Typhoon Lekima (2019)

Typhoon Lekima (Hanna)
Typhoon (JMA scale)
Category 4 super typhoon (SSHWS)
Lekima 2019-08-08 0232Z.jpg
Typhoon Lekima at peak intensity on August 8
FormedAugust 2, 2019 (2019-08-02)
DissipatedAugust 14, 2019 (2019-08-14)
Highest winds10-minute sustained: 195 km/h (120 mph)
1-minute sustained: 240 km/h (150 mph)
Lowest pressure920 hPa (mbar); 27.17 inHg
Fatalities89 total
Damage$7.6 billion (2019 USD)
Areas affectedCaroline Islands, East China, Philippines, Ryukyu Islands, Taiwan
Part of the 2019 Pacific typhoon season

Typhoon Lekima, known in the Philippines as the Typhoon Hanna, was the second-costliest typhoon in Chinese history, only behind Fitow in 2013.[1] The ninth named storm of the 2019 Pacific typhoon season, Lekima originated from a tropical depression that formed east of the Philippines on July 30. It gradually organized, became a tropical storm and was named on August 4. Lekima intensified under favourable environmental conditions and peaked as a Category 4–equivalent super typhoon. However, an eyewall replacement cycle caused the typhoon to weaken before it made landfall in Zhejiang late on August 9, as a Category 2–equivalent typhoon. Lekima weakened subsequently while moving across the East China, and made its second landfall in Shandong on August 11.

Lekima's precursor enhanced the southwestern monsoon in the Philippines, which brought heavy rain to the country. The rains caused three boats to sink and 31 people died in this accident. Lekima brought catastrophic damage in mainland China, with a death toll of 89 people and more than CN¥53.7 billion (US$7.6 billion) in damages. The system also caused minor damage in Ryukyu Islands and Taiwan.

Meteorological history

Map plotting the track and the intensity of the storm, according to the Saffir–Simpson scale

On August 2, the Japan Meteorological Agency (JMA) began to monitor a tropical depression which developed over the Philippine Sea.[2] The system slowly developed while moving northward. The Joint Typhoon Warning Center (JTWC) also monitored the system and gave the identifier 10W early on August 4.[3] The JMA upgraded the system to a tropical storm and assigned the name Lekima at 06:00 a.m. UTC that day.[4] The JTWC followed suit later that day. Though Lekima was affected by moderate wind shear, warm waters of 31 °C (88 °F) and good outflow channel allowed Lekima to slowly intensify, and Lekima became almost stationary due to the absence of steering current.[5]

On August 6, Lekima steered by a subtropical ridge to the northeast and accelerated to the northwest,[6] and the JMA upgraded Lekima to a severe tropical storm. Later that day, both JMA and JTWC upgraded Lekima to a typhoon, after the system developed a central dense overcast.[7] As Lekima continued to move northwestward, the system moved into an area of low wind shear, and it started a process of rapid intensification on August 7. The eye became evident on satellite imagery.[8] On August 8, the JTWC upgraded Lekima to a super typhoon, and stated that the system had acquired some of the annular characteristics.[9] Later that day, the JMA stated that Lekima attained maximum sustained winds of 195 km/h (121 mph).[10] At the same time, Lekima passed between Miyako-jima and Tarama-jima.[11]

Shortly thereafter, Lekima began an eyewall replacement cycle. The typhoon developed a concentric eyewall, as seen from the radar.[12][13] This cycle also caused the motion of Lekima slightly veered to the north,[14] and the JTWC downgraded Lekima back to typhoon late on August 8.[15] Environmental conditions in East China Sea became less favourable, causing Lekima to slowly weaken while approaching East China. At 1:45 a.m. China Standard Time (UTC+08:00) August 10, Lekima made landfall in Wenling, Zhejiang with two-minute sustained winds of 185 km/h (115 mph).[16] Lekima quickly weakened and turned to the north, along the western side of the subtropical ridge.[17] Lekima dropped below typhoon intensity early on August 10, and weakened further to a tropical storm later that day. Lekima emerged into the Yellow Sea early on August 11,[18] and made second landfall in Xihai'an, Qingdao, Shandong at 8:50 p.m. CST, with two-minute sustained winds of 85 km/h (53 mph).[19] The JTWC issued its final warning to the system around that time.[20] Lekima meandered over the Shandong Peninsula and Bohai Sea throughout August 12, and the JMA downgraded it to a tropical depression later that day.[21]