Seasonal Forecast for February-March-April 2020

Updated 5 February 2020

Summary of Outlook

The Northeast Monsoon season prevails over the ASEAN region until March/April before transitioning to Inter-monsoon conditions. During the Northeast Monsoon, the northern ASEAN region typically experiences the traditional dry season, while the rainy season prevails over the southern ASEAN region.

Above-normal temperature is expected over most parts of Southeast Asia during the Feb–Mar–Apr 2020 period. Below-normal rainfall is predicted mainly over Myanmar and the Philippines. There is higher chance of above-normal rainfall over areas south the equator, particularly around Java Sea areas and eastern archipelago of Indonesia.

With dry weather expected to persist over the northern ASEAN region, hotspot activities and hazy conditions in the Mekong sub-region are likely to persist. The risk of transboundary haze occurrence in the sub-region remains high. In the southern ASEAN region, hotspot activities are expected to remain generally subdued due to rainy weather. However, isolated hotspots with localised smoke plumes may emerge in Sumatra, Kalimantan and Malaysia during periods of drier weather in February and March.

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.

For February 2020, below-normal rainfall is forecasted for much of the region between 0° and 10°N. There is also an increase chance of above-normal rainfall in the northern most parts of Southeast Asia.

 

For February 2020, two models – NCEP CFSv2 and the ECMWF (Figures 1a, 1b) favour an increased chance of below-normal rainfall for much of the Southeast Asian region between 0° and 10°N, including northern Sumatra, Peninsular Malaysia and the Philippines, while the UK Met Office model predicts below-normal rainfall for only northern Sumatra and parts of the Philippines (Figure 1c). However, all three models, NCEP CFSv2, ECMWF, and UK Met Office are forecasting an increased probability of above-normal rainfall for the most northern parts of Southeast Asia. With regards to model skill, the region where below-normal rainfall is forecasted corresponds to the area with moderate to high skill, while the region where above-normal rainfall corresponds to one with only low to moderate skill.

Elsewhere, the models show inconsistent forecasts or have limited skill (see the respective sections of “Model products and verification: NCEP, ECMWF, UK Met Office”).

Rainfall Tercile Summary of NCEP model.

Rainfall Tercile Summary of ECMWF model.

Figure 1a: Rainfall tercile summary predictions of NCEP model for February 2020. Figure 1b: Rainfall tercile summary predictions of ECMWF model for February 2020 (contains modified Copernicus C3S information).

Rainfall Tercile Summary of UK Met Office model.

Rainfall Tercile Summary of MME model.

Figure 1c: Rainfall tercile summary predictions of UK Met Office model for February 2020 (contains modified Copernicus C3S information). Figure 1d: Rainfall tercile summary predictions of multi-model ensemble model for February 2020 (contains modified Copernicus C3S information).

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. More outlook and verification plots, including for tercile and quintile probabilistic forecasts for rainfall, are in the “Model products and verification: NCEP, ECMWF, UK Met Office” on the SEA-RCC Network LRF Node webpages.

 


For FMA 2020, below-normal rainfall is predicted for the most western and eastern parts of the northern ASEAN region, while the region just south of the equator may experience above-normal rainfall.

 

For FMA 2020, all three models – NCEP CFSv2, ECMWF and the UK Met Office (Figures 2a-c) – predict below-normal rainfall for the most western parts of the northern ASEAN region and the Philippines. The models also predict an increase in the probability of above-normal rainfall for regions just south of the equator. While the skill of the models is moderate to high for the Philippines and much of the Malay Peninsula, elsewhere the skill is low to moderate for this season (see the respective sections of “Model products and verification: NCEP, ECMWF, UK Met Office“).

Rainfall Tercile Summary of NCEP model.

Rainfall Tercile Summary of ECMWF model.

Figure 2a: Rainfall tercile summary predictions of NCEP model for FMA 2020. Figure 2b: Rainfall tercile summary predictions of ECMWF model for FMA 2020 (contains modified Copernicus C3S information).

Rainfall Tercile Summary of UK Met Office model.

Rainfall Tercile Summary of MME model.

Figure 2c: Rainfall tercile summary predictions of UK Met Office model for FMA 2020 (contains modified Copernicus C3S information). Figure 2d: Rainfall tercile summary predictions of multi-model ensemble model for FMA 2020 (contains modified Copernicus C3S information).

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. More outlook and verification plots, including for tercile and quintile probabilistic forecasts for rainfall, are in the “Model products and verification: NCEP, ECMWF, UK Met Office” on the SEA-RCC Network LRF Node webpages.

For February 2020, above-normal temperature is favoured over most parts of Southeast Asia, apart from the most northern parts of the region.

 

For February 2020, all three models – NCEP CFSv2, ECMWF and UK Met Office (Figures 1a-c) consistently predict a high likelihood of above-normal temperature conditions over most parts of Southeast Asia, apart from over Myanmar and northern Viet Nam where near-normal to below-normal temperatures are predicted.

The models’ skill for predicting the above-normal and below normal temperature tercile categories are moderate to high over most parts of Southeast Asia (see the respective sections of “Model products and verification: NCEP, ECMWF, UK Met Office”).

Temperature tercile Summary of NCEP model.

Temperature tercile Summary of ECMWF model.

Figure 1a: Temperature tercile summary predictions of NCEP model for February 2020. Figure 1b: Temperature tercile summary predictions of ECMWF model for February 2020 (contains modified Copernicus C3S information).

Temperature tercile Summary of UK Met Office model.

Temperature tercile Summary of MME model.

Figure 1c: Temperature tercile summary predictions of UK Met Office model for February 2020 (contains modified Copernicus C3S information). Figure 1d: Temperature tercile summary predictions of multi-model ensemble model for February 2020 (contains modified Copernicus C3S information).

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. More outlook and verification plots, including for tercile and quintile probabilistic forecasts for temperature, are in the “Model products and verification: NCEP, ECMWF, UK Met Office” on the SEA-RCC Network LRF Node webpages.


For FMA 2020, above-normal temperature is favoured over most parts of Southeast Asia.

 

For FMA 2020, all three models – NCEP CFSv2, ECMWF and UK Met Office (Figures 2 a-c) – favour above-normal temperature over most parts of Southeast Asia, with the highest likelihood over the central and southern parts of the region. The models’ skill for this season is moderate to high for much of Southeast Asia (see the respective sections of “Model products and verification: NCEP, ECMWF, UK Met Office”).

Temperature tercile Summary of NCEP model.

Temperature tercile Summary of ECMWF model.

Figure 2a: Temperature tercile summary predictions of NCEP model for FMA 2020. Figure 2b: Temperature tercile summary predictions of ECMWF model for FMA 2020 (contains modified Copernicus C3S information).

Temperature tercile Summary of UK Met Office model.

Temperature tercile Summary of MME model.

Figure 2c: Temperature tercile summary predictions of UK Met Office model for FMA 2020 (contains modified Copernicus C3S information). Figure 2d: Temperature tercile summary predictions of multi-model ensemble model for FMA 2020 (contains modified Copernicus C3S information).

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. More outlook and verification plots, including for tercile and quintile probabilistic forecasts for temperature, are in the “Model products and verification: NCEP, ECMWF, UK Met Office” on the SEA-RCC Network LRF Node webpages.