Monthly Archives: February 2022

February 28, 2022

Hotspot and Haze Assessment (H2A) Workshop 2022 for the ASEAN Region, online 22 – 23 February 2022

ASMC has conducted six workshops on hotspot and haze assessment since 2018 under its Regional Capability Building Programme for ASEAN Member States. This year a combined workshop was held for both the Mekong sub-region and southern ASEAN region, bringing together participants from both regions to discuss and share on common regional issues in fires and haze monitoring, mitigation and control.

The H2A 2022 Workshop for the ASEAN region was held online over two days on 22 -23 February 2022 and welcomed more than 42 participants from environment and disaster management sectors in countries around the ASEAN region, including Brunei, Lao PDR, Malaysia, Myanmar, Thailand and Viet Nam. Representatives from the Environment Division of the ASEAN Secretariat (ASEC) were also in attendance.

Figure 1: Group photo of participants and lecturers at the 2022 H2A workshop.

During the workshop, there were engaging discussions by participants on local issues in fires management, monitoring and suppression, as well as air quality and haze conditions in 2021. Participants also actively partook in quizzes and activities during the lectures on interpretation of satellite imageries, satellite technologies and products, sub-seasonal and seasonal predictions, and dispersion modelling. The workshop participants were updated on the review and outlook of regional weather, climate and haze situation to help them better prepare for the possibility of fires and smoke haze development in their respective countries during the upcoming months.

Dr Vong Sok, Head of Environment Division at ASEC expressed his appreciation to the workshop organisers and speakers at the end of the session and welcomed the opportunity to learn about the technical analysis and assessments at the ASMC, which is useful to support their work in the region. Ms Naila Athifa, Environmental Officer from Department of Environment, Brunei Darussalam also opined that the quizzes were a nice touch to allow interaction and check the understanding of participants.

Figure 2: Lecturers introduced participants to a range of topics relevant to fires and smoke haze monitoring and assessment in the ASEAN region

Going forward, ASMC will plan further workshops in numerical weather prediction, climate change projections, subseasonal and seasonal predictions, as well as haze monitoring to further advance regional capabilities in issues relating to weather, climate and transboundary smoke haze.

February 18, 2022

Subseasonal Weather Outlook (21 February – 6 March 2022)

Issued: 18 February 2022
First forecast week: 21 February – 27 February
Second forecast week: 28 February – 6 March

Figure 1: Rainfall Outlook

Figure 2: Temperature Outlook

Wetter conditions are expected in the next fortnight (21 February – 6 March) for much of the region encompassing the Malay Peninsula, coastal parts of southeastern Mainland Southeast Asia, the Philippines, and northeast Borneo. The highest likelihood of wetter conditions is over the Malay Peninsula in Week 1 (21 – 27 February) and over the Philippines in Week 2 (28 February – 6 March).

Wetter conditions are also expected in Week 1 (21 – 27 February) over southeastern parts of the Maritime Continent.

Cooler than usual conditions are expected for Mainland Southeast Asia in Week 1 (21– 27 February), easing in Week 2 (28 February – 6 March).

The Madden-Julian Oscillation (MJO) signal was present over the Indian Ocean (Phase 3) in the middle of February based on the RMM Index. Most models predict the MJO signal to propagate eastwards through the Maritime Continent (Phases 4 and 5) 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.

February 17, 2022

Review of Regional Weather for January 2022

1. Overview

1.1 During January 2022, the Maritime Continent experienced a mix of below- and above-average rainfall, with Mainland Southeast Asia experiencing its typical dry season, apart from northern Lao PDR and Viet Nam that experienced above-average rainfall (Figure 1). For the Maritime Continent, both satellite-derived rainfall estimates datasets (GSMaP-NRT and CMORPH-Blended) show large negative anomalies (drier conditions) over the Malay Peninsula and the southern half of the Philippines. However, there are some discrepancies between the two datasets elsewhere. CMORPH-Blended (Figure 1b) recorded below-average rainfall for much of the region, apart from the northern Philippines, and isolated parts of Sumatra and Borneo. GSMaP-NRT (Figure 1a) however, recorded more extensive areas of above-average rainfall with isolated areas of below-average rainfall primarily over parts of Borneo and Java.

1.2 The mix of below- and above-average rainfall for the Maritime Continent with no clear regional pattern is in line with the subseasonal weather outlooks for January 2022, which predicted a mix of below- to above-average rainfall depending on the outlook (27 December – 9 January, 10 – 23 January, and 24 January – 6 February), although the wetter conditions over northern Lao PDR and Viet Nam were not included in any of the outlooks.

Figure 1: Rainfall anomalies for the month of January 2022 based on GSMaP-NRT data (left) and CMORPH-Blended data (right). The climatological reference period is 2001-2021. Green colour denotes above-average rainfall (wetter), while orange denotes below-average rainfall (drier).

1.3 Near- to above-average temperature was recorded in Southeast Asia in January 2022, apart from northern Myanmar where below- to near-average temperature was recorded (Figure 2). The largest positive anomalies (more than 1°C warmer) were over central and eastern parts of Mainland Southeast Asia. For the Maritime Continent, the largest positive anomalies were over the Malay Peninsula (0.25°C – 1°C warmer), with the rest of the area near- or slightly above-average.

Figure 2: Temperature anomalies for the month of January 2022 based on ERA-5 reanalysis. The climatological reference period is 2001-2021. Red colour denotes above-average temperature (warmer), while blue denotes below-average temperature (colder).

2. Climate Drivers

2.1 A Madden-Julian Oscillation (MJO) signal was present over the Western Pacific (Phase 7) at the start of January 2022, based on the MJO phase diagram below (Figure 3). In the second week of January, the signal entered the Western Hemisphere (Phase 8) and then weakened rapidly. In the second half of January, there was no MJO signal. Phase 7 tends to bring drier conditions to the western Maritime Continent and expanding in Phase 8 to most of the Maritime Continent at this time of the year.

Figure 3: The MJO phase diagram. The diagram illustrates the movement of the MJO through different phases, which correspond to different locations along the equator (denoted in the text with the first day of the month in blue and the last day of the month in red). The distance of the index from the centre of the diagram is related to the strength of the MJO. Values within the grey circle are considered weak or indiscernible (data from the Bureau of Meteorology, Australia).

2.2 Over the tropical Pacific Ocean, La Niña conditions were present. Sea surface temperatures in the Nino3.4 region (used to monitor ENSO) and the atmospheric indicators over the tropical Pacific Ocean were consistent with La Niña conditions. La Niña events tend to bring wetter-than-average conditions to much of the Maritime Continent during the December to February period.

February 14, 2022

Review of Regional Haze Situation for January 2022

1.1 Northeast Monsoon conditions persisted over the ASEAN region in January 2022. This month, the prevailing low-level winds over regions north of the Equator blew mostly from the northeast or east while the prevailing low-level winds over regions south of the Equator blew mainly from the west or northwest. Under the influence of the Northeast Monsoon, persistent dry conditions were observed over the Mekong sub-region. Relatively dry weather was also observed over parts of Peninsular Malaysia, Singapore, the Philippines and Sumatra in January 2022. Wetter conditions were observed over regions south of the Equator during the review period in line with the monsoon rainband’s position south of the Equator.

Figure 1: Average Daily Rainfall and Mean Winds for January 2022. (Source: JAXA GsMaP and GFS, respectively)

1.2 In January 2022, hotspot activities started to increase in the Mekong sub-region as dry conditions prevailed, while wet conditions helped subdue hotspot activities in the southern ASEAN region. The hotspot counts for the Mekong sub-region in January 2022 were mostly lower compared to previous years, while the hotspot counts over the southern ASEAN region were generally similar to previous years (Figures 2 and 3).

Figure 2: Hotspot counts for the northern ASEAN region for the month of January (2018 – 2022). [Note: The hotspot counts from 2019 onwards are based on the NOAA-20 satellite, while those from 2018 are based on the Suomi-NPP satellite.]

Figure 3: Hotspot counts for the southern ASEAN region for the month of January (2018 – 2022). [Note: The hotspot counts from 2019 onwards are based on the NOAA-20 satellite, while those from 2018 are based on the Suomi-NPP satellite.]

1.3 The Mekong sub-region remained at Alert Level 1 for the month as the risk of transboundary haze remained low. However, there was an increase in hotspot activities with localized smoke plumes in persistently dry areas of the sub-region. In particular, clusters of scattered hotspots with visible smoke plumes were detected in northeastern Cambodia on several days. Elsewhere in the ASEAN region, hotspot activities remained mostly subdued (Figures 4 and 5).

Figure 4: Distribution of hotspots detected in January 2022 based on NOAA-20 satellite surveillance.

Figure 5: Maximum fire intensity in January 2022 based on NOAA-20 satellite surveillance.

February 10, 2022

Alert20220210 – Activation of Alert Level 2 for the Mekong Sub-region

Activation of Alert Level 2 for the Mekong Sub-region

In recent weeks, persistent dry conditions over the Mekong sub-region have led to an escalation of hotspot and smoke haze activities. Based on surveillance by NOAA-20 satellite, 370 and 405 hotspots were detected in the Mekong sub-region on 8 and 9 Feb 2022, respectively.

In the coming days, some showers are forecast over the southern and eastern parts of the Mekong sub-region. However, the rest of the sub-region is expected to remain dry. The prevailing winds over the sub-region are expected to strengthen and blow from the northwest or northeast. Under these conditions, there is a risk of a deterioration in the hotspot and smoke haze situation and an increased likelihood of transboundary haze.

February 4, 2022

Subseasonal Weather Outlook (7 – 20 February 2022)

Issued: 4 February 2022
First forecast week: 7 February – 13 February
Second forecast week: 14 February – 20 February

Figure 1: Rainfall Outlook

Figure 2: Temperature Outlook

Wetter conditions are expected in the next fortnight (7 – 20 February) over the region between the equator and 10°N (including the Malay Peninsula, northern Sumatra, northern Borneo and southern Philippines) and also the southern Maritime Continent.

Drier conditions are expected in the next fortnight (7 – 20 February) over central and southern Sumatra.

For temperature, warmer than usual conditions are expected over southern Mainland Southeast Asia and parts of the Philippines in Week 1 (7 – 13 February). Warmer conditions are also expected over the region around Sumatra in the next fortnight (7 – 20 February), in line with the drier conditions predicted.

Cooler than usual conditions are expected for northern parts of Mainland Southeast Asia in the next fortnight (7 – 20 February).

At the start of February, there was no Madden-Julian Oscillation (MJO) signal. Some models predict an MJO to develop over the Indian Ocean (Phase 3) in Week 1 and then propagate through the Maritime Continent (Phases 4 and 5), while other models predict the MJO to remain weak over 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.