Subseasonal Weather Outlook (19 April – 2 May 2021)

Issued 16 April 2021
First forecast week: 19 April – 25 April
Second forecast week: 26 April – 2 May


Figure 1: Rainfall Outlook


Figure 2: Temperature Outlook


Wetter conditions are expected over northern and central Philippines in Week 1 (19 – 25 April) associated with tropical cyclone activity. There is also a chance of wetter conditions over southern Myanmar, southern Thailand, southern Cambodia, and central and southern Viet Nam in Week 1.

Drier conditions than usual are expected over much of the southern ASEAN region in Week 1 (19 – 25 April). The drier conditions are expected to ease in Week 2 (26 April – 2 May).

Cooler temperatures than usual are expected over central and southeastern Mainland Southeast Asia, as well as northern and central Philippines, in the next fortnight (19 April – 2 May).

A strong Madden-Julian Oscillation (MJO) signal was present over the Western Pacific (Phase 7) in the middle of April. Most models predict this signal to continue propagating eastwards during the next fortnight, entering the Western Hemisphere and Africa (Phase 8) by 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.