Tropical Storm Dujuan Intensifying Southeast of Okinawa

After several days where vertical wind shear pushed most of the thunderstorms west of the core of the circulation, Tropical Storm Dujuan began to intensify on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Dujuan was located at latitude 18.9°N and longitude 132.7°E which put it about 620 miles (1000 km) southeast of Okinawa.  Dujuan was moving toward the west-northwest at 10 m.p.h. (16 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 988 mb.

The circulation near the core of Tropical Storm Dujuan is showing more organization.  Thunderstorms are developing closer to the center of circulation, although most of the stronger storms are still south and southwest of the center.  The distribution of thunderstorms is an indication that an upper level ridge west of Dujuan is still generating northeasterly winds over the top of the tropical storm.  Some of the storms closer to the center of circulation are starting to generate upper level divergence.

Dujuan is over water where the Sea Surface Temperatures are near 30°C.  Intensification is likely but vertical wind shear could limit the rate of intensification in the short term.  The wind shear is likely to decrease in a day or two as Dujuan moves into an area where the upper level winds are lighter.  Dujuan could become a typhoon within 24 to 36 hours and it could reach the equivalent of a major hurricane during the weekend.

Tropical Storm Dujuan is being steered toward the west-northwest by a subtropical ridge located to its northeast,  That general steering patter is expected to continue for another 24 to 36 hours.  At that time Dujuan will be between the ridge to its east and another upper level ridge to its west, and it could turn toward the northwest for a day or so.  The western ridge is expected to build north of Dujuan and turn it more toward the west in three or four days.  On its anticipated track Dujuan could approach the southern islands of Japan in three or four days.  It could be near Taiwan in five days.  Dujuan could be a strong typhoon by that time.