Typhoon Mangkhut causes heavy damage in Hong Kong, China, and Macau – Mangkhut “brought Hong Kong a record-breaking storm surge”

Desdemona Despair

Dr. Jeff Masters
16 September 2018

(Weather Underground) – Mangkhut made landfall in China at the Guangdong city of Taishan at 5 pm Sunday local time (9Z or 5 am EDT). At the time of the 6Z advisory, three hours prior to landfall, the Joint Typhoon Warning Center (JTWC) rated Mangkhut a Category 1 storm with 90 mph winds. Given the large amount of destruction Mangkhut caused during this landfall, the typhoon was likely stronger than that: the China Meteorological Agency (CMA) put Mangkhut’s maximum sustained 2-minute average winds at 6Z at 108 mph (48 m/s); this is equivalent to a borderline Category 2/Category 3 hurricane with 1-minute-average sustained winds of 110–115 mph. China’s Xinhua news service reported the storm had winds of 100 mph (162 kph) at landfall.

The official agency responsible for advisories in the Northwest Pacific, the Japan Meteorological Agency (JMA), put Mangkhut’s 6Z maximum sustained 10-minute winds at 85 mph, which is roughly equivalent to a borderline Category 1/Category 2 hurricane with 1-minute-average sustained winds of 95 mph.

Mangkhut was a huge storm at landfall, with hurricane-force winds that extended out up to 100 miles (160 km) from the center, and tropical storm-force winds that extended out up to 315 miles (510 km) from the center. This huge wind field was able to generate a significant storm surge. In Macau, which the typhoon’s eye passed about 40 miles (70 km) to the west of, a storm surge of 1.9 meters (6.2 feet) flooded the entire inner harbor, according to South China Morning Post. A pressure of 970 mb was measured there, along with peak sustained winds of 65 mph (105 kph).

In Hong Kong, the No. 10 signal – their highest level of danager alert – remained in place between 9:40 am and 7:40 pm on Sunday, only one hour shorter than the record set by Typhoon York, which ravaged the city for 11 hours in September 1999. At the 12 monitoring stations in Hong Kong, which the center passed 80 miles (130 km) to the west of, the pressure fell low as 971 mb, and winds as high as 101 mph (163 kph) were measured.

According to senior science officer Lee Suk-ming of the Hong Kong Observatory, Mangkhut “brought Hong Kong a record-breaking storm surge, which was more severe than those brought by Typhoon Wanda and Typhoon Hope.” The maximum storm surges recorded at Quarry Bay and Tai Po Kau were 2.35 meters and 3.38 meters respectively, higher than the 1.77m surge bought by Typhoon Wanda in 1962 to Quarry Bay, and the 3.23m surge in Tai Po Kau under Typhoon Hope in 1979. Storm surge records in Hong Kong extend back to 1904. Lee said the stronger storm surge in the Victoria Harbour could be attributed to years of reclamation. [more]

Typhoon Mangkhut Causes Heavy Damage in Hong Kong, China, and Macau