Tag Archives: Tropical Storm Dujuan

Tropical Storm Dujuan Develops East of Mindanao

Tropical Storm Dujuan developed east of Mindanao on Thursday. At 10:00 a.m. EST on Thursday the center of Tropical Cyclone Dujuan was located at latitude 7.3°N and longitude 131.6°E which put it about 430 miles (695 km) east of Davao, Philippines. Dujuan was moving toward the west-northwest at 4 m.p.h. (6 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.

The circulation around an area of low pressure east of the Philippines strengthened on Thursday morning and the Japan Meteorological Agency designated the system as Tropical Storm Dujuan. The distribution of thunderstorms around Tropical Storm Dujuan was asymmetrical. The strongest thunderstorms were occurring in bands in the western half of Dujuan. Bands in the eastern half of the tropical storm consisted primarily of showers and lower clouds. Storms west of the center of circulation began to generate upper level divergence which pumped mass away to the west of the tropical storm. Winds to tropical storm force extended out 100 miles (160 km) from the center of Dujuan.

Tropical Storm Dujuan will move through an environment somewhat favorable for intensification during the next 36 hours. Dujuan will move over water where the Sea Surface Temperature is near 29°C. It will move under the southern part of an upper level ridge over the Western North Pacific Ocean. The ridge will produce easterly winds which will blow toward the top of Tropical Storm Dujuan. Those winds will create moderate vertical wind shear and they are causing the asymmetrical distribution of thunderstorms. The wind shear will inhibit intensification, but it will not be strong enough to prevent Dujuan from strengthening. Tropical Storm Dujuan is likely to intensify gradually during the next 36 hours.

Tropical Storm Dujuan will move south of a high pressure system over the Western North Pacific Ocean. The high will steer Dujuan toward the west-northwest during the next several days. On its anticipated track Tropical Storm Dujuan could approach northeastern Mindano in 48 hours. Dujuan could bring gusty winds and locally heavy rain to Mindano and other parts of the southern Philippines.

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.