Tropical Storm Sinlaku was a weak

tropical cyclone A tropical cyclone is a rapidly rotating storm system with a low-pressure area, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depending on its locat ...

that impacted

Vietnam Vietnam, officially the Socialist Republic of Vietnam (SRV), is a country at the eastern edge of mainland Southeast Asia, with an area of about and a population of over 100 million, making it the world's List of countries and depende ...

Thailand Thailand, officially the Kingdom of Thailand and historically known as Siam (the official name until 1939), is a country in Southeast Asia on the Mainland Southeast Asia, Indochinese Peninsula. With a population of almost 66 million, it spa ...

and

Laos Laos, officially the Lao People's Democratic Republic (LPDR), is the only landlocked country in Southeast Asia. It is bordered by Myanmar and China to the northwest, Vietnam to the east, Cambodia to the southeast, and Thailand to the west and ...

in early August 2020. Beginning as a

tropical depression A tropical cyclone is a rapidly rotating storm system with a low-pressure area, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depending on its locat ...

on July 31 in the

South China Sea The South China Sea is a marginal sea of the Western Pacific Ocean. It is bounded in the north by South China, in the west by the Indochinese Peninsula, in the east by the islands of Taiwan island, Taiwan and northwestern Philippines (mainly Luz ...

, Sinlaku was the fifth storm of the

2020 Pacific typhoon season The 2020 Pacific typhoon season was the first of a series of four below average Pacific typhoon seasons, and became the first with below-average tropical cyclone activity since 2014, with 23 named storms, 10 of which became typhoons and only 2 ...

. It gradually organized as it took a slow west-northwest course, strengthening into a

tropical storm A tropical cyclone is a rapidly rotating storm system with a low-pressure area, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depending on its lo ...

the following day despite its monsoonal structure. The storm subsequently made landfall in Vietnam as a broad but weak tropical storm. Persistent land interaction weakened Sinlaku, leading to its dissipation on August 3. Sinlaku brought heavy

monsoon A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in Atmosphere of Earth, atmospheric circulation and precipitation associated with annu ...

al rains to much of

Southeast Asia Southeast Asia is the geographical United Nations geoscheme for Asia#South-eastern Asia, southeastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and northwest of the Mainland Au ...

, especially to

, and

. Two people were killed in Vietnam, and two people were killed in

Meteorological history

In late July 2020, an area of

atmospheric convection Atmospheric convection is the vertical transport of heat and moisture in the atmosphere. It occurs when warmer, less dense air rises, while cooler, denser air sinks. This process is driven by parcel-environment instability, meaning that a "par ...

began to persist approximately 410 km (255 mi) east of

Virac, Catanduanes Virac, officially the Municipality of Virac, is a municipality of the Philippines, municipality and capital of the Philippine Province, province of Catanduanes, Philippines. According to the 2020 census, it has a population of 76,520 people. I ...

. Afterwards, the

Joint Typhoon Warning Center The Joint Typhoon Warning Center (JTWC) is a joint United States Navy – United States Air Force command in Pearl Harbor, Hawaii. The JTWC is responsible for the issuing of tropical cyclone warnings in the North-West Pacific Ocean, South P ...

(JTWC) designated the system a low-chance of developing into a tropical cyclone. Although situated within an environment generally conducive for the formation of a tropical cyclone, the low-pressure area moved towards Luzon, emerging in the

with little to no organization. The low-pressure system then later left the

Philippine Area of Responsibility The Philippine Area of Responsibility (PAR) is an area in the Northwestern Pacific where PAGASA, the Philippines' national meteorological agency, monitors weather occurrences. Significant weather disturbances, specifically typhoons that enter o ...

and moved towards the

. By the following hours, the JTWC upgraded the disturbance's chance to develop at medium, assessing that the disturbance is a

monsoon depression The monsoon trough is a convergence zone between the wind patterns of the southern and northern hemispheres. It is a portion of the Intertropical Convergence Zone in the Western Pacific,Bin WangThe Asian Monsoon.Retrieved 2008-05-03. and is depi ...

. On the following day, July 31, the

Japan Meteorological Agency The Japan Meteorological Agency (JMA; ''気象庁, Kishō-chō'') is a division of the Ministry of Land, Infrastructure, Transport and Tourism dedicated to the Scientific, scientific observation and research of natural phenomena. Headquartered ...

(JMA) designated the invest as a tropical depression. In a favorable environment of low vertical shear, excellent equatorial outflow and 31 °C

sea surface temperature Sea surface temperature (or ocean surface temperature) is the ocean temperature, temperature of ocean water close to the surface. The exact meaning of ''surface'' varies in the literature and in practice. It is usually between and below the sea ...

s, the depression continued to organize, and by the next day, the JMA upgraded depression to a tropical storm, naming it ''Sinlaku''. The JTWC would later follow suit, upgrading the monsoon depression to tropical storm status. Sinlaku would later not intensify further, although the JMA said the storm's pressure lowered to 992 hPa (29.29 inHg). The storm would later make

landfall Landfall is the event of a storm moving over land after being over water. More broadly, and in relation to human travel, it refers to 'the first land that is reached or seen at the end of a journey across the sea or through the air, or the fact ...

on northern

, and both agencies issued final advisories on Sinlaku.

Preparations and impact

Philippines

As a low-pressure area, Sinlaku dumped heavy rain associated with the southwest monsoon over regions of Luzon and Visayas. After crossing Luzon, the storm exited the

but it intensified the monsoon.

Vietnam

In preparation for the storm, Nghệ An Province authorities recalled over 3,000 vessels carrying over 15,000 sailors to shore. Vietnam prime minister

Nguyễn Xuân Phúc Nguyễn Xuân Phúc (; born 20 July 1954) is a Vietnamese former politician who served as the 11th president of Vietnam from 2021 until his resignation in 2023 amidst a series of corruption scandals. He also was the seventh prime minister from ...

urged relevant ministries and agencies "to remain updated on the developments of the storm, and map out scenarios for the possible risks of flashfloods, landsides, and severe flooding." Nearing the northern coast, Sinlaku caused heavy rains across the area, damaging more than 4,000 hectares of crops and over 9,000 hectares of rice crops. The storm damaged over 1,400 houses, with 32 houses being flooded with 30-40 centimeters. Two people were dead, 1 in both Hoa Binh and Quang Ninh provinces, and two were injured in the province of

Lam Dong Lam or LAM may refer to: Organizations * Laguna Art Museum, California, US * Leather Archives & Museum (LA&M), Chicago, US * Lam Eng Rubber, a Malaysian manufacturer * Lam Research, American semiconductor equipment company * LAM Mozambique Ai ...

. A thunderstorm from the storm broke 29 trees in districts of

Hanoi Hanoi ( ; ; ) is the Capital city, capital and List of cities in Vietnam, second-most populous city of Vietnam. The name "Hanoi" translates to "inside the river" (Hanoi is bordered by the Red River (Asia), Red and Black River (Asia), Black Riv ...

. The Copernicus emergency satellite mapping service was activated on 3 August to support the damage assessment across northern Vietnam. Total damages were about 300 billion đồng (US$12.94 million).

Thailand

Moving towards Thailand, Sinlaku's heavy rains caused flash flooding which two people were killed. In Loei Province, the storm brought heavy rains and flash flooding, submerging around 550 households and damaging farmland in the province. In total, 1,399 households were affected by the flash floods.

Laos

Xayaboury Province Sainyabuli, (; alternatively spelled ''Sayaboury'', ''Xaignabouli'', ''Xayaburi'', or ''Xayaboury'') is the capital of Sainyabuli Province, Laos. It lies on Route 4 which along with Route 13 connects it to Luang Prabang, roughly 80 kilometres ...

, more than 1,000 people were affected and over 200 houses were damaged.

References

External links

Japan Meteorological Agency's website
{{DEFAULTSORT:Sinlaku (2020) Western Pacific tropical storms Typhoons in Vietnam Tropical cyclones in 2020 2020 Pacific typhoon season