Subseasonal Weather Outlook (11 – 24 January 2021)

Issued 8 January 2021
First forecast week: 11 January – 17 January
Second forecast week: 18 January – 24 January


Figure 1: Rainfall Outlook


Figure 2: Temperature Outlook

For rainfall in Week 1 (11 – 17 January 2021), an increased chance of wetter conditions is predicted over much of the Maritime Continent. Drier conditions are also predicted for regions around the Gulf of Thailand in Week 1. In Week 2 (18 – 24 January 2021), the wetter conditions are expected to ease, apart from over the Philippines and northern Borneo, with drier conditions expected to develop in parts of the western Maritime Continent.

An increased chance of cooler conditions is predicted over much of Mainland Southeast Asia and parts of the western Maritime Continent in Week 1 (11 – 17 January 2021) due to a surge of cool air blowing southward from the northern Asian landmass. In Week 2 (18 – 24 January 2021), the cooler conditions are expected to ease for much of this area, apart from central parts of Mainland Southeast Asia. Warmer conditions are expected to develop in the central and eastern equatorial region in Week 2.

An MJO signal is present over the Indian Ocean (Phase 3). Some models predict it to propagate eastward, entering the Maritime Continent 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.