Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Tropical Storm Sepat Moves Toward Honshu

Tropical Storm Sepat moved toward Honshu on Monday.  At 11:00 p.m. EDT on Monday the center of Tropical Storm Sepat was located at latitude 29.7°N and longitude 140.7°E which put the center about 420 miles (680 km) south of Tokyo, Japan.  Sepat was moving toward the northwest at 14 m.p.h. (22 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 1003 mb.

Tropical Storm Sepat strengthened a little on Monday morning, but Sepat was showing signs of weakening on Monday evening.  Thunderstorms were still occurring near the center of Tropical Storm Sepat.  Thunderstorms were also occurring bands revolving around the center of Sepat’s circulation.  Storms near the center of Sepat generated upper level divergence that pumped mass away from the tropical storm.  The removal of mass in the upper levels was balanced by the inflow of mass in the lower levels of Tropical Storm Sepat.  The balance of upper level divergence and inflow in the lower levels caused the surface pressure to remain steady.

The distribution of wind speeds in Tropical Storm Sepat was asymmetrical.  Winds to tropical storm force extended out 110 miles (175 km) in the eastern side of Sepat’s circulation.  The winds in the western side of Tropical Storm Sepat were blowing at less than tropical storm force.

Tropical Storm Sepat will move through an environment that will become unfavorable for intensification during the next 24 hours.  Sepat will move over water where where the Sea Surface Temperatures are near 26°C.  It will move under the northern part of an upper level low south of Japan.  The upper level low will produce northeasterly winds that will blow toward the top of Sepat’s circulation.  Those winds will cause moderate vertical wind shear.  The vertical wind shear  and marginal Sea Surface Temperatures will cause Tropical Storm Sepat to weaken during the next 24 hours.  Sepat is likely to weaken to a tropical depression on Tuesday.

Tropical Storm Sepat will move around the western end of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Sepat toward the north-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Sepat will continue to move toward Honshu.

Tropical Storm Sepat Forms Southeast of Japan

Tropical Storm Sepat formed over the Western North Pacific Ocean southeast of Japan on Sunday night.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Sepat was located at latitude 25.1°N and longitude 144.3°E which put the center about 215 miles (345 km) east of Iwo To.  Sepat was moving toward the northwest at 12 m.p.h. (19 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 low pressure system over the Western North Pacific Ocean southeast of Japan strengthened on Sunday night and the Japan Meteorological Agency designated the system as Tropical Storm Sepat.  The distribution of thunderstorms in Tropical Storm Sepat was asymmetrical.  Thunderstorms were occurring in bands in the northern side of Sepat’s circulation.  The bands in the southern side of Tropical Storm Sepat consisted primarily of showers and lower clouds.

Tropical Storm Sepat was under the eastern side of an upper level low that was south of Japan.  The upper level low was producing southerly winds that were blowing toward the top of Sepat’s circulation.  Those winds were causing moderate vertical wind shear.  The wind shear was causing the asymmetrical distribution of thunderstorms.

The distribution of wind speeds in Tropical Storm Sepat was also asymmetrical.  Winds to tropical storm force extended out 110 miles (175 km) in the eastern side of Sepat’s circulation.  The winds in the western side of Tropical Storm Sepat were blowing at less than tropical storm force.

Tropical Storm Sepat will move through an environment somewhat favorable for intensification during the next 24 hours.  Sepat will move over water where where the Sea Surface Temperatures are near 28°C.  The upper level low south of Japan will continue to cause moderate vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear will not be enough to prevent intensification.  Tropical Storm Sepat is likely to intensify during the next 24 hours.

Tropical Storm Sepat will move around the western end of a high pressure system over the Western North Pacific Ocean.  The high pressure system and the upper low south of Japan will steer Sepat toward the north-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Sepat will move toward Honshu.

Tropical Storm Wutip Makes Landfall in Southern China

Tropical Storm Wutip made landfall on the coast of southern China near Lianjiang on Friday night.  At 5:00 a.m. EDT on Saturday the center of Tropical Storm Wutip was located at latitude 21.7°N and longitude 110.3°E which put the center about 15 miles (25 km) southwest of Lianjiang, China.  Wutip was moving toward the northeast at 13 m.p.h. (21 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.

Tropical Storm Wutip strengthened to a typhoon just before it made landfall in southern China on Friday night.  Wutip weakened back to a tropical storm after it made landfall.  The circulation around Tropical Storm Wutip was small.  Winds to tropical storm force extended out 100 miles (160 km) from the center of Wutip’s circulation.

Tropical Storm Wutip will move around the northwestern part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Wutip toward the northeast during the next 24 hours.  On its anticipated track, Tropical Storm Wutip will move across Guangdong.  Wutip will pass north of Hong Kong.

Tropical Storm Wutip will bring strong winds and heavy rain to southern China.  The strongest winds and heaviest rain will occur in Guangdong . Heavy rain could cause flash floods in some locations.

Tropical Storm Wutip will weaken gradually as it moves across southern China.

Wutip Strengthens to a Typhoon Near Southern China

Former Tropical Storm Wutip strengthened to a typhoon near southern China on Friday evening.  At 11:00 p.m. EDT on Friday the center of Typhoon Wutip was located at latitude 20.8°N and longitude 109.4°E which put the center about 80 miles (130 km) southwest of Lianjiang, China.  Wutip was moving toward the north-northeast 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 979 mb.

Former Tropical Storm Wutip strengthened to a typhoon as it neared the coast of southern China on Friday evening.  The inner end of a rainband wrapped around the center of Wutip’s circulation.  A small circular eye with a diameter of 15 miles (24 km) formed at the center of Typhoon Wutip.  The eye was surrounded by a thin ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Wutip’s circulation.  Storms near the center of Wutip generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The size of the circulation around Typhoon Wutip decreased a little on Friday.  Winds to typhoon force extended out 25 miles (40 km) from the center of Wutip’s circulation.  Winds to tropical storm force extended out 100 miles (160 km) from the center of Typhoon Wutip.

Typhoon Wutip will move through an environment favorable for intensification during the next few hours before it makes landfall in China.  Wutip will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the axis of an upper level ridge over eastern China.  The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear.  However, much of the southeastern part of Wutip’s circulation will pass over Hainan.  The increased friction over land will slow the winds in that part of Tropical Storm Wutip.  Typhoon Wutip could intensify a little more during the next few hours.

Tropical Storm Wutip will move around the western part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Wutip toward the northeast during the next 24 hours.  On its anticipated track, the center Typhoon Wutip will make landfall on the coast of southern China southwest of Lianjiang.

Typhoon Wutip will bring strong winds and heavy rain to southern China on Saturday.  The strongest winds and heaviest rain will occur in Guangdong and eastern Guangxi.  Heavy rain could cause flash floods in some locations.

Tropical Storm Wutip Brings Wind and Rain to Hainan

Tropical Storm Wutip brought wind and rain to Hainan on Thursday night.  At 11:00 p.m. EDT on Thursday the center of Tropical Storm Wutip was located at latitude 18.6°N and longitude 108.5°E which put the center about 40 miles (65 km) south-southwest of Dongfang, China.  Wutip was moving toward the northwest at 9 m.p.h. (15 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. (105 km/h).  The minimum surface pressure was 983 mb.

Tropical Storm Wutip brought wind and rain to Hainan on Thursday night.  The center of Wutip’s circulation was passing just to the west of Hainan.  Bands in the eastern side of Tropical Storm Wutip were bringing strong winds and locally heavy rain to parts of Hainan.

Tropical Storm Wutip intensified on Thursday.  The inner end of a rainband wrapped around the center of Wutip’s circulation.  A small circular eye appeared to be forming at the center of Tropical Storm Wutip.  Bands of showers and thunderstorms were revolving around the center of Wutip’s circulation.  Storms near the center of Wutip generated upper level divergence that pumped mass away from the tropical storm.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Storm Wutip became more symmetrical on Thursday.  Winds to tropical storm force extended out 105 miles (165 km) from the center of Wutip’s circulation.

Tropical Storm Wutip will move through an environment that will be generally favorable for intensification during the next 24 hours.  Wutip will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the axis of an upper level ridge over eastern China.  The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear.  However, much of the eastern side of Wutip’s circulation will pass over Hainan.  The increased friction over land will slow the winds in that part of Tropical Storm Wutip.  Tropical Storm Wutip could intensify to a typhoon during the next 24 hours if the center of Wutip remains over water..

Tropical Storm Wutip will move around the western part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Wutip toward the north during the next 24 hours.  On its anticipated track, the center Tropical Storm Wutip will pass just to the west of Hainan.  Wutip will approach the coast of Guangxi in 24 hours.

Tropical Storm Wutip will continue to bring strong winds and heavy rain to Hainan on Friday.  Heavy rain could cause flash floods in some locations.  Wutip will also bring strong winds and heavy rain to Guangxi during the weekend.

Tropical Storm Wutip Forms Over South China Sea

Tropical Storm Wutip formed over the South China Sea south of Hainan on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Tropical Storm Wutip was located at latitude 16.5°N and longitude 110.6°E which put the center about 150 miles (240 km) south of Lingshui, China.  Wutip was moving toward the west 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 993 mb.

A low pressure system over the South China Sea strengthened on Wednesday and the Japan Meteorological Agency designated the system as Tropical Storm Wutip.  The distribution of thunderstorms in Tropical Storm Wutip was asymmetrical.  Thunderstorms were occurring in bands in the southern half of Wutip’s circulation.  Bands in the northern side of Tropical Storm Wutip consisted primarily of showers and lower clouds.  The storms in the southern half of Wutip began to generated upper level divergence that pumped mass away to the west of the tropical storm.

There was a large circulation around Tropical Storm Wutip, but the distribution of wind speeds was asymmetrical.  Winds to tropical storm force extended out 110 miles (170 km) in the southern half of Wutip’s circulation.  The winds in the northern half of Tropical Storm Wutip were blowing at less than tropical storm force.

Tropical Storm Wutip will move through an environment somewhat favorable for intensification during the next 24 hours.  Wutip will move over water where where the Sea Surface Temperatures are near 30°C.  It will move under the southern side of an upper level ridge over eastern China.  The upper level ridge will produce northeasterly winds that will blow toward the top of Wutip’s circulation.  Those winds will cause moderate vertical wind shear.  The vertical wind shear will inhibit intensification but the shear will probably not be enough to prevent intensification.  Tropical Storm Wutip is likely to intensify gradually during the next 24 hours.

Tropical Storm Wutip will move around the western part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Wutip toward the northwest during the next 24 hours.  On its anticipated track, Tropical Storm Wutip will approach the southwestern part of Hainan in 24 hours.

Tropical Storm Wutip will bring gusty winds and heavy rain to Hainan.  Heavy rain could cause flash floods in some locations.

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 Depression Forms Over South China Sea

A tropical depression formed over the South China Sea near the Spratly Islands on Saturday night.  At 10:00 p.m. EST on Saturday the center of the tropical Depression was located at latitude 9.5°N and longitude 114.4°E which put the center about 450 miles (725 km) east of Ho Chi Minh City, Vietnam.  The tropical depression was moving toward the northwest at 5 m.p.h. (8 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 1004 mb.

A low pressure system over the South China Sea near the Spratly Islands exhibited more organization on Saturday night and the Japan Meteorological Agency designated the system as a tropical depression.  More thunderstorms formed near the center of the tropical depression.  Thunderstorms were occurring in bands to the north and west of the center.  Bands in the southern and eastern parts of the tropical depression consisted primarily of showers and lower clouds.  Storms near the center generated upper level divergence that pumped mass away to the north and west of the tropical depression.

The tropical depression will move through an environment favorable for intensification during the next 24 hours.  The tropical depression 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 the tropical depression.  Those winds will cause moderate vertical wind shear.  The vertical wind shear will inhibit intensification, but the shear will not be enough to prevent intensification.  The tropical depression could intensify to a tropical storm on Sunday.

The tropical depression will move around the southwestern part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer the tropical depression slowly toward the northwest during the next 24 hours.  On its anticipated track, the tropical depression will move toward Vietnam.