Subseasonal Weather Outlook and Review

Subseasonal Weather Outlook (7 – 20 September 2020)

Issued 7 September 2020
First forecast week: 7 September – 13 September
Second forecast week: 14 September – 20 September

Figure 1: Rainfall Outlook

Figure 2: Temperature Outlook

 
For the northern part of Southeast Asia, drier conditions are predicted to persist for the first week (7 – 13 September), before returning to normal in the second week (14 – 20 September). For the equatorial region, wetter conditions are predicted in the first week, gradually easing in most places the following week, except for southern Thailand, northern Borneo and northern Sulawesi.

Warmer conditions are expected during the fortnight over northern and southern parts of Southeast Asia, with closer to normal temperatures in the equatorial region (corresponding to the wetter conditions in the rainfall outlook).

At the start of September, a Madden-Julian Oscillation (MJO) signal was present in the Indian Ocean (Phase 3). Most models predict this MJO to decay by the start of the first week of the forecast.
 
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.

Subseasonal Weather Outlook (7 – 20 September 2020)

Issued 7 September 2020
First forecast week: 7 September – 13 September
Second forecast week: 14 September – 20 September

Figure 1: Rainfall Outlook

Figure 2: Temperature Outlook

 
For the northern part of Southeast Asia, drier conditions are predicted to persist for the first week (7 – 13 September), before returning to normal in the second week (14 – 20 September). For the equatorial region, wetter conditions are predicted in the first week, gradually easing in most places the following week, except for southern Thailand, northern Borneo and northern Sulawesi.

Warmer conditions are expected during the fortnight over northern and southern parts of Southeast Asia, with closer to normal temperatures in the equatorial region (corresponding to the wetter conditions in the rainfall outlook).

At the start of September, a Madden-Julian Oscillation (MJO) signal was present in the Indian Ocean (Phase 3). Most models predict this MJO to decay by the start of the first week of the forecast.
 
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.