Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Typhoon Cempaka Makes Landfall in Southern China

Typhoon Cempaka made landfall in southern China on Tuesday. At 11:00 p.m. EDT on Tuesday the center of Typhoon Cempaka was located at latitude 21.8°N and longitude 111.9°E which put it about 10 miles (15 km) south of Yangjiang, China. Cempaka was moving toward the northwest at 5 m.p.h. (8 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 972 mb.

Typhoon Cempaka made landfall on the coast of southern China just to the south of Yangjiang in the province of Guangdong on Tuesday. Cempaka brought strong winds and locally heavy rain to the southwestern part of Guangdong. Winds to typhoon force extended out 25 miles (40 km) from the center of Cempaka at the time of landfall. Winds to tropical storm force extended out 100 miles (160 km) from the center of circulation.

Typhoon Cempaka will weaken rapidly as the center moves inland. However, since Cempaka will move slowly, it could drop heavy rain over the southwestern part of Guangdong province. Heavy rain could cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, former Tropical Storm In-Fa intensified to a typhoon south-southeast of Okinawa. At 11:00 a.m. EDT on Tuesday the center of Typhoon In-Fa was located at latitude 24.5°N and longitude 128.7°E which put it about 150 miles (245 km) south-southeast of Okinawa. In-Fa was moving toward the west at 7 m.p.h. (11 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 968 mb. Typhoon In-Fa is forecast to move toward the west during the next several days and to intensify to the equivalent of a major hurricane. The center of In-Fa will pass south of Okinawa during the next 24 hours. It could be over the southwestern Ryukyu Islands in 48 hours and near northern Taiwan in three days.

Cempaka Strengthens to a Typhoon Southwest of Hong Kong

Former Tropical Storm Cempaka strengthened to a typhoon southwest of Hong Kong on Monday. At 5:00 p.m. EDT on Monday the center of Typhoon Cempaka was located at latitude 21.3°N and longitude 112.4°E which put it about 130 miles (210 km) southwest of Hong Kong. Cempaka was moving toward the west-northwest at 3 m.p.h. (5 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 978 mb.

The small circulation around former Tropical Storm Cempaka strengthened quickly on Monday. A small circular eye formed at the center of Typhoon Cempaka. The eye was surrounded by a ring of strong thunderstorms. Bands of showers and thunderstorms were revolving around the core of Cempaka. Storms near the core generated upper level divergence that pumped mass away from the typhoon. Winds to typhoon force extended out 20 miles (30 km) from the center of Cempaka. Winds to tropical storm force extended out 40 miles (65 km) from the center of circulation.

Typhoon Cempaka will move through an environment favorable for intensification during the next 12 hours. Cempaka will move over water where the Sea Surface Temperatures are near 30°C. It will remain under an upper level ridge over the South China Sea. The winds are weak in the ridge and there will be little vertical wind shear. Typhoon Cempaka could intensify during the next 12 hours.

Typhoon Cempaka will move south of a surface high pressure system over eastern China. The high pressure system will steer Cempaka slowly toward the west-northwest during the next 36 hours. On its anticipated track Tropical Storm Cempaka could approach the south coast of China near Yangjiang in about 12 hours. Cempaka will bring strong winds and heavy rain to the coast of Guangdong province. Since Cempaka will move very slowly some locations could receive extremely heavy rainfall and flash floods are likely in those places. Typhoon Cempaka could also produce of storm surge of up to 7 feet (2 meters) along parts of the coast where the wind blows the water toward the shore.

Elsewhere over the Western North Pacific Ocean, Tropical Storm In-Fa stalled southeast of Okinawa. At 5:00 p.m. EDT on Monday the center of Tropical Storm In-Fa was located at latitude 24.3°N and longitude 130.9°E which put it about 265 miles (425 km) southeast of Okinawa. In-Fa was moving toward the west-northwest at 4 m.p.h. (6 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 983 mb. Tropical Storm In-Fa is forecast to move toward the west during the next several days and to intensify to a typhoon. In-Fa could be south of Okinawa in 30 hours. It could be over the southwestern Ryukyu Islands in 72 hours and near northern Taiwan in less than four days.

Tropical Storm Cempaka Forms Southwest of Hong Kong

Tropical Storm Cempaka formed southwest of Hong Kong on Sunday evening. At 11:00 p.m. EDT on Sunday the center of Tropical Storm Cempaka was located at latitude 21.0°N and longitude 113.0°E which put it about 120 miles (195 km) southwest of Hong Kong. Cempaka was moving toward the west-northwest at 3 m.p.h. (5 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 991 mb.

The circulation around a small low pressure system organized quickly on Sunday evening and the Japan Meteorological Agency designated the system as Tropical Storm Cempaka. The inner end of a rainband wrapped most of the way around the center of Cempaka and an eye appeared to be forming in the middle of the tropical storm. Bands of showers and thunderstorms were revolving around the center of Tropical Storm Cempaka. Storm near the center of circulation generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 40 miles from the center of Cempaka.

Tropical Storm Cempaka will move through an environment favorable for intensification during the next 24 hours. Cempaka will move over water where the Sea Surface Temperatures are near 30°C during the next 24 hours. It will move under an upper level ridge over the South China Sea. The winds are weak in the ridge and there will be little vertical wind shear. Tropical Storm Cempaka will intensify during the next 24 hours and there is a chance it could strengthen to a typhoon.

Tropical Storm Cempaka will move south of a surface high pressure system over eastern China. The high pressure system will steer Cempaka slowly toward the west-northwest during the next 36 hours. On its anticipated track Tropical Storm Cempaka could approach the south coast of China near Yangjiang in about 24 hours. Cempaka could be a typhoon when it approaches the coast. It will bring gusty winds and heavy rain to the coast of Guangdong province. Cempaka could also produce of storm surge of up to 7 feet (2 meters) along parts of the coast where the wind blows the water toward the shore.

Elsewhere over the Western North Pacific Ocean, Tropical Storm In-Fa strengthened southeast of Okinawa. At 11:00 p.m. EDT on Sunday the center of Tropical Storm In-Fa was located at latitude 24.1°N and longitude 131.3°E which put it about 290 miles (465 km) southeast of Okinawa. In-Fa was moving toward the north-northwest at 8 m.p.h. (13 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 986 mb. Tropical Storm In-Fa is forecast to move toward the west during the next several days and to intensify to a typhoon. In-Fa could be south of Okinawa in 36 hours. It could be over the southwestern Ryukyu Islands in three days and near northern Taiwan in four days.

Tropical Storm In-Fa Forms Southeast of Okinawa

Tropical Storm In-Fa formed southeast of Okinawa on Saturday. At 5:00 p.m. EDT on Saturday the center of Tropical Storm In-Fa was located at latitude 22.4°N and longitude 132.3°E which put it about 420 miles (675 km) southeast of Okinawa. In-Fa was moving toward the north-northwest 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 998 mb.

The circulation around a low pressure system southeast of Okinawa exhibited more organization on Saturday and the Japan Meteorological Agency designated the system as Tropical Storm In-Fa. The distribution of thunderstorms around In-Fa was asymmetrical. Thunderstorms were occurring in bands in the eastern half of Tropical Storm In-Fa. Bands on the western side of the tropical storm consisted primarily of showers and lower clouds. An upper level low centered west of Japan was producing westerly winds that were blowing toward the top of In-Fa. Those winds were causing moderate vertical wind shear and they were also contributing to the asymmetrical distribution of thunderstorms.

Tropical Storm In-Fa will move into an environment that is forecast to become more favorable for intensification during the next 48 hours. In-Fa will move over water where the Sea Surface Temperatures are near 28°C during the next two days. The upper level low west of Japan is forecast to move toward the north. When the upper low moves north, the upper level winds around In-Fa will weaken and the vertical wind shear will decrease. Tropical Storm In-Fa is likely to strengthen during the next 48 hours. When the upper level winds weaken, In-Fa could intensify more quickly. Tropical Storm In-Fa could strengthen to a typhoon within 72 hours.

Tropical Storm In-Fa will move south of a surface high pressure system centered southeast of Japan on Sunday. The high will steer In-Fa toward the northwest during the next 24 hours. A second surface high pressure system over eastern Asia is forecast to move north of Tropical Storm In-Fa on Monday. The second high pressure system will steer In-Fa more toward the west early next week. On its anticipated track Tropical Storm In-Fa could approach Okinawa in 60 hours. In-Fa could bring wind and rain to the southwestern Ryukyu Islands. In-Fa could eventually affect Taiwan and eastern China later next week.

Typhoon Champi Brings Wind and Rain to Iwo To

Typhoon Champi brought wind and rain to Iwo To on Friday night. At 11:00 p.m. EDT on Friday the center of Typhoon Champi was located at latitude 25.4°N and longitude 139.9°E which put it about 105 miles (165 km) west of Iwo To. Champi was moving toward the north at 13 m.p.h. (20 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 982 mb.

Bands of showers and thunderstorms on the eastern side of Typhoon Champi brought wind and rain to Iwo To on Friday night. Although the center of Champi was passing west of Iwo To, the circulation around the typhoon was producing gusty winds and rain over the island. The core of Typhoon Champi was passing west of Iwo To. Winds to typhoon force extended out 25 miles (40 km) from the center of Champi. However, winds to tropical storm force extended out 100 miles (160 km) from the center of circulation.

Typhoon Champi will move through an environment unfavorable for intensification during the next several days. Champi will move over water where the Sea Surface Temperatures are near 27°C. It will move under the southeastern part of an upper level trough over Japan. The trough will produce southwesterly winds which will blow toward the top of the typhoon. Those winds will cause moderate vertical wind shear. The wind shear will inhibit intensification, but Typhoon Champi could maintain its intensity during the next 12 hours. The vertical wind shear will increase on Saturday, when Champi moves closer to the upper level trough. Typhoon Champi will weaken when the shear increases. Champi will also move over cooler water by Sunday.

The upper level trough over Japan will steer Typhoon Champi toward the northeast during the weekend. On its anticipated track Champi will move away from Iwo To on Saturday. Typhoon Champi could be southeast of Tokyo in 30 hours.

Champi Strengthens to a Typhoon Southwest of Iwo To

Former Tropical Storm Chanpi strengthened to a typhoon southwest of Iwo To on Friday morning. At 5:00 a.m. EDT on Friday the center of Typhoon Champi was located at latitude 22.5°N and longitude 139.2°E which put it about 230 miles (370 km) southwest of Iwo To. Champi was moving toward the north at 11 m.p.h. (17 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 982 mb.

The circulation around Typhoon Champi exhibited better organization on Friday morning. There was a small, circular eye at the center of Champi. 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 Typhoon Champi. The strongest rainband wrapped around the northern, western and southern sides of Champi. Bands in the eastern side of the typhoon consisted mainly of showers and lower clouds. The circulation around Typhoon Champi was relatively small. Winds to typhoon force extended out 30 miles (50 km) from the center of Champi. Winds to tropical storm force extended out 100 miles (160 km) from the center of circulation.

Typhoon Champi will move through an environment somewhat favorable for intensification during the next 24 hours. Champi will move over water where the Sea Surface Temperatures are near 29°C. It will move under the southeastern part of an upper level trough over Japan. The trough will produce southwesterly winds which will blow toward the top of the typhoon. Those winds will cause some vertical wind shear. The wind shear will inhibit intensification, but Typhoon Champi could strengthen during the next 24 hours. The vertical wind shear will increase during the weekend, when Champi moves closer to the upper level trough.

Typhoon Champi will move around the western end of a surface high pressure system during the next 24 hours. The high will steer Champi toward the north during that time period. On its anticipated track the center of Typhoon Champi will pass west of Iwo To on Friday night. Bands on the eastern side of Champi could bring gusty winds and locally heavy rain to Iwo To. The upper level trough over Japan will steer Typhoon Champi toward the northeast during the weekend. Champi could be southeast of Tokyo in 48 hours.

Tropical Storm Champi Strengthens South of Iwo To

Tropical Storm Champi strengthened south of Iwo To on Wednesday. At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Champi was located at latitude 18.9°N and longitude 140.1°E which put it about 435 miles (680 km) south of Iwo To. Champi was moving toward the north 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 992 mb.

Tropical Storm Champi continued to strengthen on Wednesday. The inner end of a rainband wrapped most of the way around the center of Champi. Stronger thunderstorms were occurring in bands east and south of the center of circulation. Bands in the northwestern side of the tropical storm consisted primarily of showers and lower clouds. Storms near the center of circulation generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 70 miles (110 km) from the center of Champi.

Tropical Storm Champi will move through an environment favorable for intensification during the next 36 hours. Champi will move over an area where the Sea Surface Temperatures are near 29°C. It will move under the southeastern portion of an upper level ridge centered east of the Philippines. The ridge will produce northeasterly winds that will blow toward the top of the tropical storm. Those winds will cause some vertical wind shear. The vertical wind shear will slow the rate of intensification, but it will not be large enough prevent Tropical Storm Champi from strengthening. Champi will intensify during the next 36 hours and it is forecast to strengthen to a typhoon.

Tropical Storm Champi will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean during the next 48 hours. The high will steer Champi toward the north during the next two days. On its anticipated track Tropical Storm Champi could be southwest of Iwo To in 36 hours.

Tropical Storm Champi Develops West of the Marianas

Tropical Storm Champi developed west of the Marianas on Tuesday night. At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Champi was located at latitude 15.3°N and longitude 139.9°E which put it about 320 miles (515 km) west-northwest of Guam. Champi was moving toward the west-northwest at 9 m.p.h. (15 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 former Tropical Depression 06W strengthened on Tuesday night and the Japan Meteorological Agency designated the system as Tropical Storm Champi. More thunderstorms formed near the center of Tropical Storm Champi. The inner end of a rainband wrapped around the eastern and northern sides of the center of Champi. 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. Winds to tropical storm force extended out 50 miles (80 km) from the center of circulation.

Tropical Storm Champi will move through an environment favorable for intensification during the next 48 hours. Champi will move over an area where the Sea Surface Temperatures are near 29°C. It will move between an upper level low northeast of the Marianas and and upper level ridge over eastern Asia. The upper level winds are weak between the upper low and the ridge and there will be little vertical wind shear. Tropical Storm Champi will intensify during the next 48 hours and it could strengthen to a typhoon.

Tropical Storm Champi will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean during the next 48 hours. The high will steer Champi toward the north during the next several days. On its anticipated track Tropical Storm Champi could be southwest of Iwo To in 48 hours.

Tropical Depression Forms Southeast of Guam, Warning Issued

Tropical Depression 06W formed southeast of Guam on Sunday night and a Tropical Storm Warning was issued for Guam. At 5:00 a.m. EDT on Monday the center of Tropical Depression 06W was located at latitude 12.1°N and longitude 146.0°E which put it about 160 miles (260 km) southeast of Guam. Tropical Depression 06W was moving toward the west-northwest at 13 m.p.h. (20 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 Tropical Storm Warning was issued for Guam. A Tropical Storm Watch was issued for Rota.

A circulation center developed in a cluster of thunderstorms southeast of Guam on Sunday night and the Joint Typhoon Warning Center designated the system as Tropical Depression 06W. The distribution of thunderstorms around Tropical Depression 06W was asymmetrical. The strongest thunderstorms were occurring in bands on the eastern side of the tropical depression. Bands in the western half of the circulation consisted primarily of showers and lower clouds. Storms near the center of Tropical Depression 06W began to generate upper level divergence that pumped mass away from the tropical depression.

Tropical Depression 06W will move through an environment that is somewhat favorable for intensification during the next several days. The depression will move over an area where the Sea Surface Temperatures are near 29°C. It will move south of an upper level ridge over the Western North Pacific Ocean. The ridge will produce easterly winds that will blow toward the top of Tropical Depression 06W. Those winds will cause some vertical wind shear, but the shear will not be strong enough to prevent intensification. The tropical depression will move into an area where drier air is sinking toward the surface. The drier air will limit the formation of thunderstorms on the western side of the circulation and it will inhibit intensification. Tropical Depression 06W is forecast to intensify to a tropical storm during the next 24 hours.

Tropical Depression 06W will move around the western side of a subtropical high pressure system over the Western North Pacific Ocean. The high will steer the depression toward the northwest during the next 24 hours. On its anticipated track Tropical Depression 06W will pass near Guam in 12 hours. The tropical depression will bring gusty winds and heavy rain to parts of Guam. It will move more toward the north when it reaches the western end of the high pressure system.

Tropical Storm Koguma Nears Vietnam

The center of Tropical Storm Koguma moved closer to northern Vietnam on Saturday. At 11:00 a.m. EDT on Saturday the center of Tropical Storm Koguma was located at latitude 20.2°N and longitude 106.9°E which put it about 115 miles (185 km) southeast of Hanoi, Vietnam. Koguma was moving toward the northwest at 20 m.p.h. (32 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.

The circulation around former Tropical Depression 05W strengthened slightly on Saturday and the system was upgraded to Tropical Storm Koguma. Even though the circulation around the former tropical depression was a little stronger, the distribution of thunderstorms around Tropical Storm Koguma was still asymmetrical. The strongest thunderstorms were occurring in bands southwest of the center of Koguma. Bands in the other parts of the tropical storm consisted primarily of showers and lower clouds. An upper level ridge centered over southern China was producing moderate northeasterly winds that were blowing toward the top of the depression. Those winds were causing moderate vertical wind shear and they were also causing the asymmetrical distribution of thunderstorms.

Tropical Storm Koguma will move into an environment only marginally favorable for intensification during the next few hours. Koguma will move over an area where the Sea Surface Temperatures are near 30°C. However, the upper level ridge over southern China will continue to produce moderate vertical wind shear. The moderate wind shear will keep Tropical Storm Koguma from strengthening significantly before it reaches Vietnam. The circulation around Koguma will weaken after the center moves over Vietnam.

Tropical Storm Koguma will move around the southern part of a subtropical high pressure system over the Western North Pacific Ocean during the next 24 hours. The high pressure system will steer Koguma toward the northwest. On its anticipated track the center of Tropical Storm Koguma will make landfall on the coast of northern Vietnam south of Haiphong in a few hours. Koguma will bring gusty winds to parts of northern Vietnam. Since the heaviest rain is falling southwest of the center of Tropical Storm Koguma, heavy rain is already falling over parts of northern Vietnam, northern Laos and extreme northeastern Thailand. The heavy rain could cause flash floods in some locations.