Subseasonal Weather Outlook and Review

Drier than usual conditions are predicted over most of the southern ASEAN region in the next fortnight (28 September – 11 October). Drier than usual conditions are also predicted for parts of the northeastern Maritime Continent and southern Mainland Southeast Asia in Week 1 (28 September – 4 October).

Warmer than usual conditions are predicted over most of the ASEAN region in Week 1 (28 September – 4 October). These warmer conditions are predicted to persist over most of the southern ASEAN region in Week 2 (5 – 11 October).

A Madden-Julian Oscillation (MJO) signal was present over the Western Hemisphere (Phases 8 and 1) in the third week of September, based on the RMM index. Models predict the signal to weaken and become inactive by the start of the forecast period. During the forecast period (28 September – 11 October), most models predict no significant MJO activity.

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 than usual conditions are predicted over most of the southern ASEAN region in the next fortnight (28 September – 11 October). Drier than usual conditions are also predicted for parts of the northeastern Maritime Continent and southern Mainland Southeast Asia in Week 1 (28 September – 4 October).

Warmer than usual conditions are predicted over most of the ASEAN region in Week 1 (28 September – 4 October). These warmer conditions are predicted to persist over most of the southern ASEAN region in Week 2 (5 – 11 October).

A Madden-Julian Oscillation (MJO) signal was present over the Western Hemisphere (Phases 8 and 1) in the third week of September, based on the RMM index. Models predict the signal to weaken and become inactive by the start of the forecast period. During the forecast period (28 September – 11 October), most models predict no significant MJO activity.

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.