeast Asia.
For JJA 2022, above-normal rainfall is predicted for much of the southern ASEAN region based on the multi-model ensemble (Figure 4). Among the three models – the UK Met Office model predicts above-normal rainfall for the entire region (Figure 2), while the ECMWF model predicts near-normal rainfall over parts of the western Maritime Continent and northern Borneo (Figure 3), and the NCEP model predicts below-normal rainfall over parts of the western Maritime Continent. The models show moderate to good skill for above-normal rainfall over most of the Maritime Continent.
All models predict below-normal rainfall over western Mainland Southeast Asia, however the models’ skill is low for below-normal rainfall for this region. Elsewhere in the northern ASEAN region, there is disagreement between the models or no dominant tercile is predicted.
All models predict below-normal rainfall over western Mainland Southeast Asia, however the models’ skill is low for below-normal rainfall for this region. Elsewhere in the northern ASEAN region, there is disagreement between the models or no dominant tercile is predicted.
Figure 1: Rainfall tercile summary predictions of NCEP model for JJA 2022.
Figure 2: Rainfall tercile summary predictions of ECMWF model for JJA 2022 (contains modified Copernicus C3S information).
Figure 3: Rainfall tercile summary predictions of UK Met Office model for JJA 2022 (contains modified Copernicus C3S information).
Figure 4: Rainfall tercile summary predictions of the multi-model ensemble for JJA 2022 (contains modified Copernicus C3S information).
Figure 5: Average climatological rainfall's lower tercile boundary for JJA based on CHIRPS (Reference period: 1991-2020).
Figure 6: Average climatological rainfall's upper tercile boundary for JJA 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.