Tropical Storm Pulasan

Tropical Storm Pulasan, known in the Philippines as Tropical Storm Helen, was a tropical cyclone that impacted East China, Japan, South Korea and the Philippines in September 2024. Pulasan developed over the Philippine Sea as a tropical depression on September 15 and strengthened into the fourteenth named storm of the annual typhoon season the following day. After gaining organization, the system rapidly developed and reached its peak intensity with winds of 85 km/h (50 mph) and a central pressure of 992 hPa (29.29 inHg). Pulasan then turned northwestward, eventually moving across Okinawa Island and making landfall in Zhoushan, Zhejiang, followed by a second landfall in Shanghai, just days after Typhoon Bebinca affected the Shanghai area on September 19. As the storm moved overland, it maintained a well-defined circulation center; however, it gradually turned northeastward under the influence of prevailing mid-latitude westerlies. Pulasan reemerged over the East China Sea, just off the coast of China, showcasing a large, near-symmetric area of deep convection to the southeast on September 20. By 06:00 UTC on September 21, Pulasan had transitioned into an extratropical low as it moved east-northeastward and became embedded within the polar front jet to the north, passing over southern South Korea. The extratropical storm entered the Sea of Japan on September 22, crossed the Tōhoku region, and then emerged into the Pacific Ocean while being absorbed by another extratropical cyclone. The extratropical remnants of Pulasan were last noted by the Japan Meteorological Agency on September 24 near the International Dateline; however, the Ocean Prediction Center indicated that these remnants crossed the International Dateline and entered the Central North Pacific Ocean late on September 25. Afterward, the remnants gradually approached the coast of British Columbia, making landfall on September 27 and dissipating after moving inland the same day.

Tropical Storm Pulasan (Helen)
Pulasan approaching eastern China on September 18
Meteorological history
FormedSeptember 15, 2024
ExtratropicalSeptember 21, 2024
DissipatedSeptember 27, 2024
Tropical storm
10-minute sustained (JMA)
Highest winds85 km/h (50 mph)
Lowest pressure992 hPa (mbar); 29.29 inHg
Tropical storm
1-minute sustained (SSHWS/JTWC)
Highest winds110 km/h (70 mph)
Lowest pressure995 hPa (mbar); 29.38 inHg
Overall effects
Fatalities17
Injuries47
Missing12
Damage$4.15 million (2024 USD)
Areas affectedPhilippines, Eastern China, South Korea, Japan (especially Ishikawa Prefecture), British Columbia

Part of the 2024 Pacific typhoon season

In China, the Yangjiazhai meteorological station in Fengxian District and the Nicheng Park meteorological station in Pudong District both recorded more than 300 mm (12 in) of rainfall within a six-hour period, breaking historical records for each district since meteorological observations began. Xinhua reported that the city evacuated 112,000 people and suspended some ferry and train services. The Philippine Atmospheric, Geophysical and Astronomical Services Administration noted that the southwest monsoon, enhanced by Soulik and Pulasan, would bring strong to gale-force winds across the Philippines. Heavy rains caused by Pulasan triggered widespread landslides and flooding in the Noto Peninsula, causing extensive damage that was exacerbated by the 2024 Noto earthquake, which devastated the region in January. In South Korea, the cities of Changwon, Yeosu and Busan recorded 519.2 mm (20.44 in), 399.5 mm (15.73 in) and 390.2 mm (15.36 in) of rainfall, respectively, on September 21. The remnants of Tropical Storm Pulasan caused 15,000 customers to lose power, primarily on Vancouver Island, especially in Campbell River and Courtenay. In total, the tropical storm caused at least 17 deaths, 47 injuries, and left twelve people missing.

Meteorological history

edit
 
Map plotting the storm's track and intensity, according to the Saffir–Simpson scale
Map key
  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
  Extratropical cyclone, remnant low, tropical disturbance, or monsoon depression

Tropical Storm Pulasan emerged from an area of atmospheric convection 196 km (122 mi) west-southwest of Andersen Air Force Base, Guam on September 14.[1] Satellite imagery indicates a broad, elongated area of circulation obscured by flaring and disorganized deep convection, with the disturbance situated in a favorable environment for development.[1] At 00:00 UTC on September 15, the Japan Meteorological Agency (JMA) designated the system as a low-pressure area, having previously identified it as a tropical depression.[2][3] The United States Joint Typhoon Warning Center (JTWC) issued a tropical cyclone formation alert, noting that the system was disorganized, deep, fragmented, and had flaring convection obscuring the low-level circulation.[4] Shortly after, the depression intensified into a tropical storm and was named Pulasan by the JMA.[5] Pulasan was characterized by a large cyclonic circulation exceeding 690 miles (1,111 km) and extensive gale-force winds, leading the JTWC to classify it as a monsoon depression at 06:00 UTC on September 16,[6] before later upgrading it to a tropical storm and designating it as 15W.[7]

Pulasan was progressing north-northeastward along the northwestern edge of a mid-level subtropical high, with a band of enhanced winds encircling the eastern edge, accompanied by deep convection,[8] while the center stayed clear and was supplied with dry air from a tropical upper tropospheric trough cell to the west.[9] By 11:00 PHT (03:00 UTC) on September 17, Pulasan had entered the Philippine Area of Responsibility (PAR) and was subsequently named Helen by the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA).[10] The JMA reported that Pulasan reached its peak intensity at 06:00 UTC, with 10-minute sustained winds of 85 km/h (50 mph) and a central pressure of 992 hPa (29.29 inHg),[11] before ultimately peaking with 1-minute sustained winds of 110 km/h (70 mph).[12] Pulasan's low-level circulation has remained broad and somewhat exposed,[13] as dry air continues to encircle its southern side while the system moves northwestward along the southwestern edge of a mid-level subtropical high.[14] Pulasan exited the PAR on September 18 while traversing Okinawa Island in Japan's Ryukyu Archipelago as its circulation center strengthened with persistent convection,[15] and satellite imagery displayed flaring convection along with weak easterly outflow over the East China Sea.[16][17] On September 19, Pulasan made landfall in Zhoushan, Zhejiang, followed by a second landfall in Shanghai, just days after Typhoon Bebinca affected the Shanghai area.[18][19] As the storm moved overland, it maintained a well-defined circulation center;[20] however, the system gradually turned northeastward under the influence of mid-latitude prevailing westerlies.[21] Pulasan reemerged over the East China Sea, just off the coast of Jiangsu, China, showcasing a large, near-symmetric area of deep convection to the southeast on September 20.[22] Meanwhile, satellite imagery and surface reports from Jeju Island indicated that it was in the earliest phase of extratropical transition, with vigorous deep convection occurring over the southern semicircle.[23] By 06:00 UTC on September 21, the JMA reported that Pulasan had transitioned into an extratropical low as it moved east-northeastward and became embedded within the polar front jet to the north,[24] passing over southern South Korea.[25] The JTWC then ceased issuing advisories on the system as it underwent frontogenesis while entering the baroclinic zone.[26] The extratropical storm entered the Sea of Japan on September 22, crossed the Tōhoku region, and then emerged into the Pacific Ocean while being absorbed by another extratropical cyclone.[27] The extratropical remnants of Pulasan were last noted by the JMA on September 24 near the International Dateline;[28] however, the Ocean Prediction Center indicated that these remnants crossed the International Dateline and entered the Central North Pacific Ocean late on September 25.[29] The remnants gradually approached the coast of British Columbia,[30] making landfall on September 27,[31] moving inland,[32] and dissipating the same day.[33]

Preparations and impact

edit

The Yangjiazhai meteorological station in Fengxian District and the Nicheng Park meteorological station in Pudong District both recorded more than 300 mm (12 in) of rainfall within a six-hour period, breaking historical records for each district since meteorological observations began.[34] Due to Pulasan, winds of 83 km/h (52 mph) were recorded in Fengxian, Shanghai, where several roads and neighborhoods were flooded.[35] Xinhua reported that the city evacuated 112,000 people and suspended some ferry and train services.[36] Total damage in China was estimated at 30 million yuan (US$4.15 million).[37] PAGASA reported that the southwest monsoon, enhanced by Soulik and Pulasan, will bring strong to gale-force winds across the Philippines.[38]

 
Tropical Storm Pulasan regenerating over the East China Sea on September 21

As Pulasan approached Japan, 44,700 residents from Wajima, Suzu, and Noto in Ishikawa Prefecture were given evacuation orders, along with 16,000 others in Yamagata and Niigata Prefectures.[39] The Japan Meteorological Agency issued the highest level of alert for heavy rain across several cities in Ishikawa.[40] Heavy rains caused by Pulasan triggered widespread landslides and flooding in the Noto Peninsula, causing extensive damage which was exacerbated by the 2024 Noto earthquake which devastated the region in January.[40] The floods killed 16 people, injured 47, destroyed 673 houses and damaged 1,284 others.[41] In Wajima, 120 mm (4.7 in) of rainfall was recorded within an hour.[42] Up to ten people were left missing in the town, including four due to a landslide at a construction site.[42] In Suzu, one person drowned and another was missing. In Noto, one person was missing and two others were critically injured after a landslide struck their home. At least twelve rivers across Ishikawa overflowed, and 6,500 households were left without power in the prefecture, according to Hokuriku Electric Power Company.[40]

At least 903 people from 581 households were evacuated across six provinces in South Korea.[43] In South Korea, the cities of Changwon, Yeosu and Busan recorded 519.2 mm (20.44 in), 399.5 mm (15.73 in) and 390.2 mm (15.36 in) of rainfall respectively on September 21. Flooding affected 83 sections of public roads, leading to 18 incidents of soil loss and a wall collapse, 30 private facilities and 27 houses. Two trucks fell into a sinkhole in Busan.[43] In Yangju city, Gyeonggi province, an elderly man died after being swept away by a torrent.[44] A total of 27 private homes were flooded, affecting almost 30 private businesses, including shops and factories. Moreover, 641 areas within 22 national parks throughout the country were still unreachable.[45] The remnants of Tropical Storm Pulasan have caused wind warnings for several areas in British Columbia, including the B.C. Coast, sections of Vancouver Island, the Central Coast, and Haida Gwaii,[46] while approximately 15,000 customers lost power, primarily on Vancouver Island, especially in Campbell River and Courtenay.[47]

See also

edit

References

edit
  1. ^ a b Significant Tropical Weather Advisory for the Western and South Pacific Oceans, 19Z 14 September 2024 Reissued (Report). United States Joint Typhoon Warning Center. 14 September 2024. Archived from the original on September 14, 2024. Retrieved 14 September 2024. Alt URL
  2. ^ Warning and Summary 150000 (Report). Tokyo, Japan: Japan Meteorological Agency. September 15, 2024. Archived from the original on September 15, 2024. Retrieved September 15, 2024.
  3. ^ Prognostic Reasoning No. 1 for tropical depression (Report). Tokyo, Japan: Japan Meteorological Agency. September 15, 2024. Archived from the original on September 15, 2024. Retrieved September 15, 2024.
  4. ^ Tropical Cyclone Formation Alert (Invest 97W) (Report). United States Joint Typhoon Warning Center. 15 September 2024. Archived from the original on September 15, 2024. Retrieved 15 September 2024. Alt URL
  5. ^ Tropical Cyclone Advisory for TS Pulasan (2414) (Report). Tokyo, Japan: Japan Meteorological Agency. September 15, 2024. Archived from the original on September 15, 2024. Retrieved September 15, 2024.
  6. ^ Significant Tropical Weather Advisory for the Western and South Pacific Oceans, 06Z 16 September 2024 (Report). United States Joint Typhoon Warning Center. 16 September 2024. Retrieved 16 September 2024.
  7. ^ Prognostic Reasoning for Tropical Storm 15W (Pulasan) Warning No. 1 (Report). United States Joint Typhoon Warning Center. 16 September 2024. Archived from the original on September 17, 2024. Retrieved 16 September 2024.
  8. ^ Prognostic Reasoning No. 3 for TS Pulasan (2414) (Report). Tokyo, Japan: Japan Meteorological Agency. September 15, 2024. Archived from the original on September 16, 2024. Retrieved September 15, 2024.
  9. ^ Prognostic Reasoning for Tropical Storm 15W (Pulasan) Warning No. 4 (Report). United States Joint Typhoon Warning Center. 17 September 2024. Archived from the original on September 17, 2024. Retrieved 17 September 2024.
  10. ^ "Tropical Cyclone Bulletin #1 for Tropical Storm 'Helen' (Pulasan)" (PDF). PAGASA. 17 September 2024. Retrieved 17 September 2024.
  11. ^ Tropical Cyclone Advisory for TS Pulasan (2410) (Report). Tokyo, Japan: Japan Meteorological Agency. September 17, 2024. Archived from the original on September 17, 2024. Retrieved September 17, 2024.
  12. ^ "JTWC Best Track on Tropical Storm Pulasan (15W)". National Oceanic and Atmospheric Administration. Retrieved 27 September 2024.
  13. ^ Prognostic Reasoning for Tropical Storm 15W (Pulasan) Warning No. 6 (Report). United States Joint Typhoon Warning Center. 18 September 2024. Archived from the original on September 18, 2024. Retrieved 18 September 2024.
  14. ^ Prognostic Reasoning No. 14 for TS Pulasan (2414) (Report). Tokyo, Japan: Japan Meteorological Agency. September 18, 2024. Archived from the original on September 18, 2024. Retrieved September 18, 2024.
  15. ^ "Tropical Cyclone Bulletin #5F for Tropical Storm 'Helen' (Pulasan)" (PDF). PAGASA. 18 September 2024. Retrieved 18 September 2024.
  16. ^ Prognostic Reasoning for Tropical Storm 15W (Pulasan) Warning No. 10 (Report). United States Joint Typhoon Warning Center. 19 September 2024. Archived from the original on September 19, 2024. Retrieved 19 September 2024.
  17. ^ Prognostic Reasoning for Tropical Storm 15W (Pulasan) Warning No. 12 (Report). United States Joint Typhoon Warning Center. 19 September 2024. Archived from the original on September 19, 2024. Retrieved 19 September 2024.
  18. ^ Yoon, John (September 19, 2024). "Tropical Storm Pulasan Strikes Near Shanghai, Days After Typhoon Hit". The New York Times. Retrieved September 19, 2024.
  19. ^ "Typhoon Pulasan makes 2nd landfall in China". english.shanghai.gov.cn. Retrieved 2024-09-28.
  20. ^ Prognostic Reasoning for Tropical Depression 15W (Pulasan) Warning No. 14 (Report). United States Joint Typhoon Warning Center. 20 September 2024. Archived from the original on September 20, 2024. Retrieved 20 September 2024.
  21. ^ Prognostic Reasoning No. 22 for TS Pulasan (2414) (Report). Tokyo, Japan: Japan Meteorological Agency. September 20, 2024. Archived from the original on September 20, 2024. Retrieved September 20, 2024.
  22. ^ Prognostic Reasoning for Tropical Depression 15W (Pulasan) Warning No. 16 (Report). United States Joint Typhoon Warning Center. 20 September 2024. Archived from the original on September 20, 2024. Retrieved 20 September 2024.
  23. ^ Prognostic Reasoning for Tropical Depression 15W (Pulasan) Warning No. 17 (Report). United States Joint Typhoon Warning Center. 20 September 2024. Archived from the original on September 21, 2024. Retrieved 20 September 2024.
  24. ^ Prognostic Reasoning for Tropical Depression 15W (Pulasan) Warning No. 19 (Report). United States Joint Typhoon Warning Center. 21 September 2024. Archived from the original on September 21, 2024. Retrieved 21 September 2024.
  25. ^ Prognostic Reasoning No. 25 for Extropical Cyclone located at 34N 125E (Report). Tokyo, Japan: Japan Meteorological Agency. September 21, 2024. Archived from the original on September 21, 2024. Retrieved September 21, 2024.
  26. ^ Tropical Storm 15W (Pulasan) Warning No. 20 (Report). United States Joint Typhoon Warning Center. 21 September 2024. Archived from the original on September 21, 2024. Retrieved 21 September 2024.
  27. ^ "North Pacific Ocean Difax Version 7 Days". College Park, Maryland: Ocean Prediction Center. Archived from the original on September 24, 2024. Retrieved September 24, 2024.
  28. ^ Warning and Summary 241800 (Report). Tokyo, Japan: Japan Meteorological Agency. September 25, 2024. Archived from the original on September 25, 2024. Retrieved September 15, 2024.
  29. ^ "North Pacific Ocean Difax Version 7 Days". College Park, Maryland: Ocean Prediction Center. Archived from the original on September 27, 2024. Retrieved September 27, 2024.
  30. ^ "WPC Surface Analysis valid for 09/27/2024 at 15 UTC". wpc.ncep.noaa.gov. Weather Prediction Center. September 27, 2024. Retrieved September 27, 2024.
  31. ^ "WPC Surface Analysis valid for 09/26/2024 at 18 UTC". wpc.ncep.noaa.gov. Weather Prediction Center. September 27, 2024. Retrieved September 26, 2024.
  32. ^ "WPC Surface Analysis valid for 09/27/2024 at 06 UTC". wpc.ncep.noaa.gov. Weather Prediction Center. September 27, 2024. Retrieved September 27, 2024.
  33. ^ "WPC Surface Analysis valid for 09/27/2024 at 18 UTC". wpc.ncep.noaa.gov. Weather Prediction Center. September 27, 2024. Retrieved September 27, 2024.
  34. ^ "Shanghai evacuates hundreds of thousands as Typhoon Pulasan triggers heavy rainfall-Xinhua". english.news.cn. Retrieved 2024-09-24.
  35. ^ "Typhoon Pulasan floods Shanghai". Voice of America. 20 September 2024. Retrieved 21 September 2024.
  36. ^ "China's Shanghai hit by second major typhoon in a week – DW – 09/20/2024". dw.com. Retrieved 2024-09-24.
  37. ^ "MEMBER REPORT [China] ESCAP/WMO Typhoon Committee 19th Integrated Workshop AP-TCRC, Shanghai, China 19 – 22 November 2024" (PDF). Typhoon Committee. Retrieved 2024-11-18.
  38. ^ "Tropical Cyclone Bulletin #1 for Tropical Storm 'Helen' (Pulasan)" (PDF). PAGASA. 18 September 2024. Retrieved 18 September 2024.
  39. ^ "Japan orders evacuations as heavy rains trigger floods in earthquake-hit region". Manila Standard. 21 September 2024. Retrieved 21 September 2024.
  40. ^ a b c "Heavy rain triggers deadly landslides and floods in Japan". Ludlow Advertiser. 21 September 2024. Retrieved 21 September 2024.
  41. ^ 令和6年9月20日からの大雨による被害及び 消防機関等の対応状況 (第32報) (PDF) (Report) (in Japanese). FDMA. 21 November 2024. Retrieved 24 November 2024.
  42. ^ a b "One Dead, 7 Missing As Heavy Rains Trigger Floods In Central Japan". Channels TV. 21 September 2024. Retrieved 21 September 2024.
  43. ^ a b "Over 900 evacuated as heavy rain floods homes, roads in southern S. Korea". Yonhap News Agency. 21 September 2024. Retrieved 21 September 2024.
  44. ^ "South Korea's southern region experienced its heavy rain in 200 years and 1,500 people were evacuated". Yonhap News Agency. 22 September 2024. Retrieved 22 September 2024.
  45. ^ "Over 900 evacuated as heavy rain floods homes, roads in southern South Korea". en.inform.kz. September 23, 2024. Retrieved September 23, 2024.
  46. ^ Crawford, Emma (2024-09-27). "Wind warnings in effect across B.C. coast, other areas of province". CityNews Vancouver. Retrieved 2024-09-28.
  47. ^ "'A miracle nobody got hurt': Residents worry tree will fall during storm season". Comox Valley Record. 2024-09-28. Retrieved 2024-09-28.
edit