Rainfall

Seasonal Rainfall Outlook: December 2018 - February 2019 (DJF)

Issued: 30 Nov 2018

For DJF 2018/19, below-normal rainfall is favoured over much of the Philippines as well as parts of Myanmar and Thailand. The three models referred to here show little agreement for the rest of the ASEAN region.

For DJF 2018/2019, all three models – NCEP CFSv2, ECMWF, and UK Met Office (Figures 1-3) predict below-normal over the Philippines, southern Thailand, and parts of Myanmar and southern Vietnam. All three models have generally good skill over the Philippines with low to moderate skill elsewhere.

Assessing model predictions elsewhere, the NCEP CFSv2 model predicts above-normal rainfall over Sumatra, as well as parts of Borneo, the Malay Peninsula, Thailand, Laos, northern Vietnam, and eastern Indonesia. However, the ECMWF and UK Met Office models generally predict below-normal to near-normal rainfall for these regions, apart from eastern Indonesia, Borneo and northern Vietnam, where the UK Met Office predicts above-normal rainfall.

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Figure 1: Rainfall tercile summary predictions of NCEP model for DJF 2018-2019.
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Figure 2: Rainfall tercile summary predictions of ECMWF model for DJF 2018-2019 (contains modified Copernicus C3S information).
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Figure 3: Rainfall tercile summary predictions of UK Met Office model for DJF 2018-2019 (contains modified Copernicus C3S information).
The qualitative outlook is assessed for the region in general, and based on the latest run from models provided by the SEA-RCC LRF node. For specific updates on the national scale, the relevant ASEAN National Meteorological and Hydrological Services should be consulted.