Rainfall

Based on the NCEP CFSv2 model, above average rainfall is expected in eastern Java (Indonesia) and the Philippines (Figure 1), which is consistent with the La Niña conditions that is expected to last until the first quarter of 2018. The model has considerable skill against Aphrodite and ERA-Interim in the Philippines and has low to moderate skill in eastern Indonesia (Figure 2 and 3). Other models (ECWMF, UK Met Office and JMA) give similar forecast in the Philippines. There are differences over eastern Indonesia, where CFSv2 predicts above average rainfall while the other three models predict below average to near average to be more likely.

For the rest of the region, the model skill is either low, or there is no dominant tercile from the NCEP CFSv2 model. The other models also have no consistent predictions for the mainland Southeast Asia, apart from Peninsula Malaysia and western Sumatra (Indonesia) where above average rainfall is consistently forecast (ECWMF, UK Met Office and JMA).

Figure 1: Rainfall anomaly for January 2018.