Subseasonal Weather Outlook and Review

For Mainland Southeast Asia in Week 1 (8 – 14 December), wetter conditions are predicted over parts of the eastern portion.

For the Maritime Continent in Week 1 (8 – 14 December), wetter conditions are predicted over parts of the northeastern and southeastern portions, while drier conditions are predicted over much of the rest of the Maritime Continent.

Cooler than usual temperatures are predicted for much of the southern Maritime Continent in Week 1 (8 – 14 December).

A strong Madden-Julian Oscillation (MJO) signal was present over the Western Pacific (Phase 7) at the start of December, based on the RMM index. Models predict this signal to weaken rapidly and become indiscernible by the start of the forecast period. Some models* predict an MJO signal to emerge towards the end of Week 1 (8 – 14 December) in the Western Hemisphere and Africa (Phase 8) and then propagate slowly eastwards in Week 2 (15 – 21 December).

The outlook is assessed for the region in general, where conditions are relative to the average conditions for the corresponding time of year. For specific updates on the national scale, the relevant ASEAN National Meteorological and Hydrological Services should be consulted.

For Mainland Southeast Asia in Week 1 (8 – 14 December), wetter conditions are predicted over parts of the eastern portion.

For the Maritime Continent in Week 1 (8 – 14 December), wetter conditions are predicted over parts of the northeastern and southeastern portions, while drier conditions are predicted over much of the rest of the Maritime Continent.

Cooler than usual temperatures are predicted for much of the southern Maritime Continent in Week 1 (8 – 14 December).

A strong Madden-Julian Oscillation (MJO) signal was present over the Western Pacific (Phase 7) at the start of December, based on the RMM index. Models predict this signal to weaken rapidly and become indiscernible by the start of the forecast period. Some models* predict an MJO signal to emerge towards the end of Week 1 (8 – 14 December) in the Western Hemisphere and Africa (Phase 8) and then propagate slowly eastwards in Week 2 (15 – 21 December).

The outlook is assessed for the region in general, where conditions are relative to the average conditions for the corresponding time of year. For specific updates on the national scale, the relevant ASEAN National Meteorological and Hydrological Services should be consulted.