Category Archives: Fortnightly Weather Outlook

CR58

April 28, 2023

Subseasonal Weather Outlook (1 – 14 May 2023)

Subseasonal Weather Outlook (1 – 14 May 2023)

Issued: 28 April 2023
First forecast week: 1 May 2023 – 7 May 2023
Second forecast week: 8 May 2023 – 14 May 2023

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Figure 1: Rainfall Outlook

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Figure 2: Temperature Outlook

 

In Week 1 (1 – 7 May), drier conditions are predicted over much of central and eastern Mainland Southeast Asia, as well as northern parts of the Philippines. Also in Week 1, wetter conditions are predicted over much of the Maritime Continent.

Warmer than usual temperature is predicted over much of the eastern half of the Maritime Continent during the next fortnight (1 – 14 May). Warmer than usual temperature is also predicted over much of Mainland Southeast Asia in Week 1 (1 – 7 May).

A Madden-Julian Oscillation (MJO) signal was present over the Indian Ocean (Phase 2) at the end of April. Most models predict an MJO signal to continue propagating eastwards reaching the Western Pacific (Phases 6 and 7) in Week 2 (8 – 14 May).

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.

April 14, 2023

Subseasonal Weather Outlook (17 – 30 April 2023)

Subseasonal Weather Outlook (17 – 30 April 2023)

Issued: 14 April 2023
First forecast week: 17 April 2023 – 23 April 2023
Second forecast week: 24 April 2023 – 30 April 2023

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Figure 1: Rainfall Outlook

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Figure 2: Temperature Outlook

 

In Week 1 (17 – 23 April), drier conditions are predicted over much of Mainland Southeast Asia, the Malay Peninsula and parts of the central Maritime Continent.

Warmer than usual temperature is predicted over much of Mainland Southeast Asia and the Malay Peninsula in Week 1 (17 – 23 April), in line with the predicted drier conditions over these regions.

A Madden-Julian Oscillation (MJO) signal was present over the Western Pacific (Phases 6 and 7) in the second week of April. Most models predict this MJO signal to continue propagating eastwards before decaying over the Western Hemisphere and Africa (Phase 1) towards 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.

March 31, 2023

Subseasonal Weather Outlook (3 – 16 April 2023)

Subseasonal Weather Outlook (3 – 16 April 2023)

Issued: 31 March 2023
First forecast week: 3 April 2023 – 9 April 2023
Second forecast week: 10 April 2023 – 16 April 2023

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Figure 1: Rainfall Outlook

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Figure 2: Temperature Outlook

 

Drier conditions are expected over much of Mainland Southeast Asia in Week 1 (3 – 9 April), in particular over central parts of Mainland Southeast Asia. Drier conditions are also predicted over parts of the western and central Maritime Continent in Week 2 (10 – 16 April).

Warmer than usual temperature is predicted over much of Mainland Southeast Asia in Week 1 (3 – 9 April), in line with the predicted drier conditions. These warmer conditions are predicted to persist over central Mainland Southeast Asia and gradually ease elsewhere in Week 2 (10 – 16 April).

No discernible Madden-Julian Oscillation (MJO) signal was present at the end of March. Most models predict an MJO signal to emerge in the Western Pacific (Phases 6 and 7) during Week 1 and then slowly propagate eastwards over the rest of the forecast period. However, some models predict no discernible MJO signal during this time.

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.

March 17, 2023

Subseasonal Weather Outlook (20 March – 2 April 2023)

Subseasonal Weather Outlook (20 March – 2 April 2023)

Issued: 17 March 2023
First forecast week: 20 March 2023 – 26 March 2023
Second forecast week: 27 March 2023 – 2 April 2023

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Figure 1: Rainfall Outlook

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Figure 2: Temperature Outlook

 

Drier conditions are expected over much of the northern ASEAN region in Week 1 (20 – 26 March), in particular over central and eastern Mainland Southeast Asia and northern Philippines. These drier conditions are predicted to persist over these regions and extend further southwards to the Malay Peninsula in Week 2 (27 March – 2 April).

Warmer than usual temperature is expected over central and eastern Mainland Southeast Asia and northern Philippines in the next fortnight (20 March – 2 April), in line with the predicted drier conditions.

A Madden-Julian Oscillation (MJO) signal was present over the Western Hemisphere and Africa (Phases 8 and 1) in the middle of March. Models predict this signal to weaken and continue propagating eastwards to the Indian Ocean (Phase 2), and decay by the end of Week 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.

March 3, 2023

Subseasonal Weather Outlook (6 – 19 March 2023)

Subseasonal Weather Outlook (6 – 19 March 2023)

Issued: 3 March 2023
First forecast week: 6 March 2023 – 12 March 2023
Second forecast week: 13 March 2023 – 19 March 2023

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Figure 1: Rainfall Outlook

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Figure 2: Temperature Outlook

 

Drier conditions are expected over the southern Maritime Continent in the next fortnight (6 – 19 March). Drier conditions are also expected over southern Mainland Southeast Asia in Week 1 (6 – 12 March).

Wetter conditions are expected over much of the western Maritime Continent in Week 1 (6 – 12 March) and much of the northeastern Maritime Continent in Week 2 (13 – 19 March).

Cooler than usual temperature are predicted over much of the ASEAN region in the next fortnight (6 – 19 March), in particular over southern Mainland Southeast Asia, the western and central Maritime Continent and parts of the Philippines.

No clear Madden-Julian Oscillation (MJO) signal was present at the end of February. Models predict an MJO signal to emerge over the Western Pacific (Phases 6 and 7) by Week 1 and propagate eastwards over the Western Hemisphere and Africa (Phases 8 and 1) 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.

February 17, 2023

Subseasonal Weather Outlook (20 February – 5 March 2023)

Subseasonal Weather Outlook (20 February – 5 March 2023)

Issued: 17 February 2023
First forecast week: 20 February 2023 – 26 February 2023
Second forecast week: 27 February 2023 – 5 March 2023

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Figure 1: Rainfall Outlook

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Figure 2: Temperature Outlook

 

Wetter conditions are expected over the western Maritime Continent in the next fortnight (20 February – 5 March). Wetter conditions are also expected over the northeast Maritime Continent in Week 1 (20 – 26 February).

Cooler than usual temperature is expected over most of central and eastern Mainland Southeast Asia and also over parts of the western Maritime Continent in the next fortnight (20 February – 5 March).

A Madden-Julian Oscillation (MJO) signal was present over the Western Pacific (Phases 6 and 7) in the middle of February. Models predict this MJO signal to continue propagating eastwards and then decay in Week 1 over the Western Hemisphere (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.

February 3, 2023

Subseasonal Weather Outlook (6 – 19 February 2023)

Subseasonal Weather Outlook (6 – 19 February 2023)

Issued: 3 February 2023
First forecast week: 6 February 2023 – 12 February 2023
Second forecast week: 13 February 2023 – 19 February 2023

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Figure 1: Rainfall Outlook

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Figure 2: Temperature Outlook

 

Drier conditions are expected over parts of the western and central Maritime Continent in Week 1 (6 – 12 February). These drier conditions are predicted to persist over the central Maritime Continent in Week 2 (13 – 19 February) and likely easing over the western Maritime Continent.

Wetter conditions are predicted over the northeastern Maritime Continent and southeastern coast of Mainland Southeast Asia in Week 2 (13 – 19 February).

Warmer than usual temperature is expected over much of the eastern half of Mainland Southeast Asia and much of the Philippines in Week 1 (6 – 12 February). Warmer than usual temperature is also expected over parts of the western and central Maritime Continent in Week 1, in line with the predicted drier conditions.

A Madden-Julian Oscillation (MJO) signal was present over the Indian Ocean (Phase 3) at the start of February. Models predict the MJO signal to propagate eastwards and reach the Maritime Continent (Phases 4 and 5) during the first week of the forecast period. Some models then predict this signal to continue propagating through the Maritime Continent to the Western Pacific (Phases 6 and 7), while others predict the signal to decay over the Maritime Continent.

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.

January 20, 2023

Subseasonal Weather Outlook (23 January – 5 February 2023)

Subseasonal Weather Outlook (23 January – 5 February 2023)

Issued: 20 January 2023
First forecast week: 23 January 2023 – 29 January 2023
Second forecast week: 30 January 2023 – 5 February 2023

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Figure 1: Rainfall Outlook

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Figure 2: Temperature Outlook

 

Wetter conditions are predicted over much of the Maritime Continent and coastal parts of eastern Mainland Southeast Asia in the next fortnight (23 January – 5 February). The highest likelihood of wetter conditions is over the region between 0° and 10°N, including the Malay Peninsula, northern Borneo, and the southern Philippines, in Week 1 (23 – 29 January).

Cooler than usual temperature is predicted over much of the southern half of the ASEAN region in Week 1 (23 – 29 January), generally in line with the predicted wetter conditions.

No clear Madden-Julian Oscillation (MJO) signal was present during the third week of January. Some models predict an MJO signal to develop and propagate eastward over the Indian Ocean (Phases 2 and 3) 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.

January 6, 2023

Subseasonal Weather Outlook (9 – 22 January 2023)

Subseasonal Weather Outlook (9 – 22 January 2023)

Issued: 6 January 2023
First forecast week: 9 January 2023 – 15 January 2023
Second forecast week: 16 January 2023 – 22 January 2023

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Figure 1: Rainfall Outlook

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Figure 2: Temperature Outlook

Wetter conditions are predicted over much of southeastern Mainland Southeast Asia and the Philippines in the next fortnight (9 – 22 January). Wetter conditions are also predicted to develop over the western Maritime Continent in Week 2 (16 – 22 January).

Drier conditions are predicted over parts of the southern Maritime Continent in Week 1 (9 – 15 January).

Warmer than usual temperature is predicted around central and northeastern Mainland Southeast Asia in Week 1 (9 – 15 January).

A Madden-Julian Oscillation (MJO) signal weakened over the Western Pacific (Phase 7) at the start of January. Most models predict this MJO signal to strengthen again as the signal propagates eastward over the Western Hemisphere and Africa (Phases 8 and 1) during Week 1, and reaching the Indian Ocean (Phases 2 and 3) during 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.

December 23, 2022

Subseasonal Weather Outlook (26 December 2022 – 8 January 2023)

Subseasonal Weather Outlook (26 December 2022 – 8 January 2023)

Issued: 23 December 2022
First forecast week: 26 December 2022 – 1 January 2023
Second forecast week: 2 January 2023 – 8 January 2023

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Figure 1: Rainfall Outlook

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Figure 2: Temperature Outlook

 
Wetter conditions are expected over the southern Maritime Continent in Week 1 (26 December 2022 – 1 January 2023). Wetter conditions are also predicted over parts of the northeastern Maritime Continent in the next fortnight (26 December 2022 – 8 January 2023), extending to southeastern Mainland Southeast Asia in Week 2 (2 – 8 January 2023). Drier conditions are predicted over the western Maritime Continent and the equatorial region in Week 1.

Cooler than usual temperature is predicted over much of central and eastern Mainland Southeast Asia in the next fortnight (26 December 2022 – 8 January 2023). Cooler conditions are also expected over much of the western and southern Maritime Continent in the next fortnight. Warmer than usual temperature is predicted over parts of the eastern equatorial region in Week 1 (26 December 2022 – 1 January 2023).

In the third week of December, a weak Madden-Julian Oscillation (MJO) signal was present over the Maritime Continent (Phases 4 and 5) based on the RMM index. Most models predict this MJO signal to propagate eastwards to the Western Pacific (Phase 6) in Week 1. There is a disagreement between the models for the MJO signal to either decay or continue propagating eastwards 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.