Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Large Typhoon Trami Brings Wind and Rain to Japan

Large Typhoon Trami brought wind and rain to Japan on Saturday night.  At 11:00 p.m. EDT on Saturday the center of Typhoon Trami was located at latitude 31.8°N and longitude 132.3°E which put it about 140 miles (225 km) southwest of Kochi, Japan.  Trami was moving toward the northeast at 22 m.p.h. (33 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 950 mb.

There was still a large eye at the center of Typhoon Trami, but the ring of thunderstorms around the eye was beginning to look a little more ragged.  However, the circulation around Trami was very large.  Winds to typhoon force extended out about 155 miles (250 km) from the center of circulation.  Winds to tropical storm force extended out about 355 miles (575 km) from the center.

The Hurricane Intensity Index (HII) for Typhoon Trami was 17.8.  The Hurricane Size Index (HSI) was 49.6 and the Hurricane Wind Intensity Size Index (HWISI) was 67.4.  Typhoon Trami was capable of causing extensive serious damage.

Typhoon Trami brought strong winds and heavy rain to Okinawa and the northern Ryukyu Islands on Saturday.  There were reports of damage.  The northern eyewall of Trami passed over Kyushu.  Strong winds and heavy rain were falling in that region.  Heavy rain and strong winds will reach Shikoku shortly.  The center of Typhoon Trami could be near Kyoto in about six hours.  Trami will move northeast across Honshu on Sunday.  It will bring heavy rain and gusty winds to much of Japan.  Flash flooding will be possible over much of Japan.

Elsewhere over the Western North Pacific Ocean Tropical Storm Kong-rey was strengthening southeast of the Ryukyu Islands.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Kong-rey was located at latitude 14.1°N and longitude 138.1°E which put it about 1165 miles (1880 km) east of Manila, Philippines.  Kong-rey was moving toward the west-northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 983 mb.

Large Typhoon Trami Nears Okinawa

Large Typhoon Trami neared Okinawa late on Friday.  At 5:00 p.m. EDT on Friday the center of Typhoon Trami was located at latitude 25.1°N and longitude 126.9°E which put it about 135 miles (225 km) south-southwest of Okinawa.  Trami was moving toward the northwest at 6 m.p.h.  The maximum sustained wind speed was 105 m.p.h. (170 km) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 949 mb.

After completing an eyewall replacement cycle over a day ago that left it weaker, but larger, Typhoon Trami has been in a relatively steady state.  There is a very large eye with a diameter of almost 100 miles (160 km) at the center of circulation.  The eye is surrounded by a ring of strong thunderstorms and the strongest winds are occurring in that ring of storms.  Several bands of showers and thunderstorms are revolving around the large eye.

The circulation around Typhoon Trami is large.  Winds to typhoon force extend out about 75 miles (120 km) from the center of circulation.  Winds to tropical storm force extend out about 235 miles (380 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Trami is 17.8.  Th Hurricane Size Index (HSI) is 26.9 and the Hurricane Wind intensity Size Index (HWISI) is 44.7.  Those indices indicate that Typhoon Trami is capable of causing widespread serious damage.

Typhoon Trami is already bringing wind and rain to Okinawa and some of the Ryukyu Islands.  The northern eyewall is over Okinawa and the northern part of the large eye will reach it soon.  Trami will bring strong, damaging winds to Okinawa and the northern Ryukyu Islands during the next 24 hours.  It will also drop heavy rain and flash floods could occur.

Typhoon Trami is moving around the western end of a subtropical ridge.  it will start to move more quickly toward the northeast on Sunday.  Trami could reach Shikoku and Honshu in about 48 hours.  Trmai will still be a typhoon when it reaches the larger islands of Japan.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 30W was passing south of Guam.  At 5:00 p.m. EDT on Friday the center of Tropical Depression 30W was located at latitude 11.6°N and longitude 145.7°E which put it about 110 miles (185 km) south-southeast of Guam.  It was moving toward the northwest at 27 m.p.h. (43 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1003 mb.  Tropical Depression 30W is forecast to strengthen and it could take track similar to the path of Typhoon Trami.

Typhoon Trami Moves Slowly Toward Okinawa

Typhoon Trami moved slowly toward Okinawa on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Typhoon Trami was located at latitude 21.5°N and longitude 129.1°E which put it about 345 miles (560 km) south of Okinawa.  Trami was moving toward the north at 3 m.p.h. (5 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 949 mb.

The structure of Typhoon Trami changed significantly during the past 48 hours.  A second eyewall replacement cycle produced a larger eye and a bigger circulation.  Very slow movement of Typhoon Trami allowed the wind to mix cooler water to the surface.  Cooler water meant that there was less energy in the upper ocean to fuel the circulation.  The combination of the eyewall replacement cycle and cooler water resulted in a reduction of the wind speed and the surface pressure increased.

Although it is not as strong as it was 48 hours ago , Typhoon Trami is still a large powerful typhoon.  Winds to typhoon force extend out about 70 miles (110 km) from the center of circulation.  Winds to tropical storm force extend out about 225 miles (360 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Trami is 17.8.  The Hurricane Size Index (HSI) is 24.5 and the Hurricane Wind Intensity Size Index (HWISI) is 42.3.  Typhoon Trami is capable of producing widespread serious damage.

Typhoon Trami is likely to weaken slowly while it remains over the cooler water it has mixed to the surface.  When Trami moves north of that water in 12 to 24 hours, it will move into a more favorable environment.  Typhoon Trami will move over water where the Sea Surface Temperature is near 29°C.  It will still be in an area where the upper level winds are not too strong and there will not be much vertical wind shear.  The broad circulation and large eye will prevent rapid intensification, but Typhoon Trami could strengthen on Friday.

Typhoon Trami will still be in area where the steering winds are weak on Thursday.  It will move slowly toward the north during the next 12 to 24 hours.  Eventually a subtropical ridge over the Western North Pacific Ocean will begin to steer Typhoon Trami again.  Typhoon Trami will move toward the north at a faster rate on Friday.  On its anticipated track Typhoon Trami could be near Okinawa by late Friday.  Typhoon Trami could approach Kyushu in about 72 hours and it could move across Honshu during the weekend.

Typhoon Trami Intensifies in Equivalent of Category 5 Hurricane

Typhoon Trami intensified on Monday into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale.  At 5:00 p.m. EDT on Monday the center of Typhoon Trami was located at latitude 19.7°N and longitude 129.0°E which put it about 485 miles (780 km) south of Okinawa.  Trami was moving toward the west-northwest at 7 m.p.h. (11 km/h).  The maximum sustained wind sped was 160 m.p.h. (260 km/h) and there were wind gusts to 195 m.p.h. (315 km/h).  The minimum surface pressure was 912 mb.

Typhoon Trami went through an eyewall replacement cycle on Sunday, which temporarily interrupted its intensification.  When the inner eyewall dissipated on Monday, then Typhoon Trami resumed intensifying.  The eyewall replacement cycle caused Trami’s circulation to get larger.  There is now a large circular eye with a diameter of 40 miles (65 km) at the center of circulation.  The eye is surrounded by a ring of strong thunderstorms and the strongest winds are occurring in that ring of storms.  Several bands of showers and thunderstorms are revolving around the core of Typhoon Trami.  Storms around the core are generating large amounts of upper level divergence which is pumping mass away from the typhoon in all directions.

Typhoon Trami has a large symmetrical circulation.  Winds to typhoon force extend out about 70 miles (110 km) from the center of circulation.  Winds to tropical storm force extend out about 235 miles (380 km) from the center of circulation.  The Hurricane Intensity Index (HII) for Typhoon Trami is 35.0.  The Hurricane Size Index (HSI) is 25.3 and the Hurricane Wind Intensity Size Index (HWISI) is 60.3.

Typhoon Trami will move through an environment very favorable for intense typhoons during the next 12 to 24 hours.  Trami will move over water where the Sea Surface Temperature is near 30°C.  It will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Trami has been through one eyewall replacement cycle.  If another rainband wraps around the existing eye and eyewall and another eyewall replacement cycle starts, then weakening could occur.  An upper level trough near the east coast of China will move north of Typhoon Trami.  Westerly winds at the southern end of the trough could affect the northern portion of Trami’s circulation.  If wind shear increases later this week, then Typhoon Trami will weaken.

Typhoon Trami will move south of a subtropical ridge over the Western North Pacific Ocean.  The ridge will steer Trami in a west-northwesterly direction during the next 12 to 24 hours.  The upper level trough will weaken the ridge and Trami could turn more toward the north in a day or so.  The winds steering Typhoon Trami could weaken during the middle of the week and it could move slowly toward the north for a day or two.  On its anticipated track Typhoon Trami could approach the southern Rykyu Islands in three or four days.  Trami could still be a powerful typhoon at that time.

Trami Strengthens Into a Typhoon

Former Tropical Storm Trami strengthened into a typhoon on Saturday night.  At 11:00 p.m. EDT on Saturday the center of Typhoon Trami was located at latitude 17.0°N and longitude 134.6°E which put it about 810 miles (1310 km) southeast of Okinawa.  Trami was moving toward the west at 12 m.p.h. (19 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 965 mb.

The circulation of Typhoon Trami became more circular and symmetrical on Saturday.   An inner band of thunderstorms wrapped most of the way around the center of circulation and eye was developing at the center of Trami.  Several bands of showers and thunderstorms were revolving around the core of Typhoon Trami.  Storms near the core were generating upper level divergence which was pumping mass away from the typhoon in all directions.  Winds to typhoon force extended out about 35 miles (55 km) from the center of circulation.  Winds to tropical storm force extended out about 200 miles (320 km) from the center.

Typhoon Trami will move through an environment favorable for intensification during the next several days.  Trami will move over water where the Sea Surface Temperature is near 30°C.  it will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Trami could intensify into the equivalent of a major hurricane during the next day or two.

Typhoon Trami will move south of a subtropical ridge over the Western North Pacific Ocean.  The ridge will steer Trami toward the west-northwest during the next few days.  On its anticipated track Typhoon Trami could be east of Taiwan and southeast of the Ryukyu Islands in four or five days.  It could be a powerful typhoon at that time.

Tropical Storm Trami Develops West of the Marianas

Tropical Storm Trami developed west of the Marianas on Friday.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Trami was located at latitude 16.2°N and longitude 140.8°E which put it about 285 miles (460 km) northwest of Guam.  Trami was moving toward the west-northwest at 14 m.p.h. (22 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 993 mb.

The circulation around former Tropical Depression 28W strengthened on Friday and the Japan Meteorological Agency designated the system as Tropical Storm Trami.  An inner band of thunderstorms wrapped tightly around the northern and western sides of the center of circulation.  Several other bands of showers and thunderstorms in the eastern half of the circulation were revolving around the core of Tropical Storm Trami.  Bands in the western half of the circulation consisted primarily of showers and lower clouds.  Storms near the core of Trami were generating upper level divergence which was pumping mass away from the tropical storm.

Tropical Storm Trami will be moving through an environment favorable for intensification.  Trami will move over water where the Sea Surface Temperature is near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Trami will continue to intensify and it could become a typhoon during the next 24 hours.  A period of rapid intensification is possible once the inner core is fully developed.  Tropical Storm Trami could become the equivalent of a major hurricane during the next few days.

Tropical Storm Trami will continue to move south of a subtropical ridge over the Western North Pacific Ocean.  The ridge will steer Trami in a general west-northwesterly direction.  On its anticipated track Trami could be southeast of Okinawa and the Ryukyu Islands in four or five days.  It could be a powerful typhoon at that time.

Tropical Depression 28W Forms Over the Marianas

Tropical Depression 28W formed over the Mariana Islands on Thursday.  At 5:00 p.m. EDT on Thursday the center of Tropical Depression 28W was located at latitude 14.1°N and longitude 144.8°E which put it about 15 miles (25 km) east-northeast of Guam.  It was moving toward the northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1002 mb.  Tropical Storm Watches were issued for Rota, Saipan and Tinian.

Tropical Depression 28W was still organizing on Thursday.  A distinct center of circulation formed in an area of thunderstorms near the Marianas.  Bands of showers and thunderstorms developed around the circulation.  The strongest rainbands were forming in the eastern half of the circulation.  Bands of showers and thunderstorms were also forming in the western half of the circulation but there were fewer strong thunderstorms in that half of the tropical depression.  Storm closer to the center of circulation were starting to generate upper level divergence which was pumping mass away from the depression.

Tropical Depression 28W will move through an environment favorable for intensification.  It will move over water where the Sea Surface Temperature is near 30°C.  The tropical depression will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Tropical Depression 28W will intensify during the next few days.  It is likely to strengthen into a tropical storm on Friday and it could intensify into a typhoon during the weekend.

Tropical Depression 28W will move around the southern side of a subtropical ridge over the Western North Pacific Ocean during the next several days.  The ridge will steer the depression in a general west-northwesterly direction.  On its anticipated track the depression could be southeast of Okinawa in four or five days and it is likely to be a typhoon at that time.

Typhoon Mangkhut Makes Landfall West of Hong Kong

Typhoon Mangkhut made landfall west of Hong Kong on Sunday.  At 11:00 a.m. EDT on Sunday the center of Typhoon Mangkhut was located at latitude 22.3°N and longitude 111.0°E which put it about 65 miles (105 km) east-southeast of Yulin, China.  Mangkhut was moving toward the west-northwest at 20 m.p.h. (32 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 979 mb.

Typhoon Mangkhut made landfall on the coast of China near Yangjiang on Sunday.  The maximum sustained wind speed was near 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  There were reports that strong winds blew out windows in high rise buildings in Hong Kong.  There were strong gusty winds along the coast between Hong Kong and Yangjiang.  Strong winds blowing water toward the coast also produced a storm surge along that section of the coast.  The highest surge occurred just to the east of where the center made landfall.

Typhoon Mangkhut will drop heavy rain over Zizhiqu, Zhaungzu and Guangxi provinces while it moves farther inland.  Mangkhut will weaken slowly as it moves slowly across southern China.  The locally heavy rain could cause flash floods, especially in regions of steeper terrain.  Reports of damage and casualties caused when Typhoon Mangkhut move across northern Luzon were still coming in.

Typhoon Mangkhut Approaches Southern China

After causing significant destruction over northern Luzon, Typhoon Mangkhut approached southern China on Saturday night.  At 11:00 p.m. EDT on Saturday the center of Typhoon Mangkhut was located at latitude 21.0°N and longitude 114.4°E which put it about 130 miles (205 km) south-southeast of Hong Kong.  Mangkhut was moving toward the west-northwest at 21 m.p.h. (34 km/h).  The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 961 mb.

The inner core of Typhoon Mangkhut was disrupted when it moved across the northern end of Luzon.  The inner eyewall weakened and a larger ragged eye was at the center of the typhoon.  Recent visible satellite images seemed to show an inner rainband wrapping more tightly around the center of circulation and the inner core of Typhoon Mangkhut could be reorganizing.  A smaller eye could be redeveloping at the center of circulation.

Even though it has weakened since yesterday, Typhoon Mangkhut has a very large circulation.  Winds to typhoon force extend out about 70 miles (110 km) from the center of circulation.  Winds to tropical storm force extend out about 350 miles (565 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Mangkhut is 16.5.  The Hurricane Size Index (HSI) is 28.5 and the Hurricane Wind Intensity Index (HWISI) is 45.0.  Typhoon Mangkhut is capable of causing widespread serious damage.

Typhoon Mangkhut is moving southwest of a subtropical ridge which is steering the typhoon quickly toward the west-northwest.  On its anticipated track Typhoon Mangkhut will pass south of Hong Kong in a few hours.  Mangkhut will make landfall on the coast of south China near Yangjiang in about 12 hours.  Typhoon Mangkhut will bring strong gusty winds to southern China.  It will cause a storm surge of up to 10 feet (3 meters) along the coast.  Mangkhut will also drop heavy rain and it will cause flash floods.

Powerful Typhoon Mangkhut Hits Northern Luzon

Powerful Typhoon Mangkhut hit northern Luzon on Friday.  At 5:00 p.m. EDT on Friday the center of Typhoon Mangkhut was located at latitude 18.2°N and longitude 121.5°W which put it about 60 miles (95 km) east of Laoag, Philippines.  Mangkhut was moving toward the west-northwest at 21 m.p.h. (35 km/h).  The maximum sustained wind speed was 165 m.p.h. (270 km/h) and there were wind gusts to 200 m.p.h. (320 km/h).  The minimum surface pressure was 908 mb.

Mangkhut is a large and dangerous typhoon.  Winds to typhoon force extend out about 110 miles (175 km) from the center of circulation.  Winds to tropical storm force extend out about 330 miles (530 km) from the center.  The outer rainbands around Typhoon Mangkhut stretch from Manila, Philippines to southern Taiwan.

The Hurricane Intensity Index (HII) is 36.8.  The Hurricane Size Index (HSI) is 38.5 and the Hurricane Wind Intensity Size Index (HWISI) is 75.3.  Typhoon Mangkhut is bigger than Hurricane Katrina was when Katrina was a Category 5 hurricane on the Saffir-Simpson Scale over the Gulf of Mexico in 2005.  Typhoon Mangkhut has the potential to cause extensive catastrophic damage over parts of Luzon.

Typhoon Mangkhut will cause extensive catastrophic wind damage over northern Luzon.  It will also drop heavy rain and there will be flash floods.  The flooding will be worse in areas of steeper slopes.  There will be a significant storm surge on the coast of extreme northeastern Luzon.

Typhoon Mangkhut will weaken while it crosses northern Luzon.  Mangkhut will then move quickly off to the west-northwest. On its anticipated track Typhoon Mangkhut could be near Hong Kong in about 30 hours.