Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Tropical Storm Fengshen Moves over South China Sea

Tropical Storm Fengshen moved over the South China Sea on Sunday.  At 5:00 p.m. EDT on Sunday the center of Tropical Storm Fengshen was located at latitude 17.6°N and longitude 117.0°E which put the center about 405 miles (665 km) south-southeast of Hong Kong.  Fengshen was moving toward the northwest at 20 m.p.h. (32 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 998 mb.

Tropical Storm Fengshen started to strengthen after it moved over the South China Sea on Sunday.  The inner end of a rainband wrapped around the eastern side of the center of Fengshen’s circulation.  Other bands of showers and thunderstorms were revolving around the center of Tropical Storm Fengshen.  Storms near the center of Fengshen generated upper level divergence that pumped mass away from the tropical storm.  The removal of mass caused the surface pressure to decrease slowly.

The circulation around Tropical Storm Fengshen was relatively symmetrical.  Winds to tropical storm force extended out 115 miles (185 km) from the center of Fengshen’s circulation.

Tropical Storm Fengshen will move through an environment favorable for intensification during the next 24 hours.  Fengshen will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge that is over the South China Sea.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  There is drier air to the northwest of Fengshen, but the drier air is likely to remain outside of the tropical storm on Monday.  Tropical Storm Fengshen will intensify during the next 24 hours.

Tropical Storm Fengshen will move around the southern side of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Fengshen toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Fengshen will move toward Hainan.

Tropical Storm Fengshen Brings Wind and Rain to Philippines

Tropical Storm Fengshen brought wind and rain to the Philippines on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Fengshen was located at latitude 14.3°N and longitude 122.0°E which put the center about 115 miles (185 km) east-southeast of Manila, Philippines.  Fengshen was moving toward the west-northwest at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 998 mb.

Tropical Storm Fengshen was maintaining its intensity as it brought wind and rain to the Philippines on Saturday.  Bands of showers and thunderstorms were dropping heavy rain on parts of Luzon.  Those same bands of thunderstorms were also producing gusty winds.

The strongest winds were occurring in the eastern side of Tropical Storm Fengshen.  Winds to tropical storm force extended out 90 miles (145 km) in the eastern half of Fengshen’s circulation.  The winds in the western side of Tropical Storm Fengshen were blowing at less than tropical storm force.

Tropical Storm Fengshen will move into an environment favorable for intensification when it moves over the South China Sea on Sunday.  Fengshen will move over water where the Sea Surface Temperatures are near 29°C. It will move under the middle of an upper level ridge that is 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.  Tropical Storm Fengshen is likely to maintain its intensity during the next 12 hours while it moves across Luzon.  Fengshen will intensify when it moves over the South China Sea on Sunday.

Tropical Storm Fengshen will move around the southern side of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Fengshen toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Fengshen will move across Luzon during the next 12 hours.  Fengshen will move over the South China Sea on Sunday.

Tropical Storm Fengshen will continue to bring strong winds and locally heavy rain to Luzon during the next 24 hours.  Heavy rain is likely to cause flash floods in some locations.  The weather in Luzon will start to improve later on Sunday when Tropical Storm Fengshen moves farther away.

Tropical Storm Fengshen Forms East of Philippines

Tropical Storm Fengshen formed over the Western North Pacific Ocean east of the Philippines on Friday.  At 2:00 p.m. EDT on Friday the center of Tropical Storm Fengshen was located at latitude 12.9°N and longitude 127.4°E which put the center about 250 miles (400 km) east of Legaspi, Philippines.  Fengshen was moving toward the west at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1000 mb.

A low pressure system over the Western North Pacific Ocean east of the Philippines strengthened on Friday and the Japan Meteorological Agency designated the system as Tropical Storm Fengshen.

Thunderstorms were developing near the center of Tropical Storm Fengshen.  More thunderstorms also formed in bands revolving around the center of Fengshen’s circulation.  Storms near the center of Fengshen began to generate upper level divergence that pumped mass away from the tropical storm.  The removal of mass caused the surface pressure to decrease.

Tropical Storm Fengshen will move through an environment favorable for intensification during the next 24 hours.  Fengshen will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the southern part of an upper level ridge that is south of Japan.  The upper level ridge will produce easterly winds that will blow toward the top of Fengshen’s circulation.  Those winds will cause some vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear will not be enough to prevent intensification.  Tropical Storm Fengshen will intensify during the next 24hours.

Tropical Storm Fengshen will move around the southern side of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Fengshen toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Fengshen will move near the coast of southeastern Luzon on Saturday.

Tropical Storm Fengshen will bring strong winds and locally heavy rain to Luzon.  Heavy rain is likely to cause flash floods in some locations.

Tropical Storm Nakri Moves Away from Japan

Tropical Storm Nakri moved away from Japan on Monday.  At 5:00 p.m. EDT on Monday the center of Tropical Storm Nakri was located at latitude 34.3°N and longitude 149.1°E which put the center about 460 miles (740 km) east of Tokyo, Japan.  Nakri was moving toward the east at 23 m.p.h. (37 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. (135 km/h).  The minimum surface pressure was 985 mb.

Former Typhoon Nakri weakened back to a tropical storm on Monday as it quickly moved farther away from Japan.  Nakri was still a very well organized tropical storm.  The inner end of a rainband wrapped most of the way around the center of Nakri’s circulation.  Bands of showers and thunderstorms revolved around the center of Tropical Storm Nakri.  Storms near the center of Nakri generated upper level divergence that pumped mass away to the east of the tropical storm.

The distribution of winds speeds around Tropical Storm Nakri was fairly symmetrical.  Winds to tropical storm force extended out 155 miles (250 km) from the center of Nakri’s circulation.

Tropical Storm Nakri will move through an environment that will be unfavorable for intensification of a tropical cyclone during the next 24 hours.  Nakri will move over water where the Sea Surface Temperatures are near 25°C.  It will move under the southeastern part of an upper level trough that is over northern Japan.  The upper level trough will produce westerly winds that will blow toward the top of Nakri’s circulation.  Those winds will cause strong vertical wind shear.  Cooler Sea Surface Temperatures and strong vertical wind shear will cause Tropical Storm Nakri to weaken during the next 24 hours.  The cooler Sea Surface Temperatures and strong vertical wind shear will also cause Nakri to make a transition to an extratropical cyclone.

The upper level trough over northern Japan will steer Tropical Storm Nakri quickly toward the east during the next 24 hours.  On its anticipated track, Tropical Storm Nakri will continue to move quickly away from Japan.

Nakri Strengthens to a Typhoon

Former Tropical Storm Nakri strengthened to a typhoon south of Japan on Sunday.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Nakri was located at latitude 32.0°N and longitude 137.4°E which put the center about 285 miles (460 km) southwest of Tokyo, Japan.  Nakri was moving toward the east-northeast at 16 m.p.h. (26 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.

Former Tropical Storm Nakri strengthened to a typhoon south of Japan on Sunday.  A small circular eye was present at the center of Typhoon Nakri.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Thunderstorms were also occurring in bands in the northern and eastern parts of Nakri’s circulation.  Bands in the southern and western sides of Typhoon Nakri consisted primarily of showers and lower clouds.  Storms near the center of Nakri generated upper level divergence that pumped mass away to the east of the typhoon.

Winds to typhoon force extended out 15 miles (25 km) from the center of Typhoon Nakri.  Winds to tropical storm force extended out 110 miles (175 km) in the eastern half of Nakri’s circulation.  Winds to tropical storm force only extended out 45 miles (75 km) in the western side of Typhoon Nakri.

Typhoon Nakri will move through an environment favorable for intensification during the next 24 hours.  Nakri will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the eastern side of an upper level trough that is west of Japan.  The upper level trough will produce westerly winds that will blow toward the top of Nakri’s circulation.  However, the winds in the lower atmosphere will also blow from the west.  So, there will not be a lot of vertical wind shear. Typhoon Nakri is likely to intensify during the next 24 hours.

The upper level trough that is west of Japan will steer Typhoon Nakri toward the east-northeast during the next 24 hours.  On its anticipated track, Typhoon Nakri will pass south of Tokyo in 12 hours.

Tropical Storm Nakri Moves South of Japan

Tropical Storm Nakri moved south of Japan on Saturday.  At 11:00 a.m. EDT on Saturday the center of Tropical Storm Nakri was located at latitude 29.1°N and longitude 132.0°E which put the center about 320 miles (515 km) south-southwest of Kochi, Japan.  Nakri was moving toward the north-northeast at 13 m.p.h. (21 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 997 mb.

Tropical Storm Nakri started to strengthen on Saturday as it moved south of Japan.  The inner end of a rainband wrapped around the center of Nakri’s circulation.  An eye appeared to be forming at the center of Tropical Storm Nakri.  Bands of showers and thunderstorms were revolving around the center of Nakri’s circulation.  Storms near the center of Nakri generated upper level divergence that pumped mass away to the east of the tropical storm.  The removal of mass caused the surface pressure to decrease.

The size of the circulation around Tropical Storm Nakri was relatively small.  Winds to tropical storm force extended out 105 miles (165 km) from the center of Nakri’s circulation.

Tropical Storm Nakri will move through an environment favorable for intensification during the next 24 hours.  Nakri will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the eastern side of an upper level trough that is west of Japan.  The upper level trough will produce southwesterly winds that will blow toward the top of Nakri’s circulation.  However, the winds in the lower atmosphere will also blow from the west.  So, there will not be a lot of vertical wind shear.  Tropical Storm Nakri will intensify during the next 24 hours.  Nakri could strengthen to a typhoon on Sunday.

The upper level trough that is west of Japan will steer Tropical Storm Nakri toward the northeast during the next 24 hours.  On its anticipated track, Tropical Storm Nakri will move south of Honshu on Sunday.

Typhoon Halong Passes South of Tokyo

Typhoon Halong passed south of Tokyo on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Typhoon Halong was located at latitude 32.8°N and longitude 140.3°E which put the center about 195 miles (315 km) south of Tokyo, Japan.  Halong was moving toward the northeast 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 946 mb.

Typhoon Halong was starting to weaken as it passed south of Tokyo on Wednesday.  A circular eye with a diameter of 25 miles (40 km) was still present at the center of Halong’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 Typhoon Halong.  Storms near the center of Halong generated upper level divergence that pumped mass away to the east of the typhoon.  The removal of mass was less than the inflow of mass in the lower levels of the atmosphere.  So, the surface pressure was increasing.

The circulation around Typhoon Halong increased in size on Wednesday.  Winds to typhoon force extended out 40 miles (65 km) from the center of Halong’s circulation.  Winds to tropical storm force extended out 140 miles (225 km) from the center of Typhoon Halong.

The Hurricane Intensity Index (HII) for Typhoon Halong was 23.6.  The Hurricane Size Index (HSI) was 13.9 and the Hurricane Wind Intensity Size Index (HWISI) was 37.5.  Typhoon Halong was similar in intensity to Hurricane Dennis when Dennis hit Northwest Florida in 2005.  Halong is bigger than Dennis was.

Typhoon Halong will move through an environment that will become more unfavorable for intensification during the next 24 hours.  Halong will move over water where the Sea Surface Temperatures are near 26°C.  It will move under the southern extent of the upper level westerly winds in the middle latitudes.  The upper level westerly winds will blow toward the top of Halong’s circulation.  Those winds will cause the vertical wind shear to increase.  Cooler Sea Surface Temperatures and more vertical wind shear will cause Typhoon Halong to weaken during the next 24 hours.  Halong is likely to make a transition to an extratropical cyclone during the next few days.

The upper level westerly winds will steer Typhoon Halong quickly toward the east during the next 24 hours.  On its anticipated track, Typhoon Halong will move away from Japan on Thursday.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Nakri former southwest of Iwo To.  At 5:00 p.m. EDT on Wednesday the center of Tropical Storm Nakri was located at latitude 22.3°N and longitude 136.0°E which put the center about 625 miles (1010 km) south-southeast of Okinawa.  Nakri was moving toward the northwest at 18 m.p.h. (30 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.

Typhoon Halong Intensifies to Equivalent of a Major Hurricane

Typhoon Halong intensified to the equivalent of a major hurricane over the Western North Pacific Ocean south of Japan on Tuesday morning.  At 11:00 a.m. EDT on Tuesday the center of Typhoon Halong was located at latitude 28.4°N and longitude 137.2°E which put the center about 490 miles (785 km) south-southwest of Tokyo, Japan.  Halong was moving toward the northwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 160 m.p.h. (260 km/h).  The minimum surface pressure was 942 mb.

Typhoon Halong intensified to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale on Tuesday morning.  A circular eye with a diameter of 40 miles (65 km) was at the center of Halong’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 core of Typhoon Halong.  Storms near the core of Halong generated upper level divergence that pumped mass away from the typhoon in all directions.  The removal of large amounts of mass caused the surface pressure to decrease rapidly.

The circulation around Typhoon Halong was relatively small.  Winds to typhoon force extended out 30 miles (50 km) from the center of Halong’s circulation.  Winds to tropical storm force extended out 140 miles (225 km) from the center of Typhoon Halong.

The Hurricane Intensity Index (HII) for Typhoon Halong was 25.1.  The Hurricane Size Index (HSI) was 10.2 and the Hurricane Wind Intensity Size Index (HWISI) was 35.3.  Typhoon Halong was similar in size and intensity to Hurricane Harvey when Harvey hit Texas in 2017.

Typhoon Halong will move through an environment that is favorable for intensification during the next 24 hours.  Halong will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge that is south of Japan.  The upper level winds are weak near the middle of the upper level ridge and there will be little vertical wind shear.  Typhoon Halong will intensify during the next 24 hours.

Typhoon Halong will move around the western end of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Halong toward the north during the next 24 hours.  On its anticipated track, Typhoon Halong will move closer to Honshu.

Halong Strengthens to a Typhoon

Former Tropical Storm Halong strengthened to a typhoon west of the Ogasawara Islands south of Japan on Sunday night.  At 5:00 a.m. EDT on Monday the center of Typhoon Halong was located at latitude 25.9°N and longitude 140.5°E which put the center about 665 miles (1075 km) south of Tokyo, Japan.  Halong was moving toward the west at 7 m.p.h. (11 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 977 mb.

Former Tropical Storm Halong strengthened to a typhoon on Sunday night.  A small circular eye formed at the center of Halong’s circulation.  The eye was surrounded by a broken ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Thunderstorms were also occurring in bands in the eastern side of Typhoon Halong.  Bands in the western side of Halong’s circulation consisted primarily of showers and lower clouds.  Storms near the center of Halong generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The distribution of wind speeds in Typhoon Halong was relatively symmetrical.  Winds to typhoon force extended out 25 miles (40 km) from the center of Halong’s circulation.  Winds to tropical storm force extended out 115 miles (185 km) from the center of Typhoon Halong.

Typhoon Halong will move through an environment that is mostly favorable for intensification during the next 24 hours.  Halong will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge that is south of Japan.  The upper level winds are weak near the middle of the upper level ridge and there will be little vertical wind shear.  However, Halong will move into a region of drier air.  The drier air will inhibit the formation of thunderstorms in the western part of Halong’s circulation.  Typhoon Halong is likely to intensify during the next 24 hours if the drier air does not get pulled into the core of Halong.

Typhoon Halong will move around the southwestern part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Halong toward the northwest during the next 24 hours.  On its anticipated track, Typhoon Halong will move a little closer to Japan.

Elsewhere, the center of Tropical Storm Matmo moved over northeastern Vietnam.  At 5:00 a.m. EDT on Monday the center of Tropical Storm Matmo was located at latitude 22.4°N and longitude 106.2°E which put the center about 25 miles (40 km) east of Na Phac, Vietnam.  Matmo was moving toward the west-northwest at 13 m.p.h. (21 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.

Typhoon Matmo Brings Wind and Rain to Southern China

Typhoon Matmo brought wind and rain to southern China on Sunday morning.  At 5:00 a.m. EDT on Sunday the center of Typhoon Matmo was located at latitude 21.1°N and longitude 110.0°E which put the center about 25 miles (40 km) west of Zhanjiang, China.  Matmo was moving toward the west-northwest at 14 m.p.h. (25 km/h).  The maximum sustained wind speed was 105 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 966 mb.

Typhoon Matmo strengthened to the equivalent of a Category 2 hurricane on the Saffir-Simpson Scale before it made landfall on the coast of southern China on Sunday morning.  The center of Matmo made landfall near Zhanjiang.

Typhoon Matmo was a large typhoon at the time of landfall.  Winds to typhoon force extended out 70 miles (110 km) from the center of Matmo’s circulation.  Winds to tropical storm force extended out 175 miles (280 km) from the center of Typhoon Matmo.

The Hurricane Intensity Index (HII) for Typhoon Matmo was 17.8.  The Hurricane Size Index (HSI) was 23.2 and the Hurricane Wind Intensity Size index (HWISI) was 41.0.  Typhoon Matmo was similar in size and intensity to Hurricane Gustav when Gustav hit Louisiana in 2008.

Typhoon Matmo will move around the southern side of a high pressure system that is over southern China.  The high pressure system will steer Matmo toward the west-northwest during the next 24 hours.  On its anticipated track, Typhoon Matmo will move inland near the coast of southern China.

Typhoon Matmo will bring strong winds and heavy rain to southwestern Guangdong, Guangxi, and Hainan.  Heavy rain is likely to cause floods in some locations.  Matmo could also cause a storm surge of up to 10 feet (3 meters) along parts of the coast.  Typhoon Matmo will drop heavy rain on parts of northern Vietnam early next week.

Elsewhere over the Western North Pacific Ocean, former Tropical Depression 28W strengthened to Tropical Storm Halong east of Iwo To.  At 5:00 a.m. EDT on Sunday the center of Tropical Storm Halong was located at latitude 25.0°N and longitude 142.0°E which put the center about 65 miles (105 km) east of Iwo To.   Halong was moving toward the west-northwest at 5 m.p.h. (8 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 994 mb.