Rainfall
Monthly Rainfall Outlook: May 2018
Issued: 30 Apr 2018
Based on the NCEP CFSv2 model for May 2018 (Figure 1), below average rainfall is expected for most coastal areas north of the equator. There is moderate skill over most of this region against ERA-Interim and Aphrodite for May (Figure 2 and 3), apart from near the equator where the skill is low. Other models consulted (ECMW, JMA, and UK Met Office) show good agreement for the eastern Mainland Southeast Asia and Peninsular Malaysia, although all three models have above normal rainfall as the most likely category for coastal areas of the Andaman Sea and the Philippines.
South of the equator, there is less agreement between the models. Based on the NCEP CFSv2, above average rainfall is expected in southern Indonesia, with near to below average elsewhere. However, the other models suggest below average rainfall is more likely for all of the southern ASEAN region. In general, the NCEP CFSv2 skill is higher over southern Indonesia than for the region surrounding the equator.
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.