Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Tropical Depression Forms East of Luzon

A tropical depression formed over the Western North Pacific Ocean east of Luzon on Sunday morning. At 5:00 a.m. EDT on Sunday the center of the tropical depression was located at latitude 17.4°N and longitude 127.3°E which put it about 350 miles (565 km) east of Luzon. The tropical depression was moving toward the west 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 1000 mb.

A distinct low level center of circulation formed in an area of lower pressure east of Luzon on Sunday morning and the Japan Meteorological Agency classified the system as a tropical depression. The distribution of thunderstorms in the tropical depression was asymmetrical. Most of the thunderstorms were in bands in the western half of the tropical depression. The bands in the eastern half of the circulation consisted primarily of showers and lower clouds. A strong upper level ridge over China was producing strong northeasterly winds that were blowing toward the top of the tropical depression. Those winds were causing moderate vertical wind shear and the wind shear was causing the asymmetrical distribution of thunderstorms.

The tropical depression will move through an environment favorable for intensification during the next 24 hours. The tropical depression will move over water where the Sea Surface Temperatures are 30˚C. The upper level ridge over China will continue to produce northeasterly winds that will blow toward the top of the tropical depression. However, the upper level winds are forecast to weaken. The vertical wind shear could decrease during the next 24 hours. The tropical depression is forecast to strengthen to a tropical storm.

The tropical depression will move around the southwestern part of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer the tropical depression toward the west during the next 24 hours. On its anticipated track the tropical depression could approach northeastern Luzon in 24 hours. It is likely to be a tropical storm when it approaches Luzon. The weather system will bring gusty winds and locally heavy rain to northern Luzon. Heavy rain could cause flash floods in some locations.

Tropical Storm Meari Brings Rain to Tokyo

Tropical Storm Meari brought rain to Tokyo on Saturday morning. At 5:00 a.m. EDT on Saturday the center of Tropical Storm Meari was located at latitude 35.4°N and longitude 139.2°E which put it about 90 miles (145 km) southwest of Tokyo, Japan. Meari was moving toward the northeast at 15 m.p.h. (24 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.

Tropical Storm Meari brought rain to the region around Tokyo on Saturday morning. The heaviest rain was falling in bands in the eastern and southern parts of Meari’s circulation. Much of the heavier rain was falling south and east of Tokyo. Bands in the northern and western parts of the circulation consisted primarily of showers and lower clouds. The strongest winds were occurring along the coast of Honshu southeast of Tokyo.

Tropical Storm Meari was moving under the southern part of an upper level trough centered northwest of Japan. The upper level trough was producing southwesterly winds that were steering Meari toward the northeast. On its anticipated track Tropical Storm Meari will move east of Japan during the next 24 hours. The rain over Honshu will diminish when Meari moves away from the coast.

Tropical Storm Meari will move through an environment unfavorable for a tropical cyclone during the next several days. Meari will move over water where the Sea Surface Temperatures are colder than 26˚C. The upper level trough will continue to produce southwesterly winds that will blow toward the top of Meari’s circulation. Those winds will cause moderate vertical wind shear. The combination of colder Sea Surface Temperatures and moderate vertical wind shear could cause Tropical Storm Meari to make a transition to an extratropical cyclone during the next 48 hours. Meari could strengthen a little during the transition to an extatropical cyclone.

Tropical Storm Meari Forms South of Japan

Tropical Storm Meari formed over the Western North Pacific Ocean south of Japan on Thursday afternoon. At 5:00 p.m. EDT on Thursday the center of Tropical Storm Meari was located at latitude 29.2°N and longitude 136.0°E which put it about 500 miles (805 km) south-southwest of Tokyo, Japan. Meari was moving toward the north 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 1003 mb.

The circulation around an area of low pressure over the Western North Pacific Ocean south of Japan strengthened on Thursday afternoon and the Japan Meteorological Agency designated the system as Tropical Storm Meari. The distribution of thunderstorms around Tropical Storm Meari was asymmetrical. Thunderstorms were occurring in bands in the southern half of Meari’s circulation. Bands in the northern half of the circulation consisted primarily of showers and lower clouds. Tropical Storm Meari was under the southern part of a narrow upper level ridge south of Japan that extended from east to west. The upper level ridge was producing northerly winds that were blowing toward the top of Meari. The winds were causing vertical wind shear and they were the reason for the asymmetrical distribution of thunderstorms. Winds to tropical storm force extended out 90 miles (145 km) in the southeastern quadrant of Tropical Storm Meari. The wind in the other parts of Meari’s circulation was blowing at less than tropical storm force.

Tropical Storm Meari will move through an environment somewhat favorable for intensification during the next 36 hours. Meari will move over water where the Sea Surface Temperatures are near 28˚C. The narrow upper level ridge south of Japan will continue to cause moderate vertical wind shear during the next 12 hours. The wind shear will inhibit intensification during the next few hours. Tropical Storm Meari will move under the axis of the upper level ridge on Friday. The upper level winds are weak near the axis of the ridge and the vertical wind shear will decrease on Friday. Tropical Storm Meari will be in an environment favorable for intensification while it is under the axis of the ridge.

Tropical Storm Meari will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean. The high pressure system will steer Meari toward the north during the next 18 hours. Meari will move toward the northeast later on Friday after it moves around the western end of the high pressure system. On its anticipated track Tropical Storm Meari will approach the coast of Honshu near Tokyo in 36 hours. Meari could be a strong tropical storm when it nears Tokyo. Tropical Storm Meari will bring gusty winds and locally heavy rain to the region around Tokyo on Saturday.

Tropical Storm Mulan Brings Rain to Southern China

Tropical Storm Mulan brought rain to southern China on Wednesday. At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Mulan was located at latitude 20.9°N and longitude 108.9°E which put it about 40 miles (60 km) southwest of Beihai, China. Mulan was moving toward the west-northwest at 16 m.p.h. (26 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.

Rainbands on the northern side of Tropical Storm Mulan brought rain to parts of southern China on Wednesday. Rain fell over coastal parts of southern China from Hong Kong to the border with Vietnam. Tropical Storm Mulan also dropped locally heavy rain on Hainan Island. Rainbands in the northwestern part of Mulan’s circulation brought rain to northeastern Vietnam.

Tropical Storm Mulan will move across the Gulf of Tonkin during the next 12 hours toward northern Vietnam. Mulan will move south of a high pressure system over the Western North Pacific Ocean and eastern China. The high pressure system will steer Mulan toward the west-northwest during the next day or so. On its anticipated track the center of Tropical Storm Mulan will make landfall on the coast of northeastern Vietnam in about 12 hours.

Tropical Storm Mulan will move through an environment marginally favorable for intensification during the next few hours. Mulan will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the southern part of an upper level ridge centered over eastern Asia. The upper level ridge will produce easterly winds that will blow toward the top of Mulan’s circulation. Those winds will cause some vertical wind shear and the shear will inhibit intensification. Tropical Storm Mulan is likely to maintain its current intensity during the next 12 hours, but it could strengthen a little prior to landfall in northeastern Vietnam.

Tropical Storm Mulan Forms South of Hong Kong

Tropical Storm Mulan formed over the South China Sea south of Hing Kong on Tuesday morning. At 5:00 a.m. EDT on Tuesday the center of Tropical Storm Mulan was located at latitude 17.9°N and longitude 112.8°E which put it about 280 miles (450 km) south of Hong Kong. Mulan was moving toward the north at 13 m.p.h. (20 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 996 mb.

A small low pressure system on the eastern side of a much larger low pressure system over the South China Sea south of Hong Kong strengthened on Tuesday morning and the Japan Meteorological Agency designated the system as Tropical Storm Mulan. The circulation around Tropical Storm Mulan was embedded in a larger low pressure system over the South China Sea which had a diameter of 700 miles (1130 km). The distribution of thunderstorms around Mulan was asymmetrical. Thunderstorms were occurring mainly in bands in the eastern half of Mulan’s circulation. Bands in the western half of the circulation consisted primarily of showers and lower clouds. Storms near the center of Mulan’s circulation generated upper level divergence that pumped mass away from the tropical storm.

Tropical Storm Mulan will move through an environment marginally favorable for intensification during the next 24 hours. Mulan will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the eastern side of a broad upper level low over the South China Sea. The upper low will produce southerly winds that will blow toward the top of Mulan’s circulation. The winds at lower levels in the atmosphere will also blow from the south. So, there will be little vertical wind shear. Even though the water will be warm and there will be little vertical wind shear, the fact that Tropical Storm Mulan is a smaller low pressure system embedded in a much larger low pressure system is likely to inhibit intensification.

Tropical Storm Mulan will move around the northeastern part of the larger low pressure system over the South China Sea during the next 24 hours. The larger low pressure system will steer Mulan toward the northwest. On its anticipated track Tropical Storm Mulan could approach the south coast of China near Zhanjiang within 24 hours. Mulan will bring gusty winds and locally heavy rain to parts of southern China. Heavy rain could cause flash floods in some locations.

Tropical Storm Trases Develops over the East China Sea

Tropical Storm Trases developed over the East China Sea south of Jeju Island, South Korea on Sunday afternoon. At 2:00 p.m. EDT on Sunday the center of Tropical Storm Trases was located at latitude 30.1°N and longitude 126.3°E which put it about 175 miles (280 km) south of Jeju Island, South Korea. Trases was moving toward the north-northwest at 18 m.p.h. (29 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 998 mb.

The circulation at the center of a large low pressure system over the East China Sea strengthened on Sunday afternoon and the Japan Meteorological Agency designated the system as Tropical Storm Trases. The distribution of thunderstorms around Tropical Storm Trases was asymmetrical. Thunderstorms were occurring in bands in the southern part of Trases’ circulation. Bands in the other part of the tropical storm consisted primarily of showers and lower clouds. The air in the northern part of Tropical Storm Trases was cooler and drier. The cooler, drier air was inhibiting the formation of thunderstorms in that part of Trases.

Tropical Storm Trases will move through an environment marginally favorable for intensification during the next 12 hours. Trases will will move over water where the Sea Surface Temperatures are near 26˚C. It will move under the axis of an upper level ridge centered north of Japan. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. However, the cooler drier air on the northern side of Trases will limit the potential for intensification. Tropical Storm Trases could intensify a little during the next 12 hours. Trases will move over cooler water on Monday and it is likely to weaken at that time.

Tropical storm Trases will move around the western side of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Trases toward the north during the next 24 hours. On its anticipated track the center of Tropical Storm Trases could reach Jeju Island within 12 hours. Trases could make landfall on the west coast of South Korea on Monday. Tropical Storm Trases will bring gusty winds and locally heavy rain to parts of South Korea.

Tropical Storm Songda Develops East of Okinawa

Tropical Storm Songda developed east of Okinawa on Thursday afternoon. At 5:00 p.m. EDT on Thursday the center of Tropical Storm Songda was located at latitude 26.4°N and longitude 136.6°E which put it about 600 miles (970 km) east of Okinawa. Songda was moving toward the north-northwest at 29 m.p.h. (45 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1002 mb.

An area of low pressure strengthened east of Okinawa on Thursday afternoon and the Japan Meteorological Agency designated the system as Tropical Storm Songda. Tropical Storm Songda was revolving around the northeastern part of a much larger low pressure system (sometimes called a monsoon gyre) centered northeast of the Philippines. The interaction of Songda’s circulation with the larger low pressure system was producing an asymmetrical distribution of thunderstorms. Thunderstorms were occurring in bands in the northeastern half of Tropical Storm Songda. Bands in the southwestern half of Songda consisted primarily of showers and lower clouds. Storms near the center of Songda generated upper level divergence that pumped mass away to the northeast of the tropical storm.

Tropical Storm Songda will move through an environment marginally favorable for intensification during the next 24 hours. Songda will move over water where the Sea Surface Temperatures are near 30˚C. The circulation around the larger low pressure system will produce upper level winds from the southeast that will blow toward the top of Songda’s circulation. The winds in the lower levels of the atmosphere will also be blowing from the southeast and so there will be less vertical wind shear. The wind shear could still be strong enough to inhibit intensification. Songda could also move into a region where the air is drier. Tropical Storm Songda could strengthen a little during the next 24 hours, but wind shear and drier air are likely to limit intensification.

The large low pressure system northeast of the Philippines will steer Tropical Storm Songda toward the northwest during the next 24 hours. On its anticipated track Tropical Storm Sondga could approach the northern Ryukyu Islands within 24 hours. Songda could bring gusty winds and locally heavy rain to the northern Ryukyu Islands.

Typhoon Chaba Hits Southern China

Typhoon Chaba hit southern China on Saturday morning. At 5:00 a.m. EDT on Saturday the center of Typhoon Chaba was located at latitude 21.5°N and longitude 111.0°E which put it about 25 miles (40 km) east of Wuchuan, China. Chaba was moving toward the north-northwest at 8 m.p.h. (13 km/h). The maximum sustained wind speed was 80 m.p.h. (130 km/h) and and there were wind gusts to 95 m.p.h. (150 km/h). The minimum surface pressure was 978 mb.

The center of Typhoon Chaba made landfall on the south coast of China near Wuchuan and Dianbai in Guangdong on Saturday morning. Typhoon Chaba was strengthening when it made landfall. A small circular eye was as the center of Chaba’s circulation. Winds to typhoon force extended out 60 miles (95 km) from the center of Chaba. Winds to tropical storm force extended out 190 miles (305 km) from the center of circulation.

Typhoon Chaba will move around the western end of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Chaba toward the north-northwest during the next 24 hours. On its anticipated track Typhoon Chaba will move inland over southern China. Chaba will weaken gradually as it moves inland. Typhoon Chaba will bring strong winds and locally heavy rain to southwestern Guangdong. Heavy rain could cause flash floods in some locations. There were reports a ship broke in two in heavy seas in the South China Sea.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Aere brought gusty winds and heavy rain to the center Ryukyu Islands. At 5:00 p.m. EDT on Saturday the center of Tropical Storm Aere was located at latitude 26.3°N and longitude 129.1°E which put it about 115 miles (185 km) east-southeast of Okinawa. Aere was moving toward the north-northwest at 17 m.p.h. (19 km/h). The maximum sustained wind speed was 50 m.p.h. (80 km/h) and and there were wind gusts to 65 m.p.h. (105 km/h). The minimum surface pressure was 994 mb.

Chaba Strengthens to a Typhoon Northeast of Hainan

Former Tropical Storm Chaba strengthened to a typhoon northeast of Hainan Island on Friday afternoon. At 5:00 p.m. EDT on Friday the center of Typhoon Chaba was located at latitude 20.4°N and longitude 111.8°E which put it about 100 miles (160 km) southeast of Wuchuan, China. Chaba was moving toward the northwest at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 75 m.p.h. (120 km/h) and and there were wind gusts to 90 m.p.h. (145 km/h). The minimum surface pressure was 981 mb.

Former Tropical Storm Chaba strengthened to a typhoon over the warm water in the northern South China Sea on Friday afternoon. The inner end of a rainband wrapped around the center of Typhoon Chaba’s circulation and the strongest winds were occurring in a ring around the center. Bands of showers and thunderstorms were revolving around the core of Typhoon Chaba. Storms near the core generated upper level divergence that pumped mass away from the typhoon. Winds to typhoon force extended out 60 miles (95 km) from the center of Chaba. Winds to tropical storm force extended out 180 miles (290 km) from the center of circulation.

Typhoon Chaba will move through an environment favorable for intensification during the next 12 hours. Chaba will move over water where the Sea Surface Temperatures are near 29˚C. It will move under the middle of an upper level ridge over the northern part of the South China Sea. The upper level winds are weak near the center of the ridge and there will be little vertical wind shear. Typhoon Chaba could continue to intensify during the next 12 hours.

Typhoon Chaba will move around the western end of a high pressure system over the Western North Pacific Ocean during the next 24 hours. The high will steer Chaba toward the northwest. On its anticipated track the center of Typhoon Chaba could make landfall on the coast of southern China near Wuchuan in 12 hours. Chaba will bring strong winds and locally heavy rain to southwestern Guangdong. Heavy rain is likely to cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Aere intensified gradually southeast of Okinawa. At 5:00 p.m. EDT on Friday the center of Tropical Storm Aere was located at latitude 23.6°N and longitude 130.4°E which put it about 305 miles (495 km) southeast of Okinawa. Aere was moving toward the north-northwest at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 50 m.p.h. (80 km/h) and and there were wind gusts to 65 m.p.h. (105 km/h). The minimum surface pressure was 994 mb. Tropical Storm Aere is forecast to move toward the north-northwest and to continue to strengthen gradually. Aere could be near Okinawa in 18 hours.

Tropical Storm Chaba Strengthens South of Hong Kong

Tropical Storm Chaba strengthened over the South China Sea south of Hong Kong on Thursday night. At 11:00 p.m. EDT on Thursday the center of Tropical Storm Chaba was located at latitude 18.6°N and longitude 113.7°E which put it about 275 miles (445 km) south of Hong Kong, China. Chaba was moving toward the northwest at 10 m.p.h. (16 km/h). The maximum sustained wind speed was 60 m.p.h. (95 km/h) and and there were wind gusts to 75 m.p.h. (120 km/h). The minimum surface pressure was 991 mb.

Tropical Storm Chaba strengthened south of Hong Kong on Thursday night. The inner end of a rainband wrapped around most of the center of circulation. The strongest winds were occurring in the part of the rainband wrapped around the center. Bands of thunderstorms were occurring in the southern half of Chaba’s circulation. Bands in the northern half of Chaba contained more showers and lower clouds. Storms near the center of circulation pumped mass away to the south and west of the tropical storm. Winds to tropical storm force extended out 140 miles (225 km) from the center.

Tropical Storm Chaba will move through an environment favorable for intensification during the 24 hours. Chaba will move over water where the Sea Surface Temperatures are near 29˚C. It will move under the middle of an upper level ridge over the northern part of the South China Sea. The upper level winds are weak near the center of the ridge and there will be little vertical wind shear. Tropical Storm Chaba will continue to intensify during the next 24 hours and it could strengthen to a typhoon.

Tropical Storm Chaba will move around the western end of a high pressure system over the Western North Pacific Ocean during the next 24 hours. The high will steer Chaba toward the northwest. On its anticipated track the center of Tropical Storm Chaba could be near the northeastern part of Hainan Island in 18 hours. Chaba could approach the coast of southern China near Zhanjiang in 24 hours. Chaba could be a typhoon when it approaches southern China. It will bring strong winds and locally heavy rain. Heavy rain is likely to cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Aere formed south-southeast of Okinawa. At 11:00 p.m. EDT on Thursday the center of Tropical Storm Aere was located at latitude 20.8°N and longitude 130.8°E which put it about 470 miles (760 km) south-southeast of Okinawa. Aere was moving toward the east-northeast at 9 m.p.h. (15 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1000 mb. Tropical Storm Aere is forecast to move toward the north-northwest and to strengthen gradually. Aere could be near Okinawa in 36 hours.