Tag Archives: WP28

Pabuk Weakens to a Tropical Depression

Former Tropical Storm Pabuk weakened to a tropical depression east of southern Vietnam during Tuesday night.  At 4:00 a.m. EST on Wednesday the center of Tropical Depression Pabuk was located at latitude 9.3°N and longitude 110.0°E which put the center about 260 miles (420 km) east-southeast of Ho Chi Minh City, Vietnam.  Pabuk was moving toward the south-southwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1005 mb.

Former Tropical Storm Pabuk weakened to a tropical depression during Tuesday night.  A surface high pressure over eastern Asia produced strong northeasterly winds along the east coast of Vietnam.  Those winds transported cooler, drier air into Pabuk’s circulation.  The cooler drier air caused many of the thunderstorms in former Tropical Storm Pabuk to dissipate.  Pabuk’s circulation consisted primarily of bands of showers and lower clouds revolving around the surface center.

Tropical Depression Pabuk will move through an environment unfavorable for intensification during the next 24 hours.  Pabuk will move over water where where the Sea Surface Temperatures are near 29°C.  It will move under the western part of an upper level ridge over the Western North Pacific Ocean.  The upper level ridge will produce southeasterly winds that will blow toward the top of Pabuk’s circulation.  The combination of southeasterly winds in the upper levels and northeasterly winds in the lower levels will cause strong vertical wind shear.   The surface high pressure system over eastern Asia will continue to transport cooler, drier air into Tropical Depression Pabuk.  The combination of strong vertical wind shear and cooler, drier air will cause Tropical Depression Pabuk to continue to weaken during the next 24 hours.

Tropical Depression Pabuk will move around the southeastern side of the high pressure system over eastern Asia.  The high pressure system will steer Pabuk toward the southwest during the next 24 hours.  On its anticipated track, Tropical Depression Pabuk will remain east of Vietnam.

Tropical Storm Pabuk Moves Toward Vietnam

Tropical Storm Pabuk moved slowly toward Vietnam on Tuesday.  At 10:00 a.m. EST on Tuesday the center of Tropical Storm Pabuk was located at latitude 11.3°N and longitude 111.3°E which put the center about 335 miles (540 km) east of Ho Chi Minh City, Vietnam.  Pabuk was moving toward the west-southwest at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1000 mb.

Tropical Storm Pabuk was better organized in Tuesday morning.  More thunderstorms were occurring near the center of Pabuk’s circulation.  The inner end of a rainband wrapped around the northern and western sides of the center of Tropical Storm Pabuk.  Storms near the center of Pabuk generated upper level divergence that pumped mass away to the north and west of the tropical storm.

Even though Tropical Storm Pabuk was better organized, the distribution of thunderstorms was still asymmetrical.  Thunderstorms were occurring in bands in the northern and western sides of Pabuk’s circulation.  Bands in the southern and eastern side of Tropical Storm Pabuk consisted primarily of showers and lower clouds.

Tropical Storm Pabuk will move through an environment marginally favorable for intensification during the next 24 hours.  Pabuk will move over water where where the Sea Surface Temperatures are near 29°C.  It will move under the western part of an upper level ridge over the Western North Pacific Ocean.  The upper level ridge will produce southerly winds that will blow toward the top of Pabuk’s circulation.  Those winds will cause moderate vertical wind shear.  A surface high pressure system over eastern Asia will transport drier air around the southern side of Tropical Storm Pabuk.  The combination of drier air and moderate vertical wind shear will inhibit intensification of Tropical Storm Pabuk during the next 24 hours.  Pabuk could strengthen a little if the vertical wind shear does not get any stronger.  Tropical Storm Pabuk is likely to weaken if the upper level winds do get stronger.

Tropical Storm Pabuk will move around the southeastern side of the high pressure system over eastern Asia.  The high pressure system will steer Pabuk toward the west during the next 24 hours.  On its anticipated track, Tropical Storm Pabuk will continue to move toward Vietnam.

Tropical Storm Pabuk Develops East of Vietnam

Tropical Storm Pabuk developed over the South China Sea east of Vietnam on Monday.  At 10:00 a.m. EST on Monday the center of Tropical Storm Pabuk was located at latitude 11.5°N and longitude 112.5°E which put the center about 410 miles (660 km) east of Ho Chi Minh City, Vietnam.  Pabuk was moving toward the north at 6 m.p.h. (10 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 1001 mb.

The circulation around former Tropical Depression 28W strengthened on Monday and the Japan Meteorological Agency designated the system as Tropical Storm Pabuk.  The distribution of thunderstorms in Tropical Storm Pabuk was asymmetrical.  Thunderstorms were occurring in a band in the northern part of Pabuk’s circulation.  The bands in the other parts of Tropical Storm Pabuk consisted primarily of showers and lower clouds.

Tropical Storm Pabuk will move through an environment unfavorable for intensification during the next 24 hours.  Pabuk will move over water where where the Sea Surface Temperatures are near 29°C.  It will move under the western part of an upper level ridge over the Western North Pacific Ocean. The upper level ridge will produce southerly winds that will blow toward the top of Pabuk’s circulation.  Those winds will cause moderate vertical wind shear.  A surface high pressure system over eastern Asia will transport drier air into the western side of Tropical Storm Pabuk.  The combination of drier air and moderate vertical wind shear is likely to cause Tropical Storm Pabuk to weaken during the next 24 hours.

Tropical Storm Pabuk will move around the southeastern side of the high pressure system over eastern Asia.  The high pressure system will steer Pabuk toward the west during the next 24 hours.  On its anticipated track, Tropical Storm Pabuk will move toward Vietnam.

Tropical Storm Yamaneko Moves North of Wake Island

Tropical Storm Yamaneko moved north of Wake Island on Sunday. At 4:00 p.m. EST on Sunday the center of Tropical Storm Yamaneko was located at latitude 23.4°N and longitude 166.0°E which put it about 245 miles (395 km) north of Wake Island. Yamaneko was moving toward the north at 7 m.p.h. (11 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 1000 mb.

Tropical Storm Yamaneko moved farther north of Wake Island on Sunday. The distribution of thunderstorms in Yamaneko was asymmetrical. Thunderstorms were occurring in bands in the far eastern part of Tropical Storm Yamaneko. Bands in the rest of Yamaneko’s circulation consisted primarily of showers and lower clouds. An upper level trough southeast of Japan was producing strong southwesterly winds that were blowing across the top of Tropical Storm Yamaneko. Those winds were causing strong vertical wind shear. The strong vertical wind shear was causing the upper part of Yamaneko’s circulation to tilt toward the northeast. The strong upper level winds were also blowing off the tops of thunderstorms that started to form near the center of Yamaneko and in the western part of the circulation.

Tropical Storm Yamaneko will move through an environment that will cause it to make a transition to an extratropical cyclone during the next 36 hours. Yamaneko will move over water where the Sea Surface Temperatures are colder than 26˚C. The upper level trough southeast of Japan will continue to cause strong vertical wind shear. A combination of cooler water and strong vertical wind shear will cause Tropical Storm Yamaneko to make a transition to an extratropical cyclone.

The upper level trough will steer Tropical Storm Yamaneko toward the north-northeast during the next 36 hours. On its anticipated track, Tropical Storm Yamaneko will pass far to the west of Midway Island in 24 hours.

Tropical Storm Yamaneko Forms Northwest of Wake Island

Tropical Storm Yamaneko formed over the Western North Pacific Ocean northwest of Wake Island on Saturday afternoon. At 4:00 p.m. EST on Saturday the center of Tropical Storm Yamaneko was located at latitude 22.0°N and longitude 165.7°E which put it about 180 miles (295 km) north-northwest of Wake Island. Yamaneko was moving toward the north-northeast at 7 m.p.h. (11 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 1000 mb.

An area of low pressure over the Western North Pacific Ocean northwest of Wake Island strengthened on Saturday afternoon and the Japan Meteorological Agency designated the system as Tropical Storm Yamaneko. Thunderstorms near the center of circulation generated upper level divergence that pumped mass away to the east of the tropical storm. The inner end of a rainband wrapped around the northern and western side of the center of Yamaneko’s circulation. Other bands of thunderstorms were in the eastern half of Tropical Storm Yamaneko. Many of the bands in the western side of Yamaneko consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 130 miles (210 km) in the eastern side of Tropical Storm Yamaneko. The winds in the western side of Yamaneko were blowing at less than tropical storm force.

Tropical Storm Yamaneko will move through an environment somewhat favorable for intensification during the next 24 hours. Yamaneko will move over water where the Sea Surface Temperatures are near 27˚C. An upper level trough southeast of Japan will produce southwesterly winds that will blow toward the top of Yamaneko’s circulation. Those winds will cause some vertical wind shear. The wind shear will inhibit intensification, but the shear will not be enough to prevent Yamaneko from getting a little stronger. Tropical Storm Yamaneko is likely to intensify gradually during the next 24 hours.

The upper level trough southeast of Japan will steer Tropical Storm Yamaneko toward the north during the next 24 hours. On its anticipated track, Tropical Storm Yamaneko will move farther away from Wake Island.

Typhoon Rai Rapidly Weakens to a Tropical Storm

Former Typhoon Rai rapidly weakened to a tropical storm south-southwest of Hong Kong on Monday. At 4:00 p.m. EST on Monday the center of Tropical Storm Rai was located at latitude 20.1°N and longitude 113.5°E which put it about 190 miles (305 km) south-southwest of Hong Kong. Rai was moving toward the northeast at 13 m.p.h. (20 km/h). The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h). The minimum surface pressure was 997 mb.

A surface high pressure system over eastern Asia produced northeasterly winds that transported drier air which was pulled into the circulation of former Typhoon Rai. The drier air caused the thunderstorms in Rai’s circulation to dissipate and the circulation weakened. Bands revolving around the center of Tropical Storm Rai consisted almost entirely of showers and lower clouds. Winds to tropical storm force extended out 65 miles (105 km) from the center of circulation.

Since Tropical Storm Rai consists of a shallow circulation, it will be steered by the winds in the lower levels of he atmosphere. Rai will move around the northwestern part of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Tropical Storm Rai toward the east-northeast during the next 24 hours. On its anticipated track Tropical Storm Rai could be southwest of Taiwan in 24 hours.

Tropical Storm Rai will move through an environment unfavorable for a tropical cyclone. Rai will move over water where the Sea Surface Temperatures are near 27˚C. However, Rai will continue to be surrounded by drier air, which will prevent the formation of new thunderstorms. In addition, an upper level trough over eastern Asia will produce southwesterly winds that will blow across the top of Rai’s circulation. Those winds will cause strong vertical wind shear and the shear will also be unfavorable for intensification. Tropical Storm Rai will continue to weaken during the next 24 hours.

Typhoon Rai Brings Gusty Winds and Rain to Central Vietnam

Typhoon Rai brought gusty winds and rain to central Vietnam on Sunday. At 10:00 a.m. EST on Sunday the center of Typhoon Rai was located at latitude 15.5°N and longitude 110.8°E which put it about 185 miles (295 km) east-southeast of Da Nang, Vietnam. Rai was moving toward the north at 11 m.p.h. (17 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 951 mb.

Bands in the western side of Typhoon Rai brought gusty winds and locally heavy rain to central Vietnam on Sunday. Although the core of Typhoon Rai was east of Vietnam, the large size of the circulation resulted in rainbands in the western side of the typhoon moving over central Vietnam. The core of Rai’s circulation where the strongest winds were located remained east of the coast of Vietnam.

Typhoon Rai was weakening over the South China Sea on Sunday. An upper level ridge over the Western North Pacific Ocean was producing southerly winds that were blowing toward the top of Rai’s circulation. A surface high pressure system over Asia was producing northeasterly winds in the lower levels of the atmosphere. The combination of southerly winds in the upper levels and northeasterly winds in the lower levels was causing moderate vertical wind shear. In addition, the northeasterly winds in the lower levels were transporting drier air toward Typhoon Rai.

Some of the drier air was wrapping around the southern side of Typhoon Rai. The strongest thunderstorms were occurring in bands in the western half of Rai’s circulation. Bands in the eastern half of the typhoon consisted primarily of showers and lower clouds. A broken ring of thunderstorms surrounded the eye of Typhoon Rai and the strongest winds were occurring in that ring of storms.

Winds to typhoon force extended out 65 miles (105 km) from the center of Typhoon Rai. Winds to tropical storm force extended out 185 miles (295 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Rai was 22.1. The Hurricane Size Index (HSI) was 20.6 and the Hurricane Wind intensity Size Index (HWISI) was 42.7. Rai was capable of causing regional major damage.

Typhoon Rai will move through an environment that will become unfavorable for intensification during the next 36 hours. Rai will move over water where the Sea Surface Temperatures are near 28˚C. However, the upper level ridge and the surface high pressure system will continue to cause moderate vertical wind shear. More dry air will be pulled into Rai’s circulation. Typhoon Rai will continue to weaken during the next 36 hours.

Typhoon Rai will move around the western end of a surface high pressure system over the Western North Pacific Ocean during the next 24 hours. The high pressure system will steer Rai toward the north. On its anticipated track the core of Typhoon Rai will remain east of Vietnam. Bands in the western side of Rai’s circulation will continue to produce gusty winds and locally heavy rain along the coast of Vietnam. The center of Rai could be southeast of Hainan in 18 hours.

Typhoon Rai Rapidly Intensifies Back to Equivalent of Cat. 5 Hurricane

Typhoon Rai rapidly intensified back to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Saturday over the South China Sea. At 4:00 p.m. EST on Saturday the center of Typhoon Rai was located at latitude 12.8°N and longitude 111.9°E which put it about 355 miles (575 km) southeast of Da Nang, Vietnam. Rai was moving toward the west-northwest at 16 m.p.h. (26 km/h). The maximum sustained wind speed was 165 m.p.h. (265 km/h) and there were wind gusts to 200 m.p.h. (320 km/h). The minimum surface pressure was 910 mb.

Typhoon Rai rapidly intensified to the equivalent of a Category 5 hurricane as it moved over the warm water in the South China Sea on Saturday. The diameter of the eye at the center of Rai contracted to 25 miles (40 km) as the typhoon rapidly intensified. 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 Rai. Storms near the core generated upper level divergence that pumped large quantities of mass away to the west and north of the typhoon. The removal of so much mass allowed the surface pressure to decrease rapidly.

Winds to typhoon force extended out 45 miles (75 km) from the center of Typhoon Rai. Winds to tropical storm force extended out 150 miles (240 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Rai was 36.7. The Hurricane Size Index (HSI) was 19.6 and the Hurricane Wind intensity Size Index (HWISI) was 56.3. Rai was capable of causing regional catastrophic damage. Typhoon Rai was stronger than it was when it hit the southern Philippines.

Typhoon Rai will move through an environment that will become unfavorable for intensification during the next 36 hours. Rai will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the western end of an upper level ridge over the Western North Pacific Ocean. The ridge will produce southerly winds that will blow toward the top of Typhoon Rai’s circulation. A surface high pressure system over Asia will produce northeasterly winds in the lower levels over the atmosphere. A combination of northeasterly winds in the lower levels and southerly winds in the upper levels will cause the vertical wind shear to increase. The northeasterly winds in the lower levels will also transport drier air toward the northwestern part of Rai’s circulation. Stronger vertical wind shear and drier air will cause Typhoon Rai to weaken during the next 36 hours. If the inner end of a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could cause Rai to weaken more rapidly.

Typhoon Rai will move around the western end of a surface high pressure system over the Western North Pacific Ocean during the next 24 hours. The high pressure system will steer Rai toward the north during the next 24 hours. On its anticipated track Typhoon Rai is forecast to turn toward the north before the center of Rai reaches the coast of Vietnam. Rainbands on the western side of Typhoon Rai could bring gusty winds and locally heavy rain to the central coast of Vietnam within 18 hours.

Typhoon Rai Strengthens over South China Sea

Typhoon Rai strengthened to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale over the South China Sea on Saturday morning. At 10:00 a.m. EST on Saturday the center of Typhoon Rai was located at latitude 12.2°N and longitude 113.0°E which put it about 450 miles (725 km) southeast of Da Nang, Vietnam. Rai was moving toward the west-northwest at 17 m.p.h. (28 km/h). The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 160 m.p.h. (260 km/h). The minimum surface pressure was 942 mb.

Typhoon Rai strengthened to the equivalent of a Category 4 hurricane as it moved over the warm water in the South China Sea on Saturday morning. An eye with a diameter of 30 miles (50 km) was at the center of Rai’s 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 Rai. Storms near the core generated upper level divergence that pumped mass away to the west and north of the typhoon.

Winds to typhoon force extended out 35 miles (55 km) from the center of Typhoon Rai. Winds to tropical storm force extended out 170 miles (275 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Rai was 25.1. The Hurricane Size Index (HSI) was 14.3 and the Hurricane Wind intensity Size Index (HWISI) was 39.4. Rai was capable of causing regional severe damage.

Typhoon Rai will move through an environment that will become unfavorable for intensification during the next 48 hours. Rai will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the southern side of an upper level ridge over the Western North Pacific Ocean. The ridge will produce southeasterly winds that will blow toward the top of Typhoon Rai’s circulation. A surface high pressure system over Asia will produce northeasterly winds in the lower levels over the atmosphere. A combination of northeasterly winds in the lower levels and southeasterly winds in the upper levels will cause the vertical wind shear to increase. The northeasterly winds in the lower levels will also transport drier air toward the northwestern part of Rai’s circulation. Stronger vertical wind shear and drier air will cause Typhoon Rai to weaken during the weekend.

Typhoon Rai will move around the western end of a surface high pressure system over the Western North Pacific Ocean during the next 36 hours. The high pressure system will steer Rai toward the north during the next 36 hours. On its anticipated track Typhoon Rai is forecast to turn toward the north before the center of Rai reaches the coast of Vietnam. Rainbands on the western side of Typhoon Rai could bring gusty winds and locally heavy rain to the central coast of Vietnam in 24 hours.

Typhoon Rai Moves over South China Sea

Typhoon Rai moved over the South China Sea on Friday. At 4:00 p.m. EST on Friday the center of Typhoon Rai was located at latitude 10.9°N and longitude 116.6°E which put it about 175 miles (285 km) west-northwest of Puerto Princesa, Philippines. Rai was moving toward the west-northwest at 14 m.p.h. (22 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. (230 km/h). The minimum surface pressure was 956 mb.

Typhoon Rai strengthened back to the equivalent of a major hurricane after it moved across Palawan and over the South China Sea. An eye with a diameter of 30 miles (50 km) developed at the center of Rai’s 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 Rai. Storms near the core generated upper level divergence that pumped mass away to the west and north of the typhoon.

Winds to typhoon force extended out 40 miles (65 km) from the center of Typhoon Rai. Winds to tropical storm force extended out 165 miles (270 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Rai was 20.6. The Hurricane Size Index (HSI) was 16.4 and the Hurricane Wind intensity Size Index (HWISI) was 37.0. Rai was capable of causing regional major damage.

Typhoon Rai will move through an environment favorable for intensification during the next 24 hours. Rai will move over water where the Sea Surface Temperatures are near 30˚C. It will move under the southern side of an upper level ridge over the Western North Pacific Ocean. The ridge will produce easterly winds that will blow toward the top of Typhoon Rai’s circulation. Those winds will cause some vertical wind shear but the wind shear will be too small to prevent intensification. Typhoon Rai could strengthen again during the next 24 hours.

Typhoon Rai will move south of a surface high pressure system over the Western North Pacific Ocean during the next day or so. The high pressure system will steer Rai toward the west-northwest during the next 24 hours. Rai will move more toward the northwest when it reaches the western end of the high pressure system. On its anticipated track Typhoon Rai could approach the coast of Vietnam in 36 hours.