Typhoon Yagi

Typhoon Yagi, known in the Philippines as Severe Tropical Storm Enteng and in Vietnam as Typhoon No. 3 of 2024 (Vietnamese: Bão số 3 năm 2024), was a deadly, powerful and devastating tropical cyclone which caused extensive damage in Southeast Asia and South China in early September 2024. Yagi (ヤギ; "Goat"), which refers to the constellation of Capricornus in Japanese, also meaning "three" in Austroasiatic Sora language, distantly related to Vietnamese ba ("three"), was the eleventh named storm, the first violent typhoon, and the first super typhoon of the annual typhoon season. It is the strongest typhoon in 70 years to strike Vietnam, according to the country’s government, the strongest typhoon to strike China during the meteorological autumn, and one of the four Category 5-equivalent super typhoons recorded in the South China Sea, alongside Pamela in 1954, Rammasun in 2014 and Rai in 2021.

Yagi originated from a low-pressure area that formed on August 30, approximately 540 km (330 mi) northwest of Palau. On September 1, the system was classified as a tropical storm and named Yagi by the Japan Meteorological Agency (JMA). After making landfall over Casiguran, Aurora, in the Philippines, on September 2, Yagi weakened as it moved inland through the rugged terrain of the Cordillera Central of Luzon. It later emerged over the South China Sea and began merging with a secondary circulation west of Lingayen Gulf, with its deep convection starting to wrap and develop convective bands extending west and south. On September 5, the JMA reported that the storm reached its peak intensity with ten-minute maximum sustained winds of 195 km/h (120 mph) and a central pressure of 915 hPa (27.02 inHg). It initially peaked as a Category 5-equivalent super typhoon on the Saffir-Simpson scale, with one-minute sustained winds of 260 km/h (160 mph). After weakening due to an eyewall replacement cycle, Yagi rapidly reintensified to a second Category 5 peak with one-minute sustained winds of 270 km/h (165 mph), thus becoming the strongest tropical cyclone ever recorded in the South China Sea and the only tropical cyclone to intensify to Category 5 twice in this body. After peak intensity, Yagi began weakening before making landfall near Wenchang of China's Hainan Province on September 6. Yagi passed over northern Hainan and directly over Haikou, before moving into the open waters of the Gulf of Tonkin. It made landfall over Haiphong and Quảng Ninh, Vietnam, on September 7 and moved southwestward inland until it was last noted on September 9.

The combination of Typhoon Yagi and the southwest monsoon led to heavy rains over Luzon, causing widespread flash floods in various areas. The Hong Kong Observatory issued a Gale or Storm No. 8 warning as Typhoon Yagi approached. The Chinese island of Hainan experienced extreme rainfall and over 57,000 buildings were damaged there. In preparation for Typhoon Yagi, schools and transport services in areas within the storm's trajectory were closed. In the Philippines, 21 people were killed while 26 others were reported missing. In Vietnam, over 329,000 structures were affected and 325 people died, with 24 more missing; a majority of the casualties were caused by landslides. The remnants of Yagi caused catastrophic flooding and landslides in Myanmar, where at least 433 deaths and 79 missing were confirmed. These remnants also caused extensive flooding and deaths in Laos and Thailand. In total, the typhoon caused at least 844 deaths, 2,279 injuries, and left 129 people missing. Yagi also damaged, flooded or destroyed over 741,800 structures, resulting in over $14.7 billion (2024 USD) in damage across eight countries.

The origins of Typhoon Yagi can be traced back to August 30, when the Japan Meteorological Agency (JMA) reported that a low-pressure area had formed approximately 540 km (330 mi) northwest of Palau. The broad low-pressure area began to organize and developed into a tropical depression on August 31. Deep convection activity became concentrated around a circulation center, which was in a favorable environment with excellent equatorward and poleward outflow and warm sea surface temperatures of 29–30 °C (84–86 °F). On September 1, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) declared the system a tropical depression and named it Enteng, as it formed within the Philippine Area of Responsibility. At 03:00 UTC that day, the United States Joint Typhoon Warning Center (JTWC) issued a Tropical Cyclone Formation Alert due to its low-level circulation center (LLCC) becoming well-defined with formative banding in its northern quadrants. A few hours later, the system was classified as tropical depression 12W, exhibiting a rapidly consolidating low-level circulation, a compact central dense overcast (CDO), and deep convective banding over the western semicircle; it then intensified into a tropical storm and was named Yagi by the JMA.

Yagi then shifted northwestward along the southwestern edge of a mid-level subtropical high, which caused its convection to be sheared to the north and left the LLCC exposed. As the system progressed up the coast of Luzon island, the colder cloud tops in the CDO continued to expand, and at 14:00 PHT (06:00 UTC) on September 2, the storm made landfall in Casiguran, Aurora. Over the next six hours, Yagi moved further inland into Luzon and weakened as it interacted with the rugged terrain of the Cordillera Central. At 05:00 PHT on September 3 (21:00 UTC on September 2), it emerged over the South China Sea and began merging with a secondary circulation located west of Lingayen Gulf, with Yagi's deep convection starting to wrap and develop convective bands extending to the west and south. At around 06:00 UTC on September 3, the JMA reported that Yagi had intensified into a severe tropical storm due to warm sea surface temperatures and high ocean heat content. Early the next day, both the JMA and the JTWC upgraded the storm to a minimal typhoon as an eye began to form on satellite imagery, and Yagi started moving west-northwestward along the southwestern edge of a mid-level subtropical high, with a pinhole eye developing as the typhoon underwent rapid intensification.

On September 5, the JTWC upgraded the system to super typhoon status with estimated 1-minute maximum sustained winds of 270 km/h (165 mph)—making it a Category 5-equivalent super typhoon, only the fourth such storm in the South China Sea, after Pamela in 1954, Rammasun in 2014 and Rai in 2021—noting the sharply defined eye with a diameter of 17.3 miles (27.8 km). The JMA meanwhile upgraded Yagi to a violent typhoon, and estimated that it peaked in intensity with a minimum central pressure of 915 hPa (27.02 inHg), and 10-minute maximum sustained winds of 195 km/h (120 mph). Later that morning, it weakened as it underwent an eyewall replacement cycle, but the inner eyewall remained intact and the outer eyewall weakened. Yagi restrengthened slightly before making landfall near Wenchang in Hainan Province around 16:20 CST on September 6. This made Yagi the strongest typhoon to strike Hainan since Rammasun in 2014. After making landfall over Hainan Province, the typhoon's structure continued to feature a 24 miles (39 km) diameter eye, a nearly complete eyewall, and spiral banding in the southern semicircle. Yagi passed over northern Hainan and directly over Haikou, before entering into the open waters of the Gulf of Tonkin. On September 7, Yagi, which had steadily reorganized and rapidly intensified again with a well-defined circulation center and very strong convection—evidenced by a large band of cloud tops at −80 °C (−112 °F) or colder in the southern part of the system—made landfall over Haiphong and Quảng Ninh, Vietnam. The JTWC described it as historic, considering it one of the most intense typhoons ever to strike northern Vietnam. Shortly after landfall, the JTWC issued its final warning, which noted warming cloud tops and a filling cloud eye feature. Yagi continued to weaken rapidly as it moved southwestward along the southeastern edge of a mid-level subtropical high after it made landfall, becoming a tropical depression on September 8. The JMA continued to monitor the system until it reported that the storm dissipated at 18:00 UTC the following day.

As the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) started to track Yagi (known as "Enteng" in the Philippines) as a tropical depression on September 1, Tropical Cyclone Wind Signal No. 1 was raised in Albay; Biliran; Burias Island; Eastern Samar; Masbate; Northern Samar; Sorsogon; Ticao Island; northeastern portion of Leyte; eastern portions of Cagayan and Isabela; southern portions of Quirino and Nueva Vizcaya; and northern Quezon. Shortly after Yagi became a tropical storm, PAGASA raised Signal No. 2 for the northeastern portion of Camarines Sur, the entire province of Abra; Apayao; Babuyan Islands; Cagayan; Ilocos Norte; Ifugao; Isabela; Kalinga; Mountain Province; Polillo Islands; Quirino, and northern portions of Aurora; Camarines Norte; Ilocos Sur; and Nueva Vizcaya. At their next bulletin, the agency also added Benguet; La Union; Nueva Ecija; Rizal; Laguna; Marinduque, some parts of Batangas; Bulacan; Pampanga; and Pangasinan, as well as Metro Manila to Signal No. 1 because of gusty winds and heavy rains caused by the storm. By September 4, most signals were lowered by PAGASA as the storm left the Philippine Area of Responsibility.

Classes in Metro Manila and multiple provinces across Luzon and the Visayas were suspended on September 2 and 3. Several domestic flights to Bicol, Cagayan Valley, Mimaropa, the Visayas and Zamboanga Peninsula were also cancelled at Ninoy Aquino International Airport, while operations at six regional airports were suspended. Forced evacuations were ordered in Naga, Camarines Sur. An evacuation advisory was raised for the Marikina River after water levels reached 16 metres (52 ft). Salvage operations for the MT Terranova, which sank in Manila Bay and caused an oil spill during Typhoon Gaemi (locally called Carina) in July, were also suspended. The Premier Volleyball League postponed the championship match of its 2024 Reinforced Conference originally scheduled on September 2. The Government Service Insurance System prepared emergency loan programs for calamity-hit individuals. According to the National Disaster Risk Reduction and Management Council, 80,842 people were preemptively evacuated.