Rainfall
Monthly Rainfall Outlook: March 2021
Issued: 26 Feb 2021
For March 2021, models predict above-normal rainfall over much of the ASEAN region just north of the equator, in particular southern Mainland Southeast Asia, Malay Peninsula and the Philippines.
For March 2021, above-normal rainfall is predicted over much of the ASEAN region between 0 and 15°N, as seen in the multi-model ensemble (Figure 4). The ECMWF (Figure 2) and the UK Met Office models (Figure 3) predict the above-normal rainfall to extend further northwest to central Myanmar and northern Lao PDR. The NCEP model (Figure 1) on the other hand predicts a larger extent of above-normal rainfall to the south of the equator covering southern Sumatra, southern Indonesia and Papua, where near- to below-normal rainfall is favoured by the other two models. Model skill for above normal tercile is moderate to high for the Malay Peninsula, northeast Borneo and the Philippines, and low for the other regions mentioned.
Elsewhere, there is either disagreement between the models or the skill is low for this time of the year.
Figure 1: Rainfall tercile summary predictions of NCEP model for March 2021.
Figure 2: Rainfall tercile summary predictions of ECMWF model for March 2021 (contains modified Copernicus C3S information).
Figure 3: Rainfall tercile summary predictions of UK Met Office model for March 2021 (contains modified Copernicus C3S information).
Figure 4: Rainfall tercile summary predictions of the multi-model ensemble for March 2021 (contains modified Copernicus C3S information).
Figure 5: Average climatological rainfall's lower tercile boundary for March based on CHIRPS (Reference period: 1981-2010).
Figure 6: Average climatological rainfall's upper tercile boundary for March 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.