Typhoon Ampil (2024) Explained

Typhoon Ampil
Formed:August 11, 2024
Extratropical:August 19, 2024
Dissipated:August 23, 2024
Winds:85
Pressure:950
Winds:115
Pressure:947
Basin:WPac
Year:2024
Injuries:Several
Damage:Minimal
Areas:Japan, Alaska
Season:2024 Pacific typhoon season

Typhoon Ampil was a powerful tropical cyclone that brushed Japan and brought torrential gusty winds to Alaska in early August 2024. The seventh named storm and third typhoon of the annual typhoon season. Ampil emerged from an atmospheric convection east of Kadena Air Base and was later classified as a tropical storm on August 12 and named Ampil by the Japan Meteorological Agency. Ampil gradually intensified as it turned northward, reaching its peak intensity with ten-minute sustained winds of 85kn and a central pressure of 950abbr=onNaNabbr=on before peaking at Category 4-equivalent intensity on the Saffir–Simpson scale on August 16, with one-minute sustained winds of 115kn before making its closest approach to Japan. It then rapidly weakened as it began to undergo an extratropical transition on August 19. The remnants of Ampil accelerated east-northeastward, entering the Bering Sea, crossing the Aleutian Islands in Alaska, and then moving inland over the Russian Far East and Arctic Alaska before emerging into the Arctic Ocean and dissipated on August 23.

Ampil affected Japan during the Obon holiday week, shortly after Tropical Storm Maria caused unprecedented rainfall to northern Japan. As the storm neared the coast, hundreds of thousands in Tokyo and nearby regions were urged to evacuate. Numerous modes of transportation, such as flights and trains, were canceled due to the approaching typhoon. The NHK reported that Tokyo suffered minimal damage, while several people were injured in Kanagawa Prefecture. However, Japan was struck by a more powerful cyclone named Typhoon Shanshan one week later. Later, the remnants of Ampil caused a high surf advisory, a high wind watch, and a coastal flood advisory in Alaska, bringing strong winds and coastal waves to western Alaska. Ampil contributed to an atmospheric river when its moist core entered a low-pressure system and merged with the Pacific jet stream, which was anticipated to reach California.

Meteorological history

Typhoon Ampil emerged from an area of convection 527abbr=onNaNabbr=on east of Kadena Air Base on August 3.[1] At 18:00 UTC on August 11, the Japan Meteorological Agency (JMA) designated it as a tropical depression.[2] Soon after, the United States Joint Typhoon Warning Center (JTWC) began to re-monitoring it, noting that it was in a marginal favorable environment for development.[3] At 07:00 UTC on August 12, the agency issued a tropical cyclone formation alert on the disturbance.[4] A few hours later, they recognized the system as a tropical depression, designating it as 08W.[5] Soon after, the JMA noted that it had intensified into a tropical storm, with convective bands wrapping around a well-defined low-level circulation center, and named it Ampil.[6] [7] Ampil then turned north-northeastward as the increasing influence of the low-level flow became the primary steering mechanism. A central dense overcast was obscuring the low-level circulation center;[8] however, Ampil became distinctly better defined, featuring a well-defined center and spiral banding.[9] The JMA upgraded the system to a severe tropical storm on August 13.[10] Around 15:00 UTC on August 14, the JTWC reported that Ampil had intensified into a minimal typhoon, as animated infrared imagery indicated the development of a pinhole eye feature, which exhibited excellent equatorward outflow and good poleward outflow.[11] The JMA then reported that Ampil had intensified into a typhoon due to warm sea surface temperatures and low vertical wind shear on August 15.[12] The JMA reported that Ampil reached its peak intensity at 12:00 UTC that day with 10-minute sustained winds of 85kn and a central pressure of 950abbr=onNaNabbr=on.[13] Ampil then turned northward, along the western periphery of a mid-level subtropical ridge.[14] Ampil eventually peaked at Category 4-equivalent intensity on the Saffir-Simpson scale at 03:00 UTC on August 16,[15] with 1-minute sustained winds of 115kn and a large eye measuring 400NaN0 in diameter before making its closest approach to Japan.[16] This made Ampil the first storm in the 21st century in the Western Pacific basin to reach the 34th parallel north while at or above Category 3-equivalent strength, with only two others having been recorded—Typhoon Carmen in 1965 and Typhoon Oscar in 1995.[17]

Ampil degraded due to internal fluctuations and a symmetric central dense overcast, while convection was confined to the southern semicircle.[18] Satellite imagery depicted a well-defined 90NaN0 wide eye surrounded by deep convection,[19] though the banding diminished after encountering cold, dry air.[20] Ampil was beginning to undergo an extratropical transition, as its convective structures had dissipated by August 17.[21] The JTWC then ceased issuing advisories on the system the next day as it turned east-northeastward and merged with the mid-latitude westerlies.[22] The JMA reported that Ampil had transitioned into an extratropical low on August 19.[23] The extratropical storm entered the Bering Sea on August 20, crossed the Aleutian Islands, moved inland over the Russian Far East and Arctic Alaska, emerged into the Arctic Ocean between August 21–22, and dissipated on August 23.[24]

Preparations and impact

Japan

Typhoon Ampil arrived during Japan’s Obon holiday week—just days after Tropical Storm Maria caused record-breaking rainfall in parts of northern Japan.[25] As the strong storm brushed the coast of Japan, hundreds of thousands in Tokyo and surrounding areas were advised to evacuate. A total of around 178,000 households, over 404,000 people, were given an evacuation order. Similar notices were issued in Yokohama. Many modes of transportation like flights and trains were cancelled on August 16 as the typhoon approached.[26] Japan Airways and All Nippon Airways cancelled around 600 flights to Haneda Airport and Narita International Airport.[27] [28] East of Tokyo in the Chiba Prefecture, trees were downed and many roads were flooded. In Tokyo and in multiple bordering regions, heavy rainfall affected areas, increasing the risk of flooding and landslides. High waves warnings were issued, mainly in the Izu Islands. The Tropical Cyclone Condition of Readiness (TCCOR) was raised from TCCOR 3 to TCCOR 2 for Yokosuka Naval Base on August 15, indicating that winds of 57abbr=onNaNabbr=on or higher were possible within 24 hours.[29] A barrier obstructing Japan's Mount Fuji from a nearby convenience store was recently taken down to avoid damage.[30]

A Level 4 evacuation order was issued for Mobara and Asahi in Chiba Prefecture, along with Iwaki in Fukushima Prefecture. All buslines in the city of Mobara were cancelled. Tokyo Disneyland closed around six hours before normal closing time, and it was closed all together on August 17. The cancellation of flights and railway transportation was expected to impact over 120,000 people.[31] The NHK reported that Tokyo suffered minimal damage, while several people were injured in Kanagawa Prefecture.[32] Over 5,000 homes were left without power, though only 250 in both Ibaraki and Tochigi. Signboards were damaged, as well as bicyles and poles getting knocked over by strong winds. After the storm passed by, some flights were still delayed by Yamato Transport,[33] while energy company officials confirmed that electricity was restored to most areas.[34]

Alaska and California

The remnants of Ampil were driving a frontal boundary across Alaska, prompting a high surf advisory and a high wind watch for the Seward Peninsula, Gambell, St. Lawrence Island,[35] while a coastal flood advisory was in effect for the Bering Strait Coast, the Yukon–Kuskokwim Delta Coast, the eastern Norton Sound, and the Nulato Hills.[36] Ampil brought strong winds and coastal waves to western Alaska.[37] Ampil's remnants influenced an atmospheric river as its moist core flowed into the low-pressure system and was absorbed into the Pacific jet stream, which was expected to reach California.[38]

See also

External links

Notes and References

  1. August 3, 2024. abpw. 91W. 06Z. https://www.metoc.navy.mil/jtwc/products/abpwweb.txt. https://archive.today/20240803225751/https://www.metoc.navy.mil/jtwc/products/abpwweb.txt. 0. August 3, 2024.
  2. Web site: November 26, 2024 . RSMC Tropical Cyclone Best Track Name 2407 Ampil (2407) . dead . https://archive.md/2024.11.29-044150/https://www.wis-jma.go.jp/d/o/RJTD/Alphanumeric/Analysis/Miscellaneous/20241126/050000/A_AXPQ20RJTD260500_C_RJTD_20241126052118_31.txt . November 29, 2024 . November 29, 2024 . Japan Meteorological Agency.
  3. August 11, 2024. abpw. 91W. 1930Z. https://www.metoc.navy.mil/jtwc/products/abpwweb.txt. https://archive.today/20240811202421/https://www.metoc.navy.mil/jtwc/products/abpwweb.txt. 1. August 11, 2024.
  4. August 12, 2024. tcfa. 91W. 07Z. https://www.metoc.navy.mil/jtwc/products/wp9124web.txt. https://archive.today/20240812083759/https://www.metoc.navy.mil/jtwc/products/wp9124web.txt. August 12, 2024. August 12, 2024.
  5. August 12, 2024. prog. TD. 08W. 1. Eight. https://www.metoc.navy.mil/jtwc/products/wp0224web.txt. https://archive.today/20240812151822/https://tgftp.nws.noaa.gov/data/raw/wd/wdpn33.pgtw..txt. August 12, 2024.
  6. Prognostic Reasoning No. 4 for TS Ampil (2407) . August 8, 2024 . Japan Meteorological Agency . Tokyo, Japan . August 12, 2024 . https://web.archive.org/web/20240812195943/https://tgftp.nws.noaa.gov/data/raw/wt/wtpq32.rjtd..txt. August 12, 2024.
  7. August 8, 2024. prog. TS. 08W. 5. Ampil. https://www.metoc.navy.mil/jtwc/products/wp0224web.txt. https://archive.today/20240808090938/https://www.wis-jma.go.jp/d/o/PGTW/Alphanumeric/Warning/Tropical_cyclone/20240808/030000/A_WDPN31PGTW080300_C_RJTD_20240808025230_13.txt. August 8, 2024.
  8. August 14, 2024. prog. TS. 08W. 7. Maria. https://www.metoc.navy.mil/jtwc/products/wp0224web.txt. https://archive.today/20240814090737/https://www.wis-jma.go.jp/d/o/PGTW/Alphanumeric/Warning/Tropical_cyclone/20240814/030000/A_WDPN33PGTW140300_C_RJTD_20240814030631_73.txt. August 14, 2024.
  9. Tropical Cyclone Advisory for STS Ampil (2407) . August 13, 2024 . Japan Meteorological Agency . Tokyo, Japan . August 13, 2024 . https://archive.today/20240813093529/https://tgftp.nws.noaa.gov/data/raw/wt/wtpq52.rjtd..txt. August 13, 2024.
  10. August 13, 2024. prog. TS. 08W. 6. Ampil. https://www.metoc.navy.mil/jtwc/products/wp0224web.txt. https://archive.today/20240814090723/https://www.wis-jma.go.jp/d/o/PGTW/Alphanumeric/Warning/Tropical_cyclone/20240813/210000/A_WDPN33PGTW132100_C_RJTD_20240813205316_30.txt. August 14, 2024.
  11. August 14, 2024. prog. TY. 08W. 9. Ampil. https://www.metoc.navy.mil/jtwc/products/wp0224web.txt. https://archive.today/20240814152859/https://tgftp.nws.noaa.gov/data/raw/wd/wdpn33.pgtw..txt. August 14, 2024.
  12. Tropical Cyclone Advisory for TY Ampil (2407) . August 13, 2024 . Japan Meteorological Agency . Tokyo, Japan . August 15, 2024 . https://archive.today/20240815093648/https://www.wis-jma.go.jp/d/o/RJTD/Alphanumeric/Warning/Tropical_cyclone/20240815/000000/A_WTPQ52RJTD150000_C_RJTD_20240815005117_36.txt. August 15, 2024.
  13. Prognostic Reasoning No. 15 for TY Ampil (2407) . August 15, 2024 . Japan Meteorological Agency . Tokyo, Japan . August 15, 2024 . https://archive.today/20240815145448/https://tgftp.nws.noaa.gov/data/raw/wt/wtpq32.rjtd..txt . August 15, 2024.
  14. Prognostic Reasoning No. 14 for TY Ampil (2407) . August 15, 2024 . Japan Meteorological Agency . Tokyo, Japan . August 15, 2024 . https://archive.today/20240815092332/https://tgftp.nws.noaa.gov/data/raw/wt/wtpq32.rjtd..txt. August 15, 2024.
  15. Web site: Danger not over as typhoon passes Japan NHK WORLD-JAPAN News . August 19, 2024 . NHK WORLD . en . August 19, 2024 . https://web.archive.org/web/20240819103543/https://www3.nhk.or.jp/nhkworld/en/news/20240817_03/ . live .
  16. August 16, 2024. prog. TY. 08W. 15. Ampil. https://www.metoc.navy.mil/jtwc/products/wp0224web.txt. https://archive.today/20240816093415/https://www.wis-jma.go.jp/d/o/PGTW/Alphanumeric/Warning/Tropical_cyclone/20240816/030000/A_WDPN33PGTW160300_C_RJTD_20240816024917_37.txt. August 16, 2024.
  17. Web site: Typhoon 08W (Ampil), # 19 FINAL . August 19, 2024 . Stars and Stripes . en . August 19, 2024 . https://web.archive.org/web/20240819103549/https://www.stripes.com/theaters/asia_pacific/storm_tracker/2024-08-06/tropical-depression-06w-14771048.html . live .
  18. August 16, 2024. prog. TY. 08W. 17. Ampil. https://www.metoc.navy.mil/jtwc/products/wp0224web.txt. https://archive.today/20240816152041/https://tgftp.nws.noaa.gov/data/raw/wd/wdpn33.pgtw..txt. August 16, 2024.
  19. August 16, 2024. prog. TY. 08W. 18. Ampil. https://www.metoc.navy.mil/jtwc/products/wp0224web.txt. https://archive.today/20240817142802/https://www.wis-jma.go.jp/d/o/PGTW/Alphanumeric/Warning/Tropical_cyclone/20240816/210000/A_WDPN33PGTW162100_C_RJTD_20240817014731_12.txt. August 17, 2024.
  20. August 17, 2024. prog. TY. 08W. 19. Ampil. https://www.metoc.navy.mil/jtwc/products/wp0224web.txt. https://archive.today/20240817142831/https://www.wis-jma.go.jp/d/o/PGTW/Alphanumeric/Warning/Tropical_cyclone/20240817/030000/A_WDPN33PGTW170300_C_RJTD_20240817015918_97.txt. August 17, 2024.
  21. August 17, 2024. prog. TS. 08W. 23. Ampil. https://www.metoc.navy.mil/jtwc/products/wp0224web.txt. https://archive.today/20240818151544/https://tgftp.nws.noaa.gov/data/raw/wd/wdpn33.pgtw..txt. August 18, 2024.
  22. August 18, 2024. warn. TS. 08W. 24. Ampil. https://www.metoc.navy.mil/jtwc/products/wp0224web.txt. https://archive.today/20240818151532/https://tgftp.nws.noaa.gov/data/raw/wt/wtpn33.pgtw..txt. August 18, 2024.
  23. Tropical Cyclone Advisory for Developing Low Former STS Ampil (2407) . August 19, 2024 . Japan Meteorological Agency . Tokyo, Japan . August 19, 2024 . https://web.archive.org/web/20240819082136/https://tgftp.nws.noaa.gov/data/raw/wt/wtpq52.rjtd..txt. August 19, 2024.
  24. Multiple sources:
    • Web site: . College Park, Maryland . August 23, 2024 . North Pacific Ocean Difax Version 7 Days. dead . https://web.archive.org/web/20240823212244/https://ocean.weather.gov/Loops/index.php?category=ua&product=UA_Pac_Difax&days=7&loop=0. August 23, 2024 . August 23, 2024 . en.
    • Web site: . College Park, Maryland . August 20, 2024 . North Pacific Ocean Difax Version 7 Days. dead . https://web.archive.org/web/20240820154122/https://ocean.weather.gov/Loops/index.php?category=ua&product=UA_Pac_Difax&days=7&loop=0. August 20, 2024 . August 20, 2024 . en.
    • Web site: . College Park, Maryland . August 23, 2024 . Alaska/Arctic 24 Hour Surface Forecast 7 Days. dead . https://web.archive.org/web/20240824053110/https://ocean.weather.gov/Loops/index.php?category=arctic&product=arcsfcf24&days=7&loop=0. August 24, 2024 . August 24, 2024 . en.
  25. Web site: August 16, 2024 . Flights, trains cancelled as 'very strong' typhoon barrels towards Tokyo . August 17, 2024 . South China Morning Post . en . August 19, 2024 . https://web.archive.org/web/20240819103548/https://www.scmp.com/news/asia/east-asia/article/3274711/typhoon-ampil-barrels-towards-tokyo-disrupting-flights-power . live .
  26. Web site: Shackelford . Jessie Yeung, Taylor Ward, Robert . August 15, 2024 . Japan braces as powerful Typhoon Ampil strengthens near Tokyo . August 17, 2024 . CNN . en . August 17, 2024 . https://web.archive.org/web/20240817091424/https://www.cnn.com/2024/08/15/asia/japan-typhoon-ampil-flights-intl-hnk/index.html . live .
  27. Web site: Speed . Jessica . August 15, 2024 . 'Very strong' Typhoon Ampil set to approach eastern Japan on Friday . August 17, 2024 . The Japan Times . en . August 19, 2024 . https://web.archive.org/web/20240819103549/https://www.japantimes.co.jp/news/2024/08/15/japan/typhoon-ampil-thursday-outlook/ . live .
  28. News: Yoon . John . August 15, 2024 . Typhoon Ampil Approaches Japan, Disrupting Flights and Trains . August 17, 2024 . The New York Times . en-US . 0362-4331 . August 17, 2024 . https://web.archive.org/web/20240817123014/https://www.nytimes.com/2024/08/15/world/asia/typhoon-ampil-japan.html . live .
  29. Web site: US bases in Tokyo area pause, prepare for approaching Typhoon Ampil . August 18, 2024 . Stars and Stripes . en . August 19, 2024 . https://web.archive.org/web/20240819103551/https://www.stripes.com/theaters/asia_pacific/2024-08-15/typhoon-ampil-japan-military-bases-14870659.html . live .
  30. Web site: Caleon . Patricia . Mount Fuji Barrier Removed to Prevent Damage Amidst Typhoon Ampil . https://archive.today/20240822113403/https://www.tripzilla.com/mount-fuji-barrier-removed/152125 . August 22, 2024 . August 21, 2024 . www.tripzilla.com . en-US.
  31. News: Yoon . John . August 16, 2024 . Typhoon Ampil Lashes Eastern Japan, Forcing Evacuations . August 17, 2024 . The New York Times . en-US . 0362-4331 . August 17, 2024 . https://web.archive.org/web/20240817123013/https://www.nytimes.com/2024/08/16/world/asia/typhoon-ampil-japan.html . live .
  32. Web site: Traylor . Daniel . Kaneko . Karin . Speed . Jessica . August 16, 2024 . Typhoon Ampil lashes eastern Japan with heavy rain and wind . August 17, 2024 . The Japan Times . en . August 19, 2024 . https://web.archive.org/web/20240819103550/https://www.japantimes.co.jp/news/2024/08/16/japan/typhoon-ampil-severe-storm/ . live .
  33. Web site: Return to normal after typhoon lashes Japan NHK WORLD-JAPAN News . August 18, 2024 . NHK WORLD . en . August 18, 2024 . https://web.archive.org/web/20240818004507/https://www3.nhk.or.jp/nhkworld/en/news/20240817_11/ . live .
  34. Web site: Kageyama . Yuri . Typhoon Ampil moves away from Japan as train services resume and no major damage is reported . August 17, 2024 . www.sfgate.com . August 17, 2024 . https://web.archive.org/web/20240817123014/https://www.sfgate.com/news/world/article/typhoon-ampil-moves-away-from-japan-as-train-19661483.php . live .
  35. Web site: Morrison . Aaron . August 21, 2024 . Former Typhoon Ampil moves north into the Bering Sea . https://archive.today/20240822113521/https://www.alaskasnewssource.com/2024/08/21/former-typhoon-ampil-moves-north-into-bering-sea/ . August 22, 2024 . August 22, 2024 . en.
  36. Web site: Morrison . Aaron . August 19, 2024 . Remnants of Typhoon Ampil to bring winds and rain to Alaska . August 20, 2024 . https://archive.today/20240820162417/https://www.alaskasnewssource.com/2024/08/19/remnants-typhoon-ampil-bring-winds-rain-alaska/ . August 20, 2024 . en.
  37. Web site: Purcell . Jackie . August 23, 2024 . A sunny break again Friday for southcentral . https://archive.today/20240823034947/https://www.alaskasnewssource.com/2024/08/23/sunny-break-again-friday-southcentral/ . August 23, 2024 . August 23, 2024 . en.
  38. Web site: Porter . Greg . August 21, 2024 . Typhoon's remnants to trigger California storm, bringing a shift to cooler weather . https://archive.today/20240821132316/https://www.sfchronicle.com/weather-forecast/article/california-typhoon-ampil-storm-19666759.php . August 21, 2024 . August 21, 2024 . San Francisco Chronicle.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Typhoon Ampil (2024)".

Except where otherwise indicated, Everything.Explained.Today is © Copyright 2009-2025, A B Cryer, All Rights Reserved. Cookie policy.