 Shanshan during its peak intensity over theRyukyu Islands on August 27 | |
| Meteorological history | |
|---|---|
| Formed | August 20, 2024 |
| Dissipated | September 1, 2024 |
| Very strong typhoon | |
| 10-minute sustained (JMA) | |
| Highest winds | 175 km/h (110 mph) |
| Lowest pressure | 935hPa (mbar); 27.61 inHg |
| Category 4-equivalent typhoon | |
| 1-minute sustained (SSHWS/JTWC) | |
| Highest winds | 215 km/h (130 mph) |
| Lowest pressure | 932hPa (mbar); 27.52 inHg |
| Overall effects | |
| Fatalities | 8 |
| Injuries | 127 |
| Damage | ≥$6 billion (2024USD) |
| Areas affected | Japan, South Korea |
IBTrACS /[1][2] | |
Part of the2024 Pacific typhoon season | |
Typhoon Shanshan was a powerfultropical cyclone that moved through Japan in late August 2024. The tenthnamed storm and fourth typhoon of theannual typhoon season, Shanshan was first noted near theMariana Islands on August 20, with deep convection beginning to consolidate. The following day, theJapan Meteorological Agency (JMA) upgraded it to a tropical storm and named itShanshan. Early the next day, both the JMA and theJoint Typhoon Warning Center (JTWC) classified it as a minimal typhoon. Shanshan turned west-northwestward and stalled nearKikaijima, reaching its peak intensity with ten-minutesustained winds of175 km/h (110 mph) and a centralpressure of 935 hPa (27.61 inHg). It then peaked at Category 4-equivalent intensity on theSaffir–Simpson scale on August 27, with one-minute sustained winds of215 km/h (130 mph). As the typhoon moved through theRyukyu Islands, it further decayed, becoming cooler and less defined. Shanshan turned northward between two mid-levelsubtropical ridges and madelandfall nearSatsumasendai inKagoshima Prefecture around 8 a.m. local time on August 29. It then turned eastward along the northern edge of a subtropical high and quickly crossed theSeto Inland Sea before making landfall over the northern tip ofShikoku on August 30. Shanshan's convection has slightly increased over the past six hours as its circulation moved back over open water and began progressing east-southeastward due to interaction with a mid-latitude trough. It then moved inland over Japan and dissipated on September 1.
AfterTropical Storm Maria andTyphoon Ampil impacted Japan, Shanshan arrived a few days later. In preparation for Shanshan, storm warnings were issued for 14 communities in theSatsuma andŌsumi areas of Kagoshima Prefecture, and on August 28, the JMA issuedspecial weather warnings for Kagoshima Prefecture. This was the first emergency warning issued for Kagoshima Prefecture sinceTyphoon Nanmadol in2022. As Shanshan brushed the islands ofAmami Ōshima and Kikaijima, maximum sustained wind gusts near 100 miles per hour (160 km/h) were recorded atKikai Airport on the latter island. The JMA began issuing landslide and rockslide warnings in Kagoshima,Miyazaki, andShizuoka prefectures. As Shanshan moved ashore inKyushu, a wind gust of 85 miles per hour (137 km/h) was recorded inMakurazaki, Kagoshima. Meanwhile, heavy rainfall from Shanshan affected theSouth Korean island ofJeju. In all, the typhoon killed at least eight people, injured 127 others, and damaged hundreds of structures throughout Japan. Damages are estimated at US$6–10 billion.[3]
Extratropical cyclone, remnant low, tropical disturbance, or monsoon depressionTheorigins of Typhoon Shanshan can be traced back to August 20, when theJapan Meteorological Agency (JMA) reported that a tropical depression had formed near theMariana Islands.[4][5] At midnight on August 21, the United StatesJoint Typhoon Warning Center (JTWC) upgraded the tropical depression, designating the system as11W due to deep convection beginning to consolidate into acentral dense overcast.[6][7] Shortly after, the depression intensified into a tropical storm and wasnamedShanshan by the JMA due to lowvertical wind shear, warmsea surface temperatures, and highocean heat content.[8] However, Shanshan's movement was nearly stationary due to the weak steering flow.[8] Around 12:00UTC on August 22, the JMA upgraded it to a severe tropical storm, citingDvorak technique—a method of determining a tropical cyclone's intensity based on satellite appearance.[9] Aragged eye-like feature appeared on satellite imagery on August 23,[10] and early the next day, both the JMA and the JTWC upgraded it to a minimal typhoon.[11]
Shanshan began developing poleward outflow into the west-northwest edge of atropical upper tropospheric trough cell and then turned northward due to the interaction with an uppervortex.[12][13] Despite its medium size, it quickly organized and developed a pinhole eye on satellite imagery, with deep convection wrapping around an obscured low-level circulation center.[14] However, due to moderate wind shear, Shanshan became partially exposed and poorly organized;[15] nonetheless, on August 26, deep convection began to increase rapidly,[16] with Shanshan developing a compact eye that was obscured bycirrus cloud.[17][18] Shanshan then turned west-northwestward along the southwestern periphery of a mid-levelsubtropical high.[19] The typhoon displayed a symmetrical structure with a clear eye measuring 12.7 miles (20.4 km) in diameter,[20] which later became cloud-filled and was encircled by symmetric deep convection.[21] Shanshan underwent aneyewall replacement cycle, in which the inner eyewall deteriorated while being encased by a clearly defined outer eyewall.[22] Shanshan completed its eyewall replacement cycle on August 27 and began rapidly intensifying again,[23] featuring a symmetric eye with a diameter of 29–35 miles (46–56 km) while stalling nearKikaijima, surrounded by cold cloud tops at −94 °F (−70 °C).[24] The JMA reported that Shanshan reached its peak intensity at 15:00 UTC with 10-minutesustained winds of175 km/h (110 mph) and a centralpressure of 935 hPa (27.61 inHg),[25] before eventually peaking at Category 4-equivalent intensity on theSaffir-Simpson scale with 1-minute sustained winds of215 km/h (130 mph).[26] A study byImperial College London suggests that Shanshan's extreme winds and heavy precipitation were strengthened byclimate change.[27]
After reaching its peak intensity, the typhoon's structure further decayed on August 28, becoming cooler and less defined, which coincided with a warming of the eyewall cloud tops as it moved through theRyukyu Islands.[28] Shanshan then turned northward between two mid-level subtropical ridges and madelandfall nearSatsumasendai inKagoshima Prefecture around 8 a.m. local time on August 29.[29][30] This made Shanshan the strongest typhoon to strike Japan in decades and one of the most powerful storms to make landfall since 1960.[31] After the system made landfall, satellite imagery andradar loops showed the rapid erosion and disintegration of convective tops and feeder bands.[32] Owing to its interaction with rugged terrain, Shanshan weakened to a minimal tropical storm.[33] It then turned eastward along the northern periphery of a subtropical high,[34] quickly crossed theSeto Inland Sea, and made landfall over the northern tip ofShikoku on August 30.[35] By that time, its convection had diminished, and the low-level circulation center had become disorganized;[36] however, convection slightly increased after six hours as Shanshan's circulation moved back over open water and began moving east-southeastward due to the interaction with a mid-latitude trough.[37][38] Around 09:00 UTC on August 31, the JTWC issued its final warning on the system as it had become an exposed circulation center surrounded bystratocumulus clouds.[39] On September 1, Shanshan re-intensified into a weak tropical depression with 25 km/h (16 mph) winds and a well-defined circulation in the eastern semicircle, leading the JTWC to resume advisories as it drifted poleward along the northwestern edge of a low to mid-level subtropical ridge.[40] However, the JTWC discontinued warnings on the system as it moved inland over Japan.[41] The JMA continued to monitor the system until it dissipated at 18:00 UTC that day.[42]
In advance of Shanshan, storm warnings were issued for 14 communities in theSatsuma andŌsumi areas ofKagoshima Prefecture.[43] TheJapan Meteorological Agency (JMA) issuedspecial weather warnings for Kagoshima Prefecture at 13:00 on August 28.[44] This was the first emergency warning issued for Kagoshima Prefecture sinceTyphoon Nanmadol in2022.[45] An emergency storm warning and an emergency high tide warning were also issued for the entirety of Kagoshima Prefecture with the exception of the Amami Islands. A Level 5 emergency warning—the highest level of warning—was issued forMishima, affecting 369 residents. Across parts of Kagoshima andMiyazaki prefectures, Level 4 evacuation notices were posted, which included 27 cities in Kagoshima Prefecture and the city ofMiyazaki.[46]
Evacuation orders were issued for 996,299 people in Miyazaki Prefecture and 982,273 people in Kagoshima Prefecture.[47] Level 4 evacuation alerts were also issued for portions ofAichi Prefecture andShizuoka Prefecture;[46] a total of 342,666 people inShizuoka Prefecture were given evacuation orders.[1] The threat of mudslides caused the JMA to began issuing landslide and rockslide warnings in Kagoshima, Miyazaki, and Shizuoka prefectures.[48] TheTokaido Shinkansen route was closed betweenTokyo Station andShin-Ōsaka Station, as well as betweenHamamatsu Station andToyohashi Station, due to rainfall amounts exceeding the regulatory limits for operation. The entireKyushu Shinkansen route closed on August 29.[49][50]Japan Airlines cancelled 402 domestic flights and ten international flights between August 28 and August 30.All Nippon Airways also cancelled 210 domestic flights for the same timeframe. Over 18,400 airline passengers were affected by these cancellations.[51] InSouth Korea, a strong wind and heavy rain advisory were issued for the island ofJeju.[52] Expressways and toll stations were briefly closed at some locations, though services were restored. Commuters were advised to be aware of traffic disruptions.[45]
TheJapan Post suspended postal and delivery services in Kyushu.[53] Classes were cancelled at schools inFukuoka,[54] Kagoshima,[55] andYamaguchi prefectures.[56] TheSuper GT announced that the secondSuzuka round would be postponed to December 7–8.[57] Multiple factories ceased operations for the duration of the typhoon, affecting companies such asToyota which closed 14 plants,Nissan which closed a facility inKyushu,Honda which closed a facility inKumamoto, andMazda which announced a potential closure of factories inHiroshima andHōfu.[51] Department stores and other commercial facilities inKagoshima andAira were closed.[58] Supermarkets also planned to close early across Kyushu.[53] Overall, 5,210,258 people were ordered to evacuate across 12 prefectures.[1]
As Shanshan brushed the islands ofAmami Ōshima andKikaijima at Category 4-equivalent intensity, maximum sustained wind gusts near 100 miles per hour (160 km/h) were measured atKikai Airport on the latter island.[59] This was the strongest wind speed observed on Kikaijima in the month of August.[60] One person was injured inAmami after strong winds knocked him down while he was riding a motorcycle.[59] InYakushima, where maximum gusts of 105 miles per hour (169 km/h) were recorded in the evening of August 28, a 3,000-year-oldYakusugicedar tree named the Yayoi-sugi (弥生杉) was blown down.[61] As Shanshan moved ashore inKyushu, a wind gust of 85 miles per hour (137 km/h) was recorded inMakurazaki, Kagoshima.[59] Due to the typhoon's slow movement, a linear precipitation zone developed overKagoshima,Miyazaki, andOita prefectures, resulting in prolonged torrential rainfall across the region.[62] Overall, one person died and 29 others were injured in Kagoshima, four of them seriously, and 53 buildings were damaged in the prefecture.[1] Strong winds in Miyazaki Prefecture caused 39 injuries and damaged 886 houses,[1] including 160 in the city ofMiyazaki.[62] A metal sign at a clothing store was downed onto a vehicle, though no injuries occurred.[63] Heavy rainfall in Oita Prefecture resulted in the overflowing of the Miyakawa River inYufu, which prompted the issuance of a Level 5 emergency warning, affecting 2,311 residents.[62] InFukuoka Prefecture, two people died, 22 others were injured, one house was completely destroyed and six structures were damaged by the typhoon. One death and five injuries were reported inSaga Prefecture. There were also nine injuries inNagasaki Prefecture, six inKumamoto Prefecture and two inŌita Prefecture.[1] More than 260,000 residences in Kyushu lost access to electricity due to the storm.[64]
InAichi Prefecture, the city ofGamagōri observed record breaking rainfall amounts as Shanshan neared Japan on August 26 and 27,[65] resulting in a mudslide that killed three people and injured two others.[45][66] Across the prefecture, 29 structures were damaged. Shanshan caused flooding which damaged 545 buildings inShizuoka Prefecture, 100 inGifu Prefecture, 72 inKanagawa Prefecture, 27 inIwate Prefecture, 26 inSaitama Prefecture, 25 inTottori Prefecture and three more inHokkaido. Two people were injured inMie Prefecture.[1] One person died after a roof collapsed inTokushima Prefecture.[67] Heavy rainfall affected the South Korean island ofJeju, reaching a maximum total of 154.5 millimetres (6.08 in) nearHallasan.[52]
Tropical cyclones of the2024 Pacific typhoon season | ||
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