Typhoon Dolphin was approaching Iwo To on Sunday night. At 11:00 p.m. EDT on Sunday the center of Typhoon Dolphin was located at latitude 24.5°N and longitude 147.8°E which put the center about 445 miles (720 km) east of Iwo To. Dolphin was moving toward the west-northwest at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (235 km/h). The minimum surface pressure was 949 mb.
Typhoon Dolphin appeared to be in the middle of another eyewall replacement cycle on Sunday evening. A small circular eye was at the center of Dolphin’s circulation. The eye was surrounded a ring of thunderstorms and the strongest winds occurred in that ring of storms. A second larger ring of thunderstorms with a diameter of 35 miles (55 km) surrounded the inner eye and eyewall. Bands of showers and thunderstorms revolved around the core of Typhoon Dolphin. Storms near the core of Dolphin generated strong upper level divergence that pumped mass away from the typhoon. The removal of mass in the upper levels was less than the convergence of mass in the lower levels of the atmosphere. So, the surface pressure started to increase again on Sunday.
Multiple eyewall replacement cycles were having an effect on the structure of Typhoon Dolphin. Winds to typhoon force extended out 90 miles (145 km) in the northern side of Dolphin’s circulation. Winds to typhoon force only extended out 35 miles in the southern side of Typhoon Dolphin. Winds to tropical storm force extended out 265 miles (425 km) from the center of Dolphin’s circulation.
The Hurricane Intensity Index (HII) for Typhoon Dolphin is 20.6. The Hurricane Size Index (HSI) is 25.5 and the Hurricane Wind Intensity Size Index (HWISI) is 46.1. Typhoon Dolphin is similar in size and intensity to Hurricane Irma was when Irma hit South Florida in 2017.
Typhoon Dolphin will move through an environment that will be favorable for a powerful typhoon during the next 24 hours. Dolphin will move over water where the Sea Surface Temperatures are near 29°C. It will move under the middle of an upper level ridge that is over the Western North Pacific Ocean. The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear. Typhoon Dolphin is likely to weaken a little on Monday. as it completes the current eyewall replacement cycle.
Typhoon Dolphin will move around the southern side of a high pressure system that is over the Western North Pacific Ocean. The high pressure system will steer Dolphin toward the west-northwest during the next 24 hours. On its anticipated track, the center of Typhoon Dolphin will reach Iwo To in 24 hours. The center of Dolphin’s circulation will approach Minami Daito Jima in three days. The center of Typhoon Dolpin will be near Okinawa To in 4 days,
Typhoon Dolphin will bring strong winds and heavy rain to Iwo To. Heavy rain is likely to cause flash floods. Typhoon Dolphin will be capable of causing major damage.