Tag Archives: Taiwan

Typhoon Nida Makes Landfall Near Hong Kong

Typhoon Nida made landfall on Monday near Hong Kong on the coast of China.  At 5:00 p.m. EDT on Monday the center of Typhoon Nida was located at latitude 22.8°N and longitude 114.4°E which put it about 50 miles (80 km) east-northeast of Hong Kong.  Nida was moving toward the northwest t 13 m.p.h.  The maximum sustained wind speed was 95 m.p.h. (155 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 963 mb.

Typhoon Nida made landfall on the southeast coast of China just to the north of Hong Kong.  The core of Nida is large and the typhoon is capable of causing wind damage on a regional scale.  Wind blowing toward the coast could also generate a storm surge until Typhoon Nida moves farther inland.  However, very heavy rain and fresh water flooding are much greater risks as Nida moves farther inland over China.

A subtropical ridge north of Nida is steering the typhoon toward the northwest and that general motion is expected to continue for the next several days.  The ridge will steer Nida farther inland over southeastern China.  Typhoon Nida’s fairly slow motion and large size mean that heavy rain could fall over an expansive area.  The risk for flooding will continue as Nida moves inland.

Typhoon Nida Brushes Luzon and Heads for Hong Kong

Typhoon Nida brought wind and rain to northern Luzon on Sunday as it continued to move toward Hong Kong on the coast of China.  At 11:00 p.m. EDT on Sunday the center of Typhoon Nida was located at latitude 20.4°N and longitude 118.3°E which put it about 340 miles (545 km) east-southeast of Hong Kong.  Nida was moving toward the west-northwest at 17 m.p.h. (27 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 Nida is 10.4.  The Hurricane Size Index (HSI) is 13.1 and the Hurricane Wind Intensity Size Index (HWISI) is 23.5.  These indices suggest that Typhoon Nida will be capable of causing minor wind damage on a regional scale.

The structure of Typhoon Nida changed significantly on Sunday.  The primary rainband wrapped around the core of the circulation and a very large eye was created at the center.  The diameter of the eye is approximately 50 miles (80 km).  The strongest winds are occurring in the ring of thunderstorms that surrounds the eye.  Other spiral bands of thunderstorms are rotating around the large eye.  The thunderstorms were generating upper level divergence which pumped out mass and allowed the surface pressure to decrease.

Typhoon Nida is in an environment that would favor intensification.  It is moving over water where the Sea Surface Temperature is near 30°C.  Easterly winds are blowing in the upper levels, but there is not much vertical wind shear.  The large size of the eye of Nida is the major factor inhibiting intensification.  It takes more energy to increase the wind speed in a large typhoon than it does in a smaller storm.  If the eye contracts, then Typhoon Nida could intensify more before it makes landfall.

A subtropical ridge north of Nida is steering the typhoon toward the west-northwest and that general motion is expected to continue for another day or so.  On its anticipated track Typhoon Nida will be very near Hong Kong in about 24 hours.

As mentioned above, the large size of Typhoon Nida means that it will be capable of causing wind damage on a regional scale.  In addition, Typhoon Nida will be capable of creating a significant storm surge when it moves into the coast of China.  A large slow moving typhoon like Nida will also produce heavy rain and flooding as it moves inland.

Intensifying Tropical Storm Nida Nears Northern Philippines

Tropical Storm Nida intensified on Saturday as it slowly approached the northern portion of Luzon in the Philippines.  At 5:00 p.m. EDT (2100 UTC) the center of of Tropical Storm Nida was located at latitude 16.5°N and longitude 123.8°E which put it about 245 miles (395 km) east-northeast of Manila, Philippines.  Nida was moving toward the west-northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 50 m.p.h. (95 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 Nida has become increasingly well organized during the past 24 hours.  A primary rainband wraps about two thirds of the way around the western and southern sides of the center of circulation.  Additional spiral bands of thunderstorms are developing outside the core of the circulation.  Rising motion associated with the convection is generating upper level divergence which is pumping out mass and allowing the surface pressure to decrease.

Tropical Storm Nida is moving through an environment that is very favorable for further intensification.  It is moving over water where the Sea Surface Temperature (SST) is near 31°C.  Nida is beneath an upper level ridge where the upper level winds are light and there is little vertical wind shear.  Very warm SSTs and little wind shear will allow the circulation of Tropical Storm Nida to consolidate further and it should continue to intensify.  Nida could intensify rapidly once an eye starts to form at the center of circulation.  Tropical Storm Nida will move near or over the northeastern part of Luzon.  Interaction with land could slow or temporarily stop the intensification.  However, Tropical Storm Nida should intensify further after it move wests of the Philippines.

A subtropical ridge north of Nida is steering the tropical storm toward the west-northwest and that general motion is expected to continue.  On its anticipated track Tropical Storm Nida could move over the northern part of Luzon during the next 12 to 24 hours.  Nida could approach the area around Hong Kong as a typhoon in about 48 hours.

The primary threats posed by Tropical Storm Nida to the Philippines are locally heavy rain and flash floods.  Tropical Storm Nida could generate very heavy rain in locations where the circulation causes the wind to blow up the slopes of mountains.  Heavy rain falling on steep terrain in those locations could also cause flash flooding.  Nida could be a typhoon by the time it reaches the part of China near Hong Kong.  Nida will be capable of producing some wind damage and storm surge in addition to heavy rain and flooding when it reaches the coast of China.

Weakened Tropical Storm Nepartak Still Bringing Rain to Parts of China and Taiwan

Although Tropical Storm Nepartak was weakened significantly during its passage over the mountains on Taiwan, it is still producing heavy rain over portions of eastern China and Taiwan.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Nepartak was located at latitude 24.0°N and longitude 119.0°E which put it about 100 miles (160 km) east-southeast of Xiamen, China.  Nepartak was moving toward the northwest at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 70 m.p.h. (115 km/h) and there were wind gusts to 85 m.p.h. (140 km/h).  The minimum surface pressure was 978 mb.

Typhoon Nepartak brought damaging winds and heavy rainfall to Taiwan when the core of the tropical cyclone passed over that area.  The mountains on Taiwan significantly disrupted the lower levels of the circulation.  There are some indications on satellite imagery that the upper portion of the circulation is located northwest of the surface center.  When a typhoon crosses Taiwan, the mountains can cause the original center of circulation to weaken and a new center can sometimes form over the water on the downstream side of the island.

In any case, crossing over Taiwan caused Nepartak to weaken to a tropical storm and the circulation no longer exhibits a tight inner core.  However, there are still rainbands that are producing heavy rain and wind speeds to almost typhoon force.   Because Nepartak no longer has a tight inner core, it is unlikely to intensify significantly before the centers moves into eastern China.

A ridge northeast of Nepartak is steering the tropical storm toward the northwest and that general motion is expected to continue for the next 12 to 24 hours.  After that time Nepartak is expected to turn toward the north.  On its anticipated track Tropical Storm Nepartak will make landfall in China between Xiamen and Fuqing on Saturday.

Tropical Storm Nepartak could produce locally heavy rainfall over portions of eastern China.  Some of that region has already received a lot of rain from other weather systems.  So, the potential for additional flooding is high in some areas.

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 Koppu Still Affecting Northern Luzon

The center of Typhoon Koppu moved across northern Luzon on Sunday and it is still affecting that region.  At 11:00 p.m. EDT on Sunday the center of Typhoon Koppu was located at latitude 17.5°N and longitude 120.3°E which put it about 200 miles (320 km) north-northwest of Manila, Philippines and just west of the coast of northwestern Luzon.  Koppu was moving toward the north-northeast at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 105 m.p.h. (170 km/h).  The minimum surface pressure was 968 mb.

Passage over northern Luzon weakened Typhoon Koppu and its structure is asymmetrical.  Most of the stronger thunderstorms are located in the western half of the circulation.  Much of the eastern half of the circulation is still over Luzon and there are few thunderstorms there.  The center of circulation is just west of Luzon.  Since it is back over water, the core of the typhoon could start to reorganize.  Intensification will be limited because of the large proportion of the circulation which is over land.

Koppu is near the western end of a subtropical ridge, which is causing the typhoon to move slowly northward.  That motion could continue for another 24 to 36 hours.  Eventually the ridge is expected to strengthen and push Typhoon Koppu northward at a faster speed.  Typhoon Koppu will continue to bring heavy rain to parts of northern Luzon for another day or two.