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Typhoon Nepartak Pounding Taiwan

Typhoon Nepartak is pounding Taiwan with strong winds and heavy rain.  The eye will make landfall during the next few hours near T’aitung.  At 5:00 p.m. EDT on Thursday the center of Typhoon Nepartak was located at latitude 22.7°N and longitude 121.4°E which put it about 185 miles (305 km) south of Taipei, Taiwan.  Nepartak was moving toward the west-northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 150 m.p.h. (240 km/h) and there were wind gusts to 185 m.p.h. (295 km/h).  The minimum surface pressure was 926 mb.

Typhoon Nepartak is the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale.  The Hurricane Intensity Index (HII) for Nepartak is 31.5.  The Hurricane Size Index (HSI) is 20.5, and the Hurricane Wind Intensity Size Index (HWISI) is 52.0.  These indices mean that Typhoon Nepartak is capable of causing widespread significant damage as it crosses Taiwan.

In addition to the strong winds locally heavy rain could cause flash floods, especially in the mountains of Taiwan.

The circulation of Typhoon Nepartak is very well organized.  It has a well formed eye which is surrounded by a ring of strong thunderstorms.  Numerous rainbands are rotating around the typhoon.

The atmospheric environment is favorable for strong tropical cyclones.  The winds in the upper levels are weak and there is little vertical wind shear.  However, the mountains on Taiwan will disrupt the lower part of the circulation and Typhoon Nepartak will weaken significantly when it crosses the island.  It will take about 12 hours for the typhoon to move across Taiwan.  Nepartak could still be a typhoon when the center emerges over the Taiwan Strait on Friday.

Typhoon Nepartak is expected to also make landfall on the east coast of China between Xiamen and Fuzhou.  Although it will be much weaker, Nepartak could cause some wind damage when it reaches China.  However, heavy rain will be a greater risk because it cause significant flooding in parts of eastern China.

Dangerous Super Typhoon Nepartak Closing In On Taiwan

Dangerous Super Typhoon Nepartak closed in on Taiwan on Wednesday.  At 11:00 a.m. EDT on Wednesday the center of Typhoon Nepartak was located at latitude 20.5°N and longitude 126.3°E which put it about 480 miles (775 km) southeast of Taipei, Taiwan. Nepartak was moving toward the west-northwest at 19 m.p.h. (31 km/h).  The maximum sustained wind speed was 175 m.p.h. (280 km/h) and there were wind gusts to 210 m.p.h. (335 km/h).  The minimum surface pressure was 911 mb.

Typhoon Nepartak is the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale.  The Hurricane Intensity Index (HII) for Nepartak was 40.3.  The Hurricane Size Index (HSI) was 18.8 and the Hurricane Wind Intensity Size Index (HWISI) was 59.1.  These indices mean that Typhoon Nepartak is capable of producing regional catastrophic damage.  As a point of comparison, Typhoon Nepartak is almost as strong as and slightly smaller than Hurricane Rita was when Rita was a Category 5 hurricane over the Gulf of Mexico in 2005.

The circulation of Typhoon Nepartak is very well organized.  It is symmetrical and winds to typhoon force extend out about 45 miles (75 km) from the center.  There is a very small eye at the center of Nepartak and the eye is surrounded by a ring of very strong thunderstorms.  The thunderstorms around the eye are generating strong upper level divergence which is offsetting the flow of mass into the typhoon near the surface.  The upper level divergence is allowing the pressure to stay low and strong winds to persist.  Spiral bands of thunderstorms are rotating around the core of the typhoon.

Typhoon Nepartak is in an ideal environment for a tropical cyclone.  It is moving over water where the Sea Surface Temperature (SST) is near 31°C.  The upper level winds are weak and there is almost no vertical wind shear.  Typhoon Nepartak is likely to maintain its intensity as it approaches the coast of Taiwan.

A subtropical ridge northeast of Nepartak is steering the typhoon toward the west-northwest and that general motion is expected to continue for another 24 to 36 hours.  On its anticipated track Typhoon Nepartak will make landfall along the central portion of the east coast of Taiwan in 12 to 18 hours.  After it moves across Taiwan, Nepartak is expected to make another landfall on the east coast of China.

Nepartak is a strong and dangerous typhoon.  It is capable of causing catastrophic damage over portions of Taiwan.  Nepartak will also produce very rainfall which is likely to cause flash floods and mudslides.  Nepartak will weaken when it moves over Taiwan, but it could still be a typhoon when it reaches the east coast of China.  Nepartak could also bring heavy rain and floods to parts of eastern China.

Typhoon Nepartak Rapidly Intensifies As It Moves Toward Taiwan

Typhoon Nepartak intensified rapidly on Tuesday and it is now the equivalent of a major hurricane.  At 11:00 a.m. EDT on Tuesday the center of Typhoon Nepartak was located at latitude 17.6°N and longitude 132.7°E which put it about 945 miles (1525 km) east-southeast of Taipei, Taiwan.  Nepartak was moving toward west-northwest at 21 m.p.h. (34 km/h).  The maximum sustained wind speed was 140 m.p.h. (225 km/h) and there were wind gusts to 165 m.p.h. (270 km/h).  The minimum surface pressure was 933 mb.

Tyyphoon Nepartak is the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale.  The Hurricane Intensity Index (HII) for Nepartak is 28.3.  The Hurricane Size Index (HSI) is 16.6 and the Hurricane Wind Intensity Size Index (HWISI) is 44.9.  These indices mean that Nepartak is capable of causing regionalized significant damage.

Typhoon Nepartak is very well organized.  It has a well formed eye, which is surround by a ring of strong thunderstorms.  Additional spiral bands of thunderstorms are rotating around the core of the circulation.  Nepartak is generating strong upper level divergence which is pumping out a lot of mass and is allowing the surface pressure to decrease rapidly.

Typhoon Nepartak is in an environment that is favorable for further intensification.  It is moving over water where the Sea Surface Temperature (SST) is near 31°C.  The upper level winds are weak and there is very little vertical wind shear.  Nepartak could intensify into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale during the next 24 to 36 hours.  If one of the rainbands wraps around the existing eye, then concentric eyewalls could form.  If concentric eyewalls develop, then an ensuing eyewall replacement cycle could cause fluctuations in the intensity of Typhoon Nepartak.

A subtropical ridge northeast of Nepartak is steering the typhoon toward the west-northwest and that general motion is expected to continue for another day or two.  On its anticipated track Typhoon Nepartak could be very near the southernmost islands of Japan and the coast of Taiwan in 36 to 48 hours.  It is likely to be a strong typhoon at that time.  Nepartak could cause significant wind damage.  It could also produce heavy rain that could lead to flash floods and mudslides.

Nepartak Intensifies Into a Typhoon

Tropical Storm Nepartak intensified into a typhoon on Monday as it moved west of Guam.  At 11:00 p.m. EDT on Monday the center of Typhoon Nepartak was located at latitude 15.8°N and longitude 136.0°E which put it about 870 miles (1400 km) southeast of Okinawa.  Nepartak was moving toward the west-northwest at 20 m.p.h. (32 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 974 mb.

The Hurricane Intensity Index (HII) for Typhoon Nepartak was 10.4.  The Hurricane Size Index (HSI) was 3.7 and the Hurricane Wind Intensity Size Index (HWISI) was 14.1.

The structure of Typhoon Nepartak improved on Monday.  A circular area of strong thunderstorms developed at the center of circulation.  Those thunderstorms generated upper level divergence that pumped out mass in all directions, which allowed the surface pressure to decrease.  Several other bands of thunderstorms spiraled around the core of Nepartak.

Typhoon Nepartak is moving over water where the Sea Surface Temperature (SST) is near 31°C.  Nepartak moved into an area where the upper level winds were weaker and the vertical wind shear was reduced.  The combination of very warm water and reduced shear allowed Nepartak to organize and strengthen into a typhoon.  It is expected to remain in an environment favorable for intensification, and Nepartak will grow into a stronger typhoon during the next several days.

A ridge of high pressure northeast of Nepartak is steering the typhoon toward the west-northwest and that general motion is expected to continue for the next several days.  On its anticipated track Typhoon Nepartak could be approaching the southernmost islands of Japan and Taiwan in 48 to 60 hours.  It could be a very strong typhoon at that time.

Tropical Storm Nepartak Develops South of Guam

A center of circulation organized within an area of thunderstorms south of Guam and the system was designated Tropical Storm Nepartak.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Nepartak was located at latitude 12.2°N and longitude 141.4°E which put it about 215 miles (345 km) west-southwest of Guam.  Nepartak was moving northwest at 16 m.p.h. (26 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 989 mb.

The circulation of Tropical Storm Nepartak is still organizing.  A primary rainband wrapped around the center and a circular area of thunderstorms formed at the core of the circulation.  The area of thunderstorms is generating upper level divergence which is pumping out mass and allowing the surface pressure to decrease.  Winds to tropical storm force extend our about 100 miles (160 km) from the center of circulation.

An upper level low located north of Nepartak is producing southwesterly winds which area blowing over the top of the tropical storm.  Those winds are creating some vertical wind shear, which is slowing the intensification of Nepartak.  However, the upper low is also enhancing upper level divergence to the northeast of the tropical storm.  Nepartak is moving over water where the Sea Surface Temperature is near 30°C.  The environment is favorable for intensification and Nepartak could become a hurricane during the next several days.

A subtropical ridge located northeast of Nepartak is steering the tropical storm toward the northwest.  That general motion is expected to continue during the next few days.  On its anticipated track, Nepartak could be approaching the southernmost islands of Japan in three or four days.  It is likely to be a typhoon at that time.

Typhoon Goni Passing West of Okinawa

The center of powerful Typhoon Goni is passing west of Okinawa.  At 11:00 p.m. EDT on Sunday the center of Typhoon Goni was located at latitude 26.9°N and longitude 126.3°E which put it about 125 miles (200 km) west of Okinawa.  Goni was moving northeast at 18 m.p.h. (29 km/h).  The maximum sustained wind speed 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 937 mb.

An upper level trough northwest of Goni contributed to the development of an outflow channel which pumped out mass and allowed the typhoon to intensify on Sunday.  Goni is a strong well organized typhoon with an eye and a well formed eyewall.  Spiral bands of thunderstorms are rotating around the core of the circulation.  A weather station on Ishigaki Jima, Japan reported a wind gust to 97 m.p.h. (155 km/h) when Goni passed over the island.  Goni is moving over warm Sea Surface Temperatures (SSTs) and it could maintain its intensity for another 24 hours.  After that time it will move over cooler SSTs and the upper level trough will generate more vertical wind shear.  Goni will finally start to spin down when it moves west of Kyushu.

The upper level trough will continue to pull Goni toward the northeast.  On its anticipated track Typhoon Goni will approach western Kyushu in about 24 hours.  It could bring strong winds and heavy rain to parts of western Japan.

Typhoon Goni Heading Toward Western Japan

Typhoon Goni turned north-northeastward and began moving toward western Japan on Saturday.  At 5:00 p.m. EDT on Saturday the center of Typhoon Goni was located at latitude 22.7°N and longitude 123.4°E which put it about 270 miles (435 km) southeast of Taipei, Taiwan and about 410 miles (660 km) southwest of Okinawa.  Goni was moving toward the north-northeast at 11 m.p.h. (18 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 967 mb.

The circulation of Typhoon Goni continues to be well organized.  It has a small eye with a fairly continuous eyewall surrounding it.  There are multiple spiral bands and the strongest band is about 60 miles east of the center of circulation.  There is upper level divergence pumping out mass.  Goni is moving over warm Sea Surface Temperatures and the upper level winds are relatively light.  The environment is favorable for intensification and modest intensification is possible during the next day or so.

Goni is moving around the western end of a subtropical ridge which is steering it toward the north-northeast.  That steering pattern is expected to continue for another two or three days.  On its anticipated track Goni will be near Ishigaki Jima in about 12 hours.  It could be just west of Okinawa in about 30 hours and it could be approaching Kyushu in about 48 hours.  Goni will bring strong winds and heavy rains to any places in its path.

Typhoon Halola Nearing Ryukyu Islands

Typhoon Halola turned northwestward on Friday and it is nearing the Ryukyu Islands.  At 5:00 p.m. EDT on Friday the center of Typhoon Halola was located at latitude 25.8°N and longitude 130.2°E which put it about 185 miles (300 km) east-southeast of Okinawa and about 50 miles (80 km) west-southwest of Minamidiato Island.  Halola was moving toward the northwest 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 974 mb.

Halala weakened on Friday, but it was still a typhoon at the time of this post.  It has a well defined low level circulation, but there are fewer thunderstorms in northwestern portion of Halola.  It appears as if some drier air is moving into the northwestern side of the typhoon.  Upper level winds from the northeast are creating some vertical wind shear, but Halola has well developed upper level divergence to the south of the center.  Halola will move over water where the Sea Surface Temperature (SST) is near 28°C as it passes just north of Okinawa and it could stay at typhoon intensity for another 12 to 24 hours.  After that time it will move over cooler SSTs and the upper level winds will increase.  Halola is likely to weaken to a tropical storm over the weekend.

Typhoon Halola is moving around the western end of a subtropical ridge, which is why it has turned toward the northwest.  It will turn northward on Saturday and then turn northeastward in about 36 hours as strong upper level winds from the southwest begin to push it in that direction.  On its anticipated track the center of Typhoon Halola could pass between Okinawa and Amami in to 18 hours.  It is likely to bring wind and heavy rain to some of the Ryukyu Islands.  The center of Halola could be near or just west of Kyushu in about 36 hours.

Typhoon Halola Heading Toward Okinawa

Typhoon Halola moved steadily toward the west-northwest on Wednesday and it moved to within 550 miles of Okinawa.  At 11:00 p.m. EDT on Wednesday the center of Typhoon Halola was located at latitude 24.4°N and longitude 135.4°E which put it about 525 miles (850 km) east-southeast of Okinawa.  Halola was moving toward the west-northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 105 m.p.h. (170 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 956 mb.

The organization of Typhoon Halola improved on Wednesday.  There is an inner eye and a primary rainband may be wrapping around the center as well.  The circulation is more symmetrical and more thunderstorms formed on the western side of the typhoon.  There is well developed upper level divergence over the southeastern half of Halola.  Upper level winds from the northeast are inhibiting some of the upper level divergence over the northwestern part of Halola.  Since the typhoon is still over warm Sea Surface Temperatures (SSTs), it has the potential to intensify further during the next several days.  If the primary rainband wraps entirely around the circulation and creates concentric eyewalls, then an eyewall replacement cycle could cause fluctuations in intensity.

A subtropical ridge is steering Halola toward the west-northwest and that general motion is expected to continue for another two days.  After about 48 hours Halola will reach the western end of the ridge and turn toward the north.  Halola could threaten southwestern Japan or South Korea over the weekend.  On its anticipated track Halola will approach Okinawa in about 48 hours.  It could be a significant typhoon at that time and bring strong winds and heavy rain to the islands around Okinawa.

Halola Becomes a Typhoon South of Japan

A tropical cyclone named Halola intensified a few hundred miles south of Japan on Tuesday and it reached typhoon intensity.  At 5:00 p.m. EDT on Tuesday the center of Typhoon Halola was located at latitude 23.1°N and longitude 140.2°E which put it about 840 miles (1360 km) east-southeast of Okinawa.  Halola was moving toward the west at 11 m.p.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).  The minimum surface pressure was 967 mb.

Typhoon Halola is moving over water where the Sea Surface Temperature (SST) is near 28°C.  The circulation is relatively well organized and an eye has been visible intermittently on satellite imagery.  There are many more thunderstorms in the eastern half of the circulation and there have been breaks in the western side of the eyewall at times.  It could be that there is some drier air to the northwest of the center.  Halola is currently moving through a region where the upper level winds are relatively light and there has not been much vertical wind shear today.  The lack of wind shear has allowed upper level outflow to become well developed to the east and south of the center of circulation.  Halola has the potential to intensify further during the next 48 hours while it is a region of modest vertical wind shear.

A subtropical ridge is steering Halola toward the west and a general west-northwestward movement is expected to continue during the next several days.  In two or three days Halola will reach the western end of the subtropical ridge and it will turn toward the north.  Guidance from numerical models varies on the strength of the subtropical ridge and the timing of the northward turn.  It is possible that Halola could threaten southwestern Japan later this week.