Typhoon Halong passed south of Tokyo on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Typhoon Halong was located at latitude 32.8°N and longitude 140.3°E which put the center about 195 miles (315 km) south of Tokyo, Japan.  Halong was moving toward the northeast at 15 m.p.h. (24 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 946 mb.

Typhoon Halong was starting to weaken as it passed south of Tokyo on Wednesday.  A circular eye with a diameter of 25 miles (40 km) was still present at the center of Halong’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 center of Typhoon Halong.  Storms near the center of Halong generated upper level divergence that pumped mass away to the east of the typhoon.  The removal of mass was less than the inflow of mass in the lower levels of the atmosphere.  So, the surface pressure was increasing.

The circulation around Typhoon Halong increased in size on Wednesday.  Winds to typhoon force extended out 40 miles (65 km) from the center of Halong’s circulation.  Winds to tropical storm force extended out 140 miles (225 km) from the center of Typhoon Halong.

The Hurricane Intensity Index (HII) for Typhoon Halong was 23.6.  The Hurricane Size Index (HSI) was 13.9 and the Hurricane Wind Intensity Size Index (HWISI) was 37.5.  Typhoon Halong was similar in intensity to Hurricane Dennis when Dennis hit Northwest Florida in 2005.  Halong is bigger than Dennis was.

Typhoon Halong will move through an environment that will become more unfavorable for intensification during the next 24 hours.  Halong will move over water where the Sea Surface Temperatures are near 26°C.  It will move under the southern extent of the upper level westerly winds in the middle latitudes.  The upper level westerly winds will blow toward the top of Halong’s circulation.  Those winds will cause the vertical wind shear to increase.  Cooler Sea Surface Temperatures and more vertical wind shear will cause Typhoon Halong to weaken during the next 24 hours.  Halong is likely to make a transition to an extratropical cyclone during the next few days.

The upper level westerly winds will steer Typhoon Halong quickly toward the east during the next 24 hours.  On its anticipated track, Typhoon Halong will move away from Japan on Thursday.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Nakri former southwest of Iwo To.  At 5:00 p.m. EDT on Wednesday the center of Tropical Storm Nakri was located at latitude 22.3°N and longitude 136.0°E which put the center about 625 miles (1010 km) south-southeast of Okinawa.  Nakri was moving toward the northwest at 18 m.p.h. (30 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 1000 mb.