Tropical Storm Son-Tinh Explained
Tropical Storm Son-Tinh (Henry) |
Formed: | July 15, 2018 (re-generated on July 21) |
Dissipated: | July 24, 2018 |
Tropical Storm Son-Tinh, known in the Philippines as Tropical Storm Henry, was a weak but very deadly tropical cyclone that devastated Vietnam and Laos in July 2018. Son-Tinh originated from an area of low pressure over the Philippine Sea on July 15, 2018. Moving quickly westwards, Son-Tinh strengthened to the ninth tropical storm of the annual typhoon season on July 17. Intensifying only slightly while crossing the South China Sea, Son-Tinh made its first landfall over Hainan Island on July 18. After emerging into the Gulf of Tonkin, Son-Tinh restrengthened before making its second landfall as a tropical storm in Northern Vietnam on July 19. Once inland, Son-Tinh weakened into a low pressure area as it slowed and made a clockwise loop. The remnants of Son-Tinh then emerged back over water and regenerated into a tropical depression late on July 21.
The storm caused severe floods and mudslides in Vietnam, leading to the death of at least 32 people.[1] [2] [3] Over 82000hectare of agricultural land was inundated and at least 17,000 farm animals were swept away by the floods. The storm also caused or related to the havoc in the neighbouring country of Laos with the collapse of Attapeu dam, in which 40 people died and 98 more missing (and probably as much as 1,100 more people are missing[4]) and 6,600 more are displaced.
Meteorological history
An area of low pressure strengthened into a tropical depression on July 15, to the northwest of Manila, Philippines. Accordingly, the Joint Typhoon Warning Center (JTWC) designated it as 11W while the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) gave it the local name Henry.[5] [6] As the system moved westward at high speed, it gradually intensified as its convective structure improved, and strengthened a tropical storm by July 17, with the Japan Meteorological Agency (JMA) assigning the system the international name Son-Tinh.[7] [8]
Thereafter, however, Son-Tinh weakened slightly as it neared Hainan island due to moderate vertical wind shear.[9] Continuing to struggle to maintain intensity amid increasing wind shear, Son-Tinh crossed over Hainan island at around 03:00 UTC on July 18; despite land interaction the system continued to maintain its overall convective organization.[10] Later that day, as Son-Tinh emerged from land into the Gulf of Tonkin, Son-Tinh managed to intensify over the warm waters, with sea surface temperatures of over 28C contributing to offset otherwise unfavorable upper atmospheric conditions.[11] Before making landfall in Northern Vietnam, the JMA reported that Son-Tinh reached peak intensity with 10-minute sustained winds of 75 km/h (45 mph) and a central pressure of 994hPa.[12] Once inland over Northern Vietnam, Son-Tinh began to weaken quickly. Both the JMA and the JTWC issued their final warnings on Son-Tinh on July 19 as the system degenerated into an area of low pressure embedded in the monsoon.[13] [14] The JTWC, however, continued to track Son-Tinh's remnants for the next two days.[15]
Through July 19 and 20, Son-Tinh's remnants curved northwards and then eastwards over Northern Vietnam, before moving southeastward back into the Gulf of Tonkin on July 21.[15] Persistent convection developed over the system, aided by a tropical upper tropospheric trough to the northeast, prompting the JTWC to begin issuing advisories on Son-Tinh once again on July 21.[16] Simultaneously the JMA reported that Son-Tinh had regenerated into a tropical depression.[17] With vertical wind shear now low and sea surface temperatures remaining high near 29C, the JTWC stated that Son-Tinh intensified back into a tropical storm on July 22,[18] while the JMA continued to maintain Son-Tinh as a tropical depression.[19]
Preparations and impact
China
Total economic loss nationwide were at ¥240 million (US$35.7 million).[20]
Vietnam
See main article: 2018 Northern Vietnam floods.
On July 18, the Vietnamese government ordered all vessels to return to port.[21]
In Vietnam, the Thanh Hóa and Nghệ An provinces suffered the most damage, especially with the wake of the storm continuing to generate significant rainfall.[22] It caused major flooding in Northern Vietnam and the capital city of Hanoi. 35 people were killed, more than 5,000 houses, 82000hectare of crops, and 17,000 farm animals were either swept away, submerged, or otherwise destroyed. The storm has cut off access to several areas in the country and flood water covers several streets in the capital city. Economic losses were estimated to be ₫6.615 trillion (US$287 million).[23]
Laos
See main article: 2018 Laos dam collapse. On July 23, a hydroelectric dam under construction in Attapeu Province, south-east Laos, collapsed. As of September 25, 40 people were confirmed dead, at least 98 more were missing (and probably as much as 1,100 more people are missing) and 6,600 others were displaced.
See also
Notes and References
- News: Vietnam flood death toll rises to 27, more rain forecast. https://web.archive.org/web/20180725214730/http://uk.businessinsider.com/r-vietnam-flood-death-toll-rises-to-27-more-rain-forecast-2018-7?IR=T. dead. July 25, 2018.
- News: Storm Son Tinh kills 20, leaves 16 missing in Vietnam. Nguyen. Mai. July 21, 2018. U.S.. July 22, 2018. en-US.
- News: Storms, landslides and heat hit Asia. Sidhu. Sandi. July 22, 2018. CNN. July 22, 2018. Cullinane. Susannah.
- Web site: July 29, 2018. Laos struggles to find missing after dam collapse. June 11, 2020. Al Jazeera.
- Web site: Tropical Depression 11W (Eleven) Warning Nr 01. https://archive.today/20240523013146/https://www.webcitation.org/70w2Bc366?url=http://gwydir.demon.co.uk/advisories/WTPN31-PGTW_201807151500.htm. dead. July 15, 2018. Joint Typhoon Warning Center. May 23, 2024.
- Web site: Severe Weather Bulletin #1 For Tropical Depression Henry. July 15, 2018. Philippine Atmospheric, Geophysical and Astronomical Services Administration. https://www.webcitation.org/70w2JMzB9?url=https://pubfiles.pagasa.dost.gov.ph/tamss/weather/bulletin/SWB. July 15, 2018. July 23, 2018. dead.
- Web site: Prognostic Reasoning for Tropical Storm 11W (Son-Tinh) Warning Nr 07. https://archive.today/20240523013428/https://www.webcitation.org/70zFNXrpr?url=http://gwydir.demon.co.uk/advisories/WDPN31-PGTW_201807170300.htm. dead. July 17, 2018. Joint Typhoon Warning Center. May 23, 2024.
- Web site: TS 1809 SON-TINH (1809) UPGRADED FROM TD. July 17, 2018. Japan Meteorological Agency. https://archive.today/20240523013306/https://www.webcitation.org/70zEmL1cK?url=http://gwydir.demon.co.uk/advisories/WTPQ20-RJTD_201807170000.htm. May 23, 2024. July 23, 2018. live.
- Web site: Prognostic Reasoning for Tropical Storm 11W (Son-Tinh) Warning Nr 08. https://archive.today/20240523013348/https://www.webcitation.org/70zFNA2BH?url=http://gwydir.demon.co.uk/advisories/WDPN31-PGTW_201807170900.htm. dead. July 17, 2018. Joint Typhoon Warning Center. May 23, 2024.
- Web site: Prognostic Reasoning for Tropical Storm 11W (Son-Tinh) Warning Nr 10. https://archive.today/20240523013629/https://www.webcitation.org/710hJvR6z?url=http://gwydir.demon.co.uk/advisories/WDPN31-PGTW_201807180300.htm. dead. July 18, 2018. Joint Typhoon Warning Center. May 23, 2024. July 23, 2018.
- Web site: Prognostic Reasoning for Tropical Storm 11W (Son-Tinh) Warning Nr 12. https://archive.today/20240523013549/https://www.webcitation.org/710hJRT94?url=http://gwydir.demon.co.uk/advisories/WDPN31-PGTW_201807180900.htm. dead. July 18, 2018. Joint Typhoon Warning Center. May 23, 2024. July 23, 2018.
- Web site: TS 1809 SON-TINH (1809). July 18, 2018. Japan Meteorological Agency. https://archive.today/20240523013509/https://www.webcitation.org/710h8XzEK?url=http://gwydir.demon.co.uk/advisories/WTPQ20-RJTD_201807180300.htm. May 23, 2024. July 23, 2018. live.
- Web site: Tropical Storm 11W (Son-Tinh) Warning Nr 014. https://archive.today/20240523013749/https://www.webcitation.org/711otPu9f?url=http://gwydir.demon.co.uk/advisories/WTPN31-PGTW_201807182100.htm. dead. July 19, 2018. Joint Typhoon Warning Center. May 23, 2024.
- Web site: TD DOWNGRADED FROM TS 1809 SON-TINH (1809). July 19, 2018. Japan Meteorological Agency. https://archive.today/20240523013708/https://www.webcitation.org/711on8fxp?url=http://gwydir.demon.co.uk/advisories/WTPQ20-RJTD_201807190000.htm. May 23, 2024. July 23, 2018. live.
- Web site: Tracking data. July 22, 2018. National Oceanic and Atmospheric Administration. July 22, 2018.
- Web site: Prognostic Reasoning for Tropical Depression 11W (Son-Tinh) Warning Nr 15. https://archive.today/20240523014031/https://www.webcitation.org/717tA3sXC?url=http://gwydir.demon.co.uk/advisories/WDPN33-PGTW_201807211500.htm. dead. July 21, 2018. Joint Typhoon Warning Center. May 23, 2024. July 23, 2018.
- Web site: WARNING AND SUMMARY 210600. July 21, 2018. Japan Meteorological Agency. https://archive.today/20240523013834/https://www.webcitation.org/714rlRllz?url=http://gwydir.demon.co.uk/advisories/WWJP25-RJTD_201807210600.htm. May 23, 2024. July 23, 2018. live.
- Web site: Prognostic Reasoning for Tropical Storm 11W (Son-Tinh) Warning Nr 18. https://archive.today/20240523013949/https://www.webcitation.org/717t8vXgI?url=http://gwydir.demon.co.uk/advisories/WDPN33-PGTW_201807220900.htm. dead. July 22, 2018. Joint Typhoon Warning Center. May 23, 2024. July 23, 2018.
- Web site: WARNING AND SUMMARY 220000. July 22, 2018. Japan Meteorological Agency. https://archive.today/20240523013909/https://www.webcitation.org/716DpSDZQ?url=http://gwydir.demon.co.uk/advisories/WWJP25-RJTD_201807220000.htm. May 23, 2024. July 23, 2018. live.
- 1–2. ESCAP/WMO Typhoon Committee. Member Report: China. CMA. ESCAP/WMO Typhoon Committee. December 4, 2018. December 4, 2018. http://www.typhooncommittee.org/13IWS/index13IWS.html. December 4, 2018. https://web.archive.org/web/20181204010101/http://www.typhooncommittee.org/13IWS/docs/Members%20REport/CHina/Member_report_China_2018.pdf. dead.
- News: Vietnam orders vessels back to port, braces for Son Tinh tropical. Vu. Khanh. July 18, 2018. Reuters. July 22, 2018. en-US.
- News: At least 10 dead in Vietnam floods triggered by Typhoon Son Tinh. July 21, 2018. The New Indian Express. July 22, 2018. PTI.
- Web site: Tóm tắt các cơn bão trong năm 2018. vi. Government of Tuyen Quang province. January 5, 2019. January 20, 2019.