Tropical Storm Khanun formed near northern Luzon on Thursday.  At 11:00 p.m. EDT on Thursday the center of Tropical Storm Khanun was located near latitude 18.0°N and longitude 121.6°W which put it about 240 miles (390 km) north of Manila, Philippines.  Khanun was moving toward the west at 13 m.p.h. (21 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 994 mb.

A center of circulation developed near the surface in an area of thunderstorms on Thursday and the Japan Meteorological Agency designated the system as Tropical Storm Khanun.  The circulation of Tropical Storm Khanun was still organizing.  The center of Khanun moved across northern Luzon and the passage over land interrupted the development of the circulation.  Despite the passage over land, a primary rainband wrapped around the western side of the circulation.  Additional bands of showers and thunderstorms developed in the western half of the circulation.  The rainbands were weaker in the eastern half of Khanun, especially in the part of the circulation still over northern Luzon.

Tropical Storm Khanun will move through an environment favorable for intensification when it moves over the South China Sea.  Khanun will move over water where the Sea Surface Temperature is near 30°C.  The tropical storm is moving under the western half of an upper level ridge.  The ridge is producing easterly winds which are blowing toward the top of the circulation.  Those winds are causing moderate vertical wind shear.  The shear will slow the rate of intensification, but it should not be strong enough to prevent Tropical Storm Khanun from intensifying.  Khanun should start to strengthen once the center move farther west of Luzon.  Tropical Storm Khanun is forecast to become a typhoon during the weekend.

Tropical Storm Khanun is moving south of a ridge which is steering the tropical storm toward the west.  A generally westward motion is expected to continue during the next several days.  On its anticipated track Tropical Storm Khanun could approach Hainan Island in about 48 hours.  Khanun is likely to be a typhoon at that time.