Rainfall
Monthly Rainfall Outlook: November 2023
Issued: 31 Oct 2023
For November 2023, below-normal rainfall is predicted over most of the southern ASEAN region.
For November 2023, below-normal rainfall is predicted over most of the southern ASEAN region, with highest likelihood over the southwestern Maritime Continent based on the multi-model ensemble (Figure 4). The ECMWF model (Figure 2) shows the highest confidence for below-normal rainfall, followed by the NCEP and the UK Met Office models (Figures 1 and 3). Models’ skill is moderate to good skill for below-normal rainfall over the southern ASEAN region.
For the northern ASEAN region, a small increase in chance of below-normal rainfall is predicted for the eastern parts while a mix of below- to above-normal rainfall is predicted for the western parts (Figure 4). The NCEP model (Figure 1) has the largest extent of below-normal rainfall predicted over much of the region, while the ECMWF model (Figure 2) has the largest extent of above-normal rainfall predicted over Mainland Southeast Asia. For the northern ASEAN region, models’ skill for below-normal and above-normal rainfall is and moderate to good for the eastern parts and low to moderate for the western parts.
Figure 1: Rainfall tercile summary predictions of NCEP model for November 2023 (contains modified Copernicus C3S information).
Figure 2: Rainfall tercile summary predictions of ECMWF model for November 2023 (contains modified Copernicus C3S information).
Figure 3: Rainfall tercile summary predictions of UK Met Office model for November 2023 (contains modified Copernicus C3S information).
Figure 4: Rainfall tercile summary predictions of the multi-model ensemble for November 2023 (contains modified Copernicus C3S information).
Figure 5: Average climatological rainfall's lower tercile boundary for November based on CHIRPS (Reference period: 1991-2020).
Figure 6: Average climatological rainfall's upper tercile boundary for November 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.