Rainfall
Monthly Rainfall Outlook: January 2021
Issued: 24 Dec 2020
For January 2021, models predict above-normal rainfall over the Philippines, northern Borneo, Viet Nam and Cambodia.
For January 2021, above-normal rainfall is predicted over the Philippines, northern Borneo, parts of Viet Nam and Cambodia as see in the multi-model ensemble (Figure 4). The NCEP (Figure 1) model predicts the highest probability of above-normal rainfall for these regions while the ECMWF (Figure 2) and the UK Met Office models (Figure 3) predict a larger region with above-normal rainfall which further extending to southern Thailand and Peninsular Malaysia. The model’s skill is moderate to relatively good for the Philippines and northern Borneo, with low to moderate skill over Viet Nam and Cambodia.
For the rest of Southeast Asia, there is either disagreement between the models (equatorial regions) or the skill is low for this time of year (Mainland Southeast Asia and southern Maritime Continent).
Figure 1: Rainfall tercile summary predictions of NCEP model for January 2021.
Figure 2: Rainfall tercile summary predictions of ECMWF model for January 2021 (contains modified Copernicus C3S information).
Figure 3: Rainfall tercile summary predictions of UK Met Office model for January 2021 (contains modified Copernicus C3S information).
Figure 4: Rainfall tercile summary predictions of the multi-model ensemble for January 2021 (contains modified Copernicus C3S information).
Figure 5: Average climatological rainfall's lower tercile boundary for January based on CHIRPS (Reference period: 1981-2010).
Figure 6: Average climatological rainfall's upper tercile boundary for January based on CHIRPS (Reference period: 1981-2010).
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.