Subseasonal Weather Outlook (9 – 22 August 2021)

Subseasonal Weather Outlook (9 – 22 August 2021)

Issued 6 August 2021
First forecast week: 9 August – 15 August
Second forecast week: 16 August – 22 August

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Figure 1: Rainfall Outlook

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Figure 2: Temperature Outlook

Wetter conditions are expected in Week 1 (9 – 15 August) over most of the southern ASEAN region. These wetter conditions are expected to persist in Week 2 (16 – 22 August) except for parts of the western Maritime Continent.

Drier conditions are expected in Week 1 (9 – 15 August) over western parts of Mainland Southeast Asia.

Warmer temperatures than usual are expected in Week 1 (9 – 15 August) over most of Mainland Southeast Asia, easing in Week 2 (16 – 22 August). Elsewhere, warmer temperatures are also expected over southern parts of the Maritime Continent in the next fortnight (9 – 22 August).

Cooler temperatures than usual are expected in Week 2 (16 – 22 August) over parts of the central Maritime Continent.

An MJO signal was present over the Western Hemisphere and Africa (Phase 8) at the beginning of August, although the signal was no longer discernible based on the RMM Index by the start of the forecast period. Some models predict the MJO to reemerge in Week 1 (either in Phase 1 or Phase 2) and continue propagating eastwards over the Indian Ocean (Phases 2 and 3).
 
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.