Typhoon Hato
Typhoon Hato, known in the Philippines as Severe Tropical Storm Isang, was a powerful tropical cyclone that struck South China in late August 2017. The thirteenth named storm and fourth typhoon of the 2017 Pacific typhoon season, Hato developed as a tropical depression east of Luzon on August 19. It strengthened into a tropical storm the next day and emerged over the northern South China Sea on August 21, where it reached typhoon intensity. Undergoing rapid intensification on August 23, Hato became a Category 3-equivalent typhoon before making landfall in Jinwan, Zhuhai. The storm quickly weakened over land and dissipated on August 24.
One of the strongest typhoons to affect Macau and Hong Kong in the past 50 years, Hato caused extensive damage totaling US$6.82 billion along its path. Most of the destruction occurred in mainland China, where the storm produced a powerful storm surge that triggered severe flooding across several provinces along the Pearl River and generated wind gusts up to. Both Hong Kong and Macau raised their highest tropical cyclone signals in anticipation of Hato, which caused more than US$1 billion in damage in each territory. While weakening, the storm also brought heavy rain and a tornado to Vietnam. In total, 24 fatalities were reported.
Hato made landfall along the southern coast of Zhuhai with Category 3-equivalent intensity, featuring both one- and two-minute sustained winds of, which is strong, though not as powerful as other major typhoons. Three previous typhoons, Wanda, Ruby, and Vicente, followed similar east-southeast to west-northwest tracks, making landfall on slightly different parts of the coast. Hato's forward speed was the fastest among them, reaching, nearly twice that of Wanda.
Meteorological history
During the late hours of August 18, the Joint Typhoon Warning Center began monitoring a tropical disturbance that had developed about southeast of Taipei, Taiwan. By August 19, the Japan Meteorological Agency classified the area of low pressure as a tropical depression. Around the same time, the JTWC issued a Tropical Cyclone Formation Alert, while the JMA began issuing advisories, reporting that the system had 10-minute sustained winds of. By 03:00 UTC on August 20, the JTWC began issuing warnings, classifying the system as a tropical depression and designating it as 15W. The Philippine Atmospheric, Geophysical and Astronomical Services Administration eventually named the system Isang as it entered the Philippine Area of Responsibility. Six hours later, the JMA upgraded it to a tropical storm and assigned the international name Hato.At 15:00 UTC on August 20, the Joint Typhoon Warning Center upgraded Hato to a tropical storm after the system became better organized. By this time, Hato was located in a favorable environment with low vertical wind shear and sea surface temperatures of about. The storm failed to intensify through most of August 21 as its low-level circulation center remained partly exposed and the convection appeared sheared. Several hours later, the LLCC broadened as convection redeveloped near the center. By August 22, the sea surface temperature around Hato had warmed to about, prompting the Japan Meteorological Agency to upgrade the system to a severe tropical storm. The storm rapidly consolidated, forming a well-defined eye and developing a much-improved convective structure with tightly curved banding feeding into the LLCC. Both the JMA and JTWC upgraded Hato to a typhoon six hours later, although the system’s eye soon became less organized.
Early on August 23, the JTWC upgraded Hato to a Category 2 typhoon as its eye reformed beneath a growing central dense overcast. Hato reached its peak intensity as a Category 3-equivalent typhoon, with Dvorak estimates peaking at T5.5. The JMA assessed maximum 10-minute sustained winds of and a minimum pressure of, later revised in post-analysis to and. However, a minimum pressure of was recorded in Macau, while the China Meteorological Administration reported, suggesting a higher intensity. Hato made landfall along the southern coast of Zhuhai, Guangdong at 12:50 CST. About three hours later, the JTWC issued its final advisory as Hato moved inland. The JMA downgraded Hato to a severe tropical storm six hours later, and then to a tropical storm. The agency continued tracking Hato until 06:00 UTC on August 24.
Impact
Hong Kong
For the first time in five years, since Typhoon Vicente in 2012, the Hong Kong Observatory issued Hurricane Signal No. 10, the highest level in the tropical cyclone warning system. The HKO recorded a record-high temperature of during the typhoon. The Air Quality Health Index also reached level 8 at several monitoring stations. In response, businesses, government offices, schools, courts, and the stock market were closed. At least 121 injuries were reported as the storm swept through the city. Widespread property damage occurred, including shattered windows, collapsed scaffolding, and more than 690 reports of fallen trees, debris, and broken glass scattered across streets and major roads. Severe flooding was reported in low-lying areas such as Heng Fa Chuen, Lei Yue Mun, and Tai O due to storm surge. More than 450 flights were canceled or delayed at Hong Kong International Airport, and public transport was brought to a standstill. The estimated economic loss was around HK$4 billion.Macau
The storm was the strongest to have hit Macau in 53 years, according to Macau's Chief Executive Fernando Chui, and it was the first time in 18 years that the Macao Meteorological and Geophysical Bureau hoisted a No. 10 tropical cyclone signal. Maximum hourly mean winds of and gusts of were the highest on record in Macau. Most areas of the territory was hit by major flooding and property damages, with citywide power and water outage lasting for at least 24 hours after the passage of the storm. Overall, 10 deaths and at least 200 injuries were reported. The head of the Macao Meteorological and Geophysical Bureau resigned due to criticisms by the Macanese public that officials failed to predict the ferocity of the storm. The Corruption Agency is investigating The Meteorology Bureau's forecasting procedures and management, including the former director Fong Soi-Kun. The Macau SAR Government also announced 1.3 billion Macanese patacas would be set aside for those affected by the typhoon, with families of victims to get up to 300,000 patacas each. In total, Macau suffered an economic loss of 12.55 billion patacas.There were shortages of basic supplies locally due to residents buying up remaining stocks in response to the utilities shortages and flooding. At the request of the local government, the Chinese People's Liberation Army Macau Garrison was deployed to assist in disaster relief and cleaning up for the first time in Macau history. About 1,000 troops were called in to help remove debris and clear roads. Macau police arrested two people for using phones to spread unverified information alleging that the authorities had sought to cover up the discovery of bodies in a car park during Typhoon Hato.
A typhoon and storm surge coupling model demonstrated that the maximum storm surge height reached nearly along the coast of Macau, while that in Hong Kong was slightly below. Furthermore, a field survey of urban flooding revealed evidence of a 2.25-m inundation in downtown Macau and a 0.55-m inundation on Lantau Island, Hong Kong, which were likely exacerbated by a combination of storm surge, heavy rainfall, and surface water runoff over a complex hilly terrain.