Rainfall
Monthly Rainfall Outlook: November 2020
Issued: 26 Oct 2020
For November 2020, models predict above-normal rainfall over parts of the Maritime Continent, Viet Nam, and Lao PDR.
For November 2020, above-normal rainfall is predicted over parts of the Maritime Continent, particularly for regions south of the equator and the Philippines. Two of the models – ECMWF and UK Met Office (Figures 2 and 3) – predict a larger proportion of the region to experience above-normal rainfall, while the third model – NCEP (Figure 1) – confines the above-normal rainfall to only over the Philippines, Sumatra, and Java. All three models are also predicting an increased chance of above-normal rainfall for parts of Viet Nam and Lao PDR. The skill is moderate to relatively good for the three models for the regions where above-normal rainfall is predicted in the multi-model ensemble (Figure 4).
For Mainland Southeast Asia, there is agreement between the models that parts of Thailand and southern Myanmar have an increased chance of below-normal rainfall for November 2020. The NCEP model predicts the highest chance and is also the model that has the highest skill for the region at this time of year (moderate to relatively good). For the rest of Mainland Southeast Asia, there is either no dominant tercile predicted or the skill is low.
Figure 1: Rainfall tercile summary predictions of NCEP model for November 2020.
Figure 2: Rainfall tercile summary predictions of ECMWF model for November 2020 (contains modified Copernicus C3S information).
Figure 3: Rainfall tercile summary predictions of UK Met Office model for November 2020 (contains modified Copernicus C3S information).
Figure 4: Rainfall tercile summary predictions of the multi-model ensemble for November 2020 (contains modified Copernicus C3S information).
Figure 5: Average climatological rainfall's lower tercile boundary for November based on CHIRPS (Reference period: 1981-2010).
Figure 6: Average climatological rainfall's upper tercile boundary for November 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.