Typhoon Halong intensified into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Tuesday. At 4:00 p.m. EST on Tuesday the center of Typhoon Halong was located at latitude 20.4°N and longitude 150.6°E which put it about 345 miles (560 km) southwest of Minami Tori Shima, Japan. Halong was moving toward the north-northwest at 5 m.p.h. (8 km/h). The maximum sustained wind speed was 180 m.p.h. (290 km/h) and there were wind gusts to 220 m.p.h. (355 km/h). The minimum surface pressure was 900 mb.
Typhoon Halong intensified into one of the strongest tropical cyclones of 2019 over the Western North Pacific Ocean on Tuesday. There was a circular eye with a diameter of 15 miles (24 km) at the center of Halong. 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 Halong. Storm near the core were generating strong upper level divergence which was pumping mass away to the northeast of the typhoon.
The circulation around Typhoon along was compact and symmetrical. Winds to typhoon force extended out 25 miles (40 km) from the center of circulation. Winds to tropical storm force extended out 115 miles (185 km) from the center. The Hurricane Intensity Index (HII) for Typhoon Halong was 42.2. The Hurricane Size Index (HSI) was 9.4 and the Hurricane Wind Intensity Size Index (HWISI) was 51.6.
Typhoon Halong has probably reached its peak intensity. Halong will move over water where the Sea Surface Temperature is near 29°C. However, an upper level trough near Japan will approach Typhoon Halong from the northwest. The trough will produce strong southwesterly winds which will start to increase the vertical wind shear. More wind shear will cause Halong to weaken.
The upper level trough will start to steer Typhoon Halong toward the northeast in 12 to 24 hours. On its anticipated track Typhoon Halong will pass northwest of Minami Tori Shima on Thursday. Even though it will weaken, Halong will bring strong, gusty winds and heavy rain.
Elsewhere over the Western North Pacific Ocean, Tropical Storm Nakri developed over the South China Sea between the Philippines and Vietnam on Tuesday. At 4:00 p.m. EST on Tuesday the center of Tropical Storm Nakri was located at latitude 13.8°N and longitude 116.0°E which put it about 380 miles (615 km) west of Manila, Philippines. Nakri was moving toward the northeast at 5 m.p.h. (8 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 998 mb.
Although Tropical Storm Nakri is currently moving toward the northeast, it is forecast to move back toward the west later this week. Nakri will move through an environment favorable for intensification. It will move over water where the Sea Surface Temperature is near 28°C. Tropical Storm Nakri could strengthen into a typhoon before it reaches the coast of Vietnam.