Rainfall
Seasonal Rainfall Outlook: November 2020 - January 2021 (NDJ)
Issued: 26 Oct 2020
For NDJ 2020-2021, above-normal rainfall is predicted for the region south of the equator, as well as the Philippines and parts of Viet Nam, Lao PDR, and Cambodia.
For NDJ 2020-2021, all three models – NCEP, ECMWF, and UK Met Office (Figures 1-3) – predict an increased chance of above-normal rainfall for the region south of the equator, where the skill is moderate to high. While the models are predicting below- normal rainfall for the parts of the equatorial region itself, here the model skill is low for this time of the year.
For the northern half of Southeast Asia, the models are also predicting above-normal rainfall for the Philippines, and parts of Viet Nam, Lao PDR, and Cambodia. For these areas, model skill is relatively good. Elsewhere, the models show inconsistent forecasts or have low skill.
Figure 1: Rainfall tercile summary predictions of NCEP model for NDJ 2020-2021.
Figure 2: Rainfall tercile summary predictions of ECMWF model for NDJ 2020-2021 (contains modified Copernicus C3S information).
Figure 5: Average climatological rainfall's lower tercile boundary for NDJ based on CHIRPS (Reference period: 1981-2010).
Figure 6: Average climatological rainfall's upper tercile boundary for NDJ 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.