Tag Archives: Ryukyu Islands

Tropical Storm Choi-wan Moves Toward Taiwan

Tropical Storm Choi-wan moved toward Taiwan on Thursday. At 5:00 p.m. EDT on Thursday the center of Tropical Storm Choi-wan was located at latitude 20.0°N and longitude 118.9°E which put it about 185 miles (300 km) south-southwest of Taiwan. Choi-wan was moving toward the north-northeast 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 1002 mb.

Tropical Storm Choi-wan turned toward the north-northeast on Thursday which put it on a track towards southern Taiwan. The distribution of thunderstorms around Choi-wan was asymmetrical. The strongest thunderstorms were occurring in bands in the southwestern quadrant of Tropical Storm Choi-wan. Bands in the other quadrants of Choi-wan consisted primarily of showers and lower clouds. The distribution of wind speeds around Tropical Storm Choi-wan was also asymmetrical. Winds to tropical storm force extended out 125 miles (200 km) on the western side of Choi-wan. Winds to tropical storm force only extended out 65 miles (105 km) on the eastern side of the circulation.

Tropical Storm Choi-wan will move through an area that is mostly unfavorable for intensification during the next 36 hours. The center of Choi-wan will move over an area where the Sea Surface Temperatures are near 30°C. However, an upper level ridge centered over southern China will produce moderate northeasterly winds that will blow toward the top of the tropical storm. Those winds will cause moderate vertical wind shear and they are already responsible for the asymmetrical distribution of thunderstorms. The moderate vertical wind shear will likely prevent intensification of Tropical Storm Choi-wan.

Tropical Storm Choi-wan will move around the northwestern part of a subtropical high pressure system over the Western North Pacific Ocean. The high pressure system will steer Choi-wan toward the north-northeast during the next 24 hours. On its anticipated track the center of Tropical Storm Choi-wan will reach southern Taiwan in 12 hours. Choi-wan could drop locally heavy rain over parts of southern Taiwan. Flash floods could occur in some locations. Tropical Storm Choi-wan could approach the southern Ryuku Islands in 24 hours. Choi-wan could bring a period of gusty winds to southern Taiwan and the southern Ryukyu Islands.

Tropical Storm Chan-hom Forms Southwest of Iwo To

Tropical Storm Chan-hom formed southwest of Iwo To on Sunday night.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Chan-hom was located at latitude 22.8°N and longitude 139.0°E which put it about 215 miles (345 km) southwest of Iwo To.  Chan-hom was moving toward the west-northwest at 3 m.p.h. (5 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 998 mb.

More thunderstorms developed near the center of a low pressure system southwest of Iwo To on Sunday night and the Japan Meteorological Agency designated the system as Tropical Storm Chan-hom.  The circulation around Tropical Storm Chan-hom was still organizing.  Thunderstorms were forming near the center of circulation, but the distribution of storms was asymmetrical.  The strongest thunderstorms were developing in bands in the southern half of the tropical storm.  Bands in the northern half of Chan-hom consisted mainly of showers and lower clouds.  Storms near the center of circulation generated upper level divergence which pumped mass away to the west of the tropical storm.  Winds to tropical storm force extended out 100 miles (165 km) in the southeastern quadrant of Tropical Storm Chan-hom.  Winds in the other parts of Chan-hom were blowing at less than tropical storm force.

Tropical Storm Chan-hom will move through an environment favorable for intensification during the next several days.  Chan-hom will move over water where the Sea Surface Temperature is near 28°C.  It will move around the southern side of an upper level ridge.  The ridge will produce easterly winds which will blow toward the top of Tropical Storm Chan-hom.  Those winds will cause some vertical wind shear.  The shear will inhibit intensification but it will not be strong enough to prevent Chan-hom from intensifying.   Tropical Storm Chan-hom could strengthen into a typhoon within 72 hours.

Tropical Storm Chan-hom will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Chan-hom toward the northwest during the next two to three days.  On its anticipated track Tropical Storm Chan-hom could approach the northern Ryukyu Islands and southwestern Japan by the end of the week.

Typhoon Haishen Brings Wind and Rain to Northern Ryukyu Islands

Typhoon Haishen brought wind and rain to the northern Ryukyu Islands on Saturday.  At 11:00 p.m. EDT on Saturday the center of Typhoon Haishen was located at latitude 28.3°N and longitude 130.4°E which put it about 170 miles (280 km) east-northeast of Okinawa.  Haishen was moving toward the north-northwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h).  The minimum surface pressure was 945 mb.

The center of Typhoon Haishen passed west of Minami-Daito Jima on Saturday.  A weather station there measured a wind speed of 72 m.p.h. (116 km/h) and a pressure of 943.6 mb.

The circulation around around Typhoon Haishen developed concentric eyewalls on Saturday.  The smaller original eyewall started to weaken as low level convergence became more concentrated into the much larger outer eyewall.  The strongest winds were originally found in the inner eyewall, but those wind speeds decreased.  The stronger winds were blowing in the larger outer eyewall on Saturday night.

The concentric eyewall structure produced an increase in the size of the circulation around Typhoon Haishen.  Winds to typhoon force extended out 100 miles (160 km) from the center of circulation.  Winds to tropical storm force extended out 325 miles (530 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Haishen was 19.2.  The Hurricane Size Index (HSI) was 37.2 and the Hurricane Wind Intensity Size Index (HWISI) was 56.4.  Typhoon Haishen was capable of causing widespread serious damage.

Typhoon Haishen will move into a less favorable environment during the next 24 hours.  Haishen will move over water where the Sea Surface Temperature is near 28°C.  Drier air over Asia will get pulled into the circulation.  Wind shear will increase when Typhoon Haishen moves farther north because it will get closer to the upper level westerly winds in the middle latitudes.  The effects of the concentric eyewalls, drier air and more wind shear will cause Typhoon Haishen to gradually weaken.

Typhoon Haishen will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Haishen toward the north.  On its anticipated track the center of Typhoon Haishen will pass near the western part of Kyushu in about 12 hours.  Haishen will reach South Korea in about 24 hours.  Typhoon Haishen will bring strong winds and heavy rain to parts of Kyushu and South Korea.  Heavy rain could cause flash floods, especially in places that received heavy rain from Typhoon Maysak a few days ago.

Typhoon Haishen Intensifies to Equivalent of Major Hurricane

Typhoon Haishen intensified to the equivalent of a major hurricane over the Western North Pacific Ocean on Thursday.  At 5:00 p.m. EDT on Thursday the center of Typhoon Haishen was located at latitude 21.4°N and longitude 135.4°E which put it about 405 miles (650 km) southeast of Minamidaitojima, Japan.  Haishen was moving toward the west-northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 145 m.p.h. (235 km/h) and there were wind gusts to 175 m.p.h. (280 km/h).  The minimum surface pressure was 938 mb.

Typhoon Haishen intensified rapidly on Thursday.  A circular eye became more visible on conventional satellite images.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Haishen.  Storms near the core generated strong upper level divergence which pumped mass away from the typhoon.

The circulation around Typhoon Haishen increased in size on Thursday.  Winds to typhoon force extended out 65 miles (105 km) from the center of circulation.  Winds to tropical storm force extended out 215 miles (315 km) from the center.  The Hurricane Intensity Index (HII) was 29.9.  The Hurricane Size Index (HSI) was 23.5 and the Hurricane Wind Intensity Size Index (HWISI) was 53.4.  Typhoon Haishen was capable of causing widespread significant damage.

Typhoon Haishen will move through an environment favorable for intensification during the next 24 hours.  Haishen will move over water where the Sea Surface Temperature is near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Haishen could strengthen to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale.

Typhoon Haishen will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Typhoon Haishen toward the northwest during the next 36 hours.  Haishen will move more toward the north when it reaches the western end of the high pressure system.  On its anticipated track Typhoon Haishen could reach Minamidaitojima in about 36 hours.  Haishen could approach the northern Ryukyu Islands in about 48 hours.  Typhoon Haishen could hit South Korea in a little over three days.

Typhoon Maysak Brings Wind and Rain to South Korea

Typhoon Maysak brought wind and rain to South Korea on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Typhoon Maysak was located at latitude 36.9°N and longitude 128.9°E which put it about 30 miles (50 km) north-northwest of Busan, South Korea.  Maysak was moving toward the north-northeast at 30 m.p.h. (50 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 105 m.p.h. (165 km/h).  The minimum surface pressure was 950 mb.

The center of Typhoon Maysak made landfall on the south coast of South Korea west of Busan on Wednesday.  The large circulation around Maysak brought gusty winds and heavy rain to much of the Korean Peninsula.  Winds to typhoon force extended out 60 miles (95 km) from the center of circulation.  Winds to tropical storm force extended out 200 miles (320 km) from the center.  The heavy rain was falling on ground that was saturated by previous tropical cyclones and other weather systems.  The rain will likely cause widespread flash flooding.

Typhoon Maysak was being steered quickly toward the north by an upper level trough over eastern Asia.  On its anticipated track the center of Maysak will move along the east coast of the Korean Peninsula.  Typhoon Maysak will weaken and it will made a transition to an extratropical cyclone during the next 24 hours.

Elsewhere over the Western North Pacific Ocean, Typhoon Haishen strengthened south of Iwo To.  At 5:00 p.m. EDT on Wednesday the center of Typhoon Haishen was located at latitude 20.3°N and longitude 138.8°E which put it about 350 miles (560 km) south-southwest of Iwo To.  Haishen was moving toward the west-northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 105 m.p.h. (165 km/h).  The minimum surface pressure was 979 mb.

Typhoon Haishen will move through an environment favorable for intensification during the next 36 to 48 hours.  Haishen will move over water where the Sea Surface Temperature is near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Haishen will continue to intensify and it is likely to strengthen into the equivalent of a major hurricane.

Typhoon Haishen will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Haishen toward the northwest during the next several days.  On its anticipated track Typhoon Haishen could approach the northern Ryukyu Islands in about 72 hours.  Haishen could eventually bring wind and rain to the same areas in Kyushu and South Korea affected by Typhoon Maysak.

Typhoon Maysak Brings Wind and Rain to the Ryukyu Islands

Typhoon Maysak brought winds and rain to the Ryukyu Islands on Monday.  At 11:00 p.m. EDT on Monday the center of Typhoon Maysak was located at latitude 27.5°N and longitude 126.5°E which put it about 110 miles (175 km) west-northwest of Kadena AFB, Okinawa.  Maysak was moving toward the north-northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 160 m.p.h. (260 km/h).  The minimum surface pressure was 932 mb.

The eye and eyewall of Typhoon Maysak passed west of Okinawa on Monday.  Rainbands on the eastern side of Maysak passed over Okinawa and some of the other southern Ryukyu Islands.  A weather station at Naha reported a sustained wind speed of 58 m.p.h. (93 km/h).  A station at Kitahari (Kumejima Airport), which was closer to the center of Typhoon Maysak reported a sustained wind speed of 89 m.p.h. (144 km/h).

Satellite and radar images suggest that concentric eyewalls may have formed at the core of Typhoon Maysak.  The inner eye had a diameter of 8 miles (13 km).  A much larger outer eye with a diameter of approximately 100 miles (160 km) surrounded the inner eye.  Bands of showers and thunderstorms were revolving around the large core of Maysak.  Storms near the core were generating upper level divergence which was pumping mass away from the typhoon.

The circulation around Typhoon Maysak was large.  Winds to typhoon force extended out 70 miles (110 km) from the center of circulation.  Winds to tropical storm force extended out 200 miles (320 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Maysak was 25.1.  The Hurricane Size Index (HSI) was 25.5 and the Hurricane Wind Intensity Size Index (HWISI).  Maysak was capable of causing widespread major damage.

Typhoon Maysak will move through an environment capable of supporting a strong typhoon during the next 24 hours, but it has likely reached its peak intensity.  The formation of concentric eyewalls normally results in a weaker, but larger tropical cyclone.  The wind speed will decrease when the inner eyewall dissipates.  When that occurs, the maximum wind speeds will occur in the larger outer eyewall.  Since Maysak will move over water where the Sea Surface Temperature is near 29°C, it will remain a typhoon for another 24 to 36 hours.

Typhoon Maysak will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Maysak toward the north during the next 36 hours.  On its anticipated track the center of Typhoon Maysak will pass west of Kyushu.  Typhoon Maysak could reach South Korea in 36 hours

Elsewhere over the Western North Pacific Ocean, Tropical Depression 11W was passing southeast of Iwo To.  At 11:00 p.m. EDT on Monday the center of Tropical Depression 11W was located at latitude 21.7°N and longitude 144.2°E which put it about 290 miles (470 km) southeast of Iwo To.  The depression was moving toward the west-southwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1006 mb.

Maysak Intensifies into a Typhoon East of Luzon

Former Tropical Storm Maysak intensified into a typhoon on Saturday.  At 5:00 p.m. EDT on Saturday the center of Typhoon Maysak was located at latitude 17.2°N and longitude 128.7°E which put it about 335 miles (540 km) east of Luzon.  Maysak was moving toward the west-northwest at 4 m.p.h. (6 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 976 mb.

The circulation around Typhoon Maysak exhibited greater organization on Saturday.  The inner end of a rainband wrapped partially around the center of circulation and an eye could be forming at the center of Maysak.  Bands of showers and thunderstorms were revolving around the core of Maysak.  Storms near the core were generating upper level divergence which was pumping mass away from the core.  Winds to typhoon force extended out 30 miles (50 km) from the center of circulation.  Winds to tropical storm force extended out 185 miles (295 km) from the center.

Typhoon Maysak will move through an environment favorable for intensification during the next 36 to 48 hours.  Maysak will move over water where the Sea Surface Temperature is near 30°C.  It will move through a region where the upper level winds will be weak and there will be little vertical wind shear.  Typhoon Maysak will continue to strengthen and it could intensify rapidly when an eye and eyewall are fully formed.  Maysak could strengthen into the equivalent of a major hurricane within 24 to 36 hours.

Typhoon Maysak will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Maysak toward the north during the next several days.  On its anticipated track Typhoon Maysak will move toward the southern Ryukyu Islands.  Maysak could pass near Okinawa in about 48 hours.  Typhoon Maysak is likely to be the equivalent of a major hurricane when it passes near Okinawa.

Tropical Storm Maysak Forms East of Luzon

Tropical Storm Maysak formed east of Luzon on Friday.  At 11:00 a.m. EDT on Friday the center of Tropical Storm Maysak was located at latitude 16.4°N and longitude 129.4°E which put it about 435 miles (700 km) east of Luzon.  Maysak was moving toward the west-southwest at 7 m.p.h. (11 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 997 mb.

More thunderstorms developed near the center of a low pressure system east of Luzon on Friday and the Japan Meteorological Agency designated the system as Tropical Storm Maysak.  Thunderstorms were also forming in bands revolving around the center of Maysak.  Storm nears the center were generating upper level divergence which was pumping mass away from the tropical storm.  Winds to tropical storm force extended out 140 miles (225 km) from the center of circulation.

Tropical Storm Maysak will move through an environment favorable for intensification during the next 48 hours.  Maysak will move over water where the Sea Surface Temperature is near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Maysak will intensify quickly and it could strengthen into a typhoon within 24 hours.  Once an inner core with an eye and an eyewall is established Maysak could rapidly intensify into the equivalent of a major hurricane.

Tropical Storm Maysak will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Maysak toward the north-northwest.  On its anticipated track Tropical Storm Maysak could approach the Ryukyu Islands within 72 hours.  Maysak could be the equivalent of a major hurricane by that time.

Typhoon Bavi Passes West of Okinawa

Typhoon Bavi passed west of Okinawa on Sunday.  At 5:00 p.m. EDT on Sunday the center of Typhoon Bavi was located at latitude 27.2°N and longitude 125.6°E which put it about 595 miles (965 km) south-southwest of Chinhae, South Korea.  Bavi was moving toward the east-northeast at 4 m.p.h. (6 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 979 mb.

A circular eye developed at the center of Typhoon Bavi.  The eye was surrounded by a ring of strong thunderstorms.  Bands of showers and thunderstorms were revolving around the core of Bavi.  Storms near the core were generating upper level divergence which was pumping mass away from the typhoon.  Winds to typhoon force extended out 45 miles from the center of circulation.  Winds to tropical storm force extended out 140 miles (225 km) from the center.

Typhoon Bavi will move through an environment favorable for intensification during the next 24 to 36 hours.  Bavi will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Bavi will intensify during the next 36 hours and it could strengthen to the equivalent of a major hurricane.

Typhoon Bavi will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Bavi toward the north during the next several days.  On its anticipated track Typhoon Bavi will pass west of the northern Ryukyu Islands.  Bavi could be southeast of South Korea in about 72 hours.

Tropical Storm Bavi Forms East of Taiwan

Tropical Storm Bavi formed east of Taiwan on Friday night.  At 11:00 p.m. on Friday the center of Tropical Storm Bavi was located at latitude 23.9°N and longitude 122.8°E which put it about 85 miles (135 km) southeast of Taipei, Taiwan.  Bavi was moving toward the north-northeast at 6 m.p.h. (10 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 a low pressure system east of Taiwan strengthened on Friday night and the Japan Meteorological Agency designated the system as Tropical Storm Bavi.  The circulation around Bavi was asymmetrical.  Many of the thunderstorms were occurring in bands in the eastern half of the tropical storm.  Bands in the western half of the circulation consisted primarily of showers and lower clouds.  Storms near the center of circulation were generating upper level divergence which was pumping mass away to the east of the tropical storm.  Winds to tropical storm force extended out 80 miles (130 km) to the east of the center of circulation.  The winds on the western side of Tropical Storm Bavi were blowing at less than tropical storm force.

Tropical Storm Bavi will move through an environment favorable for intensification during the next several days.  Bavi will move over water where the Sea Surface Temperature is near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Bavi will intensify and it could strengthen into a typhoon by the end of the weekend.

Tropical Storm Bavi will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Bavi toward the north-northeast during the next few days.  On its anticipated track the center of Tropical Storm Bavi will pass west of the Ryukyu Islands including Okinawa.  Bavi could approach South Korea in about four days.  The eastern side of Bavi will bring gusty winds and locally heavy rain to the Ryukyu Islands.