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.
![]() Tropical Storm Son-Tinh nearing Vietnam on July 18 | |
Meteorological history | |
---|---|
Formed | July 15, 2018 (re-generated on July 21) |
Dissipated | July 24, 2018 |
Tropical storm | |
10-minute sustained (JMA) | |
Highest winds | 75 km/h (45 mph) |
Lowest pressure | 994 hPa (mbar); 29.35 inHg |
Tropical storm | |
1-minute sustained (SSHWS/JTWC) | |
Highest winds | 95 km/h (60 mph) |
Lowest pressure | 989 hPa (mbar); 29.21 inHg |
Overall effects | |
Fatalities | 173 |
Missing | possibly 1,100[1] |
Damage | $323 million |
Areas affected | Philippines, South China, Vietnam, Laos, Thailand, Myanmar |
IBTrACS | |
Part of the 2018 Pacific typhoon season |
The storm caused severe floods and mudslides in Vietnam, leading to the death of at least 32 people.[2][3][4] Over 82,000 hectares (200,000 acres) 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[1]) and 6,600 more are displaced.[5][6][7]
Meteorological history
editTropical storm (39–73 mph, 63–118 km/h)
Category 1 (74–95 mph, 119–153 km/h)
Category 2 (96–110 mph, 154–177 km/h)
Category 3 (111–129 mph, 178–208 km/h)
Category 4 (130–156 mph, 209–251 km/h)
Category 5 (≥157 mph, ≥252 km/h)
Unknown
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.[8][9] 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.[10][11]
Thereafter, however, Son-Tinh weakened slightly as it neared Hainan island due to moderate vertical wind shear.[12] 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.[13] 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 28 °C (82 °F) contributing to offset otherwise unfavorable upper atmospheric conditions.[14] 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 994 hPa (29.4 inHg).[15] 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.[16][17] The JTWC, however, continued to track Son-Tinh's remnants for the next two days.[18]
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.[18] 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.[19] Simultaneously the JMA reported that Son-Tinh had regenerated into a tropical depression.[20] With vertical wind shear now low and sea surface temperatures remaining high near 29 °C (84 °F), the JTWC stated that Son-Tinh intensified back into a tropical storm on July 22,[21] while the JMA continued to maintain Son-Tinh as a tropical depression.[22]
Preparations and impact
editChina
editTotal economic loss nationwide were at ¥240 million (US$35.7 million).[23]
Vietnam
editOn July 18, the Vietnamese government ordered all vessels to return to port.[24]
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.[25] It caused major flooding in Northern Vietnam and the capital city of Hanoi.[3] 35 people were killed, more than 5,000 houses, 82,000 hectares (200,000 acres) of crops, and 17,000 farm animals were either swept away, submerged, or otherwise destroyed.[3] The storm has cut off access to several areas in the country and flood water covers several streets in the capital city.[25] Economic losses were estimated to be ₫6.615 trillion (US$287 million).[26]
Laos
editOn July 23, a hydroelectric dam under construction in Attapeu Province, south-east Laos, collapsed. As of September 25, 40 people were confirmed dead,[5] at least 98 more were missing (and probably as much as 1,100 more people are missing[1]) and 6,600 others were displaced.[6][7]
See also
edit- Weather of 2018
- Tropical cyclones in 2018
- Typhoon Nina (1975) – devastating tropical cyclone in which most of the effects are located in the collapse of a dam
- Tropical Storm Amy (1994)
- Tropical Storm Linda (1997) – similarly deadly tropical cyclone to the south where Son-Tinh hit.
- Tropical Storm Soudelor (2009)
- 2011 Southeast Asian floods
- Typhoon Son-Tinh (2012) – storm with the same name that impacted the same area in 2012.
- Tropical Storm Aere (2016)
- Tropical Storm Sonca (2017) – another cyclone with similar track and floods, especially affecting Northeast Thailand (Sakon Nakhon Province).
- October 2017 Vietnam tropical depression – another deadly cyclone with similar landfalling point and floods, this time affecting the Central Vietnam.
- Tropical Storm Bebinca (2018) - another storm that made landfall at the same area.
- Tropical Storm Nangka (2020) - a tropical storm that contributed the 2020 Central Vietnam floods
- Tropical Storm Kompasu (2021)
References
edit- ^ a b c "Laos struggles to find missing after dam collapse". Al Jazeera. July 29, 2018. Retrieved June 11, 2020.
- ^ "Vietnam flood death toll rises to 27, more rain forecast". Archived from the original on July 25, 2018.
- ^ a b c Nguyen, Mai (July 21, 2018). "Storm Son Tinh kills 20, leaves 16 missing in Vietnam". U.S. Retrieved July 22, 2018.
- ^ Sidhu, Sandi; Cullinane, Susannah (July 22, 2018). "Storms, landslides and heat hit Asia". CNN. Retrieved July 22, 2018.
- ^ a b Ferrie 2018.
- ^ a b Al Jazeera 2018.
- ^ a b Channel News Asia 2018.
- ^ "Tropical Depression 11W (Eleven) Warning Nr 01". Joint Typhoon Warning Center. July 15, 2018. Archived from the original on May 23, 2024.
- ^ "Severe Weather Bulletin #1 For Tropical Depression Henry". Philippine Atmospheric, Geophysical and Astronomical Services Administration. July 15, 2018. Archived from the original (PDF) on July 15, 2018. Retrieved July 23, 2018.
- ^ "Prognostic Reasoning for Tropical Storm 11W (Son-Tinh) Warning Nr 07". Joint Typhoon Warning Center. July 17, 2018. Archived from the original on May 23, 2024.
- ^ "TS 1809 SON-TINH (1809) UPGRADED FROM TD". Japan Meteorological Agency. July 17, 2018. Archived from the original on May 23, 2024. Retrieved July 23, 2018.
- ^ "Prognostic Reasoning for Tropical Storm 11W (Son-Tinh) Warning Nr 08". Joint Typhoon Warning Center. July 17, 2018. Archived from the original on May 23, 2024.
- ^ "Prognostic Reasoning for Tropical Storm 11W (Son-Tinh) Warning Nr 10". Joint Typhoon Warning Center. July 18, 2018. Archived from the original on May 23, 2024. Retrieved July 23, 2018.
- ^ "Prognostic Reasoning for Tropical Storm 11W (Son-Tinh) Warning Nr 12". Joint Typhoon Warning Center. July 18, 2018. Archived from the original on May 23, 2024. Retrieved July 23, 2018.
- ^ "TS 1809 SON-TINH (1809)". Japan Meteorological Agency. July 18, 2018. Archived from the original on May 23, 2024. Retrieved July 23, 2018.
- ^ "Tropical Storm 11W (Son-Tinh) Warning Nr 014". Joint Typhoon Warning Center. July 19, 2018. Archived from the original on May 23, 2024.
- ^ "TD DOWNGRADED FROM TS 1809 SON-TINH (1809)". Japan Meteorological Agency. July 19, 2018. Archived from the original on May 23, 2024. Retrieved July 23, 2018.
- ^ a b "Tracking data". National Oceanic and Atmospheric Administration. July 22, 2018. Retrieved July 22, 2018.
- ^ "Prognostic Reasoning for Tropical Depression 11W (Son-Tinh) Warning Nr 15". Joint Typhoon Warning Center. July 21, 2018. Archived from the original on May 23, 2024. Retrieved July 23, 2018.
- ^ "WARNING AND SUMMARY 210600". Japan Meteorological Agency. July 21, 2018. Archived from the original on May 23, 2024. Retrieved July 23, 2018.
- ^ "Prognostic Reasoning for Tropical Storm 11W (Son-Tinh) Warning Nr 18". Joint Typhoon Warning Center. July 22, 2018. Archived from the original on May 23, 2024. Retrieved July 23, 2018.
- ^ "WARNING AND SUMMARY 220000". Japan Meteorological Agency. July 22, 2018. Archived from the original on May 23, 2024. Retrieved July 23, 2018.
- ^ CMA (December 4, 2018). Member Report: China (PDF). ESCAP/WMO Typhoon Committee. ESCAP/WMO Typhoon Committee. pp. 1–2. Archived from the original (PDF) on December 4, 2018. Retrieved December 4, 2018.
- ^ Vu, Khanh (July 18, 2018). "Vietnam orders vessels back to port, braces for Son Tinh tropical". Reuters. Retrieved July 22, 2018.
- ^ a b "At least 10 dead in Vietnam floods triggered by Typhoon Son Tinh". The New Indian Express. PTI. July 21, 2018. Retrieved July 22, 2018.
- ^ "Tóm tắt các cơn bão trong năm 2018" (in Vietnamese). Government of Tuyen Quang province. January 5, 2019. Retrieved January 20, 2019.