Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Tropical Storm Pabuk Brings Wind and Rain to Southern Thailand

Tropical Storm Pabuk brought wind and rain to southern Thailand on Friday.  At 5:00 p.m. EST on Friday the center of Tropical Storm Pabuk was located at latitude 8.7°N and longitude 98.5°E which put it about 60 miles (95 km) northeast of Phuket, Thailand.  Pabuk was moving toward the west-northwest at 10 m.p.h. (16 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.

Tropical Storm Pabuk made landfall near Sichon in southern Thailand.  Pabuk brought gusty winds to much of the Isthmus of Kra.  It also dropped heavy rain over parts of southern Thailand.  Tropical Storm Pabuk weakened when it crossed the Isthmus of Kra, but the core of the circulation appears to have remained intact.  Pabuk is moving over the Andaman Sea and it still has a well defined low level center of circulation.  Several bands of showers and thunderstorms are revolving around the core of the tropical storm.  Additional bands of showers and thunderstorms are located in the northeastern part of the circulation which is over the Gulf of Thailand.

Tropical Storm Pabuk will move into an environment favorable for intensification during the next 24 to 36 hours.  Pabuk will move over water where the Sea Surface Temperature is near 28°C.  An upper level ridge over the Western North Pacific Ocean will produce southeasterly winds which will blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear, which will inhibit intensification.  However, the wind shear may not be strong enough to prevent Tropical Storm Pabuk from strengthening.

Tropical Storm Pabuk will continue to move around the western end of the ridge over the Western North Pacific Ocean.  The ridge will steer Pabuk toward the west-northwest for another 24 to 36 hours.  Pabuk will turn more toward the north when it reaches the western end of the ridge.  On its anticipated track Tropical Storm Pabuk will reach the Andaman Islands in about 36 hours.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 01W formed southeast of the Marshall Islands.  At 4:00 p.m. EST on Friday the center of Tropical Depression 01W was located at latitude 4.9°N and longitude 174.0°E which put it about 250 miles (400 km) southeast of Majuro, Marshall Islands.  It was moving toward the northwest at 15 m.p.h. (24 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 1004 mb.  Tropical Depression 01W is forecast to move toward the west-northwest and strengthen.  On its anticipated track it could move toward Majuro, Kwajalein, Ujelang, and the Marianas.

Tropical Storm Pabuk Nears Southern Thailand

Tropical Storm Pabuk neared southern Thailand late on Thursday.  At 10:00 p.m. EST on Thursday the center of Tropical Storm Pabuk was located at latitude 8.0°N and longitude 101.0°E which put it about 110 miles (170 km) southeast of Sichon, Thailand.  Pabuk was moving toward the west-northwest at 16 m.p.h. (26 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 988 mb.

Tropical Storm Pabuk exhibited more organization on Thursday.  A broken ring of showers and thunderstorms surrounded the center of circulation.  Stronger thunderstorms were occurring in the western part of the ring, while weaker storms and showers comprised the rest of the ring.  Several bands of thunderstorms were on the western side of Tropical Storm Pabuk.  Bands of showers and thunderstorms were also on the eastern side of the circulation.  Storms near the center of circulation were generating upper level divergence which was pumping mass away to the northwest of the tropical storm.  Winds to tropical storm force extended out about 100 miles (160 km) from the center.

Tropical Storm Pabuk will move through an environment favorable for intensification for the next six to twelve hours.  Pabuk will move over water where the Sea Surface Temperature is near 28°C.  It will move around the western end of a subtropical ridge over the Western North Pacific Ocean.  The ridge will produce southeasterly winds which will blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear which will inhibit intensification.  Pabuk could intensify during the short term.  It will reach the coast of southern Thailand in less than 12 hours.  Tropical Storm Pabuk will weaken when it moves across the Isthmus of Kra.  Pabuk could strengthen again when it moves over the Andaman Sea in a day or so.

Tropical Storm Pabuk will move around the western end of the subtropical ridge, which will steer the tropical storm in a northwesterly direction.  On its anticipated track Tropical Storm Pabuk will make landfall on the coast of southern Thailand near Sichon in a few hours.  Pabuk will move across the Isthmus of Kra and into the Andaman Sea in a day or so.  Tropical Storm Pabuk could reach the Andaman Islands within 60 hours.

Tropical Storm Pabuk will bring gusty winds and heavy rain to southern Thailand.  Heavy rain could cause flash floods, especially in areas of steeper terrain.

Tropical Storm Pabuk Forms Over South China Sea

Tropical Storm Pabuk formed over the South China Sea near Pulau Laut on Tuesday.  At 10:00 p.m. EST on Tuesday the center of Tropical Storm Pabuk was located at latitude 5.9°N and longitude 108.2°E which put it about 675 miles (1090 km) east-southeast of Chumphon, Thailand.  Pabuk was moving toward the west 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 1000 mb.

More thunderstorms developed near the western side of the center of Tropical Depression 36W and the Japan Meteorological Agency designated the system as Tropical Storm Pabuk.  The distribution of thunderstorms around Tropical Storm Pabuk was asymmetrical.  Many of the stronger thunderstorms were occurring west of the center of circulation.  Pabuk was near the western end of a subtropical ridge over the Western North Pacific Ocean.  The ridge was producing southeasterly winds which were blowing toward the top of the circulation.  Those winds were causing moderate vertical wind shear and they were inhibiting upper level divergence to the west of Tropical Storm Pabuk.  The wind shear was also probably causing the asymmetrical distribution of thunderstorms.  Several bands of showers and thunderstorms were located on the northern periphery of Pabuk.

Tropical Storm Pabuk will move through an environment somewhat favorable for intensification.  Pabuk will move over water where the Sea Surface Temperature is near 28°C.  The upper level ridge over the Western North Pacific will continue to cause vertical wind shear, but the strength of the upper level winds could weaken slightly.  Wind shear will inhibit intensification, but Tropical Storm Pabuk is likely to strengthen during the next 24 to 48 hours.

The ridge over the Western North Pacific will steer Tropical Storm Pabuk toward the west-northwest during the next several days.  On its anticipated track Pabuk could approach southern Thailand in 48 to 60 hours.

Tropical Depression 35W Drops Heavy Rain on the Philippines

Tropical Depression 35W dropped heavy rain on parts of the Philippines on Friday.  At 10:00 a.m. EST on Friday the center of Tropical Depression 35W was located at latitude 10.7°N and longitude 127.3°E which put it about 135 miles (215 km) east of Tacloban, Philippines.  It was moving toward the west at 7 m.p.h. (11 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 1001 mb.

The distribution of rain around Tropical Depression 35W was asymmetrical.  Most of the heavy rain was falling in thunderstorms northwest of the center of circulation.  A few thunderstorms were developing northeast of the center, but most of the bands in the rest of the tropical depression consisted of showers and lower clouds.  Tropical Depression 35W was located southwest of a strong subtropical ridge over the Western North Pacific Ocean.  The ridge was producing strong upper level winds which were blowing from the east-southeast.  Those winds were blowing across the top of the tropical depression and they were causing strong vertical wind shear.  The strong wind shear was the reason why most of the heavy rain was falling northwest of the center of circulation.

Tropical Depression 35W will move through an environment marginally favorable for intensification.  It will move over water where the Sea Surface Temperature is near 29°C.  The subtropical ridge will continue to cause vertical wind shear.  However, the tropical depression could move under slightly weaker upper level winds when it moves a little farther to the west.  If it moves under weaker upper level winds, then Tropical Depression 35W could strengthen into a tropical storm.

The subtropical ridge will steer Tropical Depression 35W westward for another 24 to 36 hours.  When the depression moves west of the Philippines, it will encounter strong northeasterly winds blowing around a high pressure system over Asia.  Those winds will steer Tropical Depression 35W toward the southwest when it moves over the South China Sea.

Tropical Depression 35W will drop heavy rain over parts of the Philippines.  The heaviest rain is likely to fall over Samar, Cebu, Bohoi, Panay, Mindoro and the southeastern part of Luzon.  The heavy rain will cause flash floods, and mudslides could occur in regions of steeper terrain.

Tropical Storm Usagi Makes Landfall South of Ho Chi Minh City

Tropical Storm Usagi made landfall south of Ho Chi Minh City, Vietnam on Saturday night.  At 10:00 p.m. EST on Saturday the center of Tropical Storm Usagi was located at latitude 10.2°N and longitude 107.1°E which put it about 60 miles (995 km) south-southeast of Ho Chi Minh City, Vietnam.  Usagi was moving toward the west at 5 m.p.h. (8 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 984 mb.

Former Typhoon Usagi weakened as it approached the coast of southern Vietnam.  Moderate vertical wind shear caused by upper level winds blowing from the east caused Usagi to weaken slowly.  The core of Tropical Storm Usagi was still relatively intact.  A ring of strong thunderstorms surrounded the remnants of the small eye.  The strongest winds were occurring in that ring of storms.  Heavy rain was falling just to the southwest of the center of circulation.  Thunderstorms were also dropping heavy rain in a couple of bands on the northeastern periphery of the circulation.

Tropical Storm Usagi will bring gusty winds to the areas south and west of Ho Chi Minh City.  Some places in southern Vietnam and Cambodia will receive locally heavy rainfall and flash floods could occur in those areas.  Usagi will weaken slowly as it move inland over southern Vietnam.

Elsewhere over the Western North Pacific Ocean, Typhoon Man-yi was meandering slowly southeast of Okinawa.  At 10:00 p.m. EST on Saturday the center of Typhoon Man-yi was located at latitude 18.4°N and longitude 135.8°E which put it about 770 miles (1245 km) southeast of Okinawa.  Man-yi was moving toward the west at 2 m.p.h. (3 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 969 mb.

Usagi Strengthens to a Typhoon East of Southern Vietnam

Former Tropical Storm Usagi strengthened into a typhoon east of southern Vietnam on Friday night.  At 10:00 p.m. EST on Friday the center of Typhoon Usagi was located at latitude 9.6°N and longitude 109.2°E which put it about 205 miles (335 km) east-southeast of Ho Chi Minh City, Vietnam.  Usagi was moving toward the west-southwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 977 mb.

A small circular eye was visible at the center of Typhoon Usagi on both conventional and microwave satellite imagery.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Typhoon Usagi.  The strongest rain bands were in the western half of the typhoon.  Storms near the core of Usagi were generating upper level divergence which was pumping mass away from the typhoon.  Winds to typhoon force extended out about 30 miles (50 km) from the center of circulation.  Winds to tropical storm force extended out about 125 miles (200 km) from the center.

Typhoon Usagi will move through an environment favorable for intensification during the next 24 hours.  Usagi will move over water where the Sea Surface Temperature is near 29°C.  It will move south of an upper level ridge.  The ridge will produce easterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear, which will reduce the rate of intensification.  Typhoon Usagi will strengthen on Saturday.

The ridge north of Typhoon Usagi will steer the typhoon a little to the south of due west.  On its anticipated track the center of Typhoon Usagi will approach the Mouths of the Mekong River in about 24 hours.  Usagi will bring strong winds and drop heavy rain on southern Vietnam.  Winds to tropical storm force could affect Ho Chi Minh City.  There could be a storm surge of 6 to 9 feet (2 to 3 meters) along the coast.  Locally heavy rain could cause floods over portions of southern Vietnam and Cambodia.

Elsewhere over the Western North Pacific Typhoon Man-yi started to weaken southeast of Okinawa.  At 10:00 p.m. EST on Friday the center of Typhoon Man-yi was located at latitude 18.1°N and longitude 135.4°E which put it about 760 miles (1230 km) southeast of Okinawa.  Man-yi was moving toward the north at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 969 mb.

Tropical Storm Usagi Forms East of Vietnam

Tropical Storm Usagi formed over the South China Sea east of Vietnam on Thursday.  At 10:00 a.m. EST on Thursday the center of Tropical Storm Usagi was located at latitude 11.2°N and longitude 113.7°E which put it about 350 miles (565 km) east of Lien Huong, Vietnam.  Usagi was moving toward the west at 18 m.p.h. (29 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.

More thunderstorms developed near the center of former Tropical Depression 33W and the Japan Meteorological Agency designated the system as Tropical Storm Usagi.  Satellite imagery indicated that the inner end of a rainband was wrapping around the center of circulation.  Several other bands of showers and thunderstorms were in the western half of Tropical Storm Usagi.  Bands in the eastern half of the circulation consisted primarily of showers and low clouds.  An upper level ridge north Usagi was producing southeasterly winds which were blowing toward the top of the circulation.  Those winds were causing moderate vertical wind shear and they were the reason why the stronger thunderstorms were developing west of the center of circulation.  Storms near the center were producing upper level divergence which was pumping mass away to the west of the tropical storm.

Tropical Storm Usagi will move through an environment favorable for intensification during the next 24 to 36 hours.  Usagi will move over water where the Sea Surface Temperature is near 29°C.  It will continue to move south of an upper level ridge and moderate vertical wind shear will continue to affect Tropical Storm Usagi.  The wind shear will slow intensification, but Usagi will strengthen during the next day or so.  It could intensify into a typhoon during the next 36 hours.

The ridge north of Tropical Storm Usagi will steer the tropical storm on a track a little to the south of due west.  On its anticipated track the center of Tropical Storm Usagi will approach the coast of southern Vietnam in about 36 hours.  Usagi could make landfall on the portion of the coast between Cam Ranh and Vung Tau.  Tropical Storm Usagi will bring gusty winds and it could drop locally heavy rain over southern Vietnam and Cambodia.  Heavy rain could cause flash foods in some locations.

Elsewhere over the Western North Pacific, Typhoon Man-yi was moving away from the Marianas after causing power outages in southern Guam.  At 10:00 a.m. EST on Thursday the center of Typhoon Man-yi was located at latitude 13.5°N and longitude 137.8°E which put it about 1155 miles (1860 km) southeast of Okinawa.  Man-yi was moving toward the northwest at 21 m.p.h. (34 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 969 mb.

Man-yi Strengthens to a Typhoon Southwest of Guam

Former Tropical Storm Man-yi strengthened to a typhoon southwest of Guam on Wednesday.  At 10:00 p.m. EST on Wednesday the center of Typhoon Man-yi was located at latitude 11.1°N and longitude 141.1°E which put it about 300 miles (485 km) southwest of Guam.  Man-yi was moving toward the west-northwest at 27 m.p.h. (44 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. (170 km/h).  The minimum surface pressure was 973 mb.

Typhoon Man-yi strengthened quickly on Wednesday.  An inner band of thunderstorms wrapped around the center of circulation.  A small eye appeared intermittently on satellite imagery.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Other bands of showers and thunderstorms were revolving around the core of Typhoon Man-yi.  Storms near the core were generating upper level divergence which was pumping mass away from the typhoon.  Winds to typhoon force extended out about 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out about 145 miles (230 km) from the center.

Typhoon Man-yi will move through an environment somewhat favorable for intensification on Thursday.  Man-yi will move over water where the Sea Surface Temperature is near 29°C.  So, there will be enough energy in the upper ocean to support further intensification.  Typhoon Man-yi will move south of an upper level ridge.  The ridge will produce strong east-southeasterly winds which will blow toward the top of the circulation.  Those winds will produce moderate vertical wind shear.  The wind shear will inhibit upper level outflow to the east of the typhoon and they will slow the rate of intensification.  Despite the moderate vertical wind shear, Typhoon Man-yi is likely to strengthen during the next 24 hours and it could become the equivalent of a major hurricane.

The ridge will steer Typhoon Man-yi rapidly toward the northwest during the next 24 to 36 hours.  On its anticipated track Typhoon Man-yi will move quickly away from Guam and the Marianas.  Man-yi could move southeast of Okinawa this weekend.

Elsewhere over the rest of the Western North Pacific Ocean, Tropical Depression 33W was moving quickly westward over the South China Sea.  At 10:00 p.m. EDT on Wednesday the center of Tropical Depression 33W was located at latitude 11.1°N and longitude 116.2°E which put it about 505 miles (815 km) east of Cam Ranh, Vietnam.  It was moving toward the west at 25 m.p.h. (40 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.

Tropical Storm Man-yi Forms Southeast of Chuuk

Tropical Storm Man-yi formed southeast of Chuuk on Tuesday.  At 7:00 a.m. EST on Tuesday the center of Tropical Storm Man-yi was located at latitude 4.8°N and longitude 154.2°E which put it about 245 miles (395 km) southeast of Chuuk.  Man-yi was moving toward the west at 11 m.p.h. (17 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.

A Tropical Storm Watch was issued for Guam and Rota.  Tropical Storm Warnings were in effect for Chuuk Lagoon, Lukunor, Losap, Fananu, Ulul, Pulawat and Satawal.  Typhoon Watches were issued for Faraulep and Pulawat.

Tropical Depression 34W exhibited greater organization on satellite imagery and the Japan Meteorological Agency designated the system as Tropical Storm Man-yi.  More thunderstorms developed near the center of circulation.  The strongest thunderstorms were occurring in a band west of the center.  Other bands of showers and thunderstorms were developing around Tropical Storm Man-yi.  Storms near the center of circulation were generating upper level divergence which was pumping mass away to the west of the tropical storm.

Tropical Storm Man-yi will move through an environment favorable for intensification.  Man-yi will move over water where the Sea Surface Temperature is near 29°C.  It will move south of an upper level ridge.  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 intensification.  Tropical Storm Man-yi will intensify and it could strengthen into a typhoon in a day or two.

The upper level ridge will steer Tropical Storm Man-yi toward the west-northwest during the next 12 to 24 hours.  A weakness is forecast to develop in the ridge, which would allow Man-yi to move more toward the northwest.  On its anticipated track Tropical Storm Man-yi will move near Chuuk in 12 to 24 hours.  It will bring gusty winds and drop heavy rain.  Man-yi could be southeast of Guam in 36 to 48 hours.

Elsewhere over the Western North Pacific Ocean Tropical Depression 33W was dropping rain over parts of the central Philippines and Tropical Depression Toraji was moving over the Gulf of Thailand.  At 4:00 a.m. EST on Tuesday the center of Tropical Depression 33W was located at latitude 10.9°N and longitude 126.8°E which put it about 160 miles (260 km) east-southeast of Tacloban, Philippines.  It 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 1004 mb.

At 4:00 a.m. EDT the center of Tropical Depression Toraji was located at latitude 8.1°N and longitude 101.1°E which put it about 100 miles (160 km) east of Hua Sai, Malaysia.  Toraji was moving toward the west-southwest at 5 m.p.h. (8 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 1002 mb.

Tropical Storm Teraji Develops East of Vietnam

Tropical Storm Teraji developed east of Vietnam on Saturday.  At 10:00 p.m. EST on Saturday the center of Tropical Storm Teraji was located at latitude 11.1°N and longitude 110.1°E which put it about 100 miles (160 km) east of Lien Huong, Vietnam.  Teraji was moving toward the west at 5 m.p.h. (8 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 1004 mb.

A distinct low level center of circulation developed in an area of thunderstorms over the South China Sea east of southern Vietnam on Saturday and the Japan Meteorological Agency designated the system as Tropical Storm Teraji.  The circulation around Teraji was exhibiting evidence of vertical wind shear.  The center of circulation was on the eastern edge of a cluster of thunderstorms.  Tropical Storm Teraji was south of an upper level ridge.  The ridge was producing easterly winds which were causing moderate vertical wind shear.  The stronger thunderstorms were occurring in bands west of the center of circulation, which was likely an effect of the wind shear.

The ridge north of Tropical Storm Teraji will steer the tropical storm westward into southern Vietnam.  On its anticipated track Teraji will move over southern Vietnam on Sunday.  Tropical Storm Teraji will move across southern Cambodia early next week.  Thunderstorms in rainbands in the western half of Teraji could drop locally heavy and floods could occur in some locations.

Elsewhere over the Western North Pacific Ocean Tropical Depression 34W formed southeast of Palau.  At 10:00 p.m. EST on Saturday the center of Tropical Depression 34W was located at latitude 6.6°N and longitude 135.5°E which put it about 90 miles (145 km) southeast of Palau.  It was moving toward the west-southwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts tot 45 m.p.h. (75 km/h).  The minimum surface pressure was 1004 mb.