Typhoon Doksuri


Typhoon Doksuri, known in the Philippines as Super Typhoon Egay, was a powerful and highly destructive tropical cyclone which became the costliest typhoon to hit China, the costliest tropical cyclone outside of the North Atlantic, and the costliest typhoon on record, breaking the previous record of Typhoon Mireille in 1991. Doksuri was also the strongest typhoon to impact Fujian since Typhoon Meranti in 2016, and the most powerful typhoon to strike the province since records began in 1950. Aside from China, Doksuri also caused extensive damage in the Philippines, Taiwan, and Vietnam, in late July 2023. The name Doksuri means eagle in Korean.
The fifth named storm and third typhoon of the inactive 2023 Pacific typhoon season, Doksuri started as a low-pressure area in the Philippines, far off the eastern coast of Mindanao. Tracking northwestward, it rapidly intensified into a typhoon over the Philippines prior to making landfall over the Babuyan Islands. Together with the southwest monsoon, Doksuri showered most of the northern and central Luzon island with heavy rains, triggering floods in various regions of the country. Doksuri steadily weakened after interacting with land, but by late July 27, Doksuri underwent another round of rapid intensification in the South China Sea. Doksuri moved towards Fujian, China, before rapidly weakening overland, and Doksuri dissipated early on the next day.
Doksuri left behind a trail of severe destruction in its wake. The typhoon killed 137 and left 285 people injured, 27 of which were on board the MB Aya Express when the pump boat capsized. Floods were reported in 9 out of the Philippines' 17 regions, affecting over 2 million people and requiring over 300,000 to evacuate. The typhoon's close proximity and large influence to Taiwan caused around 150,000 people to lose power. The storm affected over 724,600 people and of farmland in China's southeastern province of Fujian; 44 houses were damaged, with 178 houses completely destroyed.
In Fujian, the rainfall set records for 24-hour totals, including an accumulation of more than. Torrential rains impacted many areas, with accumulations in Xiamen, Quanzhou and Putian reaching. The remnants of the storm produced heavy rainfall in Beijing. The remnants dropped up to of rainfall in Wangjiayuan Reservoir in Changping District with Doksuri setting maximum rainfall records since recordkeeping began during the Qing dynasty in 1883. Overall, Doksuri caused US$28.5 billion worth of damages across the four countries affected by the typhoon.

Meteorological history

On July 19, the Japan Meteorological Agency began tracking a low pressure area in the Philippine Sea, east of Mindanao. The agency noted its formation into a tropical depression by July 20; the Joint Typhoon Warning Center released a Tropical Cyclone Formation Alert later that day. The system maintained its intensity over the following day as it tracked further northwestward. On July 21, the system intensified into a tropical storm and was immediately named Doksuri; the Philippine meteorological agency PAGASA also noted the storm's formation and locally named it Egay. It was then designated by JTWC as the newly formed tropical depression 05W. Driven by a deep-layer subtropical ridge to its north, the storm slightly intensified as it tracked northwestward across the following day.
At 09:00 UTC on July 23, Doksuri began to rapidly intensify as it reached typhoon status over the Philippine Sea. Its rapid intensification is attributed to a lack of vertical wind shear affecting the cyclone whilst moving over very warm ocean waters. Satellite imagery showed the development of an eye-like feature, which was fully defined by 03:00 UTC on July 24. Over 24 hours, its maximum sustained wind speeds grew by and eventually reached a peak of. At 21:00 UTC, the JTWC upgraded the system into a 'super typhoon'—its highest storm category—after Doksuri attained 1-minute sustained winds of.
At 08:00 PHT on July 25, PAGASA declared Doksuri a 'super typhoon', making it the second PAGASA super typhoon of the season; the JTWC later downgraded the system from its super typhoon category by 09:00 UTC. Doksuri significantly slowed down as it approached the extreme northern Philippines, with a slight wobble in its movement. Though atmospheric conditions made further development favorable, interaction with land and some dry air around the system suppressed development. Nevertheless, it held its peak intensity of 100 knots for over 12 hours. At around 12:00 UTC, the storm was now just off the coast northwest of Cagayan, continuing its west-northwestward track. With its eye almost complete surrounded by dry air, Doksuri began to undergo an eyewall replacement cycle at 15:00 UTC. PAGASA downgraded the storm into a typhoon prior to making landfall at Fuga Island in Aparri, Cagayan, around 03:10 PHT. It completed its eyewall replacement cycle around 21:00 UTC, though it still maintained its intensity. Now moving westwards through the Luzon Strait, Doksuri made a second landfall over Dalupiri Island at 11:00 PHT on July 26. The storm significantly slowed down following landfall, remaining quasi-stationary over the Babuyan Islands.
Prolonged interaction with the rugged terrain of northern Luzon began weakening the system, which slowly began moving westwards by 09:00 UTC. Doksuri left the Philippine Area of Responsibility at around 10:00 PHT on July 27. Doksuri underwent another round of rapid intensification in the South China Sea southwest of Taiwan, forming a pinhole eye as it did so, the JTWC assessed the storm to have strengthened into of winds. Doksuri moved northwestward and subsequently made its third landfall in Jinjiang, Fujian, with two-minute sustained winds of 180 km/h on July 28. As it moved further inland, Doksuri rapidly weakened. Shortly after the landfall, the JTWC discontinued warnings on the system. Doksuri tracked northwards until it was last noted on July 29, marking its dissipation.

Preparations

Philippines

PAGASA began tracking the low pressure area that would eventually develop into Doksuri as early as July 17, 2023. The agency's first bulletin on the storm was released on July 21. Doksuri was already forecasted to reach super typhoon intensity as early as the first forecast. Initial forecasts indicated that the storm would narrowly miss the Luzon mainland, instead tracking directly towards Taiwan or the Bashi Channel, though uncertainty of the forecast track was made clear in the agency's bulletins. The Philippine Institute of Volcanology and Seismology issued lahar advisories for the Mayon Volcano as the trough of Doksuri brought rain over Caraga and Eastern Visayas.
On July 23, sea travel in areas of Bicol were suspended. The Department of the Interior and Local Government asked local governments to prepare for the disaster, and requested that mayors and governors stay within their constituencies.
As the storm began its phase of rapid intensification and began tracking closer to the Philippines, PAGASA began raising Tropical Cyclone Wind Signals for parts of northern Luzon. Expecting rough weather and a transport strike protesting the 2023 State of the Nation Address, classes in public schools and work in government offices were suspended in Metro Manila for July 24. The municipality of Taytay in Rizal, the city of Bacoor in Cavite, and the province of Pampanga also suspended classes and government work, following the same rationale. Classes and government work in Catanduanes, Iloilo, Laguna, and Cagayan were suspended due to heavy rains and floods. Workers in the private sector were excused from penalties for skipping work due to the weather; this assurance was provided by a labor advisory circulated by the Department of Labor and Employment in 2022. Two domestic flights were cancelled for the day, and sea trips between Cebu and Negros Occidental were suspended. In preparation for the storm, the Department of Social Welfare and Development prepared 51,039 food packs in DSWD- and local government unit-managed warehouses in the Cordillera Administrative Region. Telecommunications company Globe Telecom prepared emergency supplies and personnel in areas where the storm is expected to hit.
After the storm reached super typhoon status on the morning of July 25, the agency raised Signal No. 4 in extreme northern parts of Luzon. Later on the same day, the agency further raised the signal into Signal No. 5 in the eastern portion of Babuyan Islands, the first time since Typhoon Noru of the previous year and the fourth tropical cyclone to raise the highest signal by PAGASA. Now under the risk of violent, life-threatening winds, evacuations began in the island group's coastal communities — areas which stood directly on the typhoon's forecasted path. Forced evacuations began in Cagayan as heavy winds of up to battered the region. Evacuations also began in Palawan after heavy rains began as rivers quickly swelled. Around 23 domestic flights were cancelled for July 25, another eight for the following days. The Laoag International Airport, situated in northern Luzon, cancelled all its flights for July 25 and 26. Various sea ports in Calabarzon, Mimaropa, and the Bicol Region suspended operations due to strong waves. The earlier transport strike—supposed to last three days—was suspended. Local governments across Luzon and parts of Visayas also suspended classes for the 25th and 26th. Large waves forced Boracay to suspend water sports activities. By July 27, most TCWS signals were lowered by the PAGASA as the storm left the Philippine Area of Responsibility. Signals remained up, however, for areas in northern Luzon which were still within the extent of Doksuri's gale-force winds.

Taiwan

As the typhoon passed south of Taiwan, sea and land warnings were raised in the southern counties of Pingtung and Taitung and in the cities of Tainan and Kaohsiung. Annual military drills in the country were cancelled in preparation. Taiwan also issued a land warning for Doksuri at 06:00 UTC. More than 5,700 people were evacuated in southern and eastern Taiwan as Doksuri was expected to bring up to 1 metre of rainfall. All domestic flights, over 100 international flights, and many ferry lines were cancelled. Railway services were suspended starting July 26. As a precaution, some highways in Taiwan were briefly closed. The Taiwanese islands of Penghu and Kinmen were issued a "hurricane-force winds" alert advising people to prepare for gusts up to.