Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Tropical Storm Goni Prompts Watches for Marianas

Tropical Storm Goni formed east of the Marianas on Friday and watches were issued for some of the islands because of the imminent threat it posed.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Goni was located at latitude 13.0°N and longitude 148.0°E which put it about 235 miles (370 km) southeast of Saipan.  Goni was moving toward the west-northwest at 10 m.p.h. (16 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 996 mb.  A Typhoon Watch has been issued for Saipan and Tinian.  A Tropical Storm Watch has been issued for Guam and Rota.

The circulation of Tropical Storm Goni is still organizing.  Most of the thunderstorms are developing in the western half of the circulation.  An upper level ridge is generating easterly winds which are blowing across Goni and those winds are inhibiting the development of convection in the eastern part of the tropical storm.  Goni is moving over water where the Sea Surface Temperatures (SSTs) are near 29°C.  The environment supports intensification and Goni could intensify more rapidly in a day or two when the circulation is more well organized.  Goni could reach typhoon intensity within 48 hours.

A subtropical ridge is steering Goni toward the west-northwest and that general motion is expected to continue during the next few days.  On its anticipated track, the center of Goni could be very near Saipan in about 24 hours.  Goni could be a strong tropical storm on the verge of becoming a typhoon at that time.  Saipan is still recovering from the effects of Typhoon Soudelor.  Strong winds and heavy rain could set back those recovery efforts.

 

Typhoon Soudelor Making Landfall in China

Typhoon Soudelor crossed the Taiwan Strait and it is making landfall on the east coast of China near Quanzhou.  At 11:00 a.m. EDT on Saturday the center of Typhoon Soudelor was located at latitude 24.9°N and longitude 118.9°E which put it about 50 miles east of Quanzhou.  Soudelor was moving to the northwest at 10 m.p.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.

Soudelor weakened when it moved across Taiwan on Friday, but it was still a large typhoon when it made landfall in China.  Soudelor is expected to move toward the northwest while it moves farther inland over China.  Soudelor produced heavy rain when it moved over Taiwan and it could cause locally heavy rainfall over parts of eastern China before it dissipates.

Typhoon Soudelor Making Landfall in Taiwan

Powerful Typhoon Soudelor is making landfall on the east coast of Taiwan.  At 5:00 p.m. EDT on Friday the center of Typhoon Soudelor was located at latitude 23.8°N and longitude 122.1°E which put it about 125 miles (200 km) southeast of Taipei, Taiwan.  Soudelor was moving toward the northwest at 15 m.p.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 944 mb.

Soudelor is a large and powerful typhoon.  Winds to hurricane force extend out to 45 miles (70 km) from the center and tropical storm force winds extend out up to 250 miles (400 km) from the center.  Chiang Kai Shek airport reported winds to 53 m.p.h. (85 km/h) with gusts to 87 m.p.h. (140 km/h) when the center was still 125 miles away.  The Hurricane Intensity Index (HII) for Soudelor is 22.1, the Hurricane Size Index (HSI) is 17.7 and the Hurricane Wind Intensity Size Index (HWISI) is 39.8, which means that Soudelor is capable of causing regional major damage.  The HWISI for Soudelor is most similar to that for Hurricane Dennis when it hit the northwest Florida in 2005.  Soudelor is not quite as strong as Dennis was, but it is larger.  In addition to strong winds, heavy rain and the mountainous terrain of Taiwan create the potential for serious flooding.

Soudelor will weaken as it moves across Taiwan, but it could still be a typhoon when it emerges over the Taiwan Strait.  On its anticipated track, Typhoon Soudelor could make a second landfall near Fuzhou, China in 12 to 18 hours.  It could also bring strong winds and heavy rains to part of eastern China.

Strong Typhoon Soudelor Approaching Taiwan

Typhoon Soudelor continued to move steadily toward Taiwan on Thursday.  At 11:00 p.m. EDT on Thursday the center of Typhoon Soudelor was located at latitude 22.1°N and longitude 125.2°E which put it about 340 miles (550 km) south-southwest of Okinawa and about 420 miles (670 km) east-southeast of Taipei, Taiwan.  Soudelor was moving toward the west-northwest at 12 m.p.h. (19 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 944 mb.

Soudelor is a large symmetrical typhoon with multiple rainbands.  It has well-developed upper level divergence.  Soudelor completed an eyewall replacement cycle and it is now intensifying again.  The typhoon is moving over water where the Sea Surface Temperature is near 29°C and there is little vertical wind shear.  It is in a favorable environment and further intensification is possible before it makes landfall in Taiwan.  Soudelor will weaken while it moves across Taiwan.

A subtropical ridge is steering Soudelor toward the west-northwest and that general motion is expected to continue for another day or two.  On its anticipated track Soudelor will make landfall in Taiwan within 24 hours.  It will bring strong winds and heavy rainfall to Taiwan.  Soudelor has the potential to be a destructive typhoon.

Typhoon Soudelor Heading for Taiwan

Typhoon Soudelor moved steadily closer to Taiwan on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Typhoon Soudelor was located at latitude 20.6°N and longitude 129.7°E which put it about 450 miles (725 km) south-southeast of Okinawa and about 730 miles (1170 km) east-southeast of Taipei, Taiwan.  Soudelor was moving toward the west-northwest at 14 m.p.h. (23 km/h).  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h).  The minimum surface pressure was 952 mb.

Typhoon Soudelor went through an eyewall replacement cycle that resulted in temporary weakening while the inner eye dissipated and the outer eyewall contracted.  Soudelor appears to have completed the cycle and the convection in the new eyewall is growing.  The typhoon is in a very favorable environment.  The Sea Surface Temperature is near 30°C.  Upper level winds are very light and there is almost no vertical wind shear.  The circulation is very symmetrical with multiple rainbands.  Upper level divergence is pumping out mass in all directions.  Soudelor is likely to re-intensify during the next two days.

A subtropical ridge is steering Soudelor toward the west-northwest and that general steering pattern is expected to continue for another two or three days.  On its anticipated track Soudelor would reach Taiwan in less than 48 hours.  It could be a large and powerful typhoon when it gets there.  It is likely to bring strong winds and heavy rain.  Soudelor will weaken as it crosses Taiwan and then it will make a second landfall in China.

Typhoon Soudelor Becomes Equivalent of a Category 5 Hurricane

Typhoon Soudelor continued to intensify rapidly on Monday and it reached the equivalent of a Category 5 Hurricane on the Saffir-Simpson Scale.  At 5:00 p.m. EDT on Monday the center of Typhoon Soudelor was located at latitude 18.0°N and longitude 140.1°E which put it about 1020 miles (1640 km) east-southeast of Okinawa.  Soudelor was moving toward the west-northwest at 13 m.p.h. (21 km/h).  The maximum sustained wind speed was 175 m.p.h. (280 km/h) and there were wind gusts to 215 m.p.h. (350 km/h).  The minimum surface pressure was 907 mb.  The Hurricane Intensity Index (HII) for Soudelor was 40.4, the Hurricane Size Index was 13.6 and the Hurricane Wind Intensity Size Index was 54.0.  These indices mean that Soudelor is capable of producing regional catastrophic damage.

The upper level winds around Soudelor are very light and there is almost no vertical wind shear.  The typhoon has strong upper level divergence in all directions which is pumping out mass and causing the surface pressure to decrease rapidly.  It is over water where the Sea Surface Temperature is near 31°C and the circulation is extracting plenty of energy from the upper ocean.  The environment would support further intensification, but Soudelor is already a very powerful typhoon.  Soudelor rapidly completed an eyewall replacement cycle earlier today and future cycles could produce fluctuations in intensity.  Soudelor could remain a very intense typhoon for several more days.

A strong subtropical ridge is steering Typhoon Soudelor toward the west-northwest and that general steering pattern is expected to continue for the next few days.  On its anticipated track Soudelor could be near the southernmost islands of Japan in three days, near northern Taiwan in four days and near the coast of China in less than five days.  Although it is likely to weaken before it reaches any of those locations, it could still be a powerful typhoon at that time.

Typhoon Soudelor Intensifies Rapidly and Moves Over Saipan

Typhoon Soudelor intensified rapidly during the 12 hours before it moved directly over Saipan.  At 11:00 a.m. EDT on Sunday the center of Typhoon Soudelor was located at latitude 15.3°N and longitude 145.3°E which put it about 25 miles (40 km) west-northwest of Saipan.  It was moving toward the west-northwest at 11 m.p.h. (18 km/h).  The maximum sustained wind speed was 105 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (205 km/h).  The minimum surface pressure was 956 mb.  The airport on Saipan measured sustained wind to 54 m.p.h. (87 km/h) and wind gusts to 91 m.p.h. (147 km/h).  However, there were several observations when no wind speed was reported.  The minimum surface pressure reported was 958 mb.

Typhoon Soudelor organized quickly after the primary band wrapped completely around the center of circulation.  A tiny (4 mile wide) pinhole eye developed at the center of circulation and there are multiple bands of thunderstorms rotating around the center.   Soudelor is over warm Sea Surface Temperatures and there is little vertical wind shear.  Further intensification is likely and Soudelor could reach Super Typhoon status.

A subtropical ridge is steering Soudelor toward the west-northwest and that general motion is expected to continue for the next few days.  On its anticipated track Soudelor could approach the southernmost islands of Japan or Taiwan in four or five days.

Soudelor Almost a Typhoon as It Nears the Marianas

Tropical Storm Soudelor intensified on Saturday and it has almost reached typhoon status.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Soudelor was located at latitude 14.8°N and longitude 147.7°E which put it about 170 miles (275 km) east-southeast of Saipan.  Soudelor was moving toward the west-northwest at 18 m.p.h. (29 km/h).  The maximum sustained wind speed was 70 m.p.h. (115 km/h) and there were gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 978 mb.  A Typhoon Warning has been issued for Saipan and Tinian.  A Tropical Storm Warning has been issued for Rota.  A Typhoon Watch has been issued for Agrihan, Pagan and Alamagan.

The structure of Tropical Storm Soudelor improved on Saturday.  A long spiral band wrapped almost entirely around the center of circulation and numerous other spiral bands were apparent on satellite imagery.  There are more thunderstorms on the western side of the circulation.  Soudelor is moving over water where the Sea Surface Temperature is near 30°C.  An upper level ridge north of the tropical storm is causing light easterly winds over the circulation.  However, the vertical wind shear is modest and upper level divergence is increasing.  Soudelor is in a favorable environment.  Further intensification is likely and rapid intensification is possible.  Soudelor will very likely be a typhoon when it moves through Marianas.

A subtropical ridge is steering Soudelor toward the west-northwest and that pattern is expected to continue during the next few days.  On its anticipated track Soudelor will be near Saipan and Tinian in about 12 hours.  It could bring strong winds to those locations and other nearby islands.

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.