Both 'Maemi' and 'Nari' Typhoons Occurred in September... Why Are Large-Damage Autumn Typhoons Happening Consecutively?

Typhoon Nangka (No. 14) Moving North
Last 10 Years: 5.3 Typhoons in September, 3.7 in October
Sea Surface Temperature Higher This Year
Experts Say "Typhoon Impact Possible Until Early October"

Typhoon No. 12 'Muifa', Typhoon No. 13 'Merbok', and Typhoon No. 14 'Nanmadol' occurred after Typhoon Hin Nam No, the 11th typhoon.
Photo by Korea Meteorological Administration

[Asia Economy Intern Reporter Kim Gunchan] Even after Typhoon Hinnamnor, the 11th typhoon, passed, autumn typhoons continue to occur consecutively. Historically, autumn typhoons have caused significant damage to South Korea, and recently, their frequency has been increasing. It is analyzed that typhoons will continue to approach South Korea until early October.

According to the Korea Meteorological Administration (KMA), as of 3 a.m. today, the 12th typhoon 'Muifa' is moving north-northwest at a speed of 12 km/h approximately 310 km northeast of Taipei, Taiwan. Muifa is expected to make landfall near Shanghai, China, in the early morning of the 15th, move northward, and weaken into a tropical depression near Qingdao inland around the 17th.

Also, the 13th typhoon 'Merbok' is moving northwest at a speed of 14 km/h approximately 2340 km northeast of Guam as of 3 a.m. today. Merbok is forecasted to transform into an extratropical cyclone around 3 a.m. on the 16th, approximately 2750 km northeast of Tokyo, Japan.

The two typhoons currently active are not expected to have a direct impact on South Korea. However, the 26th tropical depression formed between Muifa and Merbok is developing into the 14th typhoon 'Nanmadol,' which may affect South Korea depending on its path.

According to the KMA, as of 3 a.m. today, Nanmadol is moving eastward at a speed of 13 km/h approximately 1300 km southeast of Okinawa, Japan. Nanmadol is expected to pass Okinawa and reach the sea about 280 km south-southeast of Seogwipo, Jeju, around 3 a.m. on the 19th.

On the afternoon of the 6th, affected by Typhoon No. 11 'Hinnamnor,' flooded household items were piled up at Guryongpo Market in Pohang. [Image source=Yonhap News]

Looking at past cases, many typhoons that caused significant damage to South Korea occurred in autumn. Major typhoons that passed through South Korea in autumn include Typhoon Maemi (landfall on September 12, 2003), Nari (September 16, 2007), Kompasu (September 2, 2010), Chaba (October 5, 2016), and Haishen (September 7, 2020).

There is also analysis that the frequency of autumn typhoons is increasing. According to the KMA, the average number of typhoons occurring monthly between 1991 and 2020 was 5.6 in August, 5.1 in September, and 3.5 in October. Narrowing the range to the recent 10 years (2011?2020), the numbers were 5.1 in August, 5.3 in September, and 3.7 in October, indicating an increase in autumn typhoons.

Typhoon No. 11 'Hinnamnor' brought heavy rain, causing flooding inside the POSCO Pohang Steelworks in Nam-gu, Pohang City, Gyeongbuk Province, on the morning of the 6th. [Image source=Yonhap News]

The reason autumn typhoons have been occurring consecutively this month is that sea surface temperatures in South Korean waters have been relatively high this year. Typhoons maintain strong intensity while moving north when sea surface temperatures are high. According to the KMA, this summer's sea surface temperature was 23.9°C, the second highest on record following last year's 24.1°C. In particular, Jeju Island maintained temperatures above 27°C in September, which is 2 to 3 degrees higher than the average.

It is analyzed that typhoons are likely to affect South Korea until early October. On the 11th, Kim Seung-bae, head of the Korea Meteorological Industry Association, stated on YTN News Wide, "Recently, unlike in the past, typhoons are forming at much higher latitudes rather than low latitudes," adding, "There is a high possibility that typhoons will affect South Korea until early October." He further explained, "Typhoons approach South Korea without weakening and maintain strong intensity," and "The change in typhoons due to climate change means that typhoons occur later into the season."

This content was produced with the assistance of AI translation services.