Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Typhoon Lan Continues to Move Toward Honshu

Typhoon Lan continued to move to Honshu on Saturday night. At 11:00 p.m. EDT on Saturday the center of Typhoon Lan was located at latitude 30.0°N and longitude 139.1°E which put it about 385 miles (625 km) south of Tokyo, Japan. Lan was moving toward the northwest at 8 m.p.h. (11 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 970 mb.

Typhoon Lan completed an eyewall replacement cyclone on Saturday. The smaller, inner eye and eyewall dissipated. A circular eye with a diameter of 70 miles (110 km) was at the center of Lan’s circulation on Saturday night. The large 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 large eye. Storms around the eye generated upper level divergence that pumped mass away from the typhoon.

The area of typhoon force winds in Typhoon Lan increased during the eyewall replacement cycle. Winds to typhoon force extended out 70 miles (110 km) from the center of Lan’s circulation. Winds to tropical storm force extended out 150 miles (240 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Lan was 11.5. The Hurricane Size Index (HSI) was 21.1 and the Hurricane Wind Intensity Size Index (HWISI) was 32.6.

Typhoon Lan will move through an environment favorable for intensification during the next 24 hours. Lan will move over water where the Sea Surface Temperatures are near 28°C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Typhoon Lan could strengthen during the next 24 hours, since the eyewall replacement cycle is complete.

Typhoon Lan will move around the western part of a high pressure system over the Western North Pacific Ocean during the next 24 hours. The high pressure system will steer Lan toward the northwest during the next 24 hours. On its anticipated track, Typhoon Lan will approach Honshu in less than 48 hours. The center of Lan could make landfall south of Osaka. Lan will be a typhoon when it reaches Honshu.

Elsewhere over the Western North Pacific Ocean, former Hurricane Dora weakened to a tropical storm East of Wake Island. At 11:00 p.m. EDT on Saturday the center of Tropical Storm Dora was located at latitude 18.2°N and longitude 174.7°E which put it about 570 miles (920 km) east of Wake Island. Dora was moving toward the west-northwest at 14 m.p.h. (22 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 996 mb.

Typhoon Lan Moves Toward Honshu

Typhoon Lan moved toward Honshu on Friday. At 11:00 p.m. EDT on Friday the center of Typhoon Lan was located at latitude 28.7°N and longitude 141.5°E which put it about 485 miles (785 km) south-southeast of Tokyo, Japan. Lan was moving toward the west-northwest at 7 m.p.h. (11 km/h). The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h). The minimum surface pressure was 960 mb.

Typhoon Lan was weakening on Friday night. The inner of a rainband wrapped around the existing eye and eyewall and a larger, outer eyewall formed. The formation of concentric eyewalls was disrupting the low level convergence into the inner eyewall and the inner eyewall was weakening. Since the strongest winds were occurring in the inner eyewall, the maximum wind speed decreased when the inner eyewall weakened. Bands of showers and thunderstorms were revolving around the concentric eyewalls. Storms around the concentric eyewalls generated upper level divergence that pumped mass away from the typhoon.

Winds to typhoon force extended out 35 miles (55 km) from the center of Typhoon Lan. Winds to tropical storm force extended out 140 miles (225 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Lan was 16.5. The Hurricane Size Index (HSI) was 11.4 and the Hurricane Wind Intensity Size Index (HWISI) was 27.9.

Typhoon Lan will move through an environment favorable for intensification during the next 24 hours. Lan will move over water where the Sea Surface Temperatures are near 28°C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. However, Typhoon Lan is likely to weaken during the next 24 hours even though it will be in a favorable environment. The maximum wind speed is likely to continue to decrease as the inner eyewall dissipates.

Typhoon Lan will move around the western part of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Lan toward the northwest during the next 24 hours. On its anticipated track, Typhoon Lan will approach Honshu in less than 72 hours. Lan is likely to be a typhoon when it approaches Honshu.

Typhoon Lan Rapidly Intensifies to Equivalent of a Major Hurricane

Typhoon Lan rapidly intensified to the equivalent of a major hurricane over the Western North Pacific Ocean south of Japan on Thursday. At 11:00 p.m. EDT on Thursday the center of Typhoon Lan was located at latitude 27.1°N and longitude 142.8°E which put it about 615 miles (995 km) south-southeast of Tokyo, Japan. Lan was moving toward the north at 6 m.p.h. (10 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 936 mb.

Typhoon Lan intensified to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale on Thursday. A circular eye with a diameter of 28 miles (45 km) developed at the center of Lan’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 Lan. Storms near the core generated 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 size of the circulation around Typhoon Lan increased when Lan intensified rapidly on Thursday. Winds to typhoon force extended out 45 miles (75 km) from the center of Lan’s circulation. Winds to tropical storm force extended out 160 miles (260 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Lan was 25.1. The Hurricane Size Index (HSI) was 14.0 and the Hurricane Wind Intensity Size (HWISI) was 39.1. Typhoon Lan was similar in size and intensity to Hurricane Harvey when Harvey hit Texas in 2017.

Typhoon Lan will move through an environment favorable for intensification during the next 24 hours. Lan will move over water where the Sea Surface Temperatures are near 28°C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Typhoon Lan is likely to intensify during the next 24 hours unless the inner end of a rainband wraps around the existing eye and eyewall. If concentric eyewalls form, then an eyewall replacement cycle could cause Typhoon Lan to weaken.

Typhoon Lan will move around the western part of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Lan toward the northwest during the next 24 hours. On its anticipated track, Typhoon Lan will bring strong, gusty winds and locally heavy rain to Chichi Jima during the next 24 hours. Typhoon Lan could approach Honshu in four days.

Elsewhere over the Western North Pacific Ocean, former Tropical Storm Khanun produced gusty winds and locally heavy rain over South Korea. At 5:00 p.m. EDT on Thursday the center of Tropical Depression Khanun was located at latitude 38.9°N and longitude 127.0°E which put it about 85 miles (135 km) north-northeast of Seoul, South Korea. Khanun was moving toward the northwest at 9 m.p.h. (15 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 994 mb.

Tropical Storm Khanun Hits South Korea

Tropical Storm Khanun hit South Korea on Wednesday night. At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Khanun was located at latitude 35.5°N and longitude 128.4°E which put it about 20 miles (30 km) south-southeast of Chinhae, South Korea. Khanun was moving toward the north 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 984 mb.

Tropical Storm Khanun hit the southern coast of South Korea on Wednesday night. The center of Khanun made landfall near Busan and Chinhae. Tropical Storm Khanun brought gusty winds and locally heavy rain to the southern half of South Korea. Winds to tropical storm force extended out 175 miles (285 km) from the center of Khanun’s circulation.

Tropical Storm Khanun will move around the western part of a high pressure system over the Western North Pacific Ocean during the next 24 hours. The high pressure system will steer Khanun toward the north-northwest. On its anticipated track, the center of Tropical Storm Khanun will be near Seoul in less than 12 hours. Khanun will continue to produce gusty winds and locally heavy rain in South Korea on Thursday. Heavy rain could cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, former Tropical Storm Lan intensified to a typhoon. At 11:00 p.m. EDT on Wednesday the center of Typhoon Lan was located at latitude 25.4°N and longitude 143.7°E which put it about 165 miles (265 km) east of Iwo To. Lan 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 975 mb. Typhoon Lan is forecast to move toward Honshu and to strengthen.

Tropical Storm Khanun Brings Wind and Rain to Kyushu

Tropical Storm Khanun brought wind and rain to Kyushu on Tuesday. At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Khanun was located at latitude 31.2°N and longitude 129.1°E which put it about 85 miles (135 km) west-southwest of Kagoshima, Japan. Khanun was moving toward the northwest at 7 m.p.h. (11 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 979 mb.

Bands in the eastern side of Tropical Storm Khanun brought winds and rain to Kyushu on Tuesday. There was an elliptical area of relatively clear skies at the center of Khanun’s circulation. A broken ring of thunderstorms with a diameter of 70 miles (110 km) surrounded the relatively clear area. The strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the center of Tropical Storm Khanun. Storms near the center generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 175 miles (280 km) from the center of Khanun’s circulation.

Tropical Storm Khanun will move through an environment that will be somewhat favorable for intensification during the next 24 hours. Khanun will move over water where the Sea Surface Temperatures are near 28˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Storm Khanun could intensify a little during the next 24 hours.

Tropical Storm Khanun will move around the western part of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Khanun toward the northwest during the next 24 hours. On its anticipated track, Tropical Storm Khanun will make landfall in South Korea in less than 24 hours. Khanun will bring gusty winds and locally heavy rain to South Korea. Heavy rain could cause flash floods in some locations. Bands in the eastern side of Tropical Storm Khanun will continue to produce gusty winds and locally heavy rain in Kyushu during the next 24 hours.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Lan intensified east of Iwo To. At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Lan was located at latitude 24.4°N and longitude 146.6°E which put it about 335 miles (540 km) east of Iwo To. Lan was moving toward the west at 7 m.p.h. (11 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 988 mb.

Tropical Storm Khanun Moves Toward Kyushu

Tropical Storm Khanun started to move toward Kyushu on Monday. At 11:00 p.m. EDT on Monday the center of Tropical Storm Khanun was located at latitude 29.1°N and longitude 130.7°E which put it about 195 miles (315 km) south of Kagoshima, Japan. Khanun was moving toward the north-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 981 mb.

Tropical Storm Khanun weakened on Monday. There still were no thunderstorms near the center of Khanun’s circulation. A large, mostly clear area was at the center of Tropical Storm Khanun. There were bands of showers and lower clouds within the mostly clear area. A broken ring of thunderstorms with a diameter of 90 miles (145 km) surrounded the mostly clear area. The strongest winds were occurring in the broken ring of storms. Storms in the ring generated upper level divergence that pumped mass away from the tropical storm. There were also bands of showers and thunderstorms outside the broken ring. Winds to tropical storm force extended out 200 miles (325 km) from the center of Tropical Storm Khanun.

Tropical Storm Khanun will move through an environment that will be somewhat favorable for intensification during the next 24 hours. Khanun will move over water where the Sea Surface Temperatures are near 28˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. If Tropical Storm Khanun intensifies during the next 24 hours, it is likely to strengthen slowly, because of the lack of thunderstorms in the inner core of its circulation. If thunderstorms form closer to the center of Khanun’s circulation, then it could start to intensify a little faster.

Tropical Storm Khanun will move around the western part of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Khanun toward the north-northwest during the next 24 hours. On its anticipated track, The center of Tropical Storm Khanun will be west of Kyushu in 24 hours. Bands in the eastern side of Tropical Storm Khanun will produce gusty winds and locally heavy rain in Kyushu. Heavy rain could cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Lan formed southeast of Japan. At 11:00 p.m. EDT on Monday the center of Tropical Storm Lan was located at latitude 24.6°N and longitude 148.8°E which put it about 485 miles (780 km) south of Kagoshima, Japan. Lan was moving toward the northwest 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 988 mb.

Tropical Storm Khanun Meanders over Northern Ryukyu Islands

Tropical Storm Khanun meandered over the northern Ryukyu Islands on Saturday. At 11:00 p.m. EDT on Saturday the center of Tropical Storm Khanun was located at latitude 27.5°N and longitude 129.8°E which put it about 125 miles (200 km) northeast of Okinawa. Khanun was moving toward the southeast at 8 m.p.h. (13 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 976 mb.

Tropical Storm Khanun meandered over the northern Ryukyu Islands on Saturday. The center of Khanun’s circulation was over Amami Oshima. Bands revolving around the center of Tropical Storm Khanun were bringing rain to Okinawa, Amami Oshima and other northern Ryukyu Islands. A weather station at Kadena Air Force Base was reporting a sustained wind speed of 35 m.p.h. (56 km/h) and a wind gust of 53 m.p.h. (85 km/h).

There was a large circulation around Tropical Storm Khanun. Winds to tropical storm force extended out 225 miles (360 km) from the center of Khanun. The region near the center of circulation contained bands of showers and low clouds. Farther away from the center, a band of thunderstorms stretched around the western, southern and eastern parts of Tropical Storm Khanun. Storms in that bands generated upper level divergence that pumped mass away from the tropical storm.

Tropical Storm Khanun will move through an environment that will be somewhat favorable for intensification during the next 24 hours. Khanun will move over water where the Sea Surface Temperatures are near 28˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. However, Tropical Storm Khanun will probably not intensify during the next 24 hours, because of the lack of thunderstorms in the inner core of its circulation. The large circulation around Tropical Storm Khanun seems to be in an equilibrium with its environment and the intensity may not change much during the next 24 hours..

Tropical Storm Khanun will move around the northwestern part of a subtropical high pressure system over the Western North Pacific Ocean. The high pressure system will steer Khanun slowly toward the east during the next 24 hours. On its anticipated track, the center of Tropical Storm Khanun will move a little to the east of the northern Ryukyu Islands during the next 24 hours. Tropical Storm Khanun will continue to produce strong, gusty winds and locally heavy rain in Okinawa, Amami Oshima and the other northern Ryukyu Islands. Prolonged heavy rain will cause flash floods in some locations.

Tropical Storm Khanun Brings Gusty Winds and Rain Back to Okinawa

Tropical Storm Khanun brought gusty winds and rain back to Okinawa on Friday night. A weather station at Kadena Air Force Base reported a sustained wind speed of 52 m.p.h. (84 km/h) and a wind gust of 69 m.p.h. (111 km/h). At 11:00 p.m. EDT on Friday the center of Tropical Storm Khanun was located at latitude 27.7°N and longitude 127.2°E which put it about 100 miles (160 km) northwest of Okinawa. Khanun was moving toward the east 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 972 mb.

Former Typhoon Khanun weakened to a tropical storm on Friday. The bands in the inner core of Khanun’s circulation consisted of low clouds and showers. Bands of thunderstorms were located in the eastern and southern parts of Tropical Storm Khanun. Bands in the northwestern part of Khanun also consisted primarily of showers and lower clouds. The bands of thunderstorms generated upper level divergence that pumped mass away to the east of the tropical storm. Winds to tropical storm force extended out 200 miles (325 km) from the center of Khanun’s circulation.

Tropical Storm Khanun will move through an environment that will be somewhat favorable for intensification during the next 24 hours . Khanun will move over water where the Sea Surface Temperatures are near 28˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. However, Tropical Storm Khanun is unlikely to intensify during the next 24 hours, because of the lack of thunderstorms in the inner core of its circulation. The large circulation around Tropical Storm Khanun seems to be in an equilibrium with its environment and the intensity may not change much during the next 36 hours..

Tropical Storm Khanun will move around the northwestern part of a subtropical high pressure system over the Western North Pacific Ocean. The high pressure system will steer Khanun toward the east during the next 24 hours. On its anticipated track, the center of Tropical Storm Khanun will pass north of Okinawa in 12 hours. The center of Khanun could pass over Amami Oshima in less than 24 hours. Tropical Storm Khanun will continue to produce strong, gusty winds and locally heavy rain in Okinawa, Amami Oshima and the other northern Ryukyu Islands. Heavy rain will cause flash floods in some locations.

Typhoon Khanun Stalls West of Okinawa

Typhoon Khanun stalled over the Western North Pacific Ocean west of Okinawa on Thursday. At 11:00 p.m. EDT on Thursday the center of Typhoon Khanun was located at latitude 27.1°N and longitude 124.8°E which put it about 200 miles (325 km) west of Okinawa. Khanun was moving toward the northeast at 4 m.p.h. (6 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 970 mb.

Typhoon Khanun weakened while it stalled west of Okinawa. Khanun had almost completed an eyewall replacement cyclone on Thursday night. The former inner eyewalll consisted of a ring of low clouds and showers. The strongest winds were occurring in the southern part of the ring of showers. A very large, broken outer eyewall with a diameter of 150 miles (240 km) surrounded the center of Typhoon Khanun. Bands of showers and thunderstorms were revolving around the outer eyewall. Storms around the outer eyewall generated upper level divergence that pumped mass away from the typhoon.

The circulation around Typhoon Khanun was large, even though Khanun was weaker. Winds to typhoon force extended out 50 miles (80 km) to the south of the center of Khanun. Winds to tropical storm force extended out 190 miles (305 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Khanun was 10.4. The Hurricane Size Index (HSI) was 14.7 and the Hurricane Wind Intensity Size Index (HWISI) was 25.1. Typhoon Khanun was capable of causing regional minor damage.

Typhoon Khanun will move through an environment that will be favorable for intensification during the next 24 hours. Khanun will move over water where the Sea Surface Temperatures are near 28˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. However, Typhoon Khanun is unlikely to intensify during the next 24 hours, because of the almost completed eyewall replacement cycle. The eyewall replacement cycle disrupted the inner core of Khanun. Typhoon Khanun is unlikely to intensify until the larger outer eyewall begins to contract closer to the center of circulation. Khanun could actually weaken a little more on Friday.

Typhoon Khanun will move around the northwestern part of a subtropical high pressure system over the Western North Pacific Ocean. The high pressure system will steer Khanun toward the east-northeast during the next 24 hours. On its anticipated track, Typhoon Khanun will move back toward the Ryukyu Islands during the next 24 hours. Typhoon Khanun will to produce strong, gusty winds and locally heavy rain in Okinawa and the other northern Ryukyu Islands. Heavy rain will cause flash floods in some locations. The center of Khanun could be just north of Okinawa in 36 hours.

Large Typhoon Khanun Churns West of Okinawa

Large Typhoon Khanun churned over the Western North Pacific Ocean west of Okinawa on Wednesday night. At 11:00 p.m. EDT on Wednesday the center of Typhoon Khanun was located at latitude 26.6°N and longitude 124.6°E which put it about 190 miles (310 km) west of Okinawa. Khanun was moving toward the west-northwest at 4 m.p.h. (6 km/h). The maximum sustained wind speed was 105 m.p.h. (1650 km/h) and there were wind gusts to 125 m.p.h. (200 km/h). The minimum surface pressure was 951 mb.

The inner end of a rainband wrapped around an existing eye and eyewall on Wednesday and concentric eyewalls formed in Typhoon Khanun. The inner eye had a diameter of 15 miles (25 km). The inner eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms. The inner eyewall was surrounded by a large clear area called a moat. The moat was surrounded by a large outer eyewall that had a diameter of 115 miles (185 km). Bands of showers and thunderstorms were revolving around the concentric eyewalls. Storms in the concentric eyewalls generated upper level divergence that pumped mass away from the typhoon.

The size of the circulation around Typhoon Khanun increased when the concentric eyewalls formed. Winds to typhoon force extended out 115 miles (185 km) from the center of Khanun’s circulation. Winds to tropical storm force extended out 235 miles (380 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Khanun was 17.8. The Hurricane Size Index (HSI) was 37.0 and the Hurricane Wind Intensity Size Index (HWISI) was 54.8. Khanun is capable of causing extensive serious damage. Typhoon Khanun was large than Hurricane Ivan was when Ivan hit the U.S. Gulf Coast in 2004. Khanun was not quite as strong as Ivan was.

Typhoon Khanun will move through an environment that will be favorable for a strong typhoon during the next 24 hours. Khanun will move over water where the Sea Surface Temperatures are near 28˚C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. However, Typhoon Khanun is likely to weaken during the next 24 hours, because of the concentric eyewalls. The inner eyewall is likely to weaken and the low level convergence will occur into the large, outer eyewall. Since the strongest winds are in the inner eyewall, the wind speed will decrease when the inner eyewall weakens.

Typhoon Khanun will be in an area where the steering currents are weak during the next 24 hours. On its anticipated track, Typhoon Khanun will meander west of Okinawa during the next 24 hours. Khanun is forecast to move back toward the east-northeast later this week. The center of Typhoon Khanun could pass north of Okinawa on Friday. Khanun is forecast move across the northern Ryukyu Islands in 48 hours. Typhoon Khanun will continue to produce strong, gusty winds and locally heavy rain in Okinawa and other Ryukyu Islands. Heavy rain will cause flash floods in some locations.