Tropical Storm Jongdari formed southwest of Iwo To on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Jongdari was located at latitude 20.9°N and longitude 136.9°E which put it about 410 miles (665 km) southwest of Iwo To.  Jongdari was moving toward the north at 10 m.p.h. (16 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 996 mb.

A distinct low level center of circulation developed within former Tropical Depression 15W on Tuesday afternoon and the Japan Meteorological Agency designated the system as Tropical Storm Jongdari.  The circulation of Jongdari was asymmetrical.  Most of the stronger thunderstorms were forming in bands north of the center.  Bands south of the center consisted primarily of showers and lower clouds.  Stronger storms near the center were beginning to generate upper level divergence which was pumping mass away from the core of the circulation.

Tropical Storm Jongdari will move through an environment favorable for intensification during the next several days.  Jongdari will move over water where the Sea Surface Temperature is near 28°C.  So, there will be sufficient energy in the upper ocean to support intensification.  It will move under the middle of an upper level ridge where the winds are weaker and there will be little vertical wind shear.  Intensification could be slow at first while the circulation becomes more organized, but Jongdari could strengthen more quickly when the inner core becomes more well developed.  Tropical Storm Jongari could strengthen to a typhoon with 48 hours.  It could eventually intensify into the equivalent of a major hurricane.

Tropical Storm Jongari will move around the western end of a subtropical ridge which will steer Jongari toward the northeast during the next two or three days.  When Jongari moves farther north, it will be affected by a second ridge located farther to the north.  The second ridge is forecast to strengthen and push Jongari more toward the northwest.  On its anticipated track Jongari could reach Iwo To in about 48 hours.  It could be a typhoon at that time.  Jongari could approach Tokyo in about four days and it is likely to be a typhoon when it reaches Honshu.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Wokung was churning well southeast of Japan.  At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Wokung was located at latitude 32.3°N and longitude 158.0°E which put it about 1250 miles (2015 km) east-southeast of Tokyo, Japan.  Wokung was moving toward the north-northwest at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 984 mb.