Tropical Storm Sonca (2022)

Tropical Storm Sonca was a weak but damaging tropical storm that impacted Vietnam in mid-October 2022. The thirtieth tropical depression, and nineteenth tropical storm of the 2022 Pacific typhoon season, Sonca developed from a scattered area of convection within a broad low-level center. As it became slightly organized, the Japan Meteorological Agency (JMA) classified the system as a depression on October 13, while the Joint Typhoon Warning Center (JTWC) followed suit the next day, naming the system 22W. Not long after, the system intensified into a tropical storm, receiving the name Sonca by the JMA. It soon made landfall on Da Nang, Vietnam. Sonca rapidly weakened over land, and the JTWC and JMA both issued their final advisories on Sonca.

Tropical Storm Sonca

Sonca as a tropical storm on October 14
Meteorological history
Formed	October 13, 2022
Dissipated	October 15, 2022
Tropical storm
10-minute sustained (JMA)
Highest winds	65 km/h (40 mph)
Lowest pressure	998 hPa (mbar); 29.47 inHg
Tropical storm
1-minute sustained (SSHWS/JTWC)
Highest winds	75 km/h (45 mph)
Lowest pressure	998 hPa (mbar); 29.47 inHg
Overall effects
Fatalities	12
Damage	$102 million (2022 USD)
Areas affected	Vietnam, Laos, Cambodia
Part of the 2022 Pacific typhoon season

Sonca, despite being weak caused heavy damage throughout central Vietnam, bringing 700 mm (28 in) of rainfall resulting in major flooding. Overall, Sonca was blamed for 12 fatalities, and damages inflicted costed 2.4 trillion VND (US$101.5 million.)

Meteorological history

Map plotting the storm's track and intensity, according to the Saffir–Simpson scale

Map key

Saffir–Simpson scale

  Tropical depression (≤38 mph, ≤62 km/h)
  Tropical 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

Storm type

Tropical cyclone

Subtropical cyclone

Extratropical cyclone, remnant low, tropical disturbance, or monsoon depression

Late on October 11, the JTWC began monitoring a scattered area of moderate convection within a broad low-level center 280 km (170 mi) west-southwest of Manila, Philippines.^[1] Within a marginally favorable environment of no distinct outflow established, low to moderate wind shear, and warm sea surface temperatures, the system slightly organized by the next day, with flaring convection and its center remaining exposed.^[2] Nonetheless, the JMA upgraded the system into a tropical depression on October 13.^[3] The JTWC later issued a TCFA on the system on the same day, noting fragmented deep convection was wrapping into its broad low-level center.^[4] By the next day, the JTWC initiated advisories on the storm, designating it as 22W.^[5] Moving westward, the storm intensified into a tropical storm six hours later, with the JMA naming it as Sonca.^[6] Sonca failed to intensify further as its center remained exposed, with deep convection displaced to the west due to strong wind shear,^[7] and it soon made landfall on Da Nang, Vietnam late on the same day, prompting the JTWC to issue their final advisory on the system.^[8] The JMA followed suit by October 15, as Sonca weakened into a tropical depression.^[9]

Preparations and impact

As Sonca moved inland, it brought heavy rainfall to central Vietnam, with 700 mm (28 in) of rain fell in Da Nang during a 24-hour period on October 14–15; this resulted in major flooding throughout the region. The flooding killed a reported 10 people.^[10] Initial estimated economic losses in Da Nang City caused by Sonca's heavy precipitation are around 1.48 trillion VND (US$60.8 million).^[11][12][13] Infrastructure losses in Thừa Thiên Huế province reached 337 billion VND (US$13.5 million). 2 people were killed and 4 injured in the province.^[14] Overall, damages inflicted by Sonca were 2.4 trillion VND (US$101.5 million).^{[citation needed]}

References

1. . 2022-09-23 https://web.archive.org/web/20220923070157/https://www.metoc.navy.mil/jtwc/products/abpwweb.txt. Archived from the original on 2022-09-23. Retrieved 2024-07-09. {{cite web}}: Missing or empty |title= (help)
2. Significant Tropical Weather Advisory for the Western and South Pacific Oceans (Reissued) (Report). Joint Typhoon Warning Center. October 12, 2022. Archived from the original on September 23, 2022. Alt URL
3. RSMC Tropical Cyclone Prognostic Reasoning No. 1 for TD located at 12.1N 114.4E (Report). Japan Meteorological Agency. October 13, 2022. Archived from the original on October 13, 2022.
4. Tropical Cyclone Formation Alert (Invest 90W) (Report). Joint Typhoon Warning Center. October 13, 2022. Archived from the original on October 13, 2022.
5. Prognostic Reasoning for Tropical Depression 22W (Twenty-two) Warning Nr 001 (Report). Joint Typhoon Warning Center. October 14, 2022. Archived from the original on October 14, 2022.
6. RSMC Tropical Cyclone Prognostic Reasoning No. 6 for TS 2219 Sonca (2219) (Report). Japan Meteorological Agency. October 14, 2022. Archived from the original on October 14, 2022.
7. Prognostic Reasoning for Tropical Storm 22W (Sonca) Warning Nr 003 (Report). Joint Typhoon Warning Center. October 14, 2022. Archived from the original on October 14, 2022.
8. Tropical Storm 22W (Sonca) Warning Nr 004 (Report). Joint Typhoon Warning Center. October 14, 2022. Archived from the original on October 14, 2022.
9. RSMC Tropical Cyclone Advisory for TD downgraded from TS 2219 Sonca (2219) (Report). Japan Meteorological Agency. October 15, 2022. Archived from the original on October 15, 2022.
10. "Central Vietnam flooding death toll rises to 10". VnExpress. Hanoi, Vietnam. October 16, 2022. Retrieved October 18, 2022.
11. "Đà Nẵng bị thiệt hại hơn 1.486 tỷ đồng do trận ngập lụt lịch sử". baodanang.vn (in Vietnamese). Danang, Vietnam. October 19, 2022. Retrieved October 19, 2022.
12. "Đà Nẵng thiệt hại gần 1.500 tỷ đồng trong bão số 5". daidoanket.vn (in Vietnamese). October 20, 2022. Retrieved October 20, 2022.
13. "Đà Nẵng thiệt hại gần 1.500 tỷ đồng do mưa lũ". VnExpress (in Vietnamese). October 19, 2022. Retrieved October 20, 2022.
14. "Thừa Thiên Huế thiệt hại hơn 337 tỉ đồng do mưa lũ". Tuổi Trẻ (in Vietnamese). October 20, 2022. Retrieved October 23, 2022.