Typhoon Krathon rapidly intensified to the equivalent of a major hurricane on Sunday.  At 5:00 p.m. EDT on Sunday the center of Typhoon Krathon was located at latitude 20.1°N and longitude 122.0°E which put the center about 200 miles (320 km) southeast of Kaohsiung, Taiwan.  Krathon was moving toward the west-northwest at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 950 mb.

Typhoon Krathon rapidly intensified to the equivalent of a major hurricane over the Western North Pacific Ocean south of Taiwan on Sunday.  A large circular eye with a diameter of 50 miles (80 km) was at the center of Krathon’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Typhoon Krathon.  Storms near the core of Krathon’s circulation generated upper level divergence that pumped large quatities of mass mass away from the typhoon.  The removal of large amounts of mass caused the surface pressure to decrease rapidly.

The size of the circulation around Typhoon Krathon increased as it intensified.  Winds to typhoon force extended out 60 miles (95 km) from the center of Krathon’s circulation.  Winds to tropical storm force extended out 265 miles (425 km) from the center of Typhoon Krathon.

The Hurricane Intensity Index (HII) for Typhoon Krathon was 22.1.  The Hurricane Size Index (HSI) was 23.1 and the Hurricane Wind Intensity Size Index (HWISI) was 45.2.  Typhoon Krathon was similar in size and intensity to Hurricane Jeanne when Jeanne hit southeast Florida in 2004.

Typhoon Krathon will move through an environment favorable for intensification during the next 24 hours.  Krathon will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the axis of an upper level ridge south of Japan. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear, Typhoon Krathon will intensify during the next 24 hours.  Krathon could continue to intensify rapidly during the next few hours.  Typhoon Krathon is likely strengthen to a the equivalent of a major hurricane.

Typhoon Krathon will move around the southwestern part of a high pressure system south of Japan.  The high pressure system will steer Krathon toward the northwest during the next 24 hours.  On its anticipated track, Typhoon Krathon will move closer to Taiwan.  The center Krathon’s circulation will approach the southern end of Taiwan in 36 hours. Typhoon Krathon is will be the equivalent of a major hurricane when it approaches Taiwan.  Bands in the northern side of Krathon’s circulation will begin to bring wind and rain to Taiwan on Monday.

Elsewhere over the Western North Pacific Ocean, the center of Tropical Storm Jebi passed just to the west of Iwo To.  At 5:00 p.m. EDT on Sunday the center of Tropical Storm Jebi was located at latitude 25.8°N and longitude 140.7°E which put the center about 50 miles (80 km) west-northwest of Iwo To.  Jebi was moving toward the north at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 993 mb.