GENERAL REVIEW OF SEPTEMBER 2022

For the month of September 2022, a total of 193 disasters or a daily average of 6 disasters were reported. Compared to the previous month (August), this is more than twice as many and 1.5x higher compared to September of the previous year. This is also 3.4x higher than the five-year average (2017-2021) of disaster occurrences for the month of September. September 2022 saw disasters affecting 596 per 100,000 people* and internally displacing 10 per 100,000 people*. From the start of the year 2022, a total of 11.6M persons have been affected by disasters or an average of 42,591 persons in a day. This total is already 1.2M or 11% higher than the same period of the previous year.

The ASEAN Member States that were affected are Cambodia, Indonesia, Malaysia, the Philippines, Thailand, and Viet Nam. Most of the disasters (68%) occurred in Indonesia but only accounted for 8% of the total reported affected persons for September 2022. Thailand, despite accounting for only 6% of the disaster occurrences for the month, accounted for 73% (2,916,745) of the total reported affected persons for the month. On one hand, the share of disaster occurrences for the other member states are as follows: Cambodia – 3%, Malaysia – 3%, The Philippines 8%, and Viet Nam – 10%. On the other hand, the share of affected persons for the other member states are as follows: Cambodia – 0.001%, Malaysia – 0.0004%, the Philippines – 37%, and Viet Nam – 1.6%.

Most of the disasters that have occurred in September 2022 are floods (63%) and is consistently the most recorded disaster-causing natural hazard for September of the previous year and September on a five-year average (2017-2021). The reported disasters in the region for September 2022 in comparison to the historical data (average for September 2017-2021) indicates that there were about 3.4x more reported disasters; 1.08x less people affected; 2.4x less people internally displaced; 9.8x more houses affected to some extent; 8.5x less lives lost; 12x less people suffering injuries; and lastly, 28x less people that have gone missing. The main drivers of the impacts in the ASEAN region were the monsoon situation in Thailand that have caused widespread flooding as reported by the Department of Disaster Prevention and Mitigation (DDPM) and the impacts of Tropical Cyclone (TC) NORU in the Philippines, Viet Nam, Lao PDR, Cambodia, and Thailand. The tropical cyclone affected multiple member states, but the Philippines’ resources were sufficient, and Viet Nam was able to prepare well. Thailand had requested for relief items in response to TC NORU-associated flooding which has worsened the situation in areas that have long been impacted by the monsoon situation.

Geophysically, 43 significant earthquakes (Magnitude ≥ 5.0) were reported by Indonesia’s Badan Meteorologi, Klimatologi dan Geofisika (BMKG), the Philippine Institute for Volcanology and Seismology (PHIVOLCS), the Thai Meteorological Department (TMD), and the Department of Meteorology and Hydrology (DMH) of Myanmar. This emphasizes the importance of disaster preparedness as three ASEAN Member States lie on the “Pacific Ring of Fire,” a zone of active volcanoes and frequent earthquakes.

Mount Semeru, Ili Lewotolok (Alert Level III), and Ibu, Dukono (Alert Level II) in Indonesia and Taal Volcano (lowered to Alert Level 1), Mayon, Mount Kanlaon (Alert Level 1) were reportedly tectonically active (erupting lava or releasing gas or generating seismic activity) throughout the whole of September 2022.

*Computed based on 2020 population data from worldometers.com

SEASONAL OUTLOOK

For the month of September 2022, much of the ASEAN region experienced rainfall more than what is traditionally experienced for the month. Wetter conditions (compared to the average for September 2022) were recorded over Viet Nam and Southern Borneo hence the hydrometeorological-induced disasters in Viet Nam and Indonesia. In contrast, below-average to average rainfall were recorded in Peninsular Malaysia, the Philippines, and Northern Myanmar, northern Lao PDR, northern Sumatra and northern Papua of Indonesia. Despite this, hdyrometeorological hazard-induced disasters still occurred in most of these areas (except northern Myanmar, northern Lao PDR, and northern Papua).

According to the ASEAN Specialised Meteorological Centre (ASMC), for the October-November-December period much of the ASEAN region will be experiencing above-normal rainfall. Normally, this period is regarded as the disaster season for the region. This is on top of the traditionally wet monsoon seasons in Thailand (May-October), Cambodia (May-October), Lao PDR (May-October), Viet Nam (May-November), the typhoon season in the Philippines (July-October) and the start of the rainy season in Indonesia (November-March). Therefore, the threat of hdyrometeorological hazard-induced disasters is even more likely.

In terms of temperature, below- to near-normal temperatures are favoured for parts of the equatorial region and much of the Mainland Southeast Asia, with above-normal temperature favoured elsewhere which likely means for hotspot activities to generally be subdued for the period.

The qualitative outlook is assessed for the region in general. For specific updates on the national scale, the relevant ASEAN National Meteorological and Hydrological Services should be consulted. More outlook and verification plots, including for tercile and quintile probabilistic forecasts for temperature, are in the “Model products and verification: NCEP, ECMWF, UK Met Office” on the SEA-RCC Network LRF Node webpages.

Sources: ASEAN Disaster Information Network (ADINet), ASEAN Disaster Monitoring and Response System (DMRS), ASEAN Specialised Meteorological Centre (ASMC), Badan Nasional Penanggulangan Bencana (BNPB) – Indonesia, Agensi Pengurusan Bencana Negara (NADMA) – Malaysia, National Disaster Risk Reduction and Management Council (NDRRMC) – Philippines, Department of Disaster Prevention and Mitigation (DDPM) – Thailand, Thai Meteorological Department (TMD) – TMD, Viet Nam Disaster Management Authority (VNDMA) – Viet Nam, Badan Meteorologi, Klimatologi dan Geofisika (BMKG) – Indonesia, Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) – Indonesia, Department of Meteorology and Hydrology (DMH) – Myanmar, Philippine Institute for Volcanology and Seismology (PHIVOLCS) – Philippines, Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) – Philippines

Written by : Keith Paolo Landicho, Sadhu Zukhruf Janottama, Lawrence Anthony Dimailig

GENERAL REVIEW OF DECEMBER 2021

For the month of December 2021, a total of 204 disasters were reported. The ASEAN Member States that were affected are Indonesia, Malaysia, Myanmar, the Philippines, Thailand, and Viet Nam. Most of the disasters (88.73%) occurred in Indonesia but the highest number of affected people were reported for the Philippines at more than 8 million. The number of affected persons from the Philippines comprised the majority of the tally for the month of December (87.36%) and is attributed with the developments of Tropical Cyclone RAI. The share of the disaster-affected people for the other ASEAN Member States are as follows: (1) Indonesia-8.6%, (2) Malaysia-0.71%, (3) Myanmar-0.001%, (4) Thailand-0.15%, and (5) Viet Nam-%. December 2021 saw disasters affecting 1,410 per 100,000 people* and displacing 117 per 100,000 people* in the region, which were 8 times and 28 times higher respectively compared with the previous month. December 2021 accounts for 14.51% of the total disasters (1,406), 71.69% of the total cost of damages (814.8 Million USD), and 69.83% of the total cost of assistance provided (21.1 Million USD) reported so far in the current year.

Most of the disasters that have occurred in December 2021 are floods (74.02%) and is consistently the most recorded type of disaster for December of the previous year and December on a five-year average (2016-2020). December 2021 saw disasters caused by hydrometeorological hazards (flood, rain-induced landslides, storm, winds) affecting 99.68% of the total affected persons for the month. The reported disasters in the region for December 2021 in comparison to the historical data (average for December 2016-2020) indicates that there were 7.5x more reported disasters; 3.4x more people affected; 4.6x more people displaced; 15.7x more houses affected to some extent; 5.8x more lives lost; 16.2x more people suffering injuries; and lastly, 10.5x more people that have gone missing.

*Computed based on 2020 population data from worldometers.com

ANALYSIS

According to the ASEAN Specialised Meteorological Centre (ASMC), compared to the average value from 2001-2020, during December 2021, rainfall was above-average over coastal central parts of Viet Nam, Peninsular Malaysia, and the southern half of the Philippines. The largest positive anomalies (wetter conditions) were detected over central Philippines and Peninsular Malaysia (due to Super Typhoon RAI and Tropical Depression 29W respectively, which made landfall in mid-December), for both satellite-derived rainfall estimates datasets (GSMaP-NRT and CMORPH-Blended). As expected, the start of the dry season for the northern ASEAN region resulted in negligible rainfall anomalies for the rest of Mainland Southeast Asia, where only four disasters caused by floods were reported. Meanwhile, for the equatorial ASEAN region, a mix of above- and below-average rainfalls were observed and accordingly, a number of hydrometeorological disasters were reported.

SEASONAL OUTLOOK

In the month of December 2021, the Northeast Monsoon was established over a majority of the ASEAN region and is expected to persist until late March 2022. It is during this period that inter-monsoon conditions will typically start to develop. Climatologically, the northern ASEAN region experiences its traditional dry season during the period with the prevailing low-level winds blowing from the northeast or east. Wet conditions will typically prevail over the southern ASEAN region as the monsoon rain band progresses south of the equator. This is seen to occur during the beginning of the outlook period before becoming drier and occasionally windy. This happens as the region experiences the dry phase of the Northeast Monsoon starting late January to early March. The prevailing low-level winds over the southern ASEAN region are expected to blow from the north or northwest. Hydrometeorological disasters are likely as the monsoon rain band moves towards the south of the equator and are less likely for the northern ASEAN region and the southern ASEAN region in the coming weeks during the transition into the dry phase of the Northeast Monsoon.

In the coming period (January to March 2022), there is an increased chance of above-normal rainfall over eastern parts of the Maritime Continent and the Malay Peninsula. La Niña conditions are present. Models are predicting weak to moderate La Niña conditions until March-April 2022, after which the conditions are predicted to return to neutral during April-June 2022. Warmer-than-usual temperature is expected for much of the Maritime Continent (except the Malay Peninsula where near-normal temperature is predicted) and Myanmar during JFM 2022.

Hotspot activities and smoke haze situation are seen to intensify especially in northern parts of Myanmar as the traditional dry season over the northern ASEAN region progresses. Subdued hotspot activities are expected in the southern ASEAN region due to the current wet conditions, but localised hotspots can still occur occasionally during the transition to the dry phase of the Northeast Monsoon.

*Note from ASMC: The qualitative outlook is assessed for the region in general and based on the latest runs from models provided by the SEA RCC-Network LRF node. For specific updates on the national scale, the relevant ASEAN National Meteorological and Hydrological Services should be consulted.

Sources: ASEAN Disaster Information Network (ADINet), ASEAN Disaster Monitoring and Response System (DMRS), ASEAN Specialised Meteorological Centre (ASMC), Badan Nasional Penanggulangan Bencana (BNPB) – Indonesia, Agensi Pengurusan Bencana Negara (NADMA) – Malaysia, Department of Disaster Management (DDM) – Myanmar, National Disaster Risk Reduction and Management Council (NDRRMC) – Philippines, Department of Disaster Prevention and Mitigation (DDPM) – Thailand, Viet Nam Disaster Management Authority (VNDMA) – Viet Nam, Badan Meteorologi, Klimatologi dan Geofisika (BMKG) – Indonesia, Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) – Indonesia, Department of Meteorology and Hydrology (DMH) – Myanmar, Philippine Institute for Volcanology and Seismology (PHIVOLCS) – Philippines, Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) – Philippines

Written by : Keith Paolo Landicho, Sadhu Zukhruf Janottama, Lawrence Anthony Dimailig

GENERAL REVIEW OF NOVEMBER 2021

For the month of November 2021, a total of 145 disasters were reported. The ASEAN Member States that were affected are Indonesia, Malaysia, the Philippines, Thailand, and Viet Nam. Most of the disasters (84.14%) occurred in Indonesia and the highest number of affected people were also reported in Indonesia which comprise more than half of the tally for the month of November (54.45%). The share of the disaster-affected people for other ASEAN Member States are as follows: (1) Malaysia-0.20%, (2) the Philippines-1.19%, (3) Thailand-42.72%, and (4) Viet Nam-1.45%. November 2021 saw disasters affecting 144 per 100,000 people* and displacing 4 per 100,000 people* in the region, recording a 57.11% and a 77.23% lower numbers respectively compared with the previous month. November 2021 accounts for 12.06% of the total disasters (1,202) reported so far in the current year.

Most of the disasters that have occurred in November 2021 are floods (83.45%) and is consistently the most recorded type of disaster for November of the previous year and November on a five-year average (2016-2020). November 2021 saw disasters caused by hydrometeorological hazards (flood, landslides, storm, winds) affecting 99.31% of the total affected persons for the month. The reported disasters in the region for November 2021 in comparison to the historical data (average for November 2016-2020) indicates that there were 6x more reported disasters; 2.21x less people affected; 5.62x less people displaced; 1.15x more houses affected to some extent; 4.87x less lives lost; 14.06x less people suffering injuries; and lastly, 1.36x less people that have gone missing.

Geophysically, 20 significant earthquakes (Magnitude ≥ 5.0) were reported by Indonesia’s Badan Meteorologi, Klimatologi dan Geofisika (BMKG), Myanmar’s Department of Meteorology and Hydrology (DMH), and the Philippine Institute for Volcanology and Seismology (PHIVOLCS). In Central Maluku Indonesia, a Magnitude 5.9 earthquake affected 210 people, displaced 6 people and damaged 42 houses, 1 school, and 2 worship places. Recent volcanic activity was reported for Ili Lewotolok (Alert Level III) and Semeru, Ibu, Dukono (Alert Level II) in Indonesia, and Taal (Alert Level 2) and Kanlaon (Alert Level 1) in the Philippines.

*Computed based on 2020 population data from worldometers.com

ANALYSIS

According to the ASEAN Specialised Meteorological Centre (ASMC), compared to the average value from 2001-2020, during November 2021, rainfall was near-average over much Mainland Southeast Asia, above-average rainfall over southern Mainland Southeast Asia and a mix of below- to above-average for the Maritime Continent (Figure 1). The largest positive anomalies (wetter conditions) were detected over the southern Mainland Southeast Asia for both satellite-derived rainfall estimates datasets (GSMaP-NRT and CMORPH-Blended). This is resulted to flooding in Southern and Western Region of Thailand which is affected 70.8K families (353.9K people) and cost the lives of 2 individuals. Negative anomalies (drier conditions) were recorded over central Sumatra and the Philippines, with larger negative anomalies based on CMORPH-Blended data compared to GSMaP-NRT.

SEASONAL OUTLOOK

From the second half of the month of October 2021, the Southwest Monsoon had transitioned into the inter-monsoon period. On a climatological standpoint, inter-monsoon conditions likely prevails over the ASEAN region in November before the Northeast Monsoon conditions develop in December. Inter-monsoon conditions are characteristic of light and variable in direction prevailing winds. In terms of precipitation, the monsoon rain band will be located closer to the equator hence an increase in rainfall over the equatorial ASEAN region can be expected.

In the coming period (December 2021 to February 2022), there is an increased chance of near- to above-normal rainfall over much of the Maritime Continent , and a mix of below- to above-normal rainfall over Mainland Southeast Asia with the above-normal rainfall possibly pertaining to chances of hydrometeorological disasters occurring. La Niña conditions are present and models are predicting weak to moderate La Niña conditions until March-April, after which the conditions are predicted to weaken. The negative Indian Ocean Dipole (IOD) event has ended and is expected to be neutral for the coming months. Warmer-than-usual temperature is expected for much of the Maritime Continent and Myanmar during the period of December 2021 to February 2022.

The dry season over the southern ASEAN region had ended in mid-October 2021. In the northern ASEAN region, the traditional dry season typically sets in at the end of the year. While there is an increased chance of above-normal rainfall over some parts of the northern ASEAN region, hotspot and smoke haze activity can still be expected to progressively intensify over the fire-prone areas in the Mekong sub-region, with an increased likelihood of transboundary haze occurrence during this period.

*Note from ASMC: The qualitative outlook is assessed for the region in general and based on the latest runs from models provided by the SEA RCC-Network LRF node. For specific updates on the national scale, the relevant ASEAN National Meteorological and Hydrological Services should be consulted.

Sources: ASEAN Disaster Information Network (ADINet), ASEAN Disaster Monitoring and Response System (DMRS), ASEAN Specialised Meteorological Centre (ASMC), Badan Nasional Penanggulangan Bencana (BNPB) – Indonesia, Agensi Pengurusan Bencana Negara (NADMA) – Malaysia, Department of Disaster Management (DDM) – Myanmar, National Disaster Risk Reduction and Management Council (NDRRMC) – Philippines, Department of Disaster Prevention and Mitigation (DDPM) – Thailand, Viet Nam Disaster Management Authority (VNDMA) – Viet Nam, Badan Meteorologi, Klimatologi dan Geofisika (BMKG) – Indonesia, Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) – Indonesia, Department of Meteorology and Hydrology (DMH) – Myanmar, Philippine Institute for Volcanology and Seismology (PHIVOLCS) – Philippines, Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) – Philippines

Written by : Keith Paolo Landicho, Sadhu Zukhruf Janottama, Lawrence Anthony Dimailig

GENERAL REVIEW OF OCTOBER 2021

For the month of October 2021, a total of 144 disasters were reported. The ASEAN Member States that were affected were Cambodia, Indonesia, Malaysia, the Philippines, Thailand and Viet Nam. Most of the disasters (54.86%) occurred in Indonesia but the highest number of affected people was reported in the Philippines which comprised more than half of the tally for the month of October (55%). The share of the disaster-affected people for other ASEAN Member States was as follows: (1) Cambodia-0.66%, (2) Indonesia-25.40%, (3) Malaysia-0.08%, (4) Thailand-15.89%, and (5) Viet Nam-2.97%. October 2021 saw disasters affecting 335 per 100,000 people* and displacing 11 per 100,000 people* in the region, recording a 22.63% decrease and a 35.29% respectively, from the previous month. October 2021 accounts for 13.64% of the total disasters (1,056) reported so far in the current year.

Most of the disasters that occurred in October 2021 were floods (62.5%) and this is consistently the most recorded type of disaster for October of the previous year and October on a five-year average (2016-2020). October 2021 saw hydrometeorological disasters (droughts, floods, rain-induced landslides, storms, winds) affecting 99.6% of the total affected persons for the month. The reported disasters in the region for October 2021 in comparison with the historical data (average for October 2016-2020) indicates that there were 8x more reported disasters; 1.34x fewer people affected; 1.22x fewer people displaced; 1.97x more houses affected to some extent; 6.58x fewer lives lost; 22.47x fewer people suffering injuries; and lastly, 14.05x fewer people reported missing.

Geophysically, 18 significant earthquakes (Magnitude ≥ 5.0) were reported by Indonesia’s Badan Meteorologi, Klimatologi dan Geofisika (BMKG), Myanmar’s Department of Meteorology and Hydrology (DMH), and the Philippine Institute for Volcanology and Seismology (PHIVOLCS). In Bali Indonesia, a magnitude 4.8 earthquake, albeit not a significant earthquake, affected 7,690 people and damaged 2,320 houses. Recent volcanic activity was reported for Ili Lewotolok (Alert Level III) and Semeru, Kerinci, Ibu, Karangetang, Krakatau (Alert Level II) in Indonesia, and Taal (Alert Level 2) and Kanlaon (Alert Level 1) in the Philippines.

*Computed based on 2020 population data from worldometers.com

ANALYSIS

According to the ASEAN Specialised Meteorological Centre (ASMC), compared with the average value from 2001-2020, during October 2021, rainfall was above-average over much of the northern ASEAN region and a mix of below- to above-average for the southern ASEAN region (Figure 1). The largest positive anomalies (wetter conditions) were detected over the eastern Mainland Southeast Asia for both satellite-derived rainfall estimates datasets (GSMaP-NRT and CMORPH-Blended). This is associated with the developments of Severe Tropical Storm KOMPASU. A second tropical storm, Tropical Storm LIONROCK, affected central Philippines at the beginning of October, which is the major reason for the positive anomalies in central Philippines and the ocean region around the Philippines. Negative anomalies (drier conditions) were recorded over western and northern parts of Borneo. For the rest of the ASEAN region, rainfall tended to be near-to above-average during October 2021.

SEASONAL OUTLOOK

In the second half of October 2021, according to the ASMC, the Southwest Monsoon had transitioned into the inter-monsoon period. Climatologically, the inter-monsoon conditions are likely to prevail over the ASEAN region in the coming month of November as the conditions transition into the Northeast Monsoon by December. During this inter-monsoon period, prevailing winds are forecast to be generally light and variable in direction. Increased rainfall is expected, particularly over the areas of the ASEAN region near the equator, due to the equatorial proximity of the monsoon rain band.

In the coming three months (November 2021 to January 2022), the Maritime Continent and southeastern Mainland Southeast Asia are looking at an increased chance of above-normal rainfall. The areas with the highest chances are southern and eastern parts of the Maritime Continent. La Niña conditions have been detected and are now present according to the ASMC. This entails wetter-than-average rainfall conditions and cooler conditions in the region. Additionally, most models are predicting these conditions to last or be experienced until early 2022. As the month of October ended, a negative Indian Ocean Dipole (IOD) that brought greater precipitation east of the Indian Ocean was present and this negative IOD was expected to return to neutral in the month of November 2021 (positive IOD causes droughts in Southeast Asia). Temperatures that are warmer than usual are likely for much of the Maritime Continent and Myanmar in the coming three months (November 2021-January 2022).

The dry season over the southern ASEAN region ended in October 2021. Meanwhile, for the northern ASEAN region, the traditional dry season typically sets in by year-end.
Note from ASMC: The qualitative outlook is assessed for the region in general and based on the latest runs from models provided by the SEA RCC-Network LRF node. For specific updates on the national scale, the relevant ASEAN National Meteorological and Hydrological Services should be consulted.

*Note from ASMC: The qualitative outlook is assessed for the region in general and based on the latest runs from models provided by the SEA RCC-Network LRF node. For specific updates on the national scale, the relevant ASEAN National Meteorological and Hydrological Services should be consulted.

Sources: ASEAN Disaster Information Network (ADINet), ASEAN Disaster Monitoring and Response System (DMRS), ASEAN Specialised Meteorological Centre (ASMC), Badan Nasional Penanggulangan Bencana (BNPB) – Indonesia, Agensi Pengurusan Bencana Negara (NADMA) – Malaysia, Department of Disaster Management (DDM) – Myanmar, National Disaster Risk Reduction and Management Council (NDRRMC) – Philippines, Department of Disaster Prevention and Mitigation (DDPM) – Thailand, Viet Nam Disaster Management Authority (VNDMA) – Viet Nam, Badan Meteorologi, Klimatologi dan Geofisika (BMKG) – Indonesia, Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) – Indonesia, Department of Meteorology and Hydrology (DMH) – Myanmar, Philippine Institute for Volcanology and Seismology (PHIVOLCS) – Philippines, Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) – Philippines

Written by : Keith Paolo Landicho, Sadhu Zukhruf Janottama, Lawrence Anthony Dimailig

GENERAL REVIEW OF SEPTEMBER 2021

For the month of September 2021, a total of 161 disasters were reported. The ASEAN Member States that were affected were Cambodia, Indonesia, Lao PDR, Malaysia, the Philippines, Thailand and Viet Nam. Most of the disasters (69.57%) occurred in Indonesia but Thailand where only 7.45% of the total disasters for September 2021 occurred, comprised more than half of the total number of affected people (63.47%) for the month. The share of the disaster-affected people for other ASEAN Member States was as follows: (1) Cambodia-3.28%, (2) Lao PDR-0.01%, (3) Malaysia-0.03%, (4) Philippines-19.19%, and (5) Viet Nam-1.69%. September 2021 saw disasters affecting 433 per 100,000 people* and displacing 17 per 100,000 people* in the region, nearly five times and 17 times more than the previous month, respectively. September 2021 accounted for 17.65% of the total disasters reported so far in the current year.

Most of the disasters that occurred in September 2021 were floods (63.98%) and this is consistent with September of the previous year and September on a five-year average (2016-2020). September 2021 saw hydrometeorological disasters (drought, flood, rain-induced landslides, storm, winds) affecting 99.9% of the total affected persons for the month. The reported disasters in the region for September 2021 in comparison with the historical data (average for September 2016-2020) indicates that there were 6.44x more reported disasters; 1.45x more people affected; 1.95x fewer people displaced; 5.19x more houses affected to some extent; 1.14x more lives lost; 1.91x fewer people suffering injuries; and lastly, 3.7x fewer people reported missing.

Geophysically, 17 significant earthquakes (Magnitude ≥ 5.0) were reported by Indonesia’s Badan Meteorologi, Klimatologi dan Geofisika (BMKG), Myanmar’s Department of Meteorology and Hydrology (DMH), and the Philippine Institute for Volcanology and Seismology (PHIVOLCS). Recent volcanic activity was reported for Ili Lewotolok and Merapi (Alert Level III), Semeru, Dukono, Ibu and Krakatau (Alert Level II) in Indonesia by the Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG), and Taal (Alert Level 2) and Kanlaon (Alert Level 1) by PHIVOLCS. None have resulted in disasters but are being continuously monitored.

*Computed based on 2020 population data from worldometers.com

ANALYSIS

According to the ASEAN Specialised Meteorological Centre (ASMC), compared with the average value from 2001-2020, during September 2021, rainfall was above-average over much of the ASEAN region except for northern Sumatra, northern Philippines, parts of northern Myanmar, peninsular Malaysia, Borneo and Papua (which received rainfall from below- to near-average). The largest positive anomalies (wetter conditions) were detected over eastern mainland Southeast Asia for both satellite-derived rainfall estimate datasets (GSMaP-NRT and CMORPH-Blended). This is associated with the developments of Tropical Storm CONSON and Tropical Storm DIANMU which made landfall in early September and late September respectively. As a result, hydrometeorological disaster events were reported for numerous areas in Thailand and Viet Nam.

SEASONAL OUTLOOK

For the coming month of October, it is predicted that wetter conditions than normal will set in progressively in the ASEAN region due to the transition to intermonsoon conditions taking place. For the last quarter of the year (October to December), the prevailing southeasterly or southwesterly winds over the ASEAN region are expected to weaken prior to a change in direction to blow from the northeast or northwest.

For the upcoming quarter, according to the ASEAN Specialised Meteorological Centre (ASMC), there will be an increased chance of rainfall over much of the ASEAN region with the southern and eastern parts of the maritime continent having the highest likelihood for said conditions. Models are predicting La Niña-like conditions, but the tropical region of the Pacific has yet to show consistent La Niña-like conditions. The negative Indian Ocean Dipole (IOD) detected in the past month is forecast to return to neutral before December 2021. For this time of the year, a negative IOD tends to bring above-average rainfall in the southern ASEAN region. During the last quarter of 2021 also, warmer-than-usual temperatures are expected for much of the maritime continent. In the same period, the northeastern parts of mainland Southeast Asia are predicted to experience below- to near-normal temperatures associated with the northeast monsoon surges.

Considering the persistence of the negative IOD event until December 2021, the progressive settling of wetter conditions over the ASEAN region due to the transition to intermonsoon conditions, and the disaster data records from the ASEAN Disaster Information Network, the number of disaster events (particularly hydrometeorological disasters) and the affected persons, are expected to increase in frequency and number respectively, as the year ends. National Disaster Management Organisations (NDMOs), relevant authorities and agencies, and the public are advised to take necessary preparations and actions accordingly.

*Note from ASMC: The qualitative outlook is assessed for the region in general and based on the latest runs from models provided by the SEA RCC-Network LRF node. For specific updates on the national scale, the relevant ASEAN National Meteorological and Hydrological Services should be consulted.

Sources: ASEAN Disaster Information Network (ADINet), ASEAN Disaster Monitoring and Response System (DMRS), ASEAN Specialised Meteorological Centre (ASMC), Badan Nasional Penanggulangan Bencana (BNPB) – Indonesia, Agensi Pengurusan Bencana Negara (NADMA) – Malaysia, Department of Disaster Management (DDM) – Myanmar, National Disaster Risk Reduction and Management Council (NDRRMC) – Philippines, Department of Disaster Prevention and Mitigation (DDPM) – Thailand, Viet Nam Disaster Management Authority (VNDMA) – Viet Nam, Badan Meteorologi, Klimatologi dan Geofisika (BMKG) – Indonesia, Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) – Indonesia, Department of Meteorology and Hydrology (DMH) – Myanmar, Philippine Institute for Volcanology and Seismology (PHIVOLCS) – Philippines, Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) – Philippines

Written by : Keith Paolo Landicho, Sadhu Zukhruf Janottama, Lawrence Anthony Dimailig

GENERAL REVIEW OF AUGUST 2021

For the month of August 2021, a total of 72 disasters were reported. The ASEAN Member States that were affected were Indonesia, Malaysia, Myanmar, the Philippines, Thailand and Viet Nam. Most of the disasters (72.22%) occurred in Indonesia and comprised nearly half, 45.08%, of the total number of affected people for the month. The share of the disaster-affected people for other ASEAN Member States was as follows: (1) Malaysia-0.07%, (2) Myanmar-0.03%, (3) Philippines-0.13%, (5) Thailand-53.57% and (6) Viet Nam-1.15%. August 2021 saw disasters affecting 92 per 100,000 people* and displacing 1 per 100,000 people* in the region, three times and 57 times fewer than the previous month, respectively. August 2021 accounted for 9.59% of the total disasters reported so far in the current year.

Most of the disasters that occurred in August 2021 were floods (70.83%) and this is consistent with August of the previous year and August on a five-year average (2016-2020). August 2021 saw hydrometeorological disasters (droughts, floods, rain-induced landslides, storms and winds) dominating the disasters that affected the region for the month (98.6%). The reported disasters in the region for August 2021 in comparison with the historical data (average for August 2016-2020) indicates that there were 2.88x more reported disasters; 3.25x fewer people affected; 29.18x fewer people displaced; 3.24x more houses affected to some extent; 2.89x fewer lives lost; 25.17x fewer people suffering injuries; and lastly, 18.5x fewer people reported missing.

Geophysically, 29 significant earthquakes (Magnitude ≥ 5.0) were reported by Indonesia’s Badan Meteorologi, Klimatologi dan Geofisika (BMKG), and the Philippine Institute for Volcanology and Seismology (PHIVOLCS). Recent volcanic activity was reported for Ili Lewotolok and Merapi (Alert Level III), Semeru, Dukono, and Ibu (Alert Level II) in Indonesia by the Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG), and Taal (Alert Level 2), Bulusan and Kanlaon (Alert Level 1) by PHIVOLCS. None have resulted in disasters but are continuously being monitored.

*Computed based on 2020 population data from worldometers.com

ANALYSIS

According to the ASEAN Specialised Meteorological Centre (ASMC), compared with the average value from 2001-2020, during August 2021, rainfall was above-average over much of the ASEAN region and below-average over the northeastern ASEAN region. The largest positive anomalies (wetter conditions) were detected over the equatorial region for both satellite-derived rainfall estimate datasets (GSMaP-NRT and CMORPH-Blended). Coincidingly, numerous hydrometeorological disaster events were reported for this area. A disaster (caused by thunderstorms, flooding and landslide), though minor, was reported in northern Viet Nam despite the largest negative anomalies (drier conditions) for the region for August 2021 being detected over the area.

Drought was reported in Cilacap Regency, Central Java, in Indonesia. Based on Figure 2, the equatorial region, along with central and northern Myanmar, experienced near- to below-average temperatures with the warmest anomalies being detected over northern Viet Nam.

SPOTLIGHT

According to the situational report from the Philippines’ National Disaster Risk Reduction Management Council, since 28 July 2021 the Southwest Monsoon has brought intense rains to multiple regions of the Philippines and has since affected 312,605 families (1,222,241 persons) from 1,117 barangays. Related incidents to the Southwest Monsoon that impacted multiple regions in the Philippines were floods, rain-induced landslides, a mudslide, an overflowing spillway and swollen rivers. 129 roads and three bridges were affected and 12 roads and one bridge remain impassable. 1,723 houses have reportedly been damaged. The estimated cost of damage to agriculture is reported to be around USD 4,686,168.51 incurred in Regions I, III, VIII, IX and CAR. With regard to infrastructure, an estimated USD 721,025.94 worth of damage has been reported. A total of 40 cities/municipalities were declared under a State of Calamity. Assistance (in the forms of financial, family food packs, other food items, family kits, hygiene kits, sleeping kits, kitchen kits, medical assistance, non-food items) worth USD 204,497.13 have been provided to victims in Regions I, III, VI, CAR and MIMAROPA. 

SEASONAL OUTLOOK

In the coming month, for parts of the ASEAN region north of the Equator, Southwest Monsoon conditions are forecast to continue to persist. The northern ASEAN region will continue to experience its traditional wet season and the southern ASEAN region, its traditional dry season. For October, the equatorial ASEAN region is expected to have increased rainfall during the latter part of the month as the Southwest Monsoon conditions transition into the inter-monsoon period. Southwest Monsoon-associated prevailing winds are expected to blow from the southeast or southwest and gradually weaken and become light and variable in direction during the transition into the inter-monsoon period.

An increased chance of above-normal rainfall over much of the ASEAN region is foreseen for the September to November 2021 period with the highest likelihood over central and southern parts of the Maritime Continent. La Niña-like conditions were detected in August but for the rest of the year, the forecast is still split between ENSO-neutral and La Niña conditions developing. The Indian Ocean Dipole (IOD) is currently in the negative phase and is forecast to return to neutral by November or December 2021. During a negative IOD phase, waters in the eastern Indian Ocean (near Indonesia) tend to be warmer than normal and the southern ASEAN region tend to experience above-average rainfall. Most parts of the ASEAN region will experience warmer-than-usual temperatures from September to November 2021.

Considering the IOD being in the negative phase, the outlook for the equatorial ASEAN region, the outlook for over much of the ASEAN region, and the disaster data records from the ASEAN Disaster Information Network, the number of disaster events (particularly hydrometeorological disasters) and the number of affected persons, are expected to increase in frequency and number, respectively, as the year ends. National Disaster Management Organisations (NDMOs), relevant authorities and agencies and the public are advised to take necessary preparations and actions accordingly.

*Note from ASMC: The qualitative outlook is assessed for the region in general and based on the latest runs from models provided by the SEA RCC-Network LRF node. For specific updates on the national scale, the relevant ASEAN National Meteorological and Hydrological Services should be consulted.

Sources: ASEAN Disaster Information Network (ADINet), ASEAN Disaster Monitoring and Response System (DMRS), ASEAN Specialised Meteorological Centre (ASMC), Badan Nasional Penanggulangan Bencana (BNPB) – Indonesia, Agensi Pengurusan Bencana Negara (NADMA) – Malaysia, Department of Disaster Management (DDM) – Myanmar, National Disaster Risk Reduction and Management Council (NDRRMC) – Philippines, Department of Disaster Prevention and Mitigation (DDPM) – Thailand, Viet Nam Disaster Management Authority (VNDMA) – Viet Nam, Badan Meteorologi, Klimatologi dan Geofisika (BMKG) – Indonesia, Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) – Indonesia, Department of Meteorology and Hydrology (DMH) – Myanmar, Philippine Institute for Volcanology and Seismology (PHIVOLCS) – Philippines, Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) – Philippines

Written by : Keith Paolo Landicho, Sadhu Zukhruf Janottama, Lawrence Anthony Dimailig

GENERAL REVIEW OF JULY 2021

For the month of July 2021, a total of 113 disasters were reported. The ASEAN Member States that were affected were Cambodia, Indonesia, Lao PDR, Malaysia, Myanmar, the Philippines, Thailand and Viet Nam. Most of the disasters (63.72%) occurred in Indonesia but these only comprised 13.32% of the total number of affected people for the month. The Philippines comprised 16.81% of the disasters for July but comprised 83.3% of the total number of affected people, largely due to the effects of the Southwest Monsoon with one instance being enhanced by Tropical Cyclone IN-FA. The share of disaster-affected people for other ASEAN Member States was as follows: (1) Cambodia-0.01%, (2) Lao PDR-0.3%, (3) Malaysia-0.02%, (4) Myanmar-2.74%, (5) Thailand-0.15% and (5) Viet Nam-0.14%. July 2021 saw disasters affecting 265 per 100,000 people* and displacing 57 per 100,000 people* in the region. July 2021 also accounted for 16.64% of the total disasters and almost half (49.76%) of damage costs reported so far in the current year.

Most of the disasters that occurred in July 2021 were floods (57.52%) and this is consistent with July of the previous year and July on a five-year average (2016-2020). July 2021 saw hydrometeorological disasters (floods, rain-induced landslides, storms and winds) dominating the disasters that affected the region for the month (79.58%). The reported disasters in the region for July 2021 in comparison with the historical data (average for June 2016-2020) indicates that there were 5.94x more reported disasters; 5.56x fewer people affected; 18.73x more people displaced; 7.73x more houses affected to some extent; 5.77x fewer lives lost; 45.5x fewer people suffering injuries; and lastly, 1.86x more people reported missing.

Geophysically, 38 significant earthquakes (Magnitude ≥ 5.0) were reported by Indonesia’s Badan Meteorologi, Klimatologi dan Geofisika (BMKG), the Philippine Institute for Volcanology and Seismology (PHIVOLCS), and Myanmar’s Department of Meteorology and Hydrology (DMH). On 1 July 2021, Mount Taal in the Philippines was raised to Alert Level 3 due to the volcano generating a dark phreatomagmatic plume 1 kilometre high (with no accompanying volcanic earthquake). The eruption of Mount Taal affected 22,433 people and caused the evacuation of 13,027 from the high-risk barangays of Agoncillo and Laurel in Batangas Province. Mount Taal is currently placed under Alert Level 2 (as of 23 July 2021). Volcanoes in Indonesia and the Philippines have shown recent activity but have not resulted in significant events (except for Mount Taal) and are continuously being monitored.

*Computed based on 2020 population data from worldometers.com

ANALYSIS

According to the ASEAN Specialised Meteorological Centre (ASMC), during July 2021, rainfall in the region was a mix of lower to more than the average values from 2001-2020.(Figure 1.a). Wetter conditions (positive anomalies from average values from 2001-2020) were detected over the coastal parts of southern Myanmar, southern Cambodia, northwestern Philippines, as well as the Maluku Islands for both satellite-derived rainfall estimates datasets (GSMaP-NRT and CMORPH-Blended). Coincidentally, these were the areas where disasters were reported for July 2021 with southern Myanmar and Northwestern Philippines reportedly resulting from the effects of the Southwest Monsoon. The two datasets (GSMaP-NRT and CMORPH-Blended) were also in agreement that the largest negative anomalies (drier conditions) were over the central Philippines. However, there were some discrepancies over the western and central Maritime Continent, where CMORPH-Blended recorded drier conditions than GSMaP-NRT.

SPOTLIGHT

According to the situational report from the Philippines’ National Disaster Risk Reduction Management Council, since 28 July 2021 the Southwest Monsoon has brought intense rains to multiple regions of the Philippines and has since affected 312,605 families (1,222,241 persons) from 1,117 barangays. Related incidents to the Southwest Monsoon that impacted multiple regions in the Philippines were floods, rain-induced landslides, a mudslide, an overflowing spillway and swollen rivers. 129 roads and three bridges were affected and 12 roads and one bridge remain impassable. 1,723 houses have reportedly been damaged. The estimated cost of damage to agriculture is reported to be around USD 4,686,168.51 incurred in Regions I, III, VIII, IX and CAR. With regard to infrastructure, an estimated USD 721,025.94 worth of damage has been reported. A total of 40 cities/municipalities were declared under a State of Calamity. Assistance (in the forms of financial, family food packs, other food items, family kits, hygiene kits, sleeping kits, kitchen kits, medical assistance, non-food items) worth USD 204,497.13 have been provided to victims in Regions I, III, VI, CAR and MIMAROPA. 

SEASONAL OUTLOOK

With the monsoon rain band located north of the equator in August 2021, Southwest Monsoon conditions are likely to persist over the ASEAN region. Climatologically, the Southwest Monsoon is characterised by rainy conditions in the northern ASEAN region and dry weather in the southern ASEAN region. During the August to October period, the prevailing winds in the ASEAN region are from the southeast or southwest.

For the August to October 2021 period, there is an increased chance of above-normal rainfall for much of the Maritime Continent. ENSO-neutral conditions are forecast to continue for the next three months. The Indian Ocean Dipole (IOD) is in the negative phase and models are forecasting the negative IOD to also remain for the next three months. A negative IOD tends to bring above-average rainfall for the southern ASEAN region for this time of the year. Warmer-than-usual temperatures are expected for most of the ASEAN region except for Borneo and southern Sumatra where near- to above-normal temperatures are predicted.

Sources: ASEAN Disaster Information Network (ADINet), ASEAN Specialised Meteorological Centre (ASMC), ASEAN Disaster Monitoring and Response System (DMRS), Cambodia National Committee on Disaster Management (NCDM), Badan Nasional Penanggulangan Bencana (BNPB), Malaysia Agensi Pengurusan Bencana Negara (NADMA), Myanmar Department of Disaster Management (DDM), National Disaster Risk Reduction and Management Council (NDRRMC), Thailand Department of Disaster Prevention and Mitigation (DDPM), Viet Nam Disaster Management Authority (VNDMA), Badan Meteorologi, Klimatologi dan Geofisika (BMKG), Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG), Philippine Institute for Volcanology and Seismology (PHIVOLCS)

Written by : Keith Paolo Landicho, Sadhu Zukhruf Janottama, Lawrence Anthony Dimailig

GENERAL REVIEW OF JUNE 2021

For the month of June 2021, a total of 53 disasters were reported. The ASEAN Member States affected were Indonesia, Lao PDR, the Philippines, Thailand and Viet Nam. A majority of the disasters (47.17%) occurred in Indonesia which also accounted for 31.23% of the total number of affected people for the month (Lao PDR-7.41%, the Philippines-55.73%, Thailand-4.52%, Viet Nam-0.23%). June 2021 saw disasters affecting 42 per 100,000 people* and displacing 4 per 100,000 people* in the region. June 2021 also accounted for roughly one-tenth (9.36%) of the total disasters and 44.1% of damage costs reported so far in the current year.

Most of the disasters that occurred in June 2021 were floods (45.28%) and this is consistent with June of the previous year and June on a five-year average (2016-2020). Floods for June 2021 impacted only a third (34%) of the total number of affected people with 56.34% affected by tropical cyclone-related hazards (floods, landslides, storms and winds). The reported disasters in the region for June 2021 in comparison with the historical data (average for June 2016-2020) indicates that there were 2.12x more reported disasters; 3x fewer people affected; 8.2x more people displaced; 1.76x more houses affected to some extent; 2.5x fewer lives lost; 1.5x fewer people suffering injuries; and lastly, 3.69x fewer people missing.

Geophysically, 16 significant earthquakes (Magnitude ≥ 5.0) were reported by Indonesia’s Badan Meteorologi, Klimatologi dan Geofisika (BMKG) and the Philippine Institute for Volcanology and Seismology (PHIVOLCS). A Magnitude 6.1 earthquake that occurred 67 km Southeast of Central Maluku in week 24 caused a sea level rise of 0.5m according to the BMKG, damage to 233 houses and three places of worship, and displaced 8,800 persons into 56 evacuation centres. Volcanoes in Indonesia and the Philippines have shown recent activity but have not resulted in significant events and are continuously being monitored.

*Computed based on 2020 population data from worldometers.com

ANALYSIS

According to the ASEAN Specialised Meteorological Centre (ASMC), during June 2021, areas that received above-average rainfall were the western and central Maritime Continent (except Borneo), and northeastern parts of Mainland Southeast Asia. This agrees spatially with the disaster reports for the month of June. The largest positive anomalies (wetter conditions) were recorded over Java and northern Viet Nam (due to Tropical Storm Koguma). The eastern Maritime Continent predominately experienced below-average rainfall except for central parts of the Philippines due to the development of Tropical Storm Choi-Wan.

SPOTLIGHT

Tropical Storm Choi-Wan, locally known in the Philippines as “Dante”, caused flooding and damage mostly in the central Philippines. TS Choi-Wan was the third named storm of the 2021 Pacific typhoon season and originated from an area of low pressure south-southeast of Guam later fuelled by an environment favorable for tropical cyclogenesis according to the JTWC and JMA. TS Choi-Wan made a total of eight landfalls across the Philippines affecting a number of areas of the country from 1 June up until it left the Philippine Area of Responsibility on the 4 June. The storm reportedly claimed 11 lives, caused three injuries, affected 32,800 families (137,900 persons), and displaced 16,000 persons.

SEASONAL OUTLOOK

Southwest Monsoon conditions are expected to continue in July 2021 as the prevailing low-level winds over the ASEAN region strengthen and blow from the southeast or southwest, with the passage of the monsoon rain band further north of the equator in the second half of the month. The Southwest Monsoon season is the traditional dry season for the southern ASEAN region, which typically brings extended periods of dry conditions over the region. For the northern ASEAN region, the Southwest Monsoon is the traditional wet season.

For the July to September 2021 period, models predict an increased chance of above-normal rainfall for most of the equatorial ASEAN region from 8°N to 10°S. ENSO-neutral conditions are forecast to continue for the next three months. The Indian Ocean Dipole (IOD) is close to the negative state and models are forecasting a negative IOD for the July to September 2021 period. A negative IOD tends to bring above-average rainfall for the southern ASEAN region for this time of the year. Warmer-than-usual temperature is expected for most of the ASEAN region except for Borneo and southern Sumatra where near- to above-normal temperature is predicted.

The dry season for the southern ASEAN region is expected to extend from July to October 2021. During these months, isolated to scattered hotspots are likely during dry periods and widespread hotspots can be expected during extended dry periods, which may lead to an increased risk of transboundary haze occurrence. Nonetheless, due to predicted above-normal rainfall for the southern ASEAN region from July to September 2021, a recurrence of a similar 2015 (El Niño year) or a 2019 (positive IOD year) severe haze event is unlikely. Shower activities are expected to persist for the northern ASEAN region during this period, and help to subdue hotspot and smoke haze activities.

Sources: ASEAN Disaster Information Network (ADINet), ASEAN Specialised Meteorological Centre (ASMC), ASEAN Disaster Monitoring and Response System (DMRS), Cambodia National Committee on Disaster Management (NCDM), Badan Nasional Penanggulangan Bencana (BNPB), Malaysia Agensi Pengurusan Bencana Negara (NADMA), Myanmar Department of Disaster Management (DDM), National Disaster Risk Reduction and Management Council (NDRRMC), Thailand Department of Disaster Prevention and Mitigation (DDPM), Viet Nam Disaster Management Authority (VNDMA), Badan Meteorologi, Klimatologi dan Geofisika (BMKG), Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG), Philippine Institute for Volcanology and Seismology (PHIVOLCS)

Written by : Keith Paolo Landicho, Sadhu Zukhruf Janottama, Lawrence Anthony Dimailig

GENERAL REVIEW OF MAY 2021

For the month of May 2021, a total of 105 disasters were reported. The ASEAN Member States that were affected were Cambodia, Indonesia, Malaysia, Myanmar, the Philippines, and Thailand. A majority of the disasters (64.76%) occurred in Indonesia, which also saw 69.5% of the total number of affected people for the month (Cambodia – 2.1%, Malaysia – 0.7%, Myanmar – <0.1%, Philippines – 26.1%, Thailand – 1.5%). May 2021 saw disasters affecting 60 per 100,000 people* and displacing 4 per 100,000 people* in the region. May 2021 also accounted for roughly one-fifth (20.5%) of the total disasters reported so far in the current year.

The majority of the disasters that occurred in May 2021 were floods (58%) and this is consistent with May of the previous year and May on a five-year average (2016-2020). Flood victims comprised a little over three-quarters (77%) of the total number of affected people. The reported disasters in the region for May 2021 in comparison with the historical data (average for May 2016-2020) indicates that there were 5.5 time more reported disasters; almost 5 times more people affected; almost 3 times more people displaced; twice as many houses affected to some extent; 32 times fewer lives lost; 5 times fewer people suffering injuries; and lastly, 100 times fewer people missing.

Geophysically, 28 significant earthquakes (Magnitude ≥ 5.0) were reported by Indonesia’s Badan Meteorologi, Klimatologi dan Geofisika (BMKG) and the Philippine Institute for Volcanology and Seismology (PHIVOLCS). A Magnitude 6.2 earthquake (later downgraded to M5.9) that occurred 57 km southeast of Blitar in East Java in week 20 caused injuries to two individuals, affected 6,200 persons, and caused damage to thousands of houses, and hundreds of public facilities. Volcanoes in Indonesia and the Philippines have shown recent activity but they have not resulted in significant events and are continuously being monitored.

*Computed based on 2020 population data from worldometers.com

ANALYSIS

According to the ASEAN Specialised Meteorological Centre (ASMC), during May 2021, the largest positive anomalies (wetter conditions) were detected in southern Philippines due to Tropical Depression 03W (local name: Crising). Despite below-average rainfall over the southern Maritime Continent, over half of all recorded disasters that were apparently hydrological in nature (flooding and severe local storms) were reported across Indonesia. A mixture of below and above-average rainfall was observed in Mainland Southeast Asia.

SPOTLIGHT

Over the tropical Pacific Ocean, La Niña conditions declined and returned to El Niño Southern Oscillation (ENSO)-neutral conditions by the beginning of June. The sea surface temperatures in the central and eastern Pacific Ocean continued to warm, with atmospheric indicators (cloudiness and wind anomalies) remaining consistent with the ENSO-neutral conditions. ENSO-neutral conditions are neither El Niño (warming of ocean surface, reduced rainfall in Indonesia) nor La Niña (cooling of ocean surface, increased rainfall in Indonesia), which are the extreme phases of the ENSO cycle.

SEASONAL OUTLOOK

According to the ASEAN Specialised Meteorological Centre (ASMC), through May 2021, the monsoon rain band continued to move northwards over the northern ASEAN region. Concurrently, the prevailing winds over most of the southern ASEAN region strengthened to blow mainly from the southeast or southwest, in line with the transition to Southwest Monsoon conditions. With a strengthening of the prevailing winds, Southwest Monsoon conditions are expected to become fully established in June 2021. The Southwest Monsoon season is likely to extend through the June–August period and is the traditional dry season for the southern ASEAN region, characterised by persistent dry conditions over the region. For the northern ASEAN region, the Southwest Monsoon season is the traditional rainy season.

For the June to August 2021 period, models predict a small increase in chance of above-normal rainfall over parts of the southwestern Maritime Continent. Elsewhere, there is no consistent prediction for the rainfall outlook between the models consulted for much of the region. The La Niña event is nearing its end and most ENSO indicators are generally consistent with ENSO-neutral conditions. For July and August, ENSO-neutral conditions are forecast.

Warmer-than-usual temperatures are expected for much of the ASEAN region, with higher confidence over the Maritime Continent.

As the southern ASEAN region enters the traditional dry season, increased hotspot activities and the development of smoke plumes are likely in fire-prone parts of the region. In the coming months, it is expected that the hotspot and smoke haze situation may deteriorate in parts of the southern ASEAN region that experience prolonged dry conditions.

Sources: ASEAN Disaster Information Network (ADINet), ASEAN Specialised Meteorological Centre (ASMC), ASEAN Disaster Monitoring and Response System (DMRS), Cambodia National Committee on Disaster Management (NCDM), Badan Nasional Penanggulangan Bencana (BNPB), Malaysia Agensi Pengurusan Bencana Negara (NADMA), Myanmar Department of Disaster Management (DDM), National Disaster Risk Reduction and Management Council (NDRRMC), Thailand Department of Disaster Prevention and Mitigation (DDPM), Viet Nam Disaster Management Authority (VNDMA), Badan Meteorologi, Klimatologi dan Geofisika (BMKG), Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG), Philippine Institute for Volcanology and Seismology (PHIVOLCS)

Written by : Keith Paolo Landicho, Sadhu Zukhruf Janottama, Lawrence Anthony Dimailig

GENERAL REVIEW OF APRIL 2021

For the month of April 2021, a total of 80 disasters were reported. The ASEAN Member States that were affected were Cambodia, Indonesia, the Philippines, Thailand and Viet Nam with the majority of the disasters (72.5%) occurring in Indonesia. April 2021 saw disasters affecting 174 per 100,000 people and displacing 16 per 100,000 people in the region. April 2021 also accounted for approximately one-fifth (19.6%) of the total disasters and over a quarter (27.66%) of the total economic losses reported so far in the current year.

A majority of the disasters that occurred in April 2021 were floods (60%) and this is consistent with April of the previous year and April on a five-year average (2016-2020). The reported disasters in the region for April 2021 in comparison with the historical data (average for April 2016-2020) indicates that there were 4x more reported disasters; almost 13x more people affected; almost 10x more people displaced; 20x more houses affected to some extent; 20x more lives lost; 16x more people suffering injuries; and lastly, 5x more people reported missing.

Geophysically, 30 significant earthquakes (Magnitude ≥ 5.0) were reported by Indonesia’s Meteorological, Climatological, and Geophysical Agency (BMKG) and the Philippine Institute for Volcanology and Seismology (PHIVOLCS). A Magnitude 6.7 earthquake (later downgraded to M6.1) that occurred off the southern coast of Java in week 14 claimed eight lives, caused injuries to 24 individuals, displaced 782 people and caused damage to thousands of houses, hundreds of schools, a number of hospitals and almost 100 places of worship. Volcanoes in Indonesia and the Philippines have shown recent volcanic activity but have not resulted in significant events and are being continuously monitored.

ANALYSIS

According to the ASEAN Specialised Meteorological Centre (ASMC), during April 2021, rainfall in mainland Southeast Asia and the Malay Peninsula (where a fifth of the recorded disasters occurred) was above the 2001-2020 average for the month. The largest number of positive anomalies, or wetter conditions, were recorded in Thailand (where five disasters were recorded) and Lao PDR. Other large positive anomalies that were observed were in the eastern part of Central Philippines and in Nusa Tenggara due to Typhoon SURIGAE and Tropical Cyclone SEROJA, respectively. Much of the rest of the Maritime Continent, however, experienced below-average rainfall. This is in light of the majority of the disasters recorded in April 2021 being weather-related. 

SPOTLIGHT

An unusual meteorological phenomenon—the Fujiwhara effect (two tropical cyclones forming in close proximity to one another making their trajectory and tracks difficult to predict) was observed this month. One of the two tropical cyclones—Tropical Cyclone SEROJA ripped through the Nusa Tenggara islands of Indonesia and Timor Leste. Tropical Cyclone SEROJA resulted in flooding, landslides and strong winds in 21 regencies/cities in East Nusa Tenggara and three regencies in West Nusa Tenggara, Indonesia. It resulted in 184 deaths (182 in East Nusa Tenggara and two in West Nusa Tenggara), injuries to 155 persons, 47 missing, more than 80,000 displaced, and almost 500,000 people affected. A total of 55,000 houses and 3,600 public facilities were damaged due to the effects of Tropical Cyclone SEROJA in the Nusa Tenggara islands

SEASONAL OUTLOOK

Inter-monsoon conditions typically transition into the Southwest Monsoon in June with the prevailing winds strengthening and blowing from the southeast or southwest. The Southwest Monsoon season is the traditional dry season for the southern ASEAN region, which brings persistent dry conditions over the region. For the northern ASEAN region, the Southwest Monsoon is the traditional wet season.

For the May to July 2021 period, models predict below-normal rainfall over parts of the western and central Maritime Continent, in particular over parts of Sumatra, Peninsular Malaysia and Borneo. Elsewhere, there is no consistent prediction for the rainfall outlook between the models consulted. La Niña conditions were present over the tropical Pacific Ocean at the end of April, with climate models predicting its continued weakening to neutral conditions during May – June.

Warmer-than-usual temperatures are expected for much of the Maritime Continent, with near to warmer-than-usual temperature elsewhere.

The increase in shower activities is expected to help subdue the hotspot and haze situation over the Mekong sub-region. In the southern ASEAN region, isolated hotspots with localised smoke plumes may develop in areas with below-normal rainfall over Sumatra, Peninsular Malaysia and Borneo. As the traditional dry season typically sets in during June/July, the hotspot and haze situation is expected to elevate with an increased risk of transboundary smoke haze in the region.

The qualitative outlook is assessed for the region in general and based on the latest runs from models provided by the SEA RCC-Network LRF node. For specific updates on the national scale, the relevant ASEAN Member States’ National Meteorological and Hydrological Services should be consulted.

Sources : ASEAN Disaster Information Network (ADINet), ASEAN Specialised Meteorological Centre (ASMC), ASEAN Disaster Monitoring and Response System (DMRS), Badan Nasional Penanggulangan Bencana (BNPB), Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG), Badan Meteorologi, Klimatologi dan Geofisika (BMKG), National Disaster Risk Reduction and Management Council (NDRRMC), Philippine Institute for Volcanology and Seismology (PHIVOLCS), National Disaster Management Agency – Malaysia (NADMA), Department of Disaster Prevention and Mitigation – Thailand (DDPM), Viet Nam Disaster Management Authority (VNDMA)

Written by : Keith Paolo Landicho, Sadhu Zukhruf Janottama,  Lawrence Anthony Dimailig