FLASH UPDATE #2 – Tropical Cyclone WIPHA and Southwest Monsoon
Countries under monitoring: Lao PDR, Philippines, Thailand, Viet Nam
OVERVIEW: According to NCHMF, at 1000H of 21 July 2025, the centre of Tropical Cyclone WIPHA was at about 21.2°N; 109.6°E, approximately 190km from Quang Ninh and 310km from Hai Phong It is forecast to continue moving west southwest toward Northern Viet Nam and Lao PDR. TC WIPHA continues to influence the Southwest Monsoon with significant impacts reported in the Philippines and Viet Nam.
STRENGTH & MOVEMENT: According to NCHMF, as of 21 July at 0700H UTC+7, the strongest wind near the centre of the storm was level 9 (75-88km/h), gusting to level 11, moving west-southwest at a speed of 10-15km/h.
FORECAST & ANALYSIS: According to Viet Nam’s NCHMF:
- On 21 July at 2200H, the centre of TC WIPHA will be at about 20.7°N; 108.2°E (Northern Gulf of Tonkin). Intensity: level 10–11, gusts of level 14.
- On 22 July at 1000H, the centre will be at about 20.3°N; 106.8°E (Hai Phong–Thanh Hoa sea area). Intensity: level 10–11, gusts of level 14.
- On 23 July at 1000H, TC WIPHA’s centre will be about 19.7°N; 104.3°E (over mainland Upper Lao PDR), weakening into a low pressure area.
HAZARDS & ANTICIPATED RISKS:
LAO PDR
- According to DMH Lao PDR, the combined influence of TC WIPHA and the Southwest Monsoon will cause light to moderate thunderstorms in all regions with heavy to very heavy rains with strong winds in some areas of the central and southern provinces.
- DMH Lao PDR warns of continuous heavy rain for several days that will cause landslides, flash floods and flash floods that will cause damage to lives and valuable property.
- According to ASEAN DMRS, under the influence of TC WIPHA, the northern and central provinces may receive 7.6-15.2cm of rainfall, while the rest of the country may receive 2.5 to 7.6cm. Potential wind impacts include swaying of small to large trees in some parts of Northern an Central Regions.
PHILIPPINES
- According to PAGASA, possible floods or landslides due to moderate to heavy with at times intense rains caused by the Southwest Monsoon in Zambales, Bataan, and Occidental Mindoro.
- Occasional moderate to heavy rains may cause flooding or landslides in Metro Manila, Ilocos Region, Benguet, Tarlac, Pampanga, Bulacan, Cavite, Laguna, Batangas, Rizal, and Oriental Mindoro.
- According to PAGASA, significant rainfall is likely to persist for succeeding days due to development of weather disturbances and continuous influence of the Southwest Monsoon.
THAILAND
- According to Thailand Meteorological Department (TMD), TC WIPHA and the Southwest Monsoon will bring very to very heavy rain in the Northern, Northeastern, Central, and Southern provinces. Warning for potential flash floods, flooding, overflowing rivers, and mudslides raised in 57 provinces from 20-24 July 2025.
- From 22-24 July, the following areas have been placed under surveillance for risk of the above-mentioned hazards:
- Northern Region: Mae Hong Son, Chiang Mai, Chiang Rai, Lamphun, Lampang, Phayao, Phrae, Nan, Uttaradit, Tak, Sukhothai, Kamphaeng Phet, Phitsanulok, Phichit, Phetchabun, Nakhon Sawan, and Uthai Thani
- Northeastern Region: Loei, Nong Khai, Bueng Kan, Nong Bua Lamphu, Udon Thani, Sakon Nakhon, Nakhon Phanom, Chaiyaphum, Kalasin, Mukdahan, Yasothon, Amnat Charoen, Nakhon Ratchasima, and Ubon Ratchathani
- Central Region: Kanchanaburi, Ratchaburi, Suphan Buri, Chai Nat, Sing Buri, Ang Thong, Phra Nakhon Si Ayutthaya, Lop Buri, Saraburi, Nakhon Nayok, Prachin Buri, Rayong, Chanthaburi, Trat, Phetchaburi, and Prachuap Khiri Khan
- Southern Region: Ranong and Phang Nga
- According to ASEAN DMRS, parts of Northern and Northeastern regions may receive approximately 2.5-7.6cm of rainfall due to TC WIPHA.
VIET NAM
- Strong winds and rough seas: Northwestern sea area of the North East Sea: wind level 7–8, gusting to level 10; waves 3.0–5.0m high; rough seas. Northern Gulf of Tonkin (Bach Long Vi, Co To, Van Don, Cat Hai, Hon Dau): wind level 6–7, then increasing to level 8–9, near the storm center level 10–11, gusting to level 14; waves 4.0–6.0m; rough seas. Southern Gulf of Tonkin (Hon Ngu): wind gradually increases to level 6–7, near the storm centre level 8–9, gusting to level 11; waves 2.0–4.0m high; very rough seas. Strong winds, tornadoes, large waves and rising sea levels can damage boats, coastal structures and aquaculture areas.
- Strong winds on land: From the night of 21 July, the coastal areas of Quang Ninh – Nghe An will have winds of level 7-9, near the storm centre, winds of level 10-11, gusts of level 14. In the provinces of Hai Phong, Hung Yen, Ninh Binh, and Thanh Hoa, winds of level 6, gusts of level 7-8. Strong winds of level 10–11 can knock down trees, power poles, and rip off roofs.
- Heavy rain: From 21-23 July, Northeast, Northern Delta, Thanh Hoa, Nghe An: common rain 200-350mm, some places over 600mm. Other places in the North and Ha Tinh: 100-200mm, some places over 300mm. There is risk of extremely heavy rain (>150mm/3h), flash floods, landslides, flooding in low-lying areas.
- Storm surge in the coastal areas of Hung Yen to Quang Ninh 0.5-1.0m; Ba Lat 2.4-2.6m; Hon Dau 3.9-4.3m; Cua Ong 4.6-5.0m; and Tra Co: 3.6-4.0m.There is risk of flooding in coastal areas and river delta on the afternoon of 22 July.
ANTICIPATED RISK:
- PAGASA is monitoring another Low Pressure Area (INVEST 97W), about 950 km east northeast of Eastern Visayas. The potential for development into a significant tropical depression in the next 24 hours is MEDIUM.
IMPACTS AND DAMAGES:
PHILIPPINES: Based on NDRRMC Situation Report issued on 21 July 2025 at 0700H UTC+7, the following impacts of the combined effects of the trough of TC WIPHA (Crising), and the Enhanced Southwest Monsoon have been recorded:
- 800,864 affected population (225,985 families) in 16 regions, 54 provinces, 268 cities/municipalities
- 5 deaths (3 for validation), 5 injuries (4 for validation), 7 missing individuals (for validation)
- Displaced population reached up to 266,656 (90,835 persons remain displaced, of which 70,720 families are in 319 evacuation centres
- 1,234 damaged houses (of which 299 are totally damaged)
- 167 road sections, 11 bridge sections have been affected (48% passable to all types of vehicles)
- 115 cities and municipalities experienced power disruption, 2 with interrupted water supply, and 27 with interrupted communication lines
- An estimated 3.86M USD worth of damages (houses and infrastructure)
- 301 flooded areas and 41 other related incidents (rain-induced landslides, tornado, others)
- 54 seaports affected (39% operational) and 2 airports affected (50% operational)
- 909 cities/municipalities with class suspension and 98 municipalities with work suspension
VIET NAM: Based on VDDMA’s Quick Report for 20 July 2025 issued on 21 July, the damage situation have been recorded:
- Storms caused a tourist service boat with 5 crew members and 48 passengers capsized in the vicinity of Ti Top Island-Quang Ninh at 1530H on 19 July 2025. Based on the latest update as of 0200H on 20 July 2025, 10 people have been saved, 38 bodies have been recovered, and 5 individuals remain missing.
- 4 other deaths and 11 injuries due to storms in the Northern Region
- 1,755 houses were affected, of which 19 houses were totally damaged
- 32 schools were damaged and affected36 vessels capsized and sunk
- 286.9 hectares of rice, crops, and perennial trees were damaged
PREPAREDNESS AND RESPONSE:
LAO PDR
- The DMH Lao PDR issued official notice on TC WIPHA and weather conditions and urged local authorities and communities to prepare for potential emergencies and follow any advisories issued.
- DMH Lao PDR advised the public, particularly the residents in the Southern Provinces to take precautionary measures, follow instructions from local authorities, and be prepared for the incoming tropical depression.
- DMH and NDMO Lao PDR are closely monitoring the development of weather and issue regular updates and advisories.
PHILIPPINES
- The NDRRMCOC maintains RED Alert Status ICOW with the Enhanced Southwest Monsoon and TC WIPHA (Crising).
- Personnel and assets from the military, coast guard, police, and fire protection agencies have been deployed to conduct search, rescue, and retrieval in affected areas.
- Approximately 771K USD worth of assistance have been provided to affected families.
- NDRRMC and relevant authorities have immediately responded and provided assistance to affected communities.
- Local authorities facilitated pre-emptive evacuation of vulnerable sectors in areas at risk.
- PAGASA continues to monitor and release regular updates and advisories, including localised rainfall and flood warnings in affected areas/areas at risk.
- Authorities are closely monitoring and coordinating with the relevant agencies for proactive measures related to the weather disturbances.
THAILAND
- On 20 July 2025 at 1915H UTC+7, DDPM alerted 57 provinces across the North, Northeast, Central, and South to closely monitor and prepare for flash floods, forest runoff, river overflows, and mudslides under the influence of TC WIPHA from 20–24 July 2025.
- Operational teams and equipment have been deployed to high-risk and flood-prone areas to respond promptly and assist affected communities, including efforts to drain ongoing floodwaters and issue early warnings to residents.
- TMD cautions people in the aforementioned areas should be careful of the dangers of heavy to very heavy rain and accumulated rain, which may cause flash floods and forest runoff, especially in areas on hillsides, near waterways and lowlands. TMD closely monitors the weather situation and regularly provides warnings and advisories.
- DDPM closely monitors the development of the weather systems and regularly releases reports, advisories, and implements proactive measures against hazards related to the weather disturbances.
VIET NAM
- The Prime Minister issued two directives on 19 and 20 July 2025 instructing the Ministry of National Defense to coordinate with relevant agencies and Quang Ninh province to intensify efforts in responding to the sunken ship in Quang Ninh. Deputy Prime Minister Tran Hong Ha directly led the rescue operations on-site, urging continued efforts to recover all victims and salvage the ship overnight on 19 July.
- The Prime Minister issued Official Dispatch No. 112/CD-TTg dated 19 July 2025 requesting ministries, branches and localities to focus on responding to TC WIPHA (Storm No. 3).
- The Ministry of Agriculture and Environment – VDDMA issued two early directives in preparation for TC WIPHA. On 18 July 2025, the Ministry held a meeting with relevant ministries and offices to send specialized staff to coordinate with the provinces of Quang Ninh, Hung Yen, Ninh Binh, and Phu Tho to deploy actual response to storms and floods in the localities.
- The NCHMF provides early forecast bulletins for tropical depression to serve response direction
The AHA Centre will continue to monitor for further developments and issue necessary updates.
DATA SOURCES
ASEAN Disaster Monitoring & Response System (DMRS), ASEAN Disaster Information Network (ADINet); Pacific Disaster Center (PDC Global); ASEAN Specialised Meteorological Centre (ASMC);
Lao PDR: NDMO Lao PDR, DMH;
Philippines: NDRRMC-OCD, PAGASA;
Thailand: DDPM, TMD;
Viet Nam: VDDMA, NHCMF;
Verified news media agencies
