Tropical Storm Dujuan formed over the Western North Pacific Ocean northeast of the Marianas on Wednesday. At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Dujuan was located at latitude 17.3°N and longitude 149.5°E which put the center about 260 miles (420 km) east-northeast of Saipan. Dujuan was moving toward the north-northeast at 14 m.p.h. (22 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 low pressure system over the Western North Pacific Ocean northeast of the Marianas strengthened on Wednesday and the Japan Meteorological Agency designated the system as Tropical Storm Dujuan.
The distribution of thunderstorms in Tropical Storm Dujuan was asymmetrical. Thunderstorms were occurring in bands in the southern and eastern parts of Dujuan’s circulation. Bands in the northern and western parts of Tropical Storm Dujian consisted primarily of showers and lower clouds. Storms near the center of Dujuan generated upper level divergence that pumped mass away to the northeast of the tropical storm. The removal of mass caused the surface pressure to decrease.
The strongest winds were occurring in the southern part of Tropical Storm Dujuan. Winds to tropical storm force extended out 150 miles (240 km) in the southern side of Dujuan’s circulation. The winds in the northern half of Tropical Storm Dujuan were blowing at less than tropical storm force.
Tropical Storm Dujuan will move through an environment that will be somewhat favorable for intensification during the next 24 hours. Dujuan will move over water where the Sea Surface Temperatures are near 28°C. It will move under the southeastern part of an upper level low that is north of the Marianas. The upper level low will produce southwesterly winds that will blow toward the top of Dujuan’s circulation. Those winds will cause moderate vertical wind shear. The moderate vertical wind shear will inhibit intensification, but the wind shear may not be enough to prevent intensification. Tropical Storm Dujuan is likely to intensify gradually during the next 24 hours.
The upper level low that is north of the Marianas will pull Tropical Storm Dujuan toward the north during the next 24 hours. On its anticipated track, Tropical Storm Dujuan will move north of the Marianas. The center of Dujuan could be near Iwo To in 48 hours.