Subseasonal Weather Outlook and Review

In Week 1 (23 – 29 December), drier conditions are predicted over parts of the western Maritime Continent, while wetter conditions are predicted over southeastern Mainland Southeast Asia and the northeastern Maritime Continent. These wetter conditions are likely to extend into Week 2 (30 December – 5 January).

Warmer than usual temperature is predicted over the equatorial region in Week 1 (23 – 29 December). Cooler than usual temperature is predicted over central and eastern Mainland Southeast Asia in the next fortnight (23 December – 5 January).

A Madden-Julian Oscillation (MJO) signal was present over the Maritime Continent (Phase 5) towards the middle of December. Most models predict this signal to continue propagating through the Western Pacific (Phases 6 and 7) towards the Western Hemisphere (Phase 8) during the forecast period. However, some models predict a weakening of the signal while it propagates through the Western Pacific (Phases 6 and 7), becoming temporarily indiscernible.

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.

In Week 1 (23 – 29 December), drier conditions are predicted over parts of the western Maritime Continent, while wetter conditions are predicted over southeastern Mainland Southeast Asia and the northeastern Maritime Continent. These wetter conditions are likely to extend into Week 2 (30 December – 5 January).

Warmer than usual temperature is predicted over the equatorial region in Week 1 (23 – 29 December). Cooler than usual temperature is predicted over central and eastern Mainland Southeast Asia in the next fortnight (23 December – 5 January).

A Madden-Julian Oscillation (MJO) signal was present over the Maritime Continent (Phase 5) towards the middle of December. Most models predict this signal to continue propagating through the Western Pacific (Phases 6 and 7) towards the Western Hemisphere (Phase 8) during the forecast period. However, some models predict a weakening of the signal while it propagates through the Western Pacific (Phases 6 and 7), becoming temporarily indiscernible.

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.