Typhoon Koinu Moves Southeast of Hong Kong

Typhoon Koinu moved southeast of Hong Kong on Friday night. At 11:00 p.m. EDT on Friday the center of Typhoon Koinu was located at latitude 21.1°N and longitude 115.3°E which put it about 115 miles (185 km) southeast of Hong Kong. Koinu was moving toward the west-southwest at 4 m.p.h. (6 km/h). The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h). The minimum surface pressure was 952 mb.

Typhoon Koinu intensified back to the equivalent of a major hurricane over the South China Sea southeast of Hong Kong on Friday. A circular eye with a diameter of 12 miles (19 km) was at the center of Koinu’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 revolved around the core of Typhoon Koinu. Storms near the core generated upper level divergence that pumped mass away from the typhoon.

Wins to typhoon force extended out 40 miles (65 km) from the center of Typhoon Koinu. Winds to tropical storm force extended out 285 miles (460 km) in the northeast quadrant of Koinu’s circulation. Winds to tropical storm force extended out 130 miles (210 km) in the other parts of Typhoon Koinu. The Hurricane Intensity Index (HII) for Typhoon Koinu was 22.1. The Hurricane Size Index (HSI) was 14.9 and the Hurricane Wind Intensity Size Index (HWISI) was 37.0. Typhoon Koinu was similar in size and intensity to Hurricane Harvey when Harvey hit Texas in 2017.

Typhoon Koinu will move through an environment somewhat favorable for a strong typhoon during the next 24 hours. Koinu will move over water where the Sea Surface Temperatures are near 28°C. It will move under the southern part of an upper level ridge over China. The ridge will produce easterly winds that will blow toward the top of Koinu’s circulation. Those winds will cause some vertical wind shear. The wind shear will inhibit intensification. The circulation around the northern side of Typhoon Koinu could draw in some drier air from China. Typhoon Koinu could maintain its intensity during the next 24 hours if the drier air does not reach the inner core of the circulation. Koinu is likely to weaken if the drier penetrates to the core of the circulation.

Typhoon Koinu will move will move around the southern part of a high pressure system over eastern Asia. The high pressure system will steer Koinu slowly toward the west-southwest during the next 24 hours. On its anticipated track the center Typhoon Koinu will move south of Hong Kong on Saturday.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 15W formed east-southeast of Guam. At 11:00 p.m. EDT on Friday the center of Tropical Depression 15W was located at latitude 9.9°N and longitude 154.2°E which put it about 700 miles (1130 km) east-southeast of Guam. The tropical depression was moving toward the west-northwest at 13 m.p.h. (21 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 1003 mb.

Tropical Storm Philippe Brings Gusty Winds to Bermuda

Tropical Storm Philippe brought gusty winds to Bermuda on Friday morning. At 11:00 a.m. EDT on Friday the center of Tropical Storm Philippe was located at latitude 30.7°N and longitude 64.6°W which put it about 110 miles (185 km) south of Bermuda. Philippe was moving toward the north-northeast at 16 m.p.h. (26 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 1003 mb.

The circulation around Tropical Storm Philippe brought gusty winds to Bermuda on Friday morning. A weather station at L.F. Wade International Airport (TXKF) reported a sustained wind speed of 30 m.p.h. (50 km/h) and a gust of 56 m.p.h. (91 km/h). A weather station at an elevated location near the Bermuda National Museum reported a sustained wind speed of 46 m.p.h. (74 km/h) and a wind gust of 57 m.p.h. (91 km/h). Philippe produce intermittent rain showers in Bermuda, but the heaviest rain passed to the east of Bermuda.

Tropical Storm Philippe made a transition to an extratropical cyclone on Friday morning. The circulation former Tropical Storm Philippe combined with a frontal system near Bermuda. A warm front extended to the east of the center of circulation and a cold front trailed south of the center. Winds to tropical storm force extended out 175 miles (280 km) in the eastern side of former Tropical Storm Philippe. The winds in the western side of the extratropical cyclone were blowing at less than tropical storm force.

Former Tropical Storm Philippe will move between a high pressure system over the Atlantic Ocean and an upper level trough over the Great Lakes. The high pressure system and the upper level trough will steer the extratropical cyclone toward the north during the next 48 hours. On its anticipated track, former Tropical Storm Philippe will affect the Northeast U.S. and the Canadian Maritimes during the weekend. The extratropical cyclone could produce locally heavy rain in some places. Heavy rain could cause flash floods in some locations. Gusty winds could knock down trees and localized outages of electricity are possible.

Typhoon Koinu Moves Toward Hong Kong

Typhoon Koinu moved toward Hong Kong on Thursday. At 11:00 p.m. EDT on Thursday the center of Typhoon Koinu was located at latitude 21.5°N and longitude 117.4°E which put it about 225 miles (365 km) east of Hong Kong. Koinu was moving toward the west at 8 m.p.h. (13 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. (165 km/h). The minimum surface pressure was 967 mb.

Typhoon Koinu moved over the South China Sea toward Hong Kong on Thursday. Koinu was weaker and smaller after passing over southern Taiwan on Wednesday. The circulation around Typhoon Koinu started to exhibit more organization again on Thursday evening. A circular eye with a diameter of 18 miles (30 km) was at the center of Koinu’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 revolved around the core of Typhoon Koinu. Storms near the core generated upper level divergence that pumped mass away from the typhoon.

Wins to typhoon force extended out 35 miles (55 km) from the center of Typhoon Koinu. Winds to tropical storm force extended out 285 miles (460 km) in the northeast quadrant of Koinu’s circulation. Winds to tropical storm force extended out 130 miles (210 km) in the other parts of Typhoon Koinu.

Typhoon Koinu will move through an environment somewhat favorable for intensification during the next 24 hours. Koinu will move over water where the Sea Surface Temperatures are near 28°C. It will move under the southern part of an upper level ridge over China. The ridge will produce easterly winds that will blow toward the top of Koinu’s circulation. Those winds will cause some vertical wind shear. The wind shear will inhibit intensification but the shear may not be strong enough to prevent intensification. The circulation around the northern side of Typhoon Koinu could start to draw in some drier air from China. Typhoon Koinu could intensify during the next 24 hours if the drier air does not reach the inner core of the circulation.

Typhoon Koinu will move will move around the southern part of a high pressure system over eastern Asia and the Western North Pacific Ocean. The high pressure system will steer Koinu toward the west during the next 24 hours. On its anticipated track the center Typhoon Koinu will move closer to Hong Kong on Friday.

Tropical Storm Lidia Moves South of Baja California

Tropical Storm Lidia moved south of Baja California on Wednesday. At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Lidia was located at latitude 15.6°N and longitude 109.4°W which put it about 505 miles (815 km) south of Cabo San Lucas, Mexico. Lidia was moving toward the northwest at 7 m.p.h. (11 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 1001 mb.

Tropical Storm Lidia strengthened gradually over the Eastern North Pacific Ocean south of Baja California on Wednesday. Even though Tropical Storm Lidia was a little stronger, the distribution of thunderstorms continued to be asymmetrical. Many of the thunderstorms were occurring in a bands in the western part of Lidia’s circulation. Bands in the eastern side of Tropical Storm Lidia consisted primarily of showers and lower clouds. More thunderstorms formed near the center of Lidia’s circulation on Wednesday evening. Storms near the center of circulation generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 70 miles (110 km) from the center of Lidia’s circulation.

Tropical Storm Lidia will move through an environment that will be a little more favorable for intensification during the next 24 hours. Lidia will move over water where the Sea Surface Temperatures are near 29°C. It will move under the southern part of an upper level ridge that extends from Mexico to the Eastern North Pacific Ocean. The ridge will produce easterly winds that will blow toward the top of Lidia’s circulation. Those winds will weaken a little on Thursday and there will be a little less vertical vertical wind shear. The reduction of wind shear could allow Tropical Storm Lidia intensify a little faster during the next 24 hours.

Tropical Storm Lidia will move around the western part of a high pressure system over Mexico. The high pressure system will steer Lidia toward the west-northwest during the next 24 hours. On its anticipated track, Tropical Storm Lidia will remain far to the south of Baja California on Thursday.

Typhoon Koinu Brings Wind and Rain to Taiwan

Typhoon Koinu brought wind and rain to Taiwan on Wednesday night. At 11:00 p.m. EDT on Wednesday the center of Typhoon Koinu was located at latitude 22.1°N and longitude 120.6°E which put it about 10 miles (15 km) west of Hengchun, Taiwan. Koinu was moving toward the west-northwest at 5 m.p.h. (8 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 945 mb.

Typhoon Koinu brought strong winds and heavy rain to southern Taiwan on Wednesday night. The eye of Koinu passed over the southern tip of Taiwan. The northern half of the eyewall moved across southern Taiwan. Typhoon Koinu was the equivalent of a major hurricane when it moved across Taiwan. Winds to typhoon force extended out 70 miles (110 km) from the center of Koinu’s circulation. Winds to tropical storm force extended out 230 miles (370 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Koinu was 23.6. The Hurricane Size Index (HSI) was 21.6 and the Hurricane Wind Intensity Size Index (HWISI) was 45.2. Typhoon Koinu was stronger than Hurricane Rita was when Rita hit southwest Louisiana in 2005. Koinu was a little smaller than Rita was.

Easterly winds blowing around the northern side of Typhoon Koinu will rise up the eastern slopes of mountains in Taiwan. The enhanced rising motion will produce very heavy rainfall on those eastern slopes. The heavy rain is likely to cause flash floods in some locations.

Typhoon Koinu will move will move around the southern part of a high pressure system over eastern Asia and the Western North Pacific Ocean. The high pressure system will steer Koinu toward the west during the next 24 hours. On its anticipated track the center Typhoon Koinu will move over the South China Sea on Thursday.

The core of Typhoon Koinu was partially disrupted when the eye and northern part of the eyewall moved across southern Taiwan. The disruption of the inner core of Koinu’s circulation is likely to cause Typhoon Koinu to weaken during the next 24 hours even though Koinu will move through an environment favorable for intensification. Koinu will move over water where the Sea Surface Temperatures are near 28°C. It will move under the southern part of an upper level ridge over China. The ridge will produce easterly winds that will blow toward the top of Koinu’s circulation. Those winds will cause some little vertical wind shear, but the wind shear will not be too strong. Typhoon Koinu is likely to weaken gradually during the next 24 hours because of the disruption of its inner core.

Philippe Prompts Tropical Storm Warning for Bermuda

The potential effects of Tropical Storm Philippe prompted Bermuda to issue a Tropical Storm Warning. At 5:00 p.m. EDT on Wednesday the center of Tropical Storm Philippe was located at latitude 22.6°N and longitude 65.9°W which put it about 675 miles (1085 km) south of Bermuda. Philippe was moving toward the north at 12 m.p.h. (19 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 Tropical Storm Warning was in effect for Bermuda.

Tropical Storm Philippe weakened a little more on Wednesday. An upper level trough east of Florida produced strong southwesterly winds that blew across the top of Philippe’s circulation. Those winds caused strong vertical wind shear. The strong upper level winds also blew the tops off of many of the thunderstorms in Tropical Storm Philippe. A few thunderstorms were able to develop in the southeastern quadrant of Philippe’s circulation. However, most of the bands revolving around the center of Philippe’s circulation consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 200 miles (320 km) in the eastern side of Philippe’s circulation. The winds in the western side of Tropical Storm Philippe were blowing at less than tropical storm force.

Tropical Storm Philippe will move through a region that will be unfavorable for intensification during the next 24 hours. Philippe will move over water where the Sea Surface Temperatures are near 29°C. However, the upper level trough east of Florida will continue to cause strong vertical wind shear. The strong wind shear will prevent Tropical Storm Philippe from intensifying during the next 24 hours.

Tropical Storm Philippe will move around the western part of a high pressure system over the Atlantic Ocean. The high pressure system will steer Philippe toward the north during the next 24 hours. On its anticipated track, Tropical Storm Philippe will move closer to Bermuda. Philippe could reach Bermuda on Friday.

Typhoon Koinu Approaches Taiwan

Typhoon Koinu approached Taiwan from east on Tuesday night. At 11:00 p.m. EDT on Tuesday the center of Typhoon Koinu was located at latitude 22.1°N and longitude 123.3°E which put it about 175 miles (280 km) east of Hengchun, Taiwan. Koinu was moving toward the west-northwest at 7 m.p.h. (11 km/h). The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (230 km/h). The minimum surface pressure was 953 mb.

Typhoon Koinu was the equivalent of a major hurricane as it approached Taiwan on Tuesday night. A circular eye with a diameter of 30 miles (50 km) was at the center of Koinu’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 Koinu. Storms near the core generated strong upper level divergence that pumped large quantities of mass away from the typhoon.

The size of the circulation around Typhoon Koinu increased on Tuesday. Winds to typhoon force extended out 90 miles (145 km) from the center of Koinu’s circulation. Winds to tropical storm force extended out 200 miles (320 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Koinu was 20.6. The Hurricane Size Index (HSI) was 29.2 and the Hurricane Wind Intensity Size Index (HWISI) was 49.8. Typhoon Koinu was similar in size and intensity to Hurricane Frances when Frances hit southeast Florida in 2004.

Typhoon Koinu will move through an environment favorable for intensification during the next 12 hours. Koinu 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 Koinu is likely to intensify during the next 12 hours.

Typhoon Koinu will move around the southern part of a high pressure system over eastern Asia and the Western North Pacific Ocean. The high pressure system will steer Koinu toward the west during the next 24 hours. On its anticipated track the center Typhoon Koinu will reach the coast of southeast Taiwan in less than 24 hours. Typhoon Koinu is likely to be the equivalent of a major hurricane when it approaches Taiwan. Koinu will bring strong, gusty winds and locally heavy rain to Taiwan. Heavy rain will cause flash floods in some locations. Typhoon Koinu could also cause widespread outages of electricity.

Philippe Weakens North of the Virgin Islands

Tropical Storm Philippe weakened north of the Virgin Islands on Tuesday. At 2:00 p.m. EDT on Tuesday the center of Tropical Storm Philippe was located at latitude 19.0°N and longitude 64.4°W which put it about 55 miles (90 km) northeast of St. Thomas. Philippe was moving toward the 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 1004 mb.

A Tropical Storm Watch was in effect for the British Virgin Islands.

Tropical Storm Philippe weakened north of the Virgin Islands on Tuesday. An upper level ridge over the eastern Caribbean Sea produced strong westerly winds that blew across the top of Philippe’s circulation. Those winds caused strong vertical wind shear. The strong upper level winds blew the tops off of most of the thunderstorms in the southeastern part of Tropical Storm Philippe. Most of the bands revolving around the center of Philippe’s circulation consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 170 miles (275 km) in the eastern side of Philippe’s circulation. The winds in the western side of Tropical Storm Philippe were blowing at less than tropical storm force.

Tropical Storm Philippe will move through a region that will be unfavorable for intensification during the next 24 hours. Philippe will move over water where the Sea Surface Temperatures are near 29°C. However, the upper level ridge over the eastern Caribbean Sea will continue to cause strong vertical wind shear. The wind shear will likely cause Tropical Storm Philippe to weaken more during the next 24 hours.

Tropical Storm Philippe will move around the southwestern part of a high pressure system over the Atlantic Ocean. The high pressure system will steer Philippe toward the north-northwest during the next 24 hours. On its anticipated track, Tropical Storm Philippe will move away from Puerto Rico and the Virgin Islands.

Bands in the southeastern part of Tropical Storm Philippe did drop heavy rain over the Northern Leeward Islands during Monday night and Tuesday morning. Heavy rain fell on parts of Guadeloupe, Antigua, Barbuda, and Anguilla. There were reports of flash floods in some locations.

Tropical Storm Lidia Forms Southwest of Mexico

Tropical Storm Lidia formed over the Eastern North Pacific Ocean southwest of Mexico on Tuesday morning. At 5:00 a.m. EDT on Tuesday the center of Tropical Storm Lidia was located at latitude 11.°N and longitude 107.0°W which put it about 790 miles (1270 km) south-southeast of Cabo San Lucas, Mexico. Lidia was moving toward the west-northwest at 9 m.p.h. (15 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1006 mb.

A low pressure system over the Eastern North Pacific Ocean southwest of Mexico strengthened on Tuesday morning and the U.S. National Hurricane Center designated the system as Tropical Storm Lidia. The distribution of thunderstorms in Tropical Storm Lidia was asymmetrical. Many of the thunderstorms were occurring in a bands in the western part of Lidia’s circulation. Bands in the eastern side of Tropical Storm Lidia consisted primarily of showers and lower clouds. Storms in the bands in the western part of Lidia started to generate upper level divergence that pumped mass away to the west of the tropical storm. Wind to tropical storm force extended out 35 miles (55 km) in the western side of Lidia’s circulation. The winds in the eastern part of the circulation were blowing at less than tropical storm force.

Tropical Storm Lidia will move through an environment somewhat favorable for intensification during the next 24 hours. Lidia will move over water where the Sea Surface Temperatures are near 30°C. It will move over the southern part of an upper level ridge that extends from Mexico to the Eastern North Pacific Ocean. The ridge will produce easterly winds that will blow toward the top of Lidia’s circulation. Those winds are contributing to the asymmetrical distribution of thunderstorms and they will continue to cause moderate vertical wind shear. The wind shear will inhibit intensification, but the shear may not be enough to stop Lidia from strengthening. Tropical Storm Lidia could intensify gradually during the next 24 hours.

Tropical Storm Lidia will move around the western part of a high pressure system over Mexico. The high pressure system will steer Lidia toward the west-northwest during the next 24 hours. On its anticipated track, Tropical Storm Lidia will move farther away from the west coast of Mexico.

Philippe Prompts Tropical Storm Warning for Barbuda

The proximity of Tropical Storm Philippe prompted the issuance of a Tropical Storm Warning for Barbuda. A Tropical Storm Watch was in effect for Antigua. At 11:00 a.m. EDT on Monday the center of Tropical Storm Philippe was located at latitude 17.1°N and longitude 60.7°W which put it about 80 miles (130 km) east-southeast of Barbuda. Philippe was moving toward the west-northwest at 7 m.p.h. (11 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 1000 mb.

A Tropical Storm Warning was in effect for Barbuda. A Tropical Storm Watch was in effect for Antigua.

The center of Tropical Storm Philippe moved closer to Barbuda on Monday morning. The circulation around Philippe did not change much since Sunday night. An upper level ridge over the eastern Caribbean Sea continued to produce northwesterly winds that blew toward the top of Philippe’s circulation. Those winds caused strong vertical wind shear . The vertical wind shear caused the distribution of thunderstorms in Tropical Storm Philippe to be asymmetrical. Most of the thunderstorms were occurring in bands in the southeastern part of Philippe’s circulation. Bands near the center of Tropical Storm Philippe and in the other parts of the circulation consisted primarily of showers and lower clouds. The distribution of wind speeds was also asymmetrical. Winds to tropical storm force extended out 170 miles (275 km) in the eastern side of Philippe’s circulation. The winds in the western side of Tropical Storm Philippe were blowing at less than tropical storm force.

Tropical Storm Philippe will move through a region that will be unfavorable for intensification during the next 12 hours. Philippe will move over water where the Sea Surface Temperatures are near 29°C. However, the upper level ridge over the eastern Caribbean Sea will continue to cause strong vertical wind shear. The wind shear is likely to prevent intensification of Tropical Storm Philippe during the next 12 hours. Philippe could move into a region where the upper level winds are weaker on Tuesday. If the vertical wind shear decreases, then Tropical Storm Philippe could start to intensify.

Tropical Storm Philippe will move around the southwestern part of a high pressure system over the Atlantic Ocean. The high pressure system will steer Philippe toward the northwest during the next 24 hours. On its anticipated track, the center Tropical Storm Philippe will pass near Barbuda during Monday night. The strongest winds in Philippe’s circulation are likely to pass east of Barbuda. Winds to tropical storm force could affect Barbuda, if the center moves close enough to the island. The winds in Barbuda and Antigua will blow from the south after Tropical Storm Philippe moves north of the islands. A band of heavier rain could pass over Barbuda and Antigua on Tuesday. Heavier rain could cause flash floods in some locations.