As tropical cyclones, typhoons and hurricanes are essentially the same. They get different names simply because of the distinct “producing area”: one is in the western Pacific, and the other in the eastern Pacific and the Atlantic. This is a fun fact people often mention when talking about typhoon’s place of origin. However, within the typhoon family, members are not identical either. They have unique “personalities” according to the different “birthplaces”.

The generation of a typhoon has many indispensable conditions, such as sea temperature that is high enough, humid air, weather disturbances, and a suitable distance from the equator. Constrained by these conditions, the “hometown” of typhoon is centered on the wide low-latitude ocean of the northwest Pacific Ocean. Specifically, it can be divided into three major source regions, namely, the central and northern parts of the South China Sea, the ocean to the east of the Philippine archipelago, and the sea near the Marshall Islands. The dates of typhoons’ births at each site are different.

Typhoon in the South China Sea: Little neighbor

In the nearest central and northern parts of the South China Sea, typhoons usually generate from June to September each year. From January to April, the central and northern parts of the South China Sea are relatively quiet; after entering May, typhoons gradually increase; after the peak period in summer, typhoons slowly decrease from October to December. Typhoons here, with a relatively small horizontal range, low vertical height and low intensity, are developed by the tropical depression in the South China Sea and the tropical depression shifted from the Pacific Ocean into the South China Sea. It generally has a radius from 300 km to 500 km, with the smallest less than 100 km. Its stretching height is about 6 km to 8 km and the central pressure is about 980 to 990 hectopascals. The distribution of typhoon clouds in the South China Sea is very asymmetric. Typhoon eyes vary in size and shape, with thin clouds, loose cloud walls, and little or no precipitation.

The typhoon in the South China Sea is usually small, but every rule has its exceptions. The Typhoon “Ryan” generated in the South China Sea in 1995 reached a super typhoon level with gales of up to 65 m/s around the center. “Ryan” moved north all the way along the coast and finally arrived in Japan.

Sea area to the east of the Philippine Islands: Home base of typhoons

This area has the most frequent occurrences of typhoon in the northwestern Pacific, with typhoons occurring almost all year around. From January to June, typhoons occur mainly in the area to the south of 15 degrees north latitude in Samar Island of Philippines, and the sea area to the east of Mindanao Island; after June, the area with high occurrence of typhoon is extended to the north; from July to August, typhoons appear in the sea area from Luzon Island in the Philippines to the Ryukyu Islands; in September, the typhoons move southward to waters to the east of Luzon Island; from October to December, they move to the sea to the east of the Philippines and to the south of 15 degrees north latitude.

The super typhoon in 2014, “Rammasun”, was formed in the sea to the east of the Philippines. The violent “Rammasun” rapidly intensified in the coastal area twice, inflicting serious losses on the Philippines and Hainan, Guangdong, Guangxi in China and making itself “decommissioned” from the typhoon name list.

Marshall Islands: Violent typhoons in late autumn

People may be quite unfamiliar with the name of Marshall Islands. In fact, it is indeed far away from our country. It is located deep within the Pacific Ocean and close to the International Date Line. The sea near the Marshall Islands is also one of the typhoon’s favorite homes. In the northwest and north of the Islands, typhoons are often generated. The difference is that typhoons are the most frequent in October here. The strong typhoons that hit our country occasionally after the “peak season” probably come from the distant Marshall Islands.

The most impressive typhoon from here is probably the super typhoon “Haiyan” in 2013. It was formed on Nov. 3, already late autumn and even early winter in the northern hemisphere. Its landing wind speed hit a record high when it landed in the Philippines, and it destroyed the Samar Island and the Leyte Island along the way. Despite the long journey, “Haiyan” was still strong when it struck China. It directly hit Hainan and then moved to Guangxi, inflicting severe losses in both provinces.