For the twenty-first week of 2023, a total of 17 disasters (floods, landslides, storms, and wind-related) affected the region. Indonesia, the Philippines, Thailand, and Viet Nam have reportedly been affected. Badan Nasional Penanggulangan Bencana (BNPB) of Indonesia reported floods, storms, and tornadoes in Lampung, East Kalimantan, North Sumatra, and South Sulawesi. The Philippines’ National Disaster Risk Reduction and Management Council (NDRRMC) also reported floods, storms, and winds due to southwesterly windflow and localised thunderstorms in BARMM and Region XI; and the initials impacts of Tropical Cyclone MAWAR in the Philippines. Department of Disaster Prevention and Mitigation (DDPM) reported that storms affected Central Thailand. Lastly, Viet Nam Disaster and Dyke Management Authority (VDDMA) reported storms and winds in Thua Thien Hue Province.
According to the forecast from PAGASA on 29 May at 1000 HRS UTC+7, Tropical Cyclone (TC) MAWAR (local name: Betty), currently as a typhoon category, slightly decelerates while moving northwestward over the waters east of Cagayan. At most Tropical Cyclone Wind Signal no. 2 was raised in Batanes and the northeastern portion of Cagayan including Babuyan Islands, the Philippines (full list from PAGASA). As of 29 May 2023, the NDRRMC reported the following: 1.17K families (4.6K persons) affected in 15 barangays, 4.2K persons displaced (3.7K persons inside evacuation centres, 525 persons outside evacuation centres), 9 seaports affected, and 3 roads were reportedly damaged. A total 16.6K USD worth of assistance have been provided to the affected community. The AHA Centre will continue to closely monitor the situation and stands ready to support the affected member state.
For the past week, data from the ASEAN Specialised Meteorological Centre (ASMC) showed medium to high 7-day average rainfall spreading across Sumatra, Kalimantan, Sulawesi, Maluku, and Papua in Indonesia; Central parts of Lao PDR; Sabah and Sarawak in Malaysia; Southern Myanmar; Mindanao and Luzon of the Philippines; and North Centra Coast and Northern Viet Nam. TC MAWAR, was estimated at around 470 km East of Aparri, Cagayan. MAWAR is forecasted to move generally northwestward on 29-30 May, then will turn north-northeastward or northeastward on 31 May-1 June; then may exit the Philippine Area of Responsibility (PAR) on 2 June (PAGASA, JTWC).
Eight (8) significant earthquakes (M>5.0) were recorded by Indonesia’s Badan Meteorologi, Klimatologi, dan Geofisika (BMKG) and Philippine Institute of Volcanology and Seismology (PHIVOLCS). Mount Semeru (alert level III), Ili Lewotolok (alert level II), and Ibu (alert level III) in Indonesia, and Taal (alert level 1), Mayon Volcano (alert level 1), and Kanlaon (alert level 1) in the Philippines reported recent volcanic activity according to Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG) and PHIVOLCS.
According to the ASEAN Specialised Meteorological Centre (ASMC), for the coming week, wetter conditions are expected over much of southern Mainland Southeast Asia and over much of the Philippines. Drier conditions are expected over much of the southern ASEAN region. Warmer than usual temperatures are expected over much of the southern ASEAN region and over the northern half of Mainland Southeast Asia. For the regional assessment of extremes, there is a moderate increase in chance for a very heavy rainfall event to occur in southern Myanmar, southern Thailand, southern Cambodia, central and northern Philippines; and moderate increase in chance for extreme hot conditions to occur in much of the equatorial region, central Myanmar, northern Lao PDR; and very likely in northern Myanmar and northwest Viet Nam. ENSO-neutral conditions are present. However, under ENSO-neutral conditions there can still be considerable variability in rainfall for the 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;
Viet Nam: VDDMA;
Various news agencies.