2020 Central Vietnam floods

On 7 October, a tropical depression made landfall in the Khánh Hòa province.[10] Enhanced by the seasonal northeast monsoon, many provinces nearby suffered heavy rainfall with average accumulations of 200–300 mm. In Sa Huỳnh (Quảng Ngãi), rainfall peaked at 14.17 in (360 mm). By 11 October (before Linfa made landfall), heavy floods killed 9 people.[11]

Dap Da Bridge under the water in Hue City, 10 October 2020.

On 9 October, a tropical depression formed in east Luzon. It was upgraded to a tropical storm, named Linfa on the next day. On 11 October Linfa struck the central Vietnamese coast in the province of Quảng Ngãi,[12] the area that was already flooded by previous seasonal monsoon events from 6–9 October. Linfa released historic amounts of precipitation to Central Vietnam, peaking at 90.16 inches (2,290 mm) in A Lưới (Huế)[13] making Linfa the twelfth wettest tropical cyclone on record, 59.842 inches (1,520 mm) in Hướng Linh (Quảng Trị).[14] The storm destroyed a total of 382 houses and flooded 109,034 others. In addition, the storm damaged 165.1 km of national highways and 140.1 km of provincial highways. The disaster caused big losses to agricultural production by destroying 2,141 hectares (5,290 acres) of rice crops and vegetable crops, and 2,141 hectares (5,290 acres) of aquaculture, whilst killing about 685,225 cattle and poultry.[15] In total, the storm left 174 people dead and 20 missing in Vietnam and Cambodia.

On the night of 11 October, heavy rainfall attributed from typhoon Linfa resulted in landslide at the Rào Trăng 3 Hydropower Plant in Phong Điền District of Thua Thien Hue province, leaving 17 constrution workers missing. On 12 October 2020, a military rescue team to the missing workers was hit by another landslide, killing Major General Nguyễn Văn Man and 12 other soldiers.[16] On October 15, 2020, their bodies were found by rescuers.[17]

Tropical Storm Nangka approaching Vietnam on October 13

In preparation for Nangka more than 150,000 people in Vietnam were evacuated from their homes. Some Vietnamese provinces banned vessels from heading out to sea during the storm Vinh Airport in Nghe An Province and Tho Xuan Airport in Thanh Hoa Province were closed on October 14. Vietnam Airlines and Pacific Airlines announced that eight flights were cancelled to the two airports

On 11 October, a tropical depression formed in the west of Luzon. It was upgraded to a tropical storm, named Nangka on the next day. On 13 October, Nangka acrossed the Gulf of Tonkin, and it made landfall in Ninh Bình on the next day. Wind gusts up to 120 km/h (75 mph) were reported in Nam Định.[18] Some areas in Northern Vietnam received heavy rainfall, such as 16.18 in (411 mm) in Yên Bái, 14.76 in (375 mm) in Quảng Ninh on 16 October.[19][20] The storm caused 2 deaths and 1 missing in Northern Vietnam.[21]

Ofel made landfall after entering the South China Sea then dissipated in Central Vietnam on 16 October.[22] 10 people reported dead on 21 October, likely caused by Ofel's remnant and the northeast monsoon.[23] By 20 October, rainfall had reduced significantly.[24]

On 18 October, a sudden landslide buried barracks an army economic division in Hướng Phùng Commune, Hướng Hoá District of Quảng Trị province, killing 22 soldiers. [25] Another landslide in Hướng Hóa District also kills 6 people in a family and one rescuer.

Typhoon Saudel in the South China Sea on October 23

As Saudel approached Vietnam, it began to rapidly weaken due to high vertical wind shear and was downgraded to a tropical storm on 24 October 2020. The next day, it was downgraded to a remnant low as its center became mostly devoid of any deep convection.[26] Although weakened, Saudel still brought heavy rainfall to Central Vietnam.

The storm also caused strong winds and rough seas over waters off the Malaysian state of Sabah where the Malaysian Meteorological Department (MetMalaysia) had issued a tropical strom advisory with the distance between the storm and nearest town is about 1,315 kilometers northwest of Kudat.[27]

Molave near peak intensity on 27 October near the coast of Vietnam

Nearly 1.3 million people were evacuated in Vietnam, as Prime Minister Nguyen Xuan Phuc ordered boats onshore and advised preparations for the security force and resident in the area. The prime minister also compared Molave to Typhoon Damrey of 2017.[28] Hundreds of flights were cancelled and schools were forced to close. The federal government mobilised about 250,000 troops and 2,300 vehicles to be used for search and rescue missions.[29] Members of the Vietnamese military helped load elderly people onto evacuation buses and helped direct boats onshore. Some also helped residents put sandbags on their roof.[30] On 27 October, Da Nang People's Committee had requested people to not leave their houses starting from 8:00 pm (local time) that night and urged all officials and workers to not come into work on the next day, among other measures in preparation for the typhoon.[31]

On 27 October, the typhoon caused two Vietnamese fishing boats to sink.[32] Authorities deployed search boats to search for 26 missing fishermen that were on the boats.[33]

Molave started affecting Vietnam late on 27 October. On the morning of the 28th, the entire island of Lý Sơn and its 20,000 inhabitants lost power. The island was lashed with 165 km/h (100 mph) winds for hours.[34][35] Waves as high as 6 feet (1.8 m) lashed coastal areas of Vietnam.[33]

Molave caused widespread destruction in Central Vietnam. Wind gusts peaking at 176 km/h (109 mph) were reported in the city of Quảng Ngãi.[35] Molave brought heavy rains; Sơn Kỳ (Quảng Ngãi) received 18.50 inches (470 mm) over 24 hours of rainfall.[35] The typhoon damaged or destroyed 56,163 houses and left 6.5 million people without power.[36] It killed 13 people, injured 16, and left 48 others remaining missing.[35][37][38][39][40][41]Initial losses in Quảng Nam were estimated at about 1 trillion VND ($43.14 million).[37]

Devastating landslides caused by Molave have killed at least 28 people in the communes of Nam Trà My District of Quảng Nam province. Another landslide in Phuoc Son District buried 11 people in a same family. [42]

Typhoon Goni at peak intensity shortly before landfall in the Philippines on 31 October

Goni first moved into the South China Sea, after its catastrophic landfall in Catanduanes, with its intensity ranging from 65 to 70 km/h (40 to 45 mph) before briefly weakening again into a 50 km/h (30 mph) tropical depression. Goni's convection decoupled from its low-level circulation as a result of anticyclonic wind shear generated by the nearby Tropical Storm Atsani (Siony) from Northern Luzon combined with cooler water. Goni's trough then brought showers, thunderstorms, and more flooding to an already rain-stricken Vietnam from the previous Linfa, Nangka, Ofel, Saudel and Molave which had all struck a few days earlier. Goni brought unusual floods to coastal cities of Nha Trang and Quy Nhơn.

According to the National Center for Hydro-Meteorological Forecasting, the storm would hit Da Nang and Phu Yen provinces on November 5. On November 3, just two days before the expected landfall, the only preparations done were to institute a no-sail policy within the storm's path which affected about 50,000 fishing boats.[43] The following day, Quang Ngai People's Committee Chairman Dang Van Minh asked those living in landslide-prone areas to evacuate, while the National Committee for Disaster Prevention and Search and Rescue mobilized more than 64,500 people and 1,718 vehicles for rescue operations.[44]

On November 5, Tropical Depression Goni made landfall in southern Bình Định Province, becoming the fifth tropical cyclone to strike the country in the previous 30 days.[45] A man in Quảng Ngãi Province was swept away by floodwaters on November 6. Another man went missing on November 6 after the ship he was captaining sunk. Twenty houses in Quảng Nam Province collapsed into a river and a school was damaged. In Bình Định Province, two houses were destroyed by landslides and 228 hectares (560 acres) of croplands were damaged. Roads in several provinces were damaged by erosion and landslides, including parts of the Ho Chi Minh Highway.[46]

Damage in Bình Định Province from both Goni and Etau were calculated to be ₫543 billion (US$23.5 million).[47]

Tropical Storm Etau at peak intensity.

Tropical Storm Etau became a tropical depression on November 7, 12:00 UTC,[48] and was later upgraded to a tropical storm. The storm continued its way towards Central Vietnam after crossing the Philippines.

Etau killed two people in Quảng Nam and Bình Định and damaged 31 houses when it made landfall in central Vietnam on November 10.[49] The storm produced over 250 mm (10 in) of rain in the provinces of Bình Định, Khánh Hòa, and Phú Yên.[50] The storm also caused gusty winds which uprooted trees and ripped roofs of buildings, many of which were still recovering from the adverse impacts of Typhoon Molave and the weakened Tropical Storm Goni. In addition, power outages locally affected the city of Tuy Hòa. [51]

Economic losses in Tuy An, Phú Yên were counted as 122 billion VND (US$5.26 million).[52]

Vamco approaching Vietnam at peak intensity over the South China Sea on November 13, 2020.

After crossing through the Philippines as a Category 2-equivalent typhoon, the storm gradually strengthened into Category 3 status as it exited from the Philippine Area of Responsibility at 01:30 UTC, 12 November. It now currently threatens the northern regions of Vietnam and Southern China.

On November 14, at least 460,000 people were ordered to evacuate by the government.[53] On the morning of that same day, all flights in 5 airports, included Da Nang, Chu Lai, Phu Bai, Dong Hoi and Vinh were ordered to be suspended or delayed.[54]

Vamco began affecting central Vietnam around midnight ICT on November 15. Despite having weakened, a weather station on Lý Sơn island reported hourly sustained winds of 100 km/h (62 mph) and gusts of up to 115 km/h (71 mph).[55] Strong winds downed many trees, damaged numerous homes the four provinces of Hà Tĩnh to Thừa Thiên Huế.[55] In Thuận An, Thừa Thiên Huế, strong waves lashed docking fishing ships and civilian houses.[56] In the city of Da Nang, storm surge destroyed many sea embankments, while washing rocks and debris onshore, and into streets.[56] Power outages affected 411,252 customers in six central provinces.[57] A person was killed in Thừa Thiên-Huế Province, and economic loss in Quảng Bình Province reached 450 billion đồng (US$19.4 million).[58][59]

The flooding in Nghệ An killed two people.[24] Damages in Nghệ An is about 3 trillion VND ($129.44 million).[60]

From 16 to 19 October, some areas in Hà Tĩnh received heavy rainfall (from Tropical depression Ofel): 66.57 inches (1,691 mm) in Kỳ Thượng; 52.51 inches (1,334 mm) in Lake Kim Sơn.[61] Flooding in Hà Tĩnh killed 6 people.[62] Damages in Hà Tĩnh were estimated about 5.5 trillion VND ($237.47 million).[63]

From 6 to 13 October, tropical cyclones dumped about 550-1,200 mm of rain in Quảng Bình.[13] From 16 to 19 October, remnants of Ofel brought 41.85 inches (1,063 mm) of rain in Vạn Trạch. Flooding in Quảng Bình killed 19 people,[62] flooded 95,000 houses and made 190,000 households lose power.[64] Losses caused by floods and landslides in Quảng Bình was about 3,511 billion VND ($151.49 million).[65]

From 10 to 19 October, remnants of Linfa and Ofel brought heavy rainfall to Quảng Trị. Hướng Linh district received 127.75 inches (3,245 mm) of precipitation in 13 days.[64] Landslides hit a military barrack on 17 October, killed 22 soldiers.[66] In total flood and landslides left 52 deaths and 2 missing, caused about 3,000 billion VND ($129.4 million) in damages.[67] Quang Tri authorities have asked the central government to supply materials and rescue equipment, including two amphibious vehicles, 27 boats, rescue equipment and chemicals for disinfection.[15]

In Thừa Thiên Huế, its mountainous districts received the heaviest amounts of rainfall in the region, mostly came from tropical storm Linfa. In three days, 10 October to 13, Linfa brought 90,16 inches (2,290 mm) in A Lưới; 89.60 inches (2,276mm) in Lake Khe Ngang, broke the historical record (2,244 mm in October 1999). Thượng Nhật saw the daily rainfall on 13 October was 28.3 in (719 mm).[13] In total, three tropical cyclones from 6 to 19 October dumped the average amounts of precipitation about 78 to 98.42 inches (2000–2500 mm) in the province, peaked in A Lưới with 115.78 inches (2,941 mm); Bạch Mã with 112.95 inches (2,869 mm).[64]

In total, floods caused 31 deaths and approximate 2,000 billion VND ($86.29 million) in damages in Thừa Thiên Huế.[62][68]

Floods in Da Nang killed three people.[61]

Floods in Quảng Nam killed thirteen people.[62] The city of Hội An has been flooded after heavy rainfall occurred on 7–8 October caused by tropical low 91W.[69] Total economic losses in Quảng Nam were about 11 trillion VND ($478 million).[70]

Floods and landslides due to 91W, Linfa and Ofel caused 6 deaths in Quảng Ngãi, Gia Lai, Đắk Lắk, Lâm Đồng and Kon Tum.[61]