Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Tropical Storm Wutip Brings Wind and Rain to Hainan

Tropical Storm Wutip brought wind and rain to Hainan on Thursday night.  At 11:00 p.m. EDT on Thursday the center of Tropical Storm Wutip was located at latitude 18.6°N and longitude 108.5°E which put the center about 40 miles (65 km) south-southwest of Dongfang, China.  Wutip was moving toward the northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (105 km/h).  The minimum surface pressure was 983 mb.

Tropical Storm Wutip brought wind and rain to Hainan on Thursday night.  The center of Wutip’s circulation was passing just to the west of Hainan.  Bands in the eastern side of Tropical Storm Wutip were bringing strong winds and locally heavy rain to parts of Hainan.

Tropical Storm Wutip intensified on Thursday.  The inner end of a rainband wrapped around the center of Wutip’s circulation.  A small circular eye appeared to be forming at the center of Tropical Storm Wutip.  Bands of showers and thunderstorms were revolving around the center of Wutip’s circulation.  Storms near the center of Wutip generated upper level divergence that pumped mass away from the tropical storm.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Storm Wutip became more symmetrical on Thursday.  Winds to tropical storm force extended out 105 miles (165 km) from the center of Wutip’s circulation.

Tropical Storm Wutip will move through an environment that will be generally favorable for intensification during the next 24 hours.  Wutip will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the axis of an upper level ridge over eastern China.  The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear.  However, much of the eastern side of Wutip’s circulation will pass over Hainan.  The increased friction over land will slow the winds in that part of Tropical Storm Wutip.  Tropical Storm Wutip could intensify to a typhoon during the next 24 hours if the center of Wutip remains over water..

Tropical Storm Wutip will move around the western part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Wutip toward the north during the next 24 hours.  On its anticipated track, the center Tropical Storm Wutip will pass just to the west of Hainan.  Wutip will approach the coast of Guangxi in 24 hours.

Tropical Storm Wutip will continue to bring strong winds and heavy rain to Hainan on Friday.  Heavy rain could cause flash floods in some locations.  Wutip will also bring strong winds and heavy rain to Guangxi during the weekend.

Tropical Storm Wutip Forms Over South China Sea

Tropical Storm Wutip formed over the South China Sea south of Hainan on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Tropical Storm Wutip was located at latitude 16.5°N and longitude 110.6°E which put the center about 150 miles (240 km) south of Lingshui, China.  Wutip was moving toward the west at 6 m.p.h. (10 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.

A low pressure system over the South China Sea strengthened on Wednesday and the Japan Meteorological Agency designated the system as Tropical Storm Wutip.  The distribution of thunderstorms in Tropical Storm Wutip was asymmetrical.  Thunderstorms were occurring in bands in the southern half of Wutip’s circulation.  Bands in the northern side of Tropical Storm Wutip consisted primarily of showers and lower clouds.  The storms in the southern half of Wutip began to generated upper level divergence that pumped mass away to the west of the tropical storm.

There was a large circulation around Tropical Storm Wutip, but the distribution of wind speeds was asymmetrical.  Winds to tropical storm force extended out 110 miles (170 km) in the southern half of Wutip’s circulation.  The winds in the northern half of Tropical Storm Wutip were blowing at less than tropical storm force.

Tropical Storm Wutip will move through an environment somewhat favorable for intensification during the next 24 hours.  Wutip will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the southern side of an upper level ridge over eastern China.  The upper level ridge will produce northeasterly winds that will blow toward the top of Wutip’s circulation.  Those winds will cause moderate vertical wind shear.  The vertical wind shear will inhibit intensification but the shear will probably not be enough to prevent intensification.  Tropical Storm Wutip is likely to intensify gradually during the next 24 hours.

Tropical Storm Wutip will move around the western part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Wutip toward the northwest during the next 24 hours.  On its anticipated track, Tropical Storm Wutip will approach the southwestern part of Hainan in 24 hours.

Tropical Storm Wutip will bring gusty winds and heavy rain to Hainan.  Heavy rain could cause flash floods in some locations.

Pabuk Weakens to a Tropical Depression

Former Tropical Storm Pabuk weakened to a tropical depression east of southern Vietnam during Tuesday night.  At 4:00 a.m. EST on Wednesday the center of Tropical Depression Pabuk was located at latitude 9.3°N and longitude 110.0°E which put the center about 260 miles (420 km) east-southeast of Ho Chi Minh City, Vietnam.  Pabuk was moving toward the south-southwest at 13 m.p.h. (20 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 1005 mb.

Former Tropical Storm Pabuk weakened to a tropical depression during Tuesday night.  A surface high pressure over eastern Asia produced strong northeasterly winds along the east coast of Vietnam.  Those winds transported cooler, drier air into Pabuk’s circulation.  The cooler drier air caused many of the thunderstorms in former Tropical Storm Pabuk to dissipate.  Pabuk’s circulation consisted primarily of bands of showers and lower clouds revolving around the surface center.

Tropical Depression Pabuk will move through an environment unfavorable for intensification during the next 24 hours.  Pabuk will move over water where where the Sea Surface Temperatures are near 29°C.  It will move under the western part of an upper level ridge over the Western North Pacific Ocean.  The upper level ridge will produce southeasterly winds that will blow toward the top of Pabuk’s circulation.  The combination of southeasterly winds in the upper levels and northeasterly winds in the lower levels will cause strong vertical wind shear.   The surface high pressure system over eastern Asia will continue to transport cooler, drier air into Tropical Depression Pabuk.  The combination of strong vertical wind shear and cooler, drier air will cause Tropical Depression Pabuk to continue to weaken during the next 24 hours.

Tropical Depression Pabuk will move around the southeastern side of the high pressure system over eastern Asia.  The high pressure system will steer Pabuk toward the southwest during the next 24 hours.  On its anticipated track, Tropical Depression Pabuk will remain east of Vietnam.

Tropical Storm Pabuk Moves Toward Vietnam

Tropical Storm Pabuk moved slowly toward Vietnam on Tuesday.  At 10:00 a.m. EST on Tuesday the center of Tropical Storm Pabuk was located at latitude 11.3°N and longitude 111.3°E which put the center about 335 miles (540 km) east of Ho Chi Minh City, Vietnam.  Pabuk was moving toward the west-southwest at 6 m.p.h. (10 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 1000 mb.

Tropical Storm Pabuk was better organized in Tuesday morning.  More thunderstorms were occurring near the center of Pabuk’s circulation.  The inner end of a rainband wrapped around the northern and western sides of the center of Tropical Storm Pabuk.  Storms near the center of Pabuk generated upper level divergence that pumped mass away to the north and west of the tropical storm.

Even though Tropical Storm Pabuk was better organized, the distribution of thunderstorms was still asymmetrical.  Thunderstorms were occurring in bands in the northern and western sides of Pabuk’s circulation.  Bands in the southern and eastern side of Tropical Storm Pabuk consisted primarily of showers and lower clouds.

Tropical Storm Pabuk will move through an environment marginally favorable for intensification during the next 24 hours.  Pabuk will move over water where where the Sea Surface Temperatures are near 29°C.  It will move under the western part of an upper level ridge over the Western North Pacific Ocean.  The upper level ridge will produce southerly winds that will blow toward the top of Pabuk’s circulation.  Those winds will cause moderate vertical wind shear.  A surface high pressure system over eastern Asia will transport drier air around the southern side of Tropical Storm Pabuk.  The combination of drier air and moderate vertical wind shear will inhibit intensification of Tropical Storm Pabuk during the next 24 hours.  Pabuk could strengthen a little if the vertical wind shear does not get any stronger.  Tropical Storm Pabuk is likely to weaken if the upper level winds do get stronger.

Tropical Storm Pabuk will move around the southeastern side of the high pressure system over eastern Asia.  The high pressure system will steer Pabuk toward the west during the next 24 hours.  On its anticipated track, Tropical Storm Pabuk will continue to move toward Vietnam.

Tropical Storm Pabuk Develops East of Vietnam

Tropical Storm Pabuk developed over the South China Sea east of Vietnam on Monday.  At 10:00 a.m. EST on Monday the center of Tropical Storm Pabuk was located at latitude 11.5°N and longitude 112.5°E which put the center about 410 miles (660 km) east of Ho Chi Minh City, Vietnam.  Pabuk was moving toward the north at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1001 mb.

The circulation around former Tropical Depression 28W strengthened on Monday and the Japan Meteorological Agency designated the system as Tropical Storm Pabuk.  The distribution of thunderstorms in Tropical Storm Pabuk was asymmetrical.  Thunderstorms were occurring in a band in the northern part of Pabuk’s circulation.  The bands in the other parts of Tropical Storm Pabuk consisted primarily of showers and lower clouds.

Tropical Storm Pabuk will move through an environment unfavorable for intensification during the next 24 hours.  Pabuk will move over water where where the Sea Surface Temperatures are near 29°C.  It will move under the western part of an upper level ridge over the Western North Pacific Ocean. The upper level ridge will produce southerly winds that will blow toward the top of Pabuk’s circulation.  Those winds will cause moderate vertical wind shear.  A surface high pressure system over eastern Asia will transport drier air into the western side of Tropical Storm Pabuk.  The combination of drier air and moderate vertical wind shear is likely to cause Tropical Storm Pabuk to weaken during the next 24 hours.

Tropical Storm Pabuk will move around the southeastern side of the high pressure system over eastern Asia.  The high pressure system will steer Pabuk toward the west during the next 24 hours.  On its anticipated track, Tropical Storm Pabuk will move toward Vietnam.

Tropical Depression Forms Over South China Sea

A tropical depression formed over the South China Sea near the Spratly Islands on Saturday night.  At 10:00 p.m. EST on Saturday the center of the tropical Depression was located at latitude 9.5°N and longitude 114.4°E which put the center about 450 miles (725 km) east of Ho Chi Minh City, Vietnam.  The tropical depression was moving toward the 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 1004 mb.

A low pressure system over the South China Sea near the Spratly Islands exhibited more organization on Saturday night and the Japan Meteorological Agency designated the system as a tropical depression.  More thunderstorms formed near the center of the tropical depression.  Thunderstorms were occurring in bands to the north and west of the center.  Bands in the southern and eastern parts of the tropical depression consisted primarily of showers and lower clouds.  Storms near the center generated upper level divergence that pumped mass away to the north and west of the tropical depression.

The tropical depression will move through an environment favorable for intensification during the next 24 hours.  The tropical depression will move over water where where the Sea Surface Temperatures are near 29°C.  It will move under the western part of an upper level ridge over the Western North Pacific Ocean.  The upper level ridge will produce southeasterly winds that will blow toward the top of the tropical depression.  Those winds will cause moderate vertical wind shear.  The vertical wind shear will inhibit intensification, but the shear will not be enough to prevent intensification.  The tropical depression could intensify to a tropical storm on Sunday.

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 slowly toward the northwest during the next 24 hours.  On its anticipated track, the tropical depression will move toward Vietnam.

Man-yi Weakens to a Tropical Storm

Former Typhoon Man-yi weakened to a tropical storm over the South China Sea on Monday.  At 10:00 a.m. EST on Monday the center of Tropical Storm Man-yi was located at latitude 18.6°N and longitude 115.4°E which put the center about 280 miles (450 km) south-southeast of Hong Kong.  Man-yi was moving toward the west-northwest at 10 m.p.h. (16 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 993 mb.

Former Typhoon Man-yii weakened to a tropical storm after it hit Luzon on Sunday.  An eye was no longer present at the center of Man-yi’s circulation.  Bands of showers and thunderstorms were revolving around the center of Tropical Storm Man-yi.  Storms near the center of Man-yi still generated some upper level divergence that pumped mass away to the northeast of the tropical storm.  The removal of mass was less that the amount of mass converging in the lower levels of Tropical Storm Man-yi.  So, the surface pressure was increasing.

The distribution of wind speeds around Tropical Storm Man-yi became more asymmetrical as Man-yi moved over the South China Sea.  Winds to tropical storm force extended out 275 miles (445 km) in the northern side of Man-yi’s circulation.  The large area of tropical storm force winds on the northern side of Tropical Storm Man-yi was partly due to Man-yi’s interaction with a high pressure system over China.  Winds to tropical storm force extended out 150 miles (240 km) in the southern part of Tropical Storm Man-yi.

Tropical Storm Man-yi will move through an environment unfavorable for intensification during the next 24 hours.  Man-yi will move over water where where the Sea Surface Temperatures are near 27°C.  It will move under the eastern side of an upper level trough over China.  The upper level trough will produce southwesterly winds that will blow toward the top of Man-yi’s circulation.  Those winds will cause moderate vertical wind shear.  In addition, the high pressure system over China will transport colder, drier air toward Tropical Storm Man-yi.  The effects of moderate vertical wind shear and colder, drier air will cause Tropical Storm Man-yi to weaken during the next 24 hours.

Tropical Storm Man-yi will move around the southern side of the high pressure system over China.  The high pressure system will steer Man-yi toward the west during the next 24 hours.  On its anticipated track, Tropical Storm Man-yi will move toward Hainan.

Typhoon Man-yi Hits Luzon

Powerful Typhoon Man-yi hit Luzon on Sunday morning.  At 4:00 a.m. EST on Sunday the center of Typhoon Man-yi was located at latitude 16.2°N and longitude 121.3°E which put the center about 25 miles (40 km) north of Baler, Philippines.  Man-yi was moving toward the northwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 150 m.p.h. (240 km/h) and there were wind gusts to 185 m.p.h. (295 km/h).  The minimum surface pressure was 933 mb.

The center of Typhoon Man-yi made landfall on the east coast of Luzon near Baler on Sunday morning.  Man-yi was the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale at the time of landfall.  A circular eye with a diameter of 17 miles (28 km) was at the center of Typhoon Man-yi.  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 were revolving around the core of Man-yi’s circulation.

The circulation around Typhoon Man-yi was very symmetrical.  Winds to typhoon force extended out 40 miles (65 km) from the center of Man-yi’s circulation.  Winds to tropical storm force extended out 130 miles (210 km) from the center of Typhoon Man-yi.

The Hurricane Intensity Index (HII) for Typhoon Man-yi was 31.6.  The Hurricane Size Index (HSI) was 16.0 and the Hurricane Wind Intensity Size Index (HWISI) was 47.6. Typhoon Man-yi was similar in size and intensity to Hurricane Laura when Laura hit Southwest Louisiana in 2020.

Typhoon Man-yi will move around the southern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Man-yi toward the northwest during the next 24 hours.  On its anticipated track, Typhoon Man-yi will move across Luzon during the rest of today.

Typhoon Man-yi will also bring very strong winds and heavy rain to Luzon. Heavy rain will cause flash floods and mudslides.  Man-yi could also cause a storm surge of up to 13 feet (4 meters) along the coast of Luzon.  Luzon has already been hit by a series of in recent weeks. Typhoon Man-yi is capable of causing regional severe damage.  Man-yi will seriously set back efforts to recover from the previous typhoons.

Typhoon Man-yi Intensifies to Equivalent of Cat. 5 Hurricane

Typhoon Man-yi intensified to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Saturday.  At 10:00 a.m. EST on Saturday the center of Typhoon Man-yi was located at latitude 14.2°N and longitude 124.0°E which put the center about 80 miles (130 km) east of Labo, Philippines.  Man-yi was moving toward the northwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 160 m.p.h. (260 km/h) and there were wind gusts to 195 m.p.h. (315 km/h).  The minimum surface pressure was 921 mb.

Typhoon Man-yi intensified to the equivalent of a Category 5 hurricane as it approached southeastern Luzon on Saturday.  The southwestern part of Man-yi’s eyewall passed over Catanduanes Island.

Typhoon Man-yi was very impressive on satellite images.  A circular eye with a diameter of 20 miles (32 km) was at the center of Man-yi’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 were revolving around the center of Man-yi’s circulation.  Storms near the center of Man-yi generated strong upper level divergence that pumped large amounts of mass away from the typhoon in all directions. The removal of large quantities of mass caused the surface pressure to decrease rapidly.

The size of the circulation around Typhoon Man-yi increased when Man-yi intensified.  Winds to typhoon force extended out 45 miles (75 km) from the center of Man-yi’s circulation.  Winds to tropical storm force extended out 150 miles (240 km) from the center of Typhoon Man-yi.

The Hurricane Intensity Index (HII) for Typhoon Man-yi was 35.0.  The Hurricane Size Index (HSI) was 17.6 and the Hurricane Wind Intensity Size Index (HWISI) was 52.6.  Typhoon Man-yi was similar in intensity to Hurricane Michael when Michael hit Northwest Florida in 2018.  Man-yi was bigger than Michael was.

Typhoon Man-yi will move through an environment favorable for intensification during the next few hours.  Man-yi will move over water where where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge over the Western North Pacific Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Typhoon Man-yi could continue to intensify during the next few hours.  However, the fact that the southwestern part of Man-yi’s eyewall passed over Catanduanes Island could halt its intensification.

Typhoon Man-yi will move around the southern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Man-yi toward the northwest during the next 24 hours.  On its anticipated track, Typhoon Man-yi will reach southeastern Luzon in 12 hours.  The center of Man-yi’s circulation could make landfall northeast of Baler.

Typhoon Man-yi is already bringing destructive winds to Catanduanes Island.  Typhoon Man-yi will also bring very strong winds and heavy rain to Luzon.  Heavy rain will cause flash floods and mudslides.  Man-yi could also cause a storm surge of up to 13 feet (4 meters) along the coast of Luzon. Luzon has already been hit by a series of in recent weeks.  Typhoon Man-yi is capable of causing regional catastrophic damage.  Man-yi will seriously set back efforts to recover from the previous typhoons.

Elsewhere over the Western North Pacific Ocean, Tropical Depression Usagi was still dropping heavy rain on parts of Taiwan. At 4:00 a.m. EST on Saturday the center of Tropical Depression Usagi was located at latitude 22.3°N and longitude 120.7°E which put the center about 35 miles (55 km) south of Kaohsiung, Taiwan.  Usagi was moving toward the southeast at 4 m.p.h. (6 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 1006 mb.  Continued heavy rain is likely to cause flash floods in Taiwan.

Typhoon Man-Yi Strengthens to Equivalent of a Major Hurricane

Typhoon Man-yi strengthened to the equivalent of a major hurricane as it moved toward the Philippines on Friday.  At 4:00 p.m. EST on Friday the center of Typhoon Man-yi was located at latitude 12.3°N and longitude 127.2°E which put the center about 490 miles (790 km) east-southeast of Manila, Philippines.  Man-yi was moving toward the west-northwest at 15 m.p.h. (24 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 952 mb.

Typhoon Man-yi intensified to the equivalent of a major hurricane on Friday.  A circular eye with a diameter of 25 miles (40 km) was at the center of Man-yi’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 were revolving around the center of Man-yi’s circulation.  Storms near the center of Man-yi generated strong upper level divergence that pumped mass away from the typhoon in all directions.  The removal of large quantities of mass caused the surface pressure to decrease rapidly.

The circulation around Typhoon Man-yi was very symmetrical.  Winds to typhoon force extended out 30 miles (50 km) from the center of Man-yi’s circulation.  Winds to tropical storm force extended out 125 miles (200 km) from the center of Typhoon Man-yi.

The Hurricane Intensity Index (HII) for Typhoon Man-yi was 23.6.  The Hurricane Size Index (HSI) was 10.3 and the Hurricane Wind Intensity Size Index (HWISI) was 33.9.  Typhoon Man-yi was similar in size and intensity to Hurricane Dennis when Dennis hit Northwest Florida in 2005.

Typhoon Man-yi will move through an environment favorable for intensification during the next 24 hours.  Man-yi will move over water where where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge over the Western North Pacific Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Typhoon Man-yi is likely to continue to intensify during the next 24 hours.

Typhoon Man-yi will move around the southern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Man-yi toward the west-northwest during the next 24 hours.  On its anticipated track, Typhoon Man-yi will reach southeastern Luzon in less than 18 hours.

Typhoon Man-yi will bring very strong winds and heavy rain to Luzon.  Heavy rain will cause flash floods and mudslides.  Man-yi could also cause a storm surge of up to 13 feet (4 meters) along the coast of Luzon.  Luzon has already been hit by a series of in recent weeks.  Typhoon Man-yi is capable of causing regional major damage.  Man-yi will seriously set back efforts to recover from the previous typhoons.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Usagi was bringing wind and rain to Taiwan.  At 4:00 p.m. EST on Friday the center of Tropical Storm Usagi was located at latitude 22.5°N and longitude 120.3°E which put the center about 25 miles (40 km) southwest of Kaohsiung, Taiwan.  Usagi was moving toward the north-northeast at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 998 mb.  Heavy rain is likely to cause flash floods in Taiwan.