Subseasonal Weather Outlook (15 – 28 May 2023)

Issued: 12 May 2023
First forecast week: 15 May 2023 – 21 May 2023
Second forecast week: 22 May 2023 – 28 May 2023


Figure 1: Rainfall Outlook


Figure 2: Temperature Outlook


Drier conditions are predicted over most of the central Maritime Continent during the next fortnight (15 – 28 May). Drier conditions are also predicted over much of Mainland Southeast Asia in Week 1 (15 – 21 May). Wetter conditions are predicted over most parts of the Philippines in Week 2 (22 – 28 May).

Warmer than usual conditions are expected over much of Mainland Southeast Asia and parts of the western Maritime Continent in Week 1 (15 – 21 May). These warmer conditions are predicted to gradually ease during Week 2 (22 – 28 May). Over much of the eastern Maritime Continent, warmer than usual temperature is predicted during Week 2.

A Madden-Julian Oscillation (MJO) signal was present over the Maritime Continent (Phases 4 and 5) in the first week of May. Most models predict this MJO signal to continue propagating eastwards through the Western Pacific (Phases 6 and 7) 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.