Large, powerful Typhoon Maysak churned toward South Korea on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Typhoon Maysak was located at latitude 30.1°N and longitude 126.9°E which put it about 405 miles (655 km) south-southwest of Busan, South Korea.  Maysak was moving toward the north-northeast at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 160 m.p.h. (260 km/h).  The minimum surface pressure was 932 mb.

Typhoon Maysak neared the completion of an eyewall replacement cycle on Tuesday which resulted in an increase in the size of the circulation.  The original inner eyewall had not quite dissipated, but low level convergence was focused on the much larger outer eyewall.  Winds to typhoon force extended out 90 miles (145 km) from the center of circulation.  Winds to tropical storm force extended out 240 miles (390 km) from the center of Maysak.

Typhoon Maysak was a large, dangerous tropical cyclone.  The Hurricane Intensity Index (HII) was 25.1.  The Hurricane Size Index (HSI) was 27.5 and the Hurricane Wind Intensity Size Index (HWISI) was 52.6.  Typhoon Maysak was capable of causing widespread major damage.

Since Typhoon Maysak was near the end of an eyewall replacement cycle, it will likely weaken slowly during the next 18 hours.  Maysak will move over water where the Sea Surface Temperature is near 28°C.  An upper level trough over eastern Asia will approach Typhoon Maysak on Wednesday.  The trough will produce southwesterly winds which will blow toward the top of the circulation.  Those winds will cause more vertical wind shear and the shear will cause Typhoon Maysak to weaken more quickly.

Typhoon Maysak will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Maysak toward the north during the next 24 hours.  On its anticipated track the core of Typhoon Maysak is likely to pass west of Kyushu.  Maysak could reach South Korea in about 18 hours.  Typhoon Maysak could be the equivalent of a large, major hurricane when it gets to South Korea.  Maysak will produce very strong winds over South Korea.  It will also drop heavy rain and flash floods could occur.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Haishen strengthened south of Iwo To.  At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Haishen was located at latitude 20.1°N and longitude 142.8°E which put it about 340 miles (545 km) south-southeast of Iwo To.  Haishen was moving toward the west-southwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 1000 mb.  Tropical Storm Haishen is forecast to strengthen into a typhoon and it could move toward western Japan later this week.