Tag Archives: Kaohsiung

Typhoon Doksuri Drops Heavy Rain on Taiwan

Typhoon Doksuri dropped heavy rain on parts of Taiwan on Wednesday. At 5:00 p.m. EDT on Wednesday the center of Typhoon Doksuri was located at latitude 20.3°N and longitude 119.9°E which put it about 150 miles (240 km) south-southwest of Kaohsiung Taiwan. Doksuri was moving toward the west at 7 m.p.h. (11 km/h). The maximum sustained wind speed was 105 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (200 km/h). The minimum surface pressure was 947 mb.

Bands in the northern side of Typhoon Doksuri dropped heavy rain on parts of Taiwan on Wednesday. The heaviest rain was falling in eastern Taiwan, where the wind was pushing the air up the eastern slopes of mountains.. There were reports of flooding in the northern Philippines after the southern part of Doksuri dropped heavy rain in that region. There were also reports of casualties and electricity outages in the northern Philippines.

Typhoon Doksuri exhibited more organization on Wednesday after the core of Doksuri’s circulation started to move away from northern Luzon. Radar images from Taiwan’s Central Weather Bureau showed what appeared to concentric eyewalls at the core of Typhoon Doksuri. A small circular eye was at the center of Doksuri’s circulation. The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms. The inner eyewall was surrounded by a relatively clear area, sometimes called a moat. A much larger, outer eyewall surrounded the inner eyewall and moat. Bands of showers and thunderstorms were revolving around the concentric eyewalls. Storms in the concentric eyewalls generated upper level divergence that pumped mass away from the typhoon.

Doksuri was still a large typhoon. Winds to typhoon force extended out 70 miles (110 km) from the center of Doksuri’s circulation. Winds to tropical storm force extended out 200 miles (320 km) from the center. The Hurricane Intensity Index (HII) for Typhoon Doksuri was 17.8. The Hurricane Size Index (HSI) was 23.1 and the Hurricane Wind Intensity Size Index (HWISI) was 40.9. Typhoon Doksuri was similar in size and intensity to Hurricane Gustav when Gustav Hit Louisiana in 2008. Doksuri was capable of causing widespread serious damage.

Typhoon Doksuri will move through an environment favorable for intensification during the next 24 hours. Doksuri will move over water where the Sea Surface Temperatures are near 30˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. However, the concentric eyewalls at the center of Typhoon Doksuri will inhibit intensification. Doksuri could weaken until the inner eye and eyewall dissipate. The strength of Typhoon Doksuri may not change much during the next 24 hours.

Typhoon Doksuri will move around the southwestern side of a subtropical high pressure system over the Western North Pacific Ocean. The high pressure system will steer Doksuri toward the northwest during the next 36 hours. On its anticipated track, the core of Typhoon Doksuri will pass southwest of Taiwan. Typhoon Doksuri will continue to drop heavy rain on parts of Taiwan during the next 24 hours. The heaviest rain will fall on the eastern side of mountains where the winds around Doksuri will push air up the slopes. Heavy rain is likely to cause flash floods in some locations.

Typhoon Doksuri will approach the east coast of China near Xiamen in 24 hours. Doksuri will bring strong winds and heavy rain to Fujian. Heavy rain could cause flash floods in some locations. Typhoon Doksuri could also cause a storm surge of up to 10 feet (3 meters) along the coast of Fujian.

Tropical Storm Gaemi Forms Near Southwest Taiwan

Tropical Storm Gaemi formed near Kaohsiung on the southwest coast of Taiwan late on Thursday.  At 8:00 p.m. EDT on Thursday the center of Tropical Storm Gaemi was located at latitude 22.8°N and longitude 120.2°E which put it near Kaohsiung, Taiwan.  Gaemi was moving toward the northeast at 5 m.p.h. (8 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 992 mb.

A distinct low level center of circulation developed in an area of showers and thunderstorms southwest of Taiwan on Thursday and the Japan Meteorological Agency designated the system as Tropical Storm Gaemi.  Thunderstorms developed near the core of the circulation.  Several short bands of showers and thunderstorms were revolving around the core.  Mountains in eastern Taiwan may have deflected the flow in the lower levels and contributed to the organization of a center of circulation.  Storms around the center were generating some upper level divergence which was pumping mass away to the east of the tropical storm.

Tropical Storm Gaemi is likely to weaken during the next few hours while the center of circulation moves across southern Taiwan.  Mountains in eastern Taiwan could disrupt the lower portions of the circulation when it moves over them.  If the circulation still exists when it moves east of Taiwan in a few hours, then Tropical Storm Gaemi will move into a more favorable environment for intensification.  Gaemi will move over water where the Sea Surface Temperature is near 29°C.  An upper level trough over eastern Asia is producing southwesterly winds which are blowing toward the top of the circulation.  Those winds will cause some vertical wind shear, but the shear will probably not be strong enough to tear the circulation apart.  Gaemi could remain a tropical storm for another 24 to 36 hours.  When Tropical Storm Gaemi moves farther north in a day or two, it will move over colder water and into an area with stronger vertical wind shear.  Gaemi will likely make a transition to an extratropical cyclone at that time.

The upper level trough is forecast to steer Tropical Storm Gaemi toward the northeast.  Gaemi will move across southern Taiwan during the next few hours.  It will cause gusty winds, but the greater risks will be heavy rain and flash floods.  On its anticipated track Tropical Storm Gaemi will move near the southern Ryukyu Islands of Japan.  It could pass near Ishigaki Jima and Miyako Jima in the next 12 to 18 hours.  Gaemi could be near Okinawa later on Friday.