Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Tropical Storm Nangka Makes Landfall in Vietnam

Tropical Storm Nangka made landfall on the coast of northern Vietnam on Wednesday morning.  Nangka weakened to a tropical depression after the center moved over land.  At 8:00 a.m. EDT on Wednesday the center of Tropical Depression Nangka was located at latitude 20.0°N and longitude 105.0°E which put it about 80 miles (130 km) southwest of Hanoi, Vietnam.  Nangka was moving toward the west at 12 m.p.h. (19 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 1002 mb.

The center of Tropical Storm Nangka made landfall on the coast of Vietnam about 70 miles (110 km) southeast of Hanoi on Wednesday morning.  Nangka brought gusty winds and heavy rain to the northern coast of Vietnam.  Nangka quickly weakened to a tropical depression when it moved westward over northern VIetnam.  Bands of showers and thunderstorms dropped locally heavy rain over parts of northern Vietnam.

Tropical Depression Nangka will continue to move toward the west until the circulation spins down over northern Laos on Thursday.  Nangka will continue to drop locally heavy rain over parts of northern Vietnam and northern Laos during the next 24 hours.  Heavy rain could cause flash floods in some locations.

Tropical Storm Nangka Brings Wind and Rain to Hainan

Tropical Storm Nangka brought wind and rain to Hainan Island on Tuesday.  At 11:00 a.m. EDT on Tuesday the center of Tropical Storm Nangka was located at latitude 19.1°N and longitude 110.0°E which put it about 70 miles south-southwest of Haikou, China.  Nangka was moving toward the west-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 987 mb.

The center of Tropical Storm Nangka moved directly across Hainan Island on Tuesday.  Nangka strengthened before it made landfall on the east coast of Hainan.  Winds to tropical storm force extended out 200 miles (320 km) from the center of Tropical Storm Nangka.  So, Nangka may have produced tropical storm force winds over much of Hainan.  Thunderstorms near the center of circulation and in bands revolving around the center were dropping heavy rain over parts of Hainan.  The heavy rain was likely to cause flash floods in some locations.

Tropical Storm Nangka will weaken while it moves across Hainan.  Nangka will move into an environment favorable for intensification for about 12 hours when it moves west of Hainan Island.  Nangka will move over water where the Sea Surface Temperature is near 29°C.  It will move under the southern part of an upper level ridge over eastern Asia.  The ridge will produce easterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear, but the shear will not be strong enough to prevent Tropical Storm Nangka from strengthening again.

Tropical Storm Nangka will move south of a high pressure system over eastern Asia.  The high will steer Nangka toward the west during the next 48 hours.  Tropical Storm Nangka will move west of Hainan Island in about 6 hours.  On its anticipated track Nangka will make landfall on the northern coast of Vietnam southeast of Hanoi in about 18 hours.  Tropical Storm Nangka will bring gusty winds and locally heavy rain to northern Vietnam.  Heavy rain will cause flash floods in some locations.

Tropical Storm Nangka Forms over South China Sea

Tropical Storm Nangka formed over the South China Sea on Monday.  At 11:00 a.m. EDT on Monday the center of Tropical Storm Nangka was located at latitude 18.3°N and longitude 113.8°E which put it about 200 miles (325 km) east of Hainan Island.  Nangka was moving toward the west at 17 m.p.h. (28 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 996 mb.

More thunderstorms developed near the center of a low pressure system over the South China Sea on Monday and the Japan Meteorological Agency designated the system as Tropical Storm Nangka.  The circulation around Tropical Storm Nangka exhibited more organization on Monday.  More thunderstorms formed near the center of Nangka.  Bands of showers and thunderstorms were revolving around the center of circulation.  Storms near the center generated upper level divergence which pumped mass away to the west of the tropical storm.  Winds to tropical storm force extended out 75 miles (120 km) from the center.

Tropical Storm Nangka will move through an environment favorable for intensification during the next 12 to 18 hours.  Nangka will move over water where the Sea Surface Temperature is near 30°C.  It will move south of an upper level ridge over eastern Asia.  The ridge will produce easterly winds which will blow toward the top of Tropical Storm Nangka.  Those winds will cause moderate vertical which shear.  The shear will slow the rate of intensification, but it will not be strong enough to keep Nangka from intensifying.  Tropical Storm Nangka will weaken in a day or so while the tropical storm moves over Hainan Island.  Nangka could restrengthen when it moves west of Hainan.

Tropical Storm Nangka will move south of a high pressure system over eastern Asia.  The high will steer Nangka toward the west-northwest.  On its anticipated track Tropical Storm Nangka will reach Hainan Island in less than 18 hours.  Nangka will bring gusty winds and locally heavy rain to Hainan.  Flash floods could occur in some locations.  Tropical Storm Nangka will reach northern Vietnam in two days.

Elsewhere over the Western North Pacific Ocean, Tropical Depression Chan-hom was weakening southeast of Japan.  At 5:00 a.m. EDT on Monday the center of Tropical Depression Chan-hom was located at latitude 29.2°N and longitude 142.5°E which put it about 400 miles (645 km) south-southeast of Tokyp, Japan.  Chan-hom was moving toward the south at 9 m.p.h (15 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind guts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1000 mb.

Tropical Storm Linfa Forms East of Vietnam

Tropical Storm Linfa formed east of Vietnam on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Linfa was located at latitude 15.0°N and longitude 109.9°E which put it about 155 miles (250 km) east-southeast of Da Nang, Vietnam.  Linfa was moving toward the west at 21 m.p.h. (34 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 997 mb.

More thunderstorms developed near the center of a low pressure system over the South China Sea east of Vietnam and the Japan Meteorological Agency designated the system as Tropical Storm Linfa on Saturday.  The circulation around Tropical Storm Linfa exhbited better organization.  More thunderstorms formed near the center of circulation.  Bands of showers and thunderstorms were revolving around the center of Linfa.  Storms near the center generated upper level divergence which pumped mass away to the west of the tropical storm.  Winds to tropical storm force extended out 100 miles (160 km) from the center of Linfa.

A high pressure system over eastern Asia will steer Tropical Storm Linfa quickly toward the west during the next two days.  On its anticipated track Linfa will make landfall on the coast of Vietnam south of Da Nang in about 8 hours.  Tropical Storm Linfa will move through an environment favorable for intensification until it makes landfall.  Linfa will move over water where the Sea Surface Temperature is near 29°C.  It will move under the southern part of an upper level ridge.  The ridge will produce easterly winds which will blow toward the top of Tropical Storm Linfa.  Those winds will cause moderate vertical wind shear.  The shear will limit the rate of intensification but Linfa will strengthen before it makes landfall.

Tropical Storm Linfa will make landfall on the coast of Vietnam south of Da Nang in a few hours.  Linfa will bring gusty winds and locally heavy rain to parts of central Vietnam, southern Laos, northern Cambodia and northeastern Thailand.  Heavy rain could cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Chan-hom was passing south of Japan.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Chan-hom was located at latitude 32.0°N and longitude 139.8°E which put it about 215 miles (345 km) south of Tokyo, Japan.  Chan-hom was moving toward the east at 15 m.p.h. (24 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 985 mb.

Typhoon Chan-hom Turns Toward Japan

Typhoon Chan-hom turned toward Japan on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Typhoon Chan-hom was located at latitude 27.5°N and longitude 132.9°W which put it about 515 miles (825 km) south-southwest of Osaka, Japan.  Chan-hom was moving toward the northwest at 9 m.p.h. (15 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 973 mb.

Typhoon Chan-hom strengthened slowly on Wednesday.  An eye with a diameter of 35 miles (55 km) formed at the center of Chan-hom.  The eye was surrounded by a broken 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 Chan-hom.  Storms near the core generated upper level divergence which pumped mass away to the northeast of the typhoon.

The circulation around Typhoon Chan-hom was large.  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 of Chan-hom.

Typhoon Chan-hom will move through an environment somewhat favorable for intensification during the next 24 hours.  Chan-hom will move over water where the Sea Surface Temperature is near 28°C.  It will move under the western end of an upper level ridge.  The ridge will produce southerly winds which will blow toward the top of Typhoon Chan-hom.  Those winds will cause moderate vertical wind shear, which will inhibit intensification.  The wind shear will limit intensification, but Chan-hom could get stronger during the next 24 hours.  An upper level trough over eastern Asia will cause stronger southwesterly winds to blow toward Typhoon Chan-hom in a day or so.  Those winds will cause stronger vertical wind shear and they will cause Chan-hom to start to weaken.

Typhoon Chan-hom 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 Chan-hom toward the north during that time period.  The upper trough over eastern Asia will turn Typhoon Chan-hom toward the northeast during the weekend.  On its anticipated track Typhoon Chan-hom will be southeast of Kyushu and south of Shikoku in about 48 hours.

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.

Tropical Storm Kujira Forms West of Wake Island

Tropical Storm Kujira formed west of Wake Island on Saturday.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Kujira was located at latitude 21.1°N and longitude 158.5°E which put it about 515 miles (830 km) west of Wake Island.  Kujira was moving toward the 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 maximum sustained wind speed was 1002 mb.

Tropical Storm Kujira was moving around the eastern side of an upper level low.  The upper low was causing vertical wind shear which was causing the distribution of thunderstorms to be asymmetrical.  There were few thunderstorms near the center of the circulation.  Many of the thunderstorms were occurring in bands east and south of the center of Kujira.  Bands in the western half of the circulation consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 200 miles (320 km) in the southeastern quadrant of Tropical Storm Kujjira.  The winds in the other parts of the circulation were blowing at less than tropical storm force.

Tropical Storm Kujira will move through an environment favorable for intensification after it moves away from the upper level low.  When Kujira moves away from the upper low, the vertical wind shear will decrease.  Tropical Storm Kujira will move over water where the Sea Surface Temperature is near 28°C.  Kujira will intensify when the wind shear decreases.   It could strengthen into a typhoon in two or three days.

The upper level low will pull Tropical Storm Kujira toward the northwest during the next 12 to 24 hours.  Then Kujira will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Tropical Storm Kujira toward the north for 24 to 36 hours.  Kujira will eventually be steered toward the northeast when it reaches the westerly winds in the middle latitudes.  On its anticipated track Tropical Storm Kujira will pass well to the east of Japan.

Tropical Storm Dolphin Passes Southeast of Japan

Tropical Storm Dolphin passed southeast of Japan on Wednesday.  At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Dolphin was located at latitude 32.9°N and longitude 141.4°E which put it about 200 miles (320 km) south-southeast of Tokyo, Japan.  Dolphin was moving toward the northeast at 19 m.p.h. (31 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 986 mb.

An upper level trough over eastern Asia steered Tropical Storm Dolphin quickly toward the northeast on Wednesday.  The trough carried Dolphin southeast of Tokyo.  Winds to tropical storm force extended out 175 miles from the center of Dolphin.  The northern periphery of tropical storm Dolphin was bringing gustier winds to parts of the coast of Honshu.  Most of the rain falling in Tropical Storm Dolphin fell southeast of Honshu.

The upper level trough will carry Tropical Storm Dolphin east of Japan.  Although Dolphin is currently over water where the Sea Surface Temperature is near 28°C, the tropical storm will soon move over cooler water.  The upper level trough and the cooler water will cause Tropical Storm Dolphin to make a transition to an extratropical cyclone during the next several days.

Tropical Storm Dolphin Forms South of Japan

Tropical Storm Dolphin formed south of Japan on Monday.  At 11:00 a.m. EDT on Monday the center of Tropical Storm Dolphin was located at latitude 26.0°N and longitude 135.0°E which put it about 365 miles (590 km) southwest of Tokyo, Japan.  Dolphin was moving toward the north-northeast at 5 m.p.h. (8 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 996 mb.

A distinct low level center of circulation developed near the southern side of an area of thunderstorms south of Japan on Monday and the Japan Meteorological Agency designated the system as Tropical Storm Dolphin.  The circulation around Tropical Storm Dolphin was still organizing.  The strongest thunderstorms were occurring in bands in the northern half of the circulation.  Bands in the southern half of Dolphin consisted primarily of showers and lower clouds.  Storms near the center of circulation generated upper level divergence which pumped mass away to the northeast of the tropical storm.  Winds to tropical storm force extended out 125 miles (200 km) from the center.

Tropical Storm Dolphin will move through an environment somewhat favorable for intensification during the next 36 hours.  Dolphin will move over water where the Sea Surface Temperature is near 28°C.  An upper level trough approaching Japan from the west will produce southwesterly winds which will blow toward the top of Tropical Storm Dolphin.  Those winds will cause moderate vertical wind shear and they will inhibit intensification of Dolphin.  The shear will limit intensification, but Tropical Storm Dolphin is likely to get stronger during the next 36 hours.

Tropical Storm Dolphin will move around the northwestern part of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Dolphin toward the north-northeast during the next 24 to 36 hours.  Tropical Storm Dolphin will reach the westerly winds in the middle latitudes after that period and those winds will steer Dolphin more toward the northeast during the middle of the week.  On its anticipated track Tropical Storm Dolphin could approach the coast of Honshu near Tokyo in about 72 hours.

Tropical Storm Noul Brings Wind and Rain to Central Vietnam

Tropical Storm Noul brought wind and rain to central Vietnam on Thursday night.  At 11:00 p.m. EDT on Thursday the center of Tropical Storm Noul was located at latitude 16.7°N and longitude 107.2°E which put it about 45 miles (75 km) north-northwest of Da Nang, Vietnam.  Noul was moving toward the west at 22 m.p.h. (35 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 994 mb.

The distribution of thunderstorms and rain around Tropical Storm Noul was asymmetrical.  The strongest thunderstorms and the heaviest rain were on the western side of Noul.  Tropical Storm Noul was moving under the southern part of a large upper level ridge over Asia and the Western North Pacific Ocean.  The ridge was producing strong easterly winds which were blowing toward the top of Noul.  Those winds were causing moderate vertical wind shear and they were also the cause of the asymmetrical distribution of rainfall.  Winds to tropical storm force extended out 150 miles (240 km) from the center of circulation.

The upper level ridge will steer Tropical Storm Noul quickly toward the west.  Noul will across central Vietnam and southern Laos on Friday.  Tropical Storm Noul will drop locally heavy rain over parts of central Vietnam, southern Laos and northeastern Thailand.  Flash floods could occur in some locations.