Former Tropical Storm Nalgae strengthened to a typhoon over the South China Sea south-southeast of Hong Kong on Monday. At 11:00 a.m. EDT on Monday the center of Typhoon Nalgae was located at latitude 18.2°N and longitude 116.3°E which put it about 310 miles (500 km) south-southeast of Hong Kong. Nalgae was moving toward the north-northwest at 8 m.p.h. (13 km/h). The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h). The minimum surface pressure was 981 mb.

Typhoon Nalgae strengthened gradually over the South China Sea south-southeast of Hong Kong on Monday. A large eye with a diameter of 30 miles (50 km) formed at the center of Nalgae’s circulation. A broken ring of thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the center of Typhoon Nalgae. Storms near the center of circulation generated upper level divergence that pumped mass away from the typhoon. Winds to typhoon force extended out 20 miles (30 km) in the western side of Nalgae. Winds to tropical storm force extended out 330 miles (515 km) from the center of circulation.

Typhoon Nalgae will move through an environment mostly favorable for intensification during the next 24 hours. Nalgae will move over water where the Sea Surface Temperatures are near 29˚C. It will move under the western side of an upper level ridge over the Western North Pacific. The upper level ridge will produce southerly winds that will blow toward the top of Nalgae’s circulation. Those winds will cause vertical wind shear, but the wind shear will not be strong enough to prevent intensification. Typhoon Nalgae is likely to intensify during the next 24 hours. Nalgae will move into an environment where there is drier air in the lower levels of the atmosphere when it moves closer to China. Typhoon Nalgae will weaken when the drier air gets pulled into its circulation.

Typhoon Nalgae will move around the western end of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Nalgae toward the northwest during the next 24 hours. On its anticipated track Typhoon Nalgae will move closer to Hong Kong during the next 24 hours. Nalgae will move more toward the west when it encounters the drier environment near China and weakens.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Banyan developed east of the Philippines. At 11:00 a.m. EDT on Monday the center of Tropical Storm Banyan was located at latitude 7.3°N and longitude 131.2°E which put it about 320 miles (515 km) east of Mindanao. Banyan was moving toward the west-northwest at 11 m.p.h. (17 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 1000 mb.