Category Archives: Regional Weather Outlook for Year 2023

Figure 1: Rainfall Outlook

Figure 2: Temperature Outlook

  Drier conditions are predicted over much of the southern Maritime
Continent in Week 1 (25 – 31 December 2023). Drier conditions are also
predicted over parts of the northeastern Maritime Continent in Week 1,
extending to the eastern coast of Mainland Southeast Asia in Week 2 (1 – 7
January 2024). Wetter conditions are predicted over parts of the western
Maritime continent in Week 1 (25 – 31 December 2023), extending eastwards to
Borneo in Week 2 (1 – 7 January 2024). Warmer than usual temperature is
predicted over most of the Maritime Continent during the next fortnight (25
December 2023 – 7 January 2024). Cooler than usual temperature is predicted
over much of central Mainland Southeast Asia in Week 1 (25 – 31 December
2023). A weak Madden-Julian Oscillation (MJO) signal was present over the
Western Hemisphere and Africa (Phases 8 and 1) at the start of the forecast
period. Most models predict the MJO signal to propagate through the Western
Hemisphere and Africa and reach the Indian Ocean (Phase 2) in Week 1, and then
weaken over the Indian Ocean (Phases 2 and 3) in Week 2.

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.

Drier conditions are predicted over much of the southern Maritime Continent in Week 1 (11 – 17 December), extending eastwards in Week 2 (18 – 24 December). Drier conditions are also predicted over parts of the northeastern Maritime Continent and eastern coast of Mainland Southeast Asia in Week 1.

Wetter conditions are predicted over parts of the western Maritime continent in Week 1 (11 – 17 December), extending eastwards to Borneo in Week 2 (18 – 24 December).

Warmer than usual temperature is predicted over much of the northern ASEAN region in Week 1 (11 – 17 December) and over most of the Maritime Continent during the next fortnight (11 – 24 December).

A Madden-Julian Oscillation (MJO) signal was present over the Maritime Continent (Phase 4) at the start of the forecast period. Most models predict this MJO signal to propagate eastwards to reach the Western Pacific (Phase 6) in Week 1, and then weaken over the Western Pacific (Phases 6 and 7) in Week 2.

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.

Wetter conditions are predicted over parts of southern Mainland Southeast Asia and the northern Malay Peninsula in the next fortnight (27 November – 10 December). Also, wetter conditions are predicted over much of the central and southeastern Maritime Continent in the next fortnight.

Warmer than usual temperature is predicted over most of the Maritime Continent and eastern coast of Mainland Southeast Asia during the next fortnight (27 November – 10 December).

A Madden-Julian Oscillation (MJO) signal has been present over the Western Hemisphere and Africa (Phases 8 and 1) since mid-November. Models predict the MJO signal to propagate eastwards, reaching the Indian Ocean (Phase 2) by the start of the forecast period. Most models predict the signal to weaken in Phase 3 during the first week.

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 the southern ASEAN region in the next fortnight (13 – 26 November), drier conditions are predicted, except over parts of the equatorial region where wetter conditions are predicted.

For the northern ASEAN region in Week 1 (13 – 19 November), wetter conditions are predicted over much of this region. In Week 2 (20 – 26 November), drier conditions are predicted over southern Mainland Southeast Asia.

Warmer than usual temperature is predicted over most of the Maritime Continent during the next fortnight (13 – 26 November).

No Madden-Julian Oscillation (MJO) signal was present around the start of the forecast period. Most models predict an MJO signal to develop over the Western Pacific (Phase 7) in Week 1 and then propagate to the Western Hemisphere and Africa (Phases 8 and 1).

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.

Drier conditions are predicted over much of the southwestern and central Maritime Continent in Week 1 (30 October – 5 November). These drier conditions are predicted to persist in Week 2 (6 – 12 November), particularly over much of the southwestern and southern Maritime Continent.

Wetter conditions are predicted over central Mainland Southeast Asia in Week 1 (30 October – 5 November).

Warmer than usual temperature is predicted over much of Mainland Southeast Asia in Week 1 (30 October – 5 November). These warmer conditions are predicted to gradually ease in Week 2 (6 – 12 November). Over much of the Maritime Continent, warmer than usual temperature is predicted in the next fortnight (30 October – 12 November).

During the second half of October, no clear Madden-Julian Oscillation (MJO) signal was present. Most models predict an MJO signal over the Western Hemisphere and Africa (Phases 8 and 1) during the forecast period based on the RMM Index.

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.

Drier conditions are predicted over most of the southwestern Maritime Continent in Week 1 (16 – 22 October). These drier conditions are predicted to extend eastwards to cover much of the Maritime Continent in Week 2 (23 – 29 October).

Wetter conditions are predicted over most of Mainland Southeast Asia in Week 1 (16 – 22 October).

For temperature, warmer than usual temperature is predicted over most of the Maritime Continent in the next fortnight (16 – 29 October).

In the second week of October, a Madden-Julian Oscillation (MJO) signal was present over the Western Hemisphere and Africa (Phase 1) based on the RMM index. Most models predict the MJO signal to decay with no significant activity during the forecast period.

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.

Drier conditions are predicted over much of the Maritime Continent in Week 1 (2 – 8 October). These drier conditions are predicted to persist in Week 2 (9 – 15 October), although with lower likelihood over Borneo and the southern Philippines.

Wetter conditions are predicted over much of Mainland Southeast Asia in Week 2 (9 – 15 October).

For temperature over Mainland Southeast Asia, warmer than usual temperature is predicted in Week 1 (2 – 8 October). In Week 2 (9 – 15 October), warmer than usual temperature is predicted to persist over the southeastern part of the region. For the Maritime Continent, warmer than usual temperature is also predicted over most of the region in the next fortnight (2 – 15 October).

In the second half of September, there was no clear Madden-Julian Oscillation (MJO) signal. Most models predict no significant MJO signal during the forecast period.

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.

Wetter conditions are predicted over the parts of the equatorial region, including the northwestern Maritime Continent, northern Borneo and the southern Philippines in Week 1 (18 – 24 September). Wetter conditions are also predicted over southern Mainland Southeast Asia in Week 2 (25 September – 1 October).

Drier conditions are predicted over most of the southern Maritime Continent in Week 1 (18 – 24 September). These drier conditions are predicted to extend northwards during Week 2 (25 September – 1 October) to cover much of the southern ASEAN region.

Warmer than usual temperature is predicted over much of Mainland Southeast Asia in the next fortnight (18 September – 1 October). In Week 1 (18 – 24 September), warmer than usual temperature is predicted to develop over parts of the equatorial region. By Week 2 (25 September – 1 October), warmer temperature is predicted over much of the southern ASEAN region, in line with the predicted drier conditions.

By the middle of September, there was no clear Madden-Julian Oscillation (MJO) signal. Most models predict no significant MJO activity during the forecast period.

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.

Wetter conditions are predicted over parts of Mainland Southeast Asia and the northern half of the Philippines in Week 1 (4 – 10 September).

Drier conditions are predicted over much of the southern ASEAN region in the next fortnight (4 – 17 September), with the highest likelihood over the southwestern part of the region.

Warmer than usual temperature is predicted over most of the southern ASEAN region in the next fortnight (4 – 17 September), in line with the predicted drier conditions. Elsewhere, in Week 1 (4 – 10 September), warmer than usual temperature is predicted over much of northern and central Mainland Southeast Asia.

No coherent Madden-Julian Oscillation (MJO) signal was present in the second half of August. Some models predict an MJO signal to develop over the Indian Ocean (Phase 3) or the Maritime Continent (Phases 4 and 5) during the first week of September. These models then predict the signal to propagate eastwards into the Western Pacific (Phases 6 and 7) by the end of the forecast period.

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.

Wetter conditions are predicted over parts of Mainland Southeast Asia and the Philippines in the next fortnight (21 August – 3 September).

Drier conditions are predicted over much of the central Maritime Continent in Week 1 (21 – 27 August). These drier conditions are predicted to extend eastward covering much of the southern half of the Maritime Continent in Week 2 (28 August – 3 September).

Warmer than usual temperature is predicted over much of the Maritime Continent in the next fortnight (21 August – 3 September), in line with the predicted drier conditions. Warmer than usual temperature is also predicted over much of northern Mainland Southeast Asia in the next fortnight.

No coherent Madden-Julian Oscillation (MJO) signal was present during the first half of August. During the forecast period, models predict no strong MJO signal, although a few models predict a weak MJO signal to develop over the Western Hemisphere and Africa (Phases 8 and 1) and then propagate eastwards.

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.