In the fortieth week of 2023, the ASEAN region experienced 24 disaster events that affected Indonesia, Malaysia, Myanmar, the Philippines, and Viet Nam. Cambodia and Thailand also reported disaster events that began in week 37 and continued into week 40. The National Committee for Disaster Management (NCDM) Cambodia reported floods in 11 provinces that began in week 37. In Indonesia, the Badan Nasional Penanggulangan Bencana (BNPB) reported floods, landslides, and wind-related incidents in Aceh, West Java, Central Java, and North Sumatra. Additionally, Bali and Lampung in Indonesia experienced drought conditions. In Malaysia, the Agensi Pengurusan Bencana Negara (NADMA) reported flooding in Kelantan. In Myanmar, Department of Disaster Management (DDM) reported flooding in Bago, Mon, and Yangon. The National Disaster Risk Reduction and Management Council (NDRRMC) and Department of Social Welfare (DSWD) documented flooding incidents in Region X and the impacts of Tropical Cyclone KOINU in Regions 1, 2, 6, and CAR in the Philippines. Meanwhile, the Department of Disaster Prevention and Mitigation (DDPM) in Thailand reported flooding incidents in 28 provinces since week 38. Lastly, Viet Nam Disaster and Dyke Management Authority (VDDMA) reported flooding, landslides, storms, and winds in Yen Bai, Binh Phuoc, Binh Thuan, Dong Nai, and Ho Chi Minh.
From 26 Sep to 6 Oct, the Southwest Monsoon caused floods in various provinces of Thailand, including Phetchabun, Mae Hong Son, Lamphun, Uttaradit, Chiang Mai, Lampang, Sukhothai, Nan, Tak, Ka Paeng Phet, Phrae, Loei, Chaiyaphum, Nakhon Ratchasima, Udon Thani, Yasothon, Kalasin, Khon Kaen, Ubon Ratchathani, Chachoengsao, Prachinburi, Nakhon Nayok, Trat, Kanchanaburi, Lopburi, Samut Prakan, Satun, and Yala. According to the Department of Disaster Prevention and Mitigation (DDPM), these events have affected more than 33.6K families. As of 6 Oct, the floods still persist in four provinces (Tak, Kalasin, Ubon Ratchatani and Samut Prakan) and have affected more than 13.7K families. Meanwhile in Cambodia since 16 Sep, flooding and landslides have been reported in 11 provinces. According to the National Committee for Disaster Management (NCDM), as of 6 Oct initial impact reports are as follows: 3 casualties, 36.9K families affected, and 1.9K families displaced. Reports of damages include 25K houses, 140 schools, more than 400 km roads, and more than 30K hectares of rice. Relevant government authorities have carried out necessary actions to address the situation.
For the past week, data from the ASEAN Specialised Meteorological Centre (ASMC) showed moderate to high 7-day average rainfall spreading across Cambodia; northern Sumatra, Kalimantan, and Papua in Indonesia; Central and Southern Lao PDR; Peninsular, Sabah, and Sarawak Malaysia; lower parts of Myanmar; the Philippines Sea associated with the development of TC KOINU, and West Philippine Sea; Eastern and Northeastern of Thailand; and central and southern parts of Viet Nam. As of 1400 HRS UTC+7, Tropical Cyclone KOINU was located approximately 720 km East of Hanoi, Viet Nam. According to NCHMF, KOINU may weaken into a Tropical Depression on 10 Oct early morning over the Northeastern Sea of Hainan, then weakening into a low-pressure area on 10 October (afternoon) over Hainan Islands Area. However, global model forecast indicates KOINU may weaken into a low-pressure in the Gulf of Tonkin near the coastal areas over Quang Binh Province of Viet Nam on 11 Oct (JTWC).
Eight (8) significant earthquakes (M>5.0) were recorded by Indonesia’s Badan Meteorologi, Klimatologi, dan Geofisika (BMKG) and the Philippine Institute of Volcanology and Seismology (PHIVOLCS). Mount Ibu (alert level II), Ili Lewotolok (alert level II), Semeru (alert level III), and Dukono (alert level II) in Indonesia, and Mayon (alert level 3), Taal (alert level 1), and Kanlaon (alert level 1) in the Philippines reported recent volcanic activity according to Indonesia’s Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) and PHIVOLCS.
According to the ASEAN Specialised Meteorological Centre (ASMC), for the coming week, drier conditions are predicted over much of the Maritime Continent with lower likelihood over Borneo and the southern Philippines; wetter conditions are predicted over much of Mainland Southeast Asia; and warmer than usual temperature is predicted over most of the ASEAN region. For the regional assessment of extremes, there is a small increase in chance for a very heavy rainfall event to occur in Myanmar and the parts of western Thailand; a small increase in chance in southern Mainland Southeast Asia, the western Maritime Continent, and the eastern equatorial region, and a moderate increase in chance in the parts of the Philippines and the southern Maritime Continent for extreme hot conditions. El Niño conditions are predicted to strengthen over the next few months. A Positive Indian Ocean Dipole (IOD) is currently present. At the seasonal timescale during September to November, both positive IOD and El Niño events bring drier conditions to much of the ASEAN region.
ASEAN Disaster Monitoring & Response System (DMRS); ASEAN Specialised Meteorological Centre (ASMC); Joint Typhoon Warning Centre (JTWC);
Indonesia: BNPB, BMKG, PVMBG;
Philippines: NDRRMC, PAGASA, PHIVOLCS, DSWD;
Viet Nam: VDDMA, NCHMF;
Various news agencies.