Rainfall
Monthly Rainfall Outlook: December 2017
Issued: 28 Nov 2017
Based on the NCEP CFSv2 model, above average rainfall is expected mostly over 0 to 10°N and the coastal areas of Vietnam and eastern Philippines (Figure 1). There is moderate to good skill over these regions for CFSv2 (Figures 2 and 3). Other models (ECMWF, UK Met Office, and JMA) give similar forecast over these locations. There are differences over eastern Indonesia, where CFSv2 predicts below normal rainfall, while the other three models predict near normal to above normal rainfall to be more likely.
There are no consistent predictions with all the models for the rest of Southeast Asia (Mainland Southeast Asia, Borneo, and Central and Southern Sumatra). Models generally have poor skill over these areas this time of the year.
Figure 1: Rainfall anomaly for December 2017
Figure 2: Anomaly Correlation Coefficient (ACC) of NCEP’s rainfall forecasts against APHRODITE.
Figure 3: Anomaly Correlation Coefficient (ACC) of NCEP’s rainfall forecasts against ERA-Interim.
The 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.