Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Tropical Storm Ampil Forms South of Japan

Tropical Storm Ampil formed over the Western North Pacific Ocean south of Japan on Monday afternoon.  At 5:00 p.m. EDT on Monday the center of Tropical Storm Ampil was located at latitude 24.7°N and longitude 138.1°E which put the center about 760 miles (1225 km) south of Tokyo, Japan.  Ampil was moving toward the northeast at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 992 mb.

A low pressure system over the Western North Pacific Ocean south of Japan strengthened on Monday afternoon and the Japan Meteorological Agency designated the system as Tropical Storm Ampil.  More thunderstorms developed near the center of Ampil’s circulation.  The inner end of a rainband wrapped part of the way around the center of Tropical Storm Ampil.  Other bands of showers and thunderstorms were revolving around the center of circulation.  Storms near the center generated upper level divergence that pumped mass away from the tropical storm.  The removal of mass caused the surface pressure to decrease.

Tropical Storm Ampil will move through an environment favorable for intensification during the next 24 hours.  Ampil will move over water where the Sea Surface Temperatures are near 30°C.  It will move under a small upper level ridge that is in between and upper level low southwest of Japan and an upper level low east of Japan.  The upper level winds are weak in the small ridge and there will be little vertical wind shear.  Tropical Storm Ampil will intensify during the next 24 hours.  Ampil could intensify rapidly at times.  Tropical Storm Ampil is likely to strengthen to a typhoon within 36 hours.

Tropical Storm Ampil will move around the western side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Ampil toward the north during the next 24 hours.  On its anticipated track, Tropical Storm Ampil will move closer to central Honshu.

Elsewhere over the Western North Pacific Ocean, former Tropical Storm Maria weakened to a tropical depression over the Sea of Japan, and a subtropical cyclone east of Japan made a transition to Tropical Storm Son-tinh.

At 5:00 p.m. EDT on Monday the center of Tropical Depression Maria was located at latitude 41.0°N and longitude 138.7°E which put the center about 100 miles (160 km) west-southwest of Aomori, Japan.  Maria was moving toward the north-northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 999 mb.

At 5:00 p.m. EDT on Monday the center of Tropical Storm Son-tinh was located at latitude 3.7°N and longitude 149.0°E which put the center about 560 miles (905 km) east of Tokyo, Japan. Son-tinh was moving toward the northwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 993 mb.

 

Tropical Storm Maria Brings Wind and Rain to Northern Honshu

Tropical Storm Maria brought wind and rain to northern Honshu on Sunday night.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Maria was located at latitude 39.4°N and longitude 141.2°E which put the center about 10 miles (15 km) east of Hanamaki, Japan.  Maria was moving toward the northwest at 14 m.p.h. (22 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 984 mb.

Tropical Storm Maria brought wind and rain to northern Honshu on Sunday night.  The center of Maria’s circulation made landfall near Kesennuma in Miyagi prefecture.  Tropical Storm Maria exhibited more organization as it neared landfall in northern Honshu.  A small circular eye appeared on both satellite images and radar images from the Japan Meteorological Agency.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of thunderstorms were revolving around the center of Maria’s circulation.

The circulation around Tropical Storm Maria was fairly symmetrical at the time of landfall.  Winds to tropical storm force extended out 120 miles (195 km) from the center of Maria’s circulation.

Tropical Storm Maria will move around the western end of a high pressure system over the North Pacific Ocean.  The high pressure system will steer Maria toward the northwest during the next 24 hours.  On its anticipated track, Tropical Storm Maria will move over Iwate and Akita prefectures.  Maria could move over the Sea of Japan in 12 hours.

Tropical Storm Maria will weaken steadily as it moves across northern Honshu.  Maria will continue to bring gusty winds and locally heavy rain to parts of Iwate and Akita prefectures during the next 12 to 24 hours.  Heavy rain could cause flash floods in some locations.

Tropical Storm Maria Moves Toward Northern Honshu

Tropical Storm Maria moved toward northern Honshu on Saturday night.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Maria was located at latitude 37.7°N and longitude 144.4°E which put the center about 235 miles (355 km) east-southeast of Sendai, Japan.  Maria was moving toward the north-northwest at 9 m.p.h. (15 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 981 mb.

Tropical Storm Maria exhibited more organization on Saturday night as it moved closer to northern Honshu.  The inner end of a rainband wrapped around the center of Maria’s circulation.  A small circular eye appeared intermittently on satellite images.  Bands of showers and thunderstorms revolved around the center of Tropical Storm Maria.  Storms near the center generated upper level divergence that pumped mass away from the tropical storm.

The distribution of wind speeds around Tropical Storm Maria was more symmetrical on Saturday.  Winds to tropical storm force extended out 155 miles (250 km) from the center to Maria’s circulation.

Tropical Storm Maria will move through an environment somewhat favorable for intensification during the next 18 hours.  Maria will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the eastern part of an upper level ridge over Japan.  The upper level winds are weak in that part of the ridge and there will be little vertical wind shear.  Tropical Storm Maria could intensify during the next 18 hours, but it is more likely that Maria will maintain its current intensity.

Tropical Storm Maria will move around the southwestern part of a high pressure system over the North Pacific Ocean.  The high pressure system will steer Maria toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Maria will approach the coast of northern Honshu in less than 24 hours.

Tropical Storm Maria will bring strong winds and locally heavy rain to northern Honshu.  Heavy rain could cause flash floods in some locations.

Tropical Storm Maria Spins East of Japan

Tropical Storm Maria was spinning east of Japan on Friday.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Maria was located at latitude 34.5°N and longitude 145.8°E which put the center about 400 miles (645 km) east of Tokyo, Japan.  Maria was moving toward the north at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 987 mb.

Former Typhoon Maria weakened back to a tropical storm over the Western North Pacific Ocean east of Japan on Friday.  The wind in the western part of Maria appeared to pull drier air around the southern side of Maria’s circulation.  The drier caused many of the thunderstorms in southern side of Tropical Storm Maria to dissipate.  Bands in the southern half of Maria’s circulation consisted primarily of showers and lower clouds.  Thunderstorms were still occurring in bands in the northern half of Tropical Storm Maria.

The distribution of wind speeds in Tropical Storm Maria was asymmetrical.  Winds to tropical storm force extended out 140 miles (225 km) in the eastern side of Maria’s circulation.  Winds to tropical storm force only extended out 85 miles (135 km) in the western side of Tropical Storm Maria.

Tropical Storm Maria will move through an environment somewhat favorable for intensification during the next 24 hours.  Maria will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the eastern part of an upper level trough over Japan.  The upper level trough will produce southwesterly winds that will blow toward the top of Maria’s circulation.  Those winds will cause some vertical wind shear.  The vertical wind shear and the drier air in Tropical Storm Maria will inhibit intensification.  Tropical Storm Maria could intensify during the next 24 hours even with the effects of the wind shear and drier air.

Tropical Storm Maria will move around the western side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Maria toward the north during the next 24 hours.  On its anticipated track, Tropical Storm Maria will move closer to eastern Japan.  Maria could start to move toward Honshu during the weekend.

 

Maria Intensifies to a Typhoon Southeast of Japan

Former Tropical Storm Maria intensified to a typhoon southeast of Japan on Thursday.  At 5:00 p.m. EDT on Thursday the center of Typhoon Maria was located at latitude 30.5°N and longitude 145.8°E which put the center about 505 miles (815 km) southeast of Tokyo, Japan.  Maria was moving toward the north at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 969 mb.

Former Tropical Storm Maria intensified to a typhoon over the Western North Pacific Ocean southeast of Japan on Thursday.  A small circular eye formed at the center of Maria’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms revolved around the core of Typhoon Maria.  Storm near the core generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The circulation around Typhoon Maria was very small.  Winds to typhoon force extended out 25 miles (40 km) in the eastern side of Maria’s circulation.  Winds to tropical storm force extended out 70 miles (110 km) from the center of Typhoon Maria.

Typhoon Maria will move through an environment favorable for intensification during the next 24 hours.  Maria will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the southeastern part of an upper level trough over Japan.  The upper level trough will produce southwesterly winds that will blow toward the top of Maria’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Tropical Storm Maria is likely to continue to intensify during the next 24 hours.

Typhoon Maria will move around the western side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Maria toward the north during the next 24 hours.  On its anticipated track, Typhoon Maria will move closer to eastern Japan.

 

Tropical Storm Maria Forms South of Japan

Tropical Storm Maria formed south of Japan on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Tropical Storm Maria was located at latitude 26.1°N and longitude 143.3°E which put the center about 695 miles (1120 km) south-southeast of Tokyo, Japan.  Maria was moving toward the east-northeast at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 994 mb.

A low pressure system over the Western North Pacific Ocean south-southeast of Tokyo strengthened on Wednesday and the Japan Meteorological Agency designated the system as Tropical Storm Maria.  More thunderstorms formed near the center of Maria’s circulation.  More thunderstorms also developed in bands in the southern and eastern parts of Tropical Storm Maria.  Bands in the northern and western parts of Maria consisted primarily of showers and lower clouds.  Storms near the center of Maria’s circulation began to generate upper level divergence that pumped mass away from the tropical storm.

Winds to tropical storm force extended out 120 miles (195 km) from the center of Tropical Storm Maria.

Tropical Storm Maria will move through an environment favorable for intensification during the next 24 hours.  Maria will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the southeastern part of an upper level trough over Japan.  The upper level trough will produce southwesterly winds that will blow toward the top of Maria’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Tropical Storm Maria will intensify during the next 24 hours.  Maria could strengthen to a typhoon by Friday.

Tropical Storm Maria will move around the western side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Maria toward the north during the next 24 hours.  On its anticipated track, Tropical Storm Maria will move closer to eastern Japan.

Tropical Storm Gaemi Brings Wind and Rain to Eastern China

Tropical Storm Gaemi brought wind and rain to parts of eastern China on Thursday.  At 11:00 a.m. EDT on Thursday the center of Tropical Storm Gaemi was located at latitude 25.9°N and longitude 119.1°E which put the center about 25 miles (40 km) west of Fuzhou, China.  Gaemi was moving toward the northwest at 6 m.p.h. (10 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 973 mb.

Former Typhoon Gaemi weakened to a tropical storm on Thursday before it made landfall on the east coast of China.  The center of Gaemi’s circulation made landfall southeast of Fuzhou near Fuqing.  Showers and thunderstorms in bands in the eastern and southern parts of Tropical Storm Gaemi were dropping heavy rain.  The bands in the northern and western parts of Gaemi’s circulation consisted primarily of showers and lower clouds.

The circulation around Tropical Storm Gaemi was large.  Winds to tropical storm force extended out 220 miles (350 km) from the center of Gaemi’s circulation.  The strongest winds were occurring in bands that were still over water in the eastern and southern parts of Tropical Storm Gaemi.

Tropical Storm Gaemi will move toward the northwest during the next 24 hours.  Gaemi will weaken as it moves farther inland over eastern China.  Tropical Storm Gaemi will drop heavy rain over parts of Fujian, Jiangxi and Zhejiang.  Heavy rain is likely to cause floods in some locations.

Typhoon Gaemi Batters Taiwan

Typhoon Gaemi battered Taiwan on Wednesday.  At 11:00 a.m. EDT on Wednesday the center of Typhoon Gaemi was located at latitude 24.0°N and longitude 121.4°E which put the center about 100 miles (160 km) south of Taipei, Taiwan.  Gaemi was moving toward the northwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 928 mb.

The inner end of a rainband wrapped around the existing eye and eyewall of Typhoon Gaemi as it approached the east coast of Taiwan.  Concentric eyewalls formed in the core of Gaemi’s circulation.  The diameter of the inner eye was 7 miles (11 km).  The inner eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Typhoon Gaemi.

The inner eye of Typhoon Gaemi began to make a counterclockwise loop inside the outer eyewall as Gaemi neared the east coast of Taiwan.  Mountains in Taiwan also deflected winds blowing around the western side of Typhoon Gaemi.  The deflection of the winds by the mountains also contributed to the counterclockwise loop of the inner eye.  The inner eye made landfall near Yilan City after it completed the counterclockwise loop.

The circulation around Typhoon Gaemi was large.  Winds to typhoon force extended out 105 miles (165 km) from the center of Gaemi’s circulation.  Winds to tropical storm force extended out 315 miles (510 km) from the center of Typhoon Gaemi.

Typhoon Gaemi was the equivalent of a major hurricane at the time of landfall.  The Hurricane Intensity Index (HII) was 23.6.  The Hurricane Size Index (HSI) was 35.2 and the Hurricane Wind Intensity Size Index (HWISI) was 58.8.  Typhoon Gaemi was as strong as Hurricane Katrina was when Katrina made landfall on the coast of the Gulf of Mexico in 2005.  Gaemi was larger than Katrina was when Katrina made landfall.

Typhoon Gamei was producing strong winds in Taiwan.  Gaemi was also dropping very heavy rain over parts of Taiwan.  Prolonged heavy rain is likely to cause flash floods in many locations.  Typhoon Gaemi was also causing a storm surge of up to 13 feet (4 meters) along the coast of northern Taiwan where the wind was blowing water toward the coast.

Typhoon Gaemi will move toward the northwest during the next 24 hours.  Gaemi will continue to produce strong winds and heavy rain in Taiwan for another 12 to 24 hours.  The center of Typhoon Gaemi will move over the Taiwan Strait in a few hours.  Gaemi will make another landfall on the east coast of China in about 18 hours.

Typhoon Gaemi Strengthens to Equivalent of a Major Hurricane

Typhoon Gaemi strengthened to the equivalent of a major hurricane east of Taiwan on Tuesday.  At 5:00 p.m. EDT on Tuesday the center of Typhoon Gaemi was located at latitude 23.1°N and longitude 123.2°E which put the center about 200 miles (325 km) southeast of Taipei, Taiwan.  Gaemi was moving toward the northwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 140 m.p.h. (225 km/h) and there were wind gusts to 165 m.p.h. (265 km/h).  The minimum surface pressure was 948 mb.

Typhoon Gaemi rapidly intensified to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale east of Taiwan on Tuesday.  A small circular eye with a diameter of 6 miles (10 km) formed at the center of Gaemi’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storm.  Bands of showers and thunderstorms were revolving around the core of Typhoon Gaemi.  Storms near the core generated strong upper level divergence that pumped mass away from the typhoon.  The removal of large amounts of mass caused the surface pressure to decrease rapidly.

The circulation around Typhoon Gaemi was large.  Winds to typhoon force extended out 100 miles (160 km) from the center of Gaemi’s circulation.  Winds to tropical storm force extended out 345 miles (555 km) from the center of Typhoon Gaemi.

The Hurricane Intensity Index (HII) for Typhoon Gaemi was 28.3.  The Hurricane Size Index (HSI) was 31.0 and the Hurricane Wind Intensity Size Index (HWISI) was 59.3.  Typhoon Gaemi was similar in size to Hurricane Wilma when Wilma hit South Florida in 2005.  Gaemi is stronger than Wilma was when it hit South Florida.

Typhoon Gaemi will move through an environment favorable for intensification during the next 12 hours.  Gaemi will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the axis of an upper level ridge over the Western North Pacific Ocean.  The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear.  Typhoon Gaemi could continue to intensify during the next 12 hours.

Typhoon Gaemi will move around the western part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Typhoon Gaemi toward the northwest during the next 24 hours.  On its anticipated track, Typhoon Gaemi will approach the coast of northeastern Taiwan in 12 hours.

Typhoon Gaemi will bring very strong winds and torrential rain to Taiwan.  Gaemi will be capable of causing extensive severe damage.  Heavy rain is likely to cause widespread flash floods.  Typhoon Gaemi will also be capable of causing a storm surge of up to 13 feet (4 meters) along the east coast of Taiwan.

Typhoon Gaemi will also bring strong winds and heavy rain to the southern Ryukyu Islands.  The strongest part Gaemi’s circulation will pass southwest of the Ryukyu Islands, but the typhoon is likely to some wind damage.  Heavy rain could cause flash floods in some locations.

Typhoon Gaemi will move toward the east coast of China after is crosses northern Taiwan.  Gaemi could approach the coast of China in less than 36 hours.  Typhoon Gaemi will weaken when it moves over Taiwan, but Gaemi could still be a typhoon when it reaches China.

Elsewhere, former Tropical Storm Prapiroon weakened to a tropical depression over northern Vietnam.  At 11:00 a.m. EDT on Tuesday the center of Tropical Depression Prapiroon was located at latitude 22.0°N and longitude 107.0°E which put the center about 25 miles (40 km) northeast of Lang Son, Vietnam.  Prapiroon was moving toward the north-northwest at 5 m.p.h. (8 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 994 mb.

Gaemi Intensifies to Typhoon Southeast of Taiwan

Former Tropical Storm Gaemi intensified to a typhoon over the Western North Pacific Ocean southeast of Taiwan on Monday.  At 5:00 p.m. EDT on Monday the center of Typhoo Gaemi was located at latitude 18.8°N and longitude 124.7°E which put the center about 405 miles (655 km) southeast of Hualien, Taiwan.  Gaemi was moving toward the west at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 977 mb.

Former Tropical Storm Gaemi exhibited more organization on Monday as it strengthened to a typhoon.  The inner end of a rainband wrapped around the center of Gaemi’s circulation.  An eye appeared to be forming at the center of Typhoon Gaemi.  A ring of showers and thunderstorms surrounded the developing eye.  The ring was thickest in the southeastern side of the eye and thinnest in the northwestern side.  Other bands of thunderstorms were occurring southern and eastern parts of Gaemi’s circulation.  Bands in the northern and western parts of Typhoon Gaemi consisted primarily of showers and lower clouds.

Winds to typhoon force extended out 45 miles (75 km) from the center of Typhoon Gaemi.  Winds to tropical storm force extended out 155 miles (250 km) from the center of Gaemi’s circulation.

Typhoon Gaemi will move through an environment favorable for intensification during the next 24 hours.  Gaemi will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the axis of an upper level ridge over the Western North Pacific Ocean.  The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear.  Typhoon Gaemi will continue to intensify during the next 24 hours.

Typhoon Gaemi will move around the western part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Typhoon Gaemi toward the northwest during the next 24 hours.  On its anticipated track, Typhoon Gaemi will approach the east coast of Taiwan in 36 hours.

Typhoon Gaemi will bring strong winds and heavy rain to Taiwan during the middle of the week.  Heavy rain is likely to cause flash floods.

Elsewhere, Tropical Storm Prapiroon brought wind and rain to northern Vietnam.  At 5:00 p.m. EDT on Monday the center of Tropical Storm Prapiroon was located at latitude 21.2°N and longitude 107.9°E which put the center about 40 miles (65 km) east of Cam Pha, Vietnam.  Prapiroon was moving toward the northwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 985 mb.