Tag Archives: Jeju Island

Powerful Typhoon Hinnamnor Heads Toward South Korea

Powerful Typhoon Hinnamnor headed toward South Korea on Sunday night. At 11:00 p.m. EDT on Sunday the center of Typhoon Hinnamnor was located at latitude 30.5°N and longitude 125.3°E which put it about 440 miles (710 km) southwest of Busan, South Korea. Hinnamnor was moving toward the north at 14 m.p.h. (22 km/h). The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 155 m.p.h. (250 km/h). The minimum surface pressure was 947 mb.

Typhoon Hinnamnor was a large and dangerous storm as it headed toward South Korea on Sunday night. Winds to typhoon force extended out 80 miles (130 km) from the center of Hinnamnor’s circulation. Winds to tropical storm force extended out 260 miles (420 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Hinnamnor was 23.6. The Hurricane Size Index (HSI) was 29.4 and the Hurricane Wind Intensity Size Index (HWISI) was 53.0. Typhoon Hinnamnor was capable of causing widespread major damage.

The circulation around Typhoon Hinnamnor was very well organized. A small eye with a diameter of 12 miles (19 km) was at the center of Hinnamnor’s circulation. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Typhoon Hinnamnor. Storms near the core generated upper level divergence that pumped mass away from the typhoon.

Typhoon Hinnamnor will move into an environment less favorable for a strong typhoon during the next 24 hours. Hinnamnor will move over water where the Sea Surface Temperatures are 28˚C. An upper level trough over China will produce southwesterly winds that will blow toward the top of Hinnamnor’s circulation. Those winds will cause the vertical wind shear to increase during the next 24 hours. Typhoon Hinnamnor will start to weaken when the wind shear increases.

The upper level trough over China will steer Typhoon Hinnamnor toward the northeast during the next 24 hours. On its anticipated track, the center of Typhoon Hinnamnor will be near Jeju Island in 12 hours. Hinnamnor will approach the coast of South Korea near Busan in 18 hours. Although Typhoon Hinnamnor will weaken as it approaches South Korea, it will still be a large, powerful typhoon. Hinnamnor will bring strong gusty winds and locally heavy rain to South Korea. Heavy rain could cause flash floods in some locations. Typhoon Hinnamnor could also bring gusty winds and locally heavy rain to parts of Japan.

Tropical Storm Trases Develops over the East China Sea

Tropical Storm Trases developed over the East China Sea south of Jeju Island, South Korea on Sunday afternoon. At 2:00 p.m. EDT on Sunday the center of Tropical Storm Trases was located at latitude 30.1°N and longitude 126.3°E which put it about 175 miles (280 km) south of Jeju Island, South Korea. Trases was moving toward the north-northwest at 18 m.p.h. (29 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 998 mb.

The circulation at the center of a large low pressure system over the East China Sea strengthened on Sunday afternoon and the Japan Meteorological Agency designated the system as Tropical Storm Trases. The distribution of thunderstorms around Tropical Storm Trases was asymmetrical. Thunderstorms were occurring in bands in the southern part of Trases’ circulation. Bands in the other part of the tropical storm consisted primarily of showers and lower clouds. The air in the northern part of Tropical Storm Trases was cooler and drier. The cooler, drier air was inhibiting the formation of thunderstorms in that part of Trases.

Tropical Storm Trases will move through an environment marginally favorable for intensification during the next 12 hours. Trases will will move over water where the Sea Surface Temperatures are near 26˚C. It will move under the axis of an upper level ridge centered north of Japan. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. However, the cooler drier air on the northern side of Trases will limit the potential for intensification. Tropical Storm Trases could intensify a little during the next 12 hours. Trases will move over cooler water on Monday and it is likely to weaken at that time.

Tropical storm Trases will move around the western side of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Trases toward the north during the next 24 hours. On its anticipated track the center of Tropical Storm Trases could reach Jeju Island within 12 hours. Trases could make landfall on the west coast of South Korea on Monday. Tropical Storm Trases will bring gusty winds and locally heavy rain to parts of South Korea.