Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Typhoon Jebi Brings Wind and Rain to Japan

Typhoon Jebi brought wind and rain to Japan on Monday night.  At 11:00 p.m. EDT on Monday the center of Typhoon Jebi was located at latitude 33.9°N and longitude 134.4°E which put it about 15 miles (25 km) southwest of Tokushima.  Jebi was moving toward the north-northeast at 25 m.p.h. (40 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 945 mb.

Typhoon Jebi made landfall over eastern Shikoku on Monday night.  Jebi brought strong winds and dropped heavy rain over Shikoku and Honshu.  It retained about two thirds of an eyewall and the strongest winds were occurring in that partial eyewall.  There was a gap in the eyewall west of the center of circulation.  Several bands of showers and thunderstorms were revolving around the core of Typhoon Jebi.  Winds to typhoon force extended out about 70 miles (110 km) from the center of circulation.  Winds to tropical storm force extended out about 200 miles from the center.

An upper level trough northwest of Japan will steer Typhoon Jebi quickly toward the north-northeast.  On its anticipated track Typhoon Jebi will move quickly across eastern Shikoku.  The center of  Jebi will make landfall on Honshu near Kobe and it will move quickly toward the Sea of Japan.  Typhoon Jebi will drop heavy rain over Kobe, Osaka and Kyoto.  Heavy rain could cause flash floods in some parts of Shikoku and Honshu.  Jebi will weaken when it moves over the cooler water in the Sea of Japan.

Typhoon Jebi Moves Closer to Japan

Typhoon Jebi moved closer to Japan on Sunday.  At 11:00 p.m. EDT on Sunday the center of Typhoon Jebi was located at latitude 26.7°N and longitude 133.0°E which put it about 620 miles (1000 km) south of Kyoto, Japan.  Jebi was moving toward the northwest at 13 m.p.h. (20 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. (235 km/h).  The minimum surface pressure was 940 mb.

The circulation of Typhoon Jebi remained very well organized.  There was a circular eye at the center of circulation.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Typhoon Jebi.  Storms around the core were generating upper level divergence which was pumping mass away toward the northeast of the typhoon.

Winds to typhoon force extended out about 70 miles (110 km) from the center of circulation.  Winds to tropical storm force extended out about 230 miles (370 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Jebi was 20.6.  The Hurricane Size Index (HSI) was 24.4 and the Hurricane Wind Intensity Size Index (HWISI) was 45.0.

Typhoon Jebi will move into an environment that will become less favorable for strong typhoons.  Jebi will move over water where the Sea Surface Temperature is near 28°C.  So, there will be enough energy in the upper ocean to maintain the circulation.  However, an upper level trough northwest of Japan will produce southwesterly winds which will blow toward the top of the circulation.  Those winds will produce increasing vertical wind shear.  They will also inhibit the upper level divergence to the south of the typhoon.  Jebi will likely continue to weaken slowly on Monday.

Typhoon Jebi will move around the western end of a ridge over the Western North Pacific Ocean.  Jebi will move toward the north when it rounds the end of the ridge.  The upper level trough northwest of Japan will steer Typhoon Jebi toward the northeast when it nears Japan.  On its anticipated track Typhoon Jebi could approach Shikoku and Honshu in a little over 24 hours.  Jebi is forecast to be a typhoon when it reaches Japan.  It will bring gusty winds and drop locally heavy rain.  The rain will create the potential for flash floods.

Typhoon Jebi Turns Toward Japan

Typhoon Jebi turned toward Japan on Saturday.  At 11:00 p.m. EDT on Saturday the center of Typhoon Jebi was located at latitude 23.1°N and longitude 135.4°E which put it about 410 miles (665 km) west-southwest of Iwo To.  Jebi was moving toward the northwest at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 130 m.p.h. (215 km/h) and there wind gusts to 160 m.p.h. (260 km/h).  The minimum surface pressure was 939 mb.

Typhoon Jebi was nearing the completion of an eyewall replacement cycle on Saturday night.  The original inner eyewall had mostly dissipated, although a portion of the lower part of that eyewall was evident on satellite images.  A large circular eye was present at the center of Typhoon Jebi.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Multiple bands of showers and thunderstorms were revolving around the core of Typhoon Jebi.  Storms around the core were generating strong upper level divergence.  Winds to typhoon force extended out about 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out about 175 miles (280 km) from the center.

Typhoon Jebi will move through an environment capable of supporting a typhoon during the next 48 hours.  Jebi will move over water where the Sea Surface Temperature is near 28°C.  Typhoon Jebi will move through an area where the upper level winds are relatively weak on Sunday. Jebi will move closer to an upper level trough northwest of Japan on Monday.  Stronger southwesterly winds will cause more vertical wind shear and Typhoon Jebi will start to weaken at that time.

Typhoon Jebi will move around the western end of a subtropical ridge over the Western North Pacific Ocean.  Jebi will turn more toward the north on Sunday.  The upper level trough northwest of Japan will steer Typhoon Jebi more toward the northeast on Monday.  On its anticipated track Typhoon Jebi could approach Shikoku and Honshu in about two days.  Jebi is forecast to be a typhoon when it approaches Japan.

Typhoon Jebi Strengthens to Equivalent of Cat. 5 Hurricane

Powerful Typhoon Jebi strengthened into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Friday.  At 11:00 a.m. EDT on Friday the center of Typhoon Jebi was located at latitude 18.8°N and longitude 141.0°E which put it about 400 miles (645 km) south of Iwo To.  Jebi was moving toward the west-northwest at 14 m.p.h. (22 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 907 mb.

The circulation of Typhoon Jebi was very well organized and symmetrical.  There was a circular eye at the center of circulation.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Numerous bands of showers and thunderstorms were revolving around the core of the circulation.  Storms near the core were generating strong upper level divergence which was pumping mass away from the typhoon in all directions.

Jebi is a large and powerful typhoon.  Winds to typhoon force extended out about 65 miles (105 km) from the center of circulation.  Winds to tropical storm force extended out about 195 miles (315 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Jebi was 40.4.  The Hurricane Size Index (HSI) was 21.6 and the Hurricane Wind intensity Size Index (HWISI) was 62.0.

Typhoon Jebi may have reached its maximum intensity.  Microwave satellite imagery suggested that an inner rainband may have wrapped around the existing eye and eyewall.  If that has occurred, then an eyewall replacement cycle may have begun.  An eyewall replacement cycle will cause a typhoon to weaken when the inner eyewall, where the strongest wind are, dissipates.

Typhoon Jebi will move around the western end of a subtropical ridge over the Western North Pacific Ocean.  Jebi will gradually turn toward the north as it moves around the end of the ridge.  On its anticipated track Typhoon Jebi should pass west of Iwo To.  Jebi could be approaching Japan in three days or so.

Typhoon Jebi Hits Northern Marianas

Typhoon Jebi hit the Northern Mariana Islands on Thursday.  At 11:00 a.m. EDT on Thursday the center of Typhoon Jebi was located at latitude 17.8°N and longitude 146.2°E which put it about 35 miles (55 km) east-southeast of Pagan.  Jebi was moving toward the west at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 125 m.p.h. (205 km/h) and there were wind gusts to 155 m.p.h. (230 km/h).  The minimum surface pressure was 940 mb.  A Typhoon Warning was in effect for Agrihan, Pagan and Alamagan.

Typhoon Jebi was very well organized.  There was a small eye at the center of circulation.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Typhoon Jebi.  Storms near the core were generating strong upper level divergence which was pumping mass away from the typhoon.

Winds to typhoon force extended out about 50 miles (80 km) from the center of circulation.  Winds to tropical storm force extended out about 185 miles (295 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Jebi was 23.6.  The Hurricane Size Index (HSI) was 19.4 and the Hurricane Wind Intensity Size Index (HWISI) was 43.0.  Those indices indicate that Typhoon Jebi was capable of causing major damage.

Typhoon Jebi will be moving through an environment favorable for intensification during the next day or so.  Jebi will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there is little vertical wind shear.  Typhoon Jebi is forecast to intensify during the next 24 hours.  If an outer rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could cause the typhoon to weaken at least temporarily.

Typhoon Jebi will move around the western end of a subtropical ridge over the Western North Pacific Ocean.  Jebi will make a gradual turn toward the north during the next few days while it moves around the end of the ridge.  On its anticipated track Typhoon Jebi will move slowly away from the Northern Marianas.  Weather conditions should slowly improve when Jebi moves away.  The center of Jebi is forecast to pass south of Iwo To.  Typhoon Jebi could approach Honshu in four or five days.

Typhoon Jebi Intensifies Rapidly East of Northern Marianas

Typhoon Jebi intensified rapidly east of the Northern Marianas on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Typhoon Jebi was located at latitude 17.5°N and longitude 149.8°E which put it about 270 miles (435 km) east of Pagan.  Jebi was moving toward the west at 12 m.p.h. (19 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. (205 km/h).  The minimum surface pressure was 959 mb.  A Typhoon Warning was in effect for Agrihan, Pagan and Alamagan in the Northern Marianas.

The circulation of Typhoon Jebi was very well organized and it was symmetrical.  A small circular eye formed at the center of circulation.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Several bands of thunderstorms were revolving around the core of Typhoon Jebi.  Storms around the core were generating strong upper level divergence which was pumping large quantities of mass away from the typhoon.  Winds to typhoon force extended out about 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out about 100 miles (160 km) from the center.

Typhoon Jebi will be moving through an environment very favorable for further intensification.  Jebi will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Jebi is likely to intensify into the equivalent of a major hurricane on Thursday.

Typhoon Jebi will move south of a subtropical ridge over the Western North Pacific for several more days.  The ridge will steer Jebi in a general westerly direction during that time.  Typhoon Jebi will reach the western end of the ridge in about 48 hours.  Jebi will make a gradual turn toward the north when it reaches the end of the ridge.  On its anticipated track Typhoon Jebi will reach the northernmost Mariana Islands within 24 hours.  Jebi will be capable of causing major damage when it arrives.  Jebi is forecast to pass south of Iwo To, but it will turn toward the major islands of Japan during the weekend.

Tropical Storm Jebi Forms East of the Marianas

Tropical Storm Jebi formed east of the Marianas on Monday.  At 11:00 p.m. EDT on Monday the center of Tropical Storm Jebi was located at latitude 15.8°N and longitude 156.6°E which put it about 745 miles (1200 km) east of Saipan.  Jebi was moving toward the northwest at 17 m.p.h. (28 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 distinct low level center of circulation developed in a cluster of showers and thunderstorms east of the Northern Marianas and the Japan Meteorological Agency designated the system as Tropical Storm Jebi.  The circulation of Jebi was still organizing.  A primary rainband wrapped around the eastern and northern sides of the center of circulation.  Other bands of showers and thunderstorms were developing in the eastern half of the circulation.  Storms near the center started to generate upper level divergence.

Tropical Storm Jebi will move through an environment favorable for intensification during the next several days.  Jebi will move over water where the Sea Surface Temperature is near 29°C.  It will move under the western end of an upper level ridge.  The ridge will produce southerly winds which will cause some vertical wind shear.  Two upper level lows northwest and northeast of Jebi will enhance upper level divergence to the north of the tropical storm.  Tropical Storm Jebi will strengthen and it could become a typhoon later this week.

Tropical Storm Jebi will move southwest of a ridge over the Western North Pacific Ocean.  The ridge is forecast to strengthen and it will steer Jebi in a general west-northwesterly direction during the next several days.  On its anticipated track Tropical Storm Jebi could be near the northernmost Mariana Islands in about three days.  Jebi could be a typhoon by that time.  Jebi could be south of Iwo To by the end of the week.

Typhoon Cimaron Brings Wind and Rain to Japan

Typhoon Cimaron brought wind and rain to Japan on Thursday.  At 2:00 p.m. EDT on Thursday the center of Typhoon Cimaron was located at latitude 35.9°N and longitude 135.1°E which put it about 70 miles west of Fukui, Japan.  Cimaron was moving toward the north at 26 m.p.h. (42 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 979 mb.

The center of Typhoon Cimaron moved near the eastern end of Shikoku early on Wednesday.  Cimaron moved quickly northward and the center passed over Awaji Island.  Typhoon Cimaron made landfall on Honshu west of Kobe and Osaka near Akashi.  Cimaron continued to move quickly toward the north across Honshu and the center of circulation emerged over the Sea of Japan later on Thursday.  Kansai International Airport reported a sustained wind speed of 65 m.p.h. (105 km/h).  Komoda, Japan reported a sustained wind speed of 63 m.p.h. (102 km/h).

Typhoon Cimaron dropped locally heavy rain over parts of Shikoku and southwestern Honshu.  Kobe measured 4.75 inches (120.5 mm) of rain and there could have been higher amounts in mountainous regions where the wind was blowing up the slopes.  The potential for flash floods exists in areas of steep terrain.

Typhoon Cimaron is forecast to weaken over the Sea of Japan.  It will move over cooler water.  In addition, an upper level trough over eastern Asia will produce strong westerly winds that will cause significant vertical wind shear.  The trough is forecast to turn Typhoon Lane toward the east and it could make another landfall over northern Honshu or Hokkaido.  Cimaron will weaken to a tropical storm, but it could drop heavy rain over those areas.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Soulik was making landfall on the southwestern coast of South Korea near Mokp’o.  At 11:00 a.m. EDT on Thursday the center of Tropical Soulik was located at latitude 35.2°N and longitude 126.8°E which put it about 90 miles (145 km) south-southwest of Kunsan, South Korea.  Soulik was moving toward the north-northeast at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 985 mb.

The upper level trough over eastern Asia was also causing strong vertical wind shear over Tropical Storm Soulik.  Soulik was weakening as it approached the coast, but it will still be capable of dropping locally heavy rain over portions of South Korea.  The heavy rain could create the potential for flash floods.

Typhoon Soulik Strikes Cheju Island

Typhoon Soulik struck Cheju Island on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Typhoon Soulik was located at latitude 33.0°N and longitude 125.7°E which put it about 50 miles (80 km) west of Cheju Island.  Soulik was moving toward the north-northwest at 12 m.p.h. (19 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 969 mb.

Typhoon Soulik had a large eye and the eastern eyewall, which was the strongest part of the circulation, moved directly over Cheju Island on Wednesday.  The island would have experienced winds to typhoon force and heavy rain.  The heavy rain could produce flash floods.  Typhoon Soulik weakened as it approached Cheju.  The circulation appeared to draw some drier air around the western and southern side of the circulation.  The heaviest rain was falling in the northern and eastern quadrants of the typhoon.  Soulik was moving over cooler water and an upper level trough over eastern Asia was causing vertical wind shear.

The upper level trough will turn Typhoon Soulik toward the northeast during the next 24 hours.  On its anticipated track the center of Typhoon Soulik could pass near the southwestern tip of South Korea in about 12 hours.  Soulik could make landfall near Kunsan in about 24 hours.  The eastern side of Typhoon Soulik, which is the stronger side, will pass over much of South Korea during the next 24 hours.  Soulik will produce gusty winds and it will drop locally heavy rain.  The rain could produce flash floods on the Korean peninsula.

Elsewhere over the tropical Western North Pacific Ocean, Typhoon Cimaron moved closer to Japan.  At 5:00 p.m. EDT on Wednesday the center of Typhoon Cimaron was located at latitude 29.4°N and longitude 135.6°E which put it about 335 miles (540 km) south of Osaka, Japan.  Cimaron was moving toward the northwest at 23 m.p.h. (37 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.

Typhoon Cimaron is forecast to move quickly toward Japan during the next 24 hours.  On its anticipated track Cimaron will approach the coasts of Shikoku and Honshu between Tokushima and Tanabe in about 12 hours.  Cimaron is forecast to be a typhoon when it makes landfall in Japan.  It will bring strong winds and Cimaron will drop locally heavy rain.  Flash floods could occur, especially in regions of steeper terrain.

Typhoon Soulik Threatens South Korea, Cimaron Heads Toward Japan

Typhoon Soulik threatened South Korea on Tuesday night and Typhoon Cimaron headed toward Japan.  At 11:00 p.m. EDT on Tuesday the center of Typhoon Soulik was located at latitude 30.8°N and longitude 127.3°E which put it about 200 miles (320 km) south-southeast of Cheju, South Korea.  Soulik was moving toward the northwest at 13 m.p.h. (20 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 956 mb.

There was a large eye with a diameter of 65 miles (105 km) at the center of Typhoon Soulik.  A ring of strong thunderstorms surround the eye, but there were some breaks in the ring of storms.  The strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Typhoon Soulik.  Winds to typhoon force extended out about 70 miles (110 km) from the center of circulation.  Winds to tropical storm force extended out about 250 miles (400 km) from the center.

Typhoon Soulik will move around the western end of a subtropical ridge over the Western North Pacific Ocean.  The ridge will steer Soulik more toward the north during the next 24 to 36 hours.  On its anticipated track Typhoon Soulik will be near Cheju Island in 18 to 24 hours.  Soulik could be near Seoul, South Korea in less than 48 hours.   Typhoon Soulik will move over cooler water when it moves northward.  Vertical wind shear will also increase as an upper level trough approaches the typhoon from the west.  Soulik is likely to be a typhoon when it approaches Cheju Island.  It will drop heavy rain over South Korea and there will be a risk for flash floods.

At 11:00 p.m. EDT on Tuesday the center of Typhoon Cimaron was located at latitude 24.8°N and longitude 139.3°E which put it about 95 miles (150 km) west-southwest of Iwo To.  Cimaron was moving toward the northwest at 19 m.p.h. (31 km/h).  The maximum sustained wind speed was 125 m.p.h. (205 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 944 mb.

Upper level divergence from Typhoon Soulik had less of an effect on the outflow from Typhoon Cimaron and Cimaron strengthened on Tuesday.  Typhoon Cimaron strengthened into the equivalent of a major hurricane.  Cimaron was moving around the western end of a subtropical ridge.   On its anticipated track Typhoon Cimaron could be near the coast of Shikoku and Honshu in about 36 hours.