Subseasonal Weather Outlook (14 – 27 December 2020)

Issued 11 December 2020
First forecast week: 14 December – 20 December
Second forecast week: 21 December – 27 December


Figure 1: Rainfall Outlook


Figure 2: Temperature Outlook

For the next fortnight (14 – 27 December), an increased chance of wetter conditions is predicted over the Philippines, parts of central and southern Viet Nam, southern Thailand and southern Myanmar. An increased chance of wetter conditions is also predicted around the southeastern part of the Maritime Continent in the first week (14 – 20 December). Drier conditions are predicted over parts of the equatorial region, in particular Borneo and central Sumatra for the next fortnight (14 – 27 December).

There is an increased chance of cooler conditions over southern parts of Indonesia in the first week (14 – 20 December), easing in the second week (21 – 27 December).

A weak Madden-Julian Oscillation (MJO) signal is present over the eastern Maritime Continent (Phase 5). Most models predict this MJO to continue propagating slowly eastwards over the Pacific, although weakening due in part to the La Niña conditions.

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.