REGIONAL SUMMARY:
During the forty-second week of 2025, a total of 25 disaster events were reported across the ASEAN region, including droughts, earthquakes, floods, landslides, storms, and wind-related incidents affecting Indonesia, Malaysia, Philippines, and Viet Nam. In addition to these four ASEAN Member States, in Thailand, flooding caused by heavy rainfall and the overflow of rivers—first reported in Week 37—continued to be reported by the Department of Disaster Prevention and Mitigation (DDPM) in Phitsanulok, Sukhothai, Phichit, Nakhon Sawan, Uthai Thani, Chainat, Singburi, Ang Thong, Suphan Buri, Phra Nakhon Si Ayutthaya, Pathum Thani, Nonthaburi, Nakhon Pathom, Ubon Ratchathani, Udon Thani, and Chachoengsao Provinces. In Indonesia, Badan Nasional Penanggulangan Bencana (BNPB) recorded multiple disasters across Aceh, West Java, Central Java, East Java, West Nusa Tenggara, Papua, South Sulawesi, and North Sumatra. In Malaysia, Agensi Pengurusan Bencana Negara (NADMA) reported flooding and storms in Pahang, Selangor, Johor, and Melaka. In the Philippines, National Disaster Risk Reduction and Management Council (NDRRMC) reported disasters situations in Regions II, III, CALABARZON, MIMAROPA, V, VI, VIII due to the effects of Tropical Cyclone FENGSHEN (locally named “Ramil”), as well as M6.0 earthquake in Surigao del Norte (Region XIII) and flooding in North Cotabato. In Viet Nam, Viet Nam Disaster and Dyke Management Authority (VDDMA) reported flooding and wind-related disasters in Quang Tri, Hue, and Khanh Hoa Provinces.
HIGHLIGHT:
A low-pressure area located east of Southeastern Luzon, the Philippines, developed into a tropical depression that was later named Tropical Cyclone FENGSHEN internationally ( “Ramil” locally in the Philippines). FENGSHEN subsequently intensified into a tropical storm and made landfall over Sorsogon on 18 October, before continuing its northwestward movement across the Bicol mainland and making another landfalls over Quezon and Bataan on 19 October (PAGASA). FENGSHEN exited the Philippine Area of Responsibility (PAR) on the morning of 20 October and is forecasted to move northwestward to westward today, before turning west-southwestward to southwestward by early morning of 21 October towards mainland Southeast Asia (PAGASA). FENGSHEN (Storm No. 12 locally in Viet Nam) is expected to make landfall over central Viet Nam, between Da Nang and Quang Ngai Provinces, around 23 October (NCHMF).
According to NDRRMC, TC FENGSHEN has affected several regions in the Philippines, including Regions II, III, CALABARZON, MIMAROPA, V, VI, and VIII. As of 20 October at 0500H UTC+7, FENGSHEN has impacted approximately 37.8K families (133.2K persons), with 2.3K families (7.5K persons) displaced across 166 evacuation centres (ECs) and 1.7K families (6.2K persons) displaced outside ECs in Regions II, III, VI, and VIII. Reported casualties include 7 fatalities (for validation), 1 injured (for validation), and 2 missing persons (for validation). Reports of damages include 12 affected road sections (seven of which remain impassable), 10 bridges (all still impassable), and 68 damaged houses (57 partially and 11 totally damaged).
The AHA Centre continues to closely monitor these situation, in coordination with the affected and potentially affected ASEAN Member States, and stands ready to provide support should the need arise.
HYDRO-METEO-CLIMATOLOGICAL:
For the past week, data from the ASEAN Specialised Meteorological Centre (ASMC) indicated medium to high 7-day average rainfall over Brunei Darussalam, Cambodia, Indonesia, Lao PDR, Malaysia, Myanmar, Philippines, Thailand, and Viet Nam. In addition to TC FENGSHEN, which is currently located over the Viet Nam East Sea (see Highlights section above for details), 2 tropical disturbances are being monitored for their potential impacts on the ASEAN region — INVEST 93B, located approx. 850 km northwest of Banda Aceh, and INVEST 95S, located approx. 355 km southwest of Padang. Both disturbances are expected to bring moderate to heavy rainfall over several provinces in Sumatra, Indonesia, before tracking away from ASEAN region (BMKG).
GEOPHYSICAL:
Eleven (11) significant earthquakes (M>5.0) were recorded by Indonesia’s Badan Meteorologi, Klimatologi, dan Geofisika (BMKG) and the Philippines Institute of Volcanology and Seismology (PHIVOLCS). Mount Marapi (alert level II), Semeru (alert level II), Lewotobi Laki-laki (alert level IV), and Ibu (alert level II) in Indonesia, and Kanlaon (alert level 2), Taal (alert level 1), Mayon (alert level 1), and Bulusan (alert level 1) volcanoes in the Philippines reported recent volcanic activity according to Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) and PHIVOLCS.
OUTLOOK:
According to the ASEAN Specialised Meteorological Centre (ASMC), for the coming week, wetter conditions are predicted over much of the central and southern Maritime Continent. For the regional assessment of extremes, there is a small increase in chance for very heavy rainfall event to occurs over Central Viet Nam, southern Borneo, southern Sulawesi, southern Sumatra, and Java; and a small increase in chance for extreme hot conditions to occurs over Central Myanmar, northern Sumatra, western coast of Peninsular Malaysia, northern Borneo, and the Philippines. A negative IOD is currently present. Models predict potential for La Niña conditions to develop in the coming months.
Sources:
ASEAN Disaster Monitoring & Response System (DMRS); ASEAN Specialised Meteorological Centre (ASMC); Joint Typhoon Warning Centre (JTWC);
Indonesia: BNPB, BMKG, PVMBG;
Malaysia: NADMA;
Philippines: NDRRMC, PAGASA, PHIVOLCS;
Thailand: DDPM;
Viet Nam: VDDMA, NCHMF;
Various news agencies.
