Typhoon Sarika, known in the Philippines as Typhoon Karen, was a powerful tropical cyclone which affected the Philippines, South China, and Vietnam in mid-October 2016. The twenty-first named storm and the tenth typhoon of the annual Pacific typhoon season, Sarika developed from a tropical disturbance east of the Philippines on October 13. The system steadily strengthened as it traveled westwards, becoming a tropical storm later that day and then a typhoon on October 15. Rapid intensification commenced as Sarika turned to the west-northwest towards Luzon, reaching its peak intensity just before making landfall in Aurora early on October 16. Sarika weakened significantly as it crossed land, emerging over the South China Sea as a minimal typhoon, then weakening further to a severe tropical storm on October 17. Sarika maintained its strength for the rest of the day and made landfall in Hainan province in China on October 18. Turning to the northwest, Sarika weakened quickly as it emerged into the Gulf of Tonkin, before moving onshore once again in Guangxi province on October 19. The system dissipated shortly after.
Sarika produced significant impacts in the Philippines as a strong typhoon. Strong winds and flooding rainfall caused landslides, power outages, and disruptions of telecommunications services. Nearly 13,000 homes were damaged or destroyed, and more than 200,000 people were displaced. Agricultural damage in the Philippines was severe, totaling ₱3.63 billion (US$ million). Damage to infrastructure was valued at ₱226 million (US$ million). No fatalities occurred, though several mountaineers and sailors were rescued. While not as strong at subsequent landfalls in China, Sarika combined with the northeast monsoon to produce heavy rains across South China and northeast Vietnam. Hong Kong saw its October hourly rainfall record broken by thunderstorms from Sarika on October 19. A person went missing after a boat capsized near Wang Chau Island. Gusty winds and torrential rains affected Hainan, Guangxi, and Guangdong. In particular, Sarika was the strongest October typhoon to hit Hainan since 1971, where nearly 6,000 houses were damaged, 130,000 people lost access to telecommunications services, and almost of banana, cassava, papaya, and rubber crops were impacted. Direct economic losses in the province reached ¥4.56 billion (US$ million). Another of crops were damaged in Guangxi and Guangdong. In total, Sarika killed at least one person and caused economic losses reaching US$894 million.
Meteorological history
Sarika was first noted by the United States-based Joint Typhoon Warning Center (JTWC) as a disorganized tropical disturbance on October 11, while it was about southeast of Manila. The system quickly consolidated within a favorable environment of low wind shear and high sea surface temperatures of about , leading the JTWC to issue a Tropical Cyclone Formation Alert. By 00:00 UTC on October 13, the system's low-level circulation center became increasingly symmetric as it tracked northwestwards and the Japan Meteorological Agency (JMA) upgraded the disturbance to a tropical depression. The JTWC followed suit six hours later. Intensification slowed thereafter as an upper-level anticyclone suppressed outflow on the eastern side of the system. However, the system managed to intensify into a tropical storm by 18:00 UTC on October 13 as it traveled west-northwestwards along a subtropical ridge. At this point, the system was given the name Sarika by the JMA. The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA), which had been tracking the storm since October 12, assigned it the local name Karen.
On October 14, the anticyclone that had been hampering outflow diminished, allowing the system to once again quickly gain organization. The system intensified into a severe tropical storm at 12:00 UTC, and then a typhoon at 00:00 UTC the next day. As Sarika traversed warm seas with surface temperatures reaching , the system developed a small, well-defined eye that was apparent on both infrared and microwave satellite imagery, signalling the onset of rapid intensification. Sarika reached peak intensity as a very strong typhoon at 18:00 UTC on October 15, assessed by the JMA to have sustained winds of and a minimum pressure of . The JTWC simultaneously assessed Sarika to have winds of , equivalent to Category 4 status on the Saffir–Simpson scale. Just half an hour later, Sarika made its first landfall near Baler, Aurora in the Philippines. Significant weakening occurred in the six hours that Sarika traversed Luzon as the mountainous terrain disrupted its circulation, with the JMA and JTWC estimating that winds fell to . The system recovered a ragged eye as it continued west-northwest under the influence the subtropical ridge, and exited the Philippine Area of Responsibility on October 16.
Despite continued favorable conditions, Sarika struggled to reintensify as its eye remained ragged, with the JMA assessing that it weakened further to a severe tropical storm at 00:00 UTC on October 17. The JTWC, however, maintained that the system remained a typhoon as it crossed the South China Sea. The broad system turned northwest late on October 17 as it began to round the subtropical ridge. At 01:50 UTC on October 18, Sarika made landfall on Hainan Island near Hele, Wanning with winds of according to the JMA. Bringing wind gusts of to the island, Sarika became the strongest October typhoon to impact Hainan since 1971. The system weakened quickly into a tropical storm as it moved across Hainan, before emerging into the Gulf of Tonkin at 16:00 UTC. Sarika's convective structure continued to fall apart, and the system weakened into a tropical depression prior to its final landfall near Fangchenggang, Guangxi at 06:10 UTC on October 19. Sarika dissipated inland over Guangxi before 00:00 UTC on October 20.
Preparations Philippines
In anticipation of the typhoon, PAGASA issued Public Storm Warnings for a number of areas. In particular, signal number 3 – indicating an expectation of winds of within the next 18 hours – was issued for the provinces of Pangasinan, Zambales, Tarlac, Nueva Ecija, Aurora, Quezon, La Union, Benguet, Nueva Vizcaya, Quirino, Catanduanes, and Camarines Norte. A total of 39,934 people across the Ilocos, Cagayan Valley, Central Luzon, Calabarzon, and Bicol administrative regions were evacuated. Schools were closed in all of these regions, as well as the National Capital Region and the Cordillera Administrative Region, from October 16 to 18. Flights arriving and departing between October 15 and 18 were cancelled because of the adverse weather conditions, with 259 domestic flights and 62 international flights affected. Ports in Luzon and the Visayas were closed, stranding up to 4,000 passengers.
The National Disaster Risk Reduction and Management Council (NDRRMC) was placed on red alert on October 15, requiring all associated agencies to be fully staffed and prepared. The Department of Social Welfare and Development set aside ₱1.28 billion (US$ million) worth of standby funds, including 494,222 family food packs worth ₱745 million (US$ million), for immediate disaster relief. The 7th Infantry Division of the Philippine Army was placed on standby for disaster operations. The Department of Health stockpiled ₱22.2 million (US$) worth of medicine and other logistics for emergency use.
China The Hong Kong Observatory (HKO) issued Standby Signal No. 1 at 13:20 UTC on October 16, as winds began to shift with the approach of Sarika. This was raised to Strong Wind Signal No. 3 at 05:40 UTC on October 17, when Sarika was south-southwest of Hong Kong. Classes for kindergartens and schools for disabled children were cancelled, although children daycare centers, elderly centers, and rehabilitation centers remained open. Bunker operations at the Port of Hong Kong were suspended for the duration of the strong wind signal. On October 18, as Sarika moved away from Hong Kong, the HKO replaced the tropical cyclone warnings with a Strong Monsoon Signal. However, as heavy rains continued to impact Hong Kong, the HKO issued a Black Rainstorm Warning on the afternoon of October 19, the first time they had done so in October since the Rainfall Warning System came into place in 1992.
As Sarika approached South China, the State Flood Control and Drought Relief Headquarters activated a , and sent six teams to Hainan, Guangdong, Guizhou, Yunnan, and Guangxi to prepare for disaster relief. Around 660,000 people were evacuated from Hainan, including 13,700 from low-lying areas in Wanning. High-speed train services were suspended from October 17. Haikou Meilan International Airport suspended operations from October 17 to 18 and cancelled 281 flights, while 248 flights were cancelled at Sanya Phoenix International Airport. Schools in eight counties in Hainan were closed for three days. Tourist sites were also shut to the public. Workplaces, businesses, and schools were shut in the coastal city of Sanya. On October 17, the National Marine Environmental Forecasting Center issued a red alert – the highest category on China's severe weather warning system – for ocean waves, and an orange alert – the second highest category – for stormy weather. A total of 25,396 fishing boats were recalled to various ports in Hainan.
In Guangdong, authorities enacted a Level II emergency response, with storm surge expected to be enhanced by a concurrent high tide. Authorities evacuated 55,800 people in dangerous areas. Ships were forbidden from passing through the Qiongzhou Strait after 21:00 UTC October 16, and were instead diverted to Zhanjiang. A total of 14,181 ships returned to port in Guangdong.
In Guangxi, authorities activated a Level III emergency response. A yellow alert was issued on October 19, ahead of heavy rainfall. 57,300 residents were moved to safety and schools were closed. Ferry services from Beihai to Hainan and Weizhou Island were halted. About 1,000 tourists on Weizhou Island, as well as residents of low-lying areas in the northern half of the island, were evacuated to the mainland. The Nanning–Guangzhou high-speed railway ceased ticket sales for trips on October 19. A total of 7,259 fishing boats were recalled to the Port of Beihai, resulting in 22,522 occupants seeking shelter. In all, 12,044 ships sought shelter across Guangxi. Twelve flights were cancelled at Beihai Fucheng Airport. The Guangxi Maritime Safety Administration readied several tugboats in case of emergencies. Further inland, yellow alerts were issued for Guizhou on October 19 in anticipation of heavy rainfall and flash flooding.
Vietnam As Sarika approached, officials instructed district governments to evacuate people at risk of floods, fearing that earlier severe flooding in central Vietnam could be worsened by the system. A total of 770 ships in Hạ Long Bay were called back to shore. The People's Army of Vietnam prepared 280,000 soldiers and 3,200 vehicles to conduct search and rescue operations. Schools in Quảng Ninh were closed on October 19, and many businesses in Hạ Long were shut. Vietnam Airlines cancelled all flights in and out of Cat Bi International Airport on October 19. Farmers in Hải Phòng rushed to harvest of rice fields before the typhoon's rainbands arrived.
Impact Philippines