Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Co-may Strengthens to a Typhoon

Former Tropical Storm Co-may strengthened to a typhoon over the Western North Pacific Ocean west of northern Luzon on Thursday.  At 5:00 a.m. EDT on Thursday the center of Tropical Storm Co-may was located at latitude 16.2°N and longitude 119.6°E which put the center about 65 miles (105 km) west of Baguio, Philippines.  Co-may was moving toward the east at 9 m.p.h. (15 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 974 mb.

Former Tropical Storm Co-may strengthened to a typhoon as it approached the coast of northwestern Luzon on Thursday.  Numerous thunderstorms were occurring near the center of Co-may’s circulation.  Bands of showers and thunderstorms were revolving around the center of Typhoon Co-may.  Storms near the center of Co-may generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The circulation around Typhoon Co-may was small.  Winds to typhoon force extended out 20 miles (30 km) from the center of Co-may’s circulation.  Winds to tropical storm force extended out 100 miles (160 km) from the center of Typhoon Co-may.

Typhoon Co-may will move through an environment somewhat favorable for intensification during the next few hours.  Co-may will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southeastern side of an upper level low that is centered over the east coast of China.  The upper level low will produce southwesterly winds that will blow toward the top of Co-may’s circulation.  Those winds will cause moderate vertical wind shear. The vertical wind shear will inhibit intensification, but the wind shear may not be enough to prevent intensification. Typhoon Co-may could intensify a little more during the next few hours.

Typhoon Co-may will get pulled toward the northeast by the much larger circulation around Tropical Storm Francisco.  On its anticipated track, Typhoon Co-may will make landfall on the coast of northern Luzon near Bolinao in a few hours.  The center of Co-may will pass just west of Baguio.  The center will pass south of Vigan.

Typhoon Co-may will bring strong winds and locally heavy rain to northern Luzon.  Heavy rain could cause flash floods and mudslides.  Typhoon Co-may is likely to cause widespread outages of electricity in northern Luzon.  Co-may could also cause a storm surge of up to 7 feet (2 meters) along the coast of northwestern Luzon.

Elsewhere over the Western North Pacific Ocean, the center of Tropical Storm Francisco was approaching  Okinawa.  At 5:00 a.m. EDT on Thursday the center of Tropical Storm Francisco was located at latitude 25.2°N and longitude 127.4°E which put the center about 110 miles (175 km) south of Okinawa.  Francisco was moving toward the north at 12 m.p.h. (19 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 987 mb.

Tropical Storm Co-may Forms West of Luzon

Tropical Storm Co-may formed over the Western North Pacific Ocean west of Luzon on Wednesday.  At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Co-may was located at latitude 17.7°N and longitude 118.7°E which put the center about 150 miles (240 km) west of Vigan, Philippines.  Co-may was moving toward the west at 9 m.p.h. (15 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 992 mb.

A low pressure system over the Western North Pacific Ocean west of Luzon strengthened on Wednesday and the Japan Meteorological Agency designated the system as Tropical Storm Co-may.

The circulation around Tropical Storm Co-may was organizing quickly.  More thunderstorms formed near the center of Co-may’s circulation.  Bands of showers and thunderstorms were revolving around the center of Tropical Storm Co-may.  Storms near the center of Co-may generated upper level divergence that pumped mass away from the tropical storm.  The removal of mass caused the surface pressure to decrease.

The strongest winds were occurring in the western side of Tropical Storm Co-may.  Winds to tropical storm force extended out 100 miles (160 km) in the western half of Co-may’s circulation.  The winds in the eastern side of Tropical Storm Co-may were blowing at less than tropical storm force.

Tropical Storm Co-may will move through an environment favorable for intensification during the next 24 hours.  Co-may will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southeastern side of an upper level low that is centered east of Taiwan.  The upper level low will produce southwesterly winds that will blow toward the top of Co-may’s circulation.  Those winds will cause some vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear will not be enough to prevent intensification.  Tropical Storm Co-may will intensify during the next 24 hours.  Co-may could strengthen to a typhoon on Thursday.

Tropical Storm Co-may will get pulled toward the northeast by the much larger circulation around Tropical Storm Francisco.  On its anticipated track, Tropical Storm Co-may will approach northern Luzon in 24 hours.

Tropical Storm Co-may could be a typhoon when it approaches the coast of northwestern Luzon.  Co-may will bring strong winds and locally heavy rain to northern Luzon.  Heavy rain could cause flash floods and mudslides.  Tropical Storm Co-may is likely to cause widespread outages of electricity in northern Luzon.  Co-may could also cause a storm surge of up to 7 feet (2 meters) along the coast of northwestern Luzon.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Francisco strengthened a little as it moved toward the southern Ryukyu Islands.  At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Francisco was located at latitude 22.5°N and longitude 129.1°E which put the center about 325 miles (525 km) south-southeast of Okinawa.  Francisco was moving toward the northwest at 7 m.p.h. (11 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 994 mb.

Tropical Storm Francisco Develops South of Okinawa

Tropical Storm Francisco developed over the Western North Pacific Ocean south of Okinawa on Tuesday.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Francisco was located at latitude 21.2°N and longitude 129.7°E which put the center about 415 miles (670 km) south-southeast of Okinawa.  Francisco 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 996 mb.

A low pressure system over the Western North Pacific Ocean south of Okinawa strengthened on Tuesday and the Japan Meteorological Agency designated the system as Tropical Storm Francisco.

More thunderstorms formed near the center of Tropical Storm Francisco on Tuesday night.  Thunderstorms were also occurring in bands in the eastern side of Francisco’s circulation.  Bands in the western side of Tropical Storm Francisco consisted primarily of showers and lower clouds.  Storms near the center of Francisco generated upper level divergence that pumped mass away to the east and south of the tropical storm.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Storm Francisco was large.  Winds to tropical storm force extended out 185 miles (295 km) from the center of Francisco’s circulation.

Tropical Storm Francisco will move through an environment somewhat favorable for intensification during the next 24 hours.  Francisco will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the eastern side of an upper level low that is centered east of Taiwan.  The upper level low will produce southerly winds that will blow toward the top of Francisco’s circulation.  Those winds will cause moderate vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear may not be enough to prevent intensification.  Tropical Storm Francisco is likely to intensify during the next 24 hours.

Tropical Storm Francisco will move around the western side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Francisco toward the northwest during the next 24 hours.  On its anticipated track, Tropical Storm Francisco will move toward the southern Ryukyu Islands.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 11W formed north of Luzon.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Depression 11W was located at latitude 18.5°N and longitude 120.1°E which put the center about 295 miles (470 km) north of Manila, Philippines.  The tropical depression was moving toward the west-southwest at 12 m.p.h. (19 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 997 mb.

Tropical Storm Wipha Brings Wind and Rain to Northern Vietnam

Tropical Storm Wipha brought wind and rain to northern Vietnam on Monday.  At 5:00 p.m. EDT on Monday the center of Tropical Storm Wipha was located at latitude 20.8°N and longitude 107.2°E which put the center about 30 miles (50 km) east of Haiphong, Vietnam.  Wipha was moving toward the west-southwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 984 mb.

Tropical Storm Wipha brought wind and rain to parts of northern Vietnam on Monday.  The strongest winds were occurring in the part of Wipha’s circulation that was over the Gulf of Tonkin.

Winds to tropical storm force extended out 150 miles (240 km) in the southern side of Tropical Storm Wipha.  Winds to tropical storm force extended out 85 miles (135 km) in the northern side of Wipha’s circulation.

Tropical Storm Wipha will move around the southern part of a high pressure system over China.  The high pressure system will steer Wipha toward the west-southwest during the next 24 hours.  On its anticipated track, Tropical Storm Wipha will move across northern Vietnam.  The center of Wipha’s circulation will pass south of Hanoi in about 12 hours.  Wipha will move over northern Laos on Tuesday night.

Tropical Storm Wipha will weaken gradually as it moves across northern Vietnam.  Wipha will weaken to a tropical depression on Tuesday.

Tropical Storm Wipha will continue to produce strong winds and to drop heavy rain as it moves across northern Vietnam.  Heavy rain is likely to cause floods in some locations.  Wipha will also drop heavy rain over parts of northern Laos.  Additional floods could occur in that region.

Tropical Storm Wipha Brings Wind and Rain to Southern China

Tropical Storm Wipha brought wind and rain to southern China on Sunday.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Wipha was located at latitude 21.6°N and longitude 111.2°E which put the center about 70 miles (110 km) east-northeast of Zhanjiang, China.  Wipha was moving toward the west at 16 m.p.h. (26 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 980 mb.

Former Typhoon Wipha weakened to a tropical storm after it made landfall on the coast of southern China west of Hong Kong.  Tropical Storm Wipha was bringing strong winds and heavy rain to parts of southern China on Sunday.

A weather station at Hong Kong airport (VHHH) reported a sustained wind speed of 46 knots (53 m.p.h. or 85 km/h) as the center of then Typhoon Wipha passed south of the station.  The same weather station also reported a wind gust of 65 knots (75 m.p.h. or 120 km/h).

The circulation around Tropical Storm Wipha remains well organized even though the center of Wipha’s circulation has been overland for a few hours.  A broken ring of thunderstorms surrounds the center of Tropical Storm Wipha.  The strongest winds are occurring in that ring of storms.  Thunderstorms are occurring in bands in the western side of Wipha’s circulation.  Bands in the northern and eastern parts of Tropical Storm Wipha consist primarily of showers and lower clouds.

The strongest winds in Tropical Storm Wipha are occurring in the part of Wipha’s circulation that is over the northern South China Sea.  Winds to tropical storm force extended out 155 miles (250 km) from the center of Tropical Storm Wipha.

Tropical Storm Wipha will move around the southern part of a high pressure system over eastern China.  The high pressure system will steer Wipha toward the west-southwest during the next 24 hours.  On its anticipated track, the center of Tropical Storm Wipha will move along the coast of southern China during the next 12 hours.  The center of Wipha’s circulation could move over the northern Gulf of Tonkin on Monday.

Tropical Storm Wipha will bring strong winds and locally heavy rain to southwestern Guangdong.  Heavy rain could cause flash floods in some location.  Tropical Storm Wipha will also produce strong winds and heavy rain in southern Guangxi and in Hainan.  Tropical Storm Wipha could bring strong winds and locally heavy rain to northern Vietnam early next week.

Tropical Storm Wipha will weaken slowly as long as the center of circulation remains over land.  If the center of Wipha’s circulation  moves over the Gulf of Tonkin on Monday, then Wipha would move through an environment somewhat favorable for intensification.  Tropical Storm Wipha would move over water where the Sea Surface Temperatures are near 29°C.  It would move under the southern side of an upper level ridge that is over China.  The upper level ridge will produce northeasterly winds that will blow toward the top of Wipha’s circulation. Those winds will cause some vertical wind shear.  The vertical wind shear will inhibit intensification but the wind shear may not be enough to prevent intensification. Tropical Storm Wipha could intensify a little  on Monday if the center of Wipha’s circulation moves over the Gulf of Tonkin.

Wipha Intensifies to a Typhoon Near Hong Kong

Former Tropical Storm Wipha intensified to a typhoon near Hong Kong on Saturday night.  At 11:00 p.m. EDT on Saturday the center of Typhoon Wipha was located at latitude 21.6°N and longitude 113.9°E which put the center about 55 miles (95 km) south-southeast of Hong Kong.  Wipha was moving toward the west at 15 m.p.h. (24 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 970 mb.

Former Tropical Storm Wipha intensified to a typhoon on Saturday night near Hong Kong.  The center of Typhoon Wipha was still over water just to the south-southeast of Hong Kong.  The inner end of a rainband wrapped most of the way around the center of Wipha’s circulation. Thunderstorms were occurring in bands in the southern and eastern parts of Typhoon Wipha. Bands in the northern part of Wipha’s circulation  consisted primarily of showers and lower clouds.  Storms near the center of Wipha generated upper level divergence that pumped mass away to the southwest of the tropical storm.  The removal of mass caused the surface pressure to decrease.

The strongest winds were occurring in the southern side of Typhoon Wipha.  Winds to typhoon force extended out 30 miles (50 km) in the southern half of Wipha’s circulation.  Winds to tropical storm force extended out 155 miles (250 km from the center of Typhoon Wipha.

Typhoon Wipha will move through an environment favorable for intensification during the next 12 hours . Wipha will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southeastern side of an upper level ridge that is over China.  The upper level ridge will produce northeasterly winds that will blow toward the top of Wipha’s circulation.  Those winds will cause some vertical wind shear.  The vertical wind shear will inhibit intensification but the wind shear may be enough to prevent intensification. Typhoon Wipha could intensify a little more during the next 12 hours.

Typhoon Wipha will move around the southern part of a high pressure system over eastern China.  The high pressure system will steer Wipha toward the west during the next 24 hours.  On its anticipated track, the center of Typhoon Wipha will pass just south of Hong Kong during the next few hours.  The center of Wipha’s circulation will also pass just south of Macau.  The center of Typhoon Wipha could be near Yangjiang in 18 hours.

Typhoon Wipha will bring strong winds and locally heavy rain to Hong Kong.  Heavy rain could cause flash floods and mudslides.  Wipha will also bring strong winds and heavy rain to southern Guangdong including Macau.  Typhoon Wipha will produce strong wins and heavy rain in southern Guangxi and in Hainan.

Tropical Storm Wipha Strengthens

Tropical Storm Wipha strengthened as it moved closer to Hong Kong on Saturday.  At 11:00 a.m. EDT on Saturday the center of Tropical Storm Wipha was located at latitude 21.1°N and longitude 117.1°E which put the center about 240 miles (390 km) east-southeast of Hong Kong.  Wipha was moving toward the west-northwest at 12 m.p.h. (19 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 976 mb.

Tropical Storm Wipha strengthened on Saturday as it moved closer to Hong Kong.  The inner end of a rainband wrapped most of the way around the center of Wipha’s circulation.  More thunderstorms formed near the center of Tropical Storm Wipha.  Thunderstorms were also occurring in bands in the southern and eastern parts of Wipha’s circulation.  Bands in the northwestern quadrant of Tropical Storm Wipha consisted primarily of showers and lower clouds.  Storms near the center of Wipha generated upper level divergence that pumped mass away to the southwest of the tropical storm.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Storm Wipha was large.  Winds to tropical storm force extended out 195 miles (315 km) from the center of Wipha’s circulation.

Tropical Storm Wipha will move through an environment favorable for intensification during the next 12 hours.  Wipha will move over water where the Sea Surface Temperatures are near 29°C. It will move under the southeastern side of an upper level ridge that is over China.  The upper level ridge will produce northeasterly winds that will blow toward the top of Wipha’s circulation.  Those winds will cause some vertical wind shear.  The vertical wind shear will inhibit intensification but the wind shear may be enough to prevent intensification.  Tropical Storm Wipha could intensify during the next 12 hours.  Wipha could strengthen to a typhoon during that time.

Tropical Storm Wipha will move around the southern part of a high pressure system over the Western North Pacific Ocean and eastern China.  The high pressure system will steer Wipha toward the west-northwest during the next 18 hours.  On its anticipated track, the center of Tropical Storm Wipha will be near Hong Kong in 18 hours.

Tropical Storm Wipha will bring strong winds and locally heavy rain to Hong Kong.  Heavy rain could cause flash floods and mudslides.  Tropical Storm Wipha will also bring strong winds and heavy rain to southern Guangdong.

Tropical Storm Wipha Passes Near Northern Luzon

The center of Tropical Storm Wipha passed just to the north of northern Luzon on Friday.  At 11:00 a.m. EDT on Friday the center of Tropical Storm Wipha was located at latitude 19.6°N and longitude 122.0°E which put the center about 80 miles (130 km) north-northeast of Aparri, Philippines.  Wipha was moving toward the northwest at 13 m.p.h. (21 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 991 mb.

The center of Tropical Storm Wipha was passing between northern Luzon and Taiwan on Friday.  More thunderstorms formed near the center of Wipha’s circulation on Friday.  Numerous bands of showers and thunderstorms were revolving around the center of Tropical Storm Wipha.  Storms near the center of Wipha generated upper level divergence that pumped mass away to the south and west of the tropical storm.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Storm Wipha was very large.  Winds to tropical storm force extended out 205 miles (330 km) from the center of Wipha’s circulation.

Tropical Storm Wipha will move through an environment favorable for intensification during the next 24 hours.  Wipha will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southern side of an upper level ridge that is north of the Philippines.  The upper level ridge will produce easterly winds that will blow toward the top of Wipha’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Tropical Storm Wipha will intensify during the next 24 hours.  Wipha could strengthen to a typhoon during the weekend.

Tropical Storm Wipha will move around the southwestern part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Wipha toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Wipha could approach Hong Kong in 36 hours.

Tropical Storm Wipha will produce gusty winds and locally heavy rain in northern Luzon and southern Taiwan during the rest of today.  Heavy rain could produce flash floods in some locations.

Tropical Storm Nari Moves Across Hokkaido

Tropical Storm Nari moved across Hokkaido on Monday.  At 5:00 p.m. EDT on Monday the center of Tropical Storm Nari was located at latitude 43.6°N and longitude 144.6°E which put the center about 45 miles (75 km) east-southeast of Kitami, Japan.  Nari was moving toward the north-northeast at 33 m.p.h. (54 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.

Tropical Storm Nari was making a transition to an extratropical cyclone as it moved across Hokkaido on Monday.  Most of the bands revolving around the center of Nari’s circulation consisted primarily of showers and lower clouds.  There were still a few thunderstorms in bands in the southeastern part of Tropical Storm Nari.

The strongest winds were occurring in the eastern side of Tropical Storm Nari.  Winds to tropical storm force extended out 140 miles (225 km) in the eastern side of Nari’s circulation.  The winds in the western part of Tropical Storm Nari were blowing at less than tropical storm force.

Tropical Storm Nari will move into the upper level westerly winds in the middle latitudes.  Those winds will steer Nari toward the east-northeast during the next 24 hours.  On its anticipated track, Tropical Storm Nari will move quickly away from Hokkaido in a few hours.

Tropical Storm Nari will move through an environment very unfavorable for a tropical cyclone during the next 24 hours.  Nari will move over water where where the Sea Surface Temperatures are near 12°C.  It will move under the eastern side of an upper level low west of Japan.  The upper level low will produce strong southwesterly winds that will blow toward the top of Nari’s circulation.  Those winds will cause strong vertical wind shear.  The cold water and strong vertical wind shear will cause Tropical Storm Nari to continue its transition to an extratropical cyclone.

Tropical Storm Nari will continue to produce strong winds and isolated heavy rain in Hokkaido during the next few hours.  Weather conditions in Hokkaido will improve on Tuesday when Nari moves rapidly away from the area.

Tropical Storm Nari Strengthens Southeast of Tokyo

Tropical Storm Nari strengthened over the Western North Pacific Ocean southeast of Tokyo on Sunday.  At 5:00 p.m. EDT on Sunday the center of Tropical Storm Nari was located at latitude 33.2°N and longitude 143.0°E which put the center about 300 miles (485 km) southeast of Tokyo, Japan.  Nari was moving toward the north at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 984 mb.

Tropical Storm Nari strengthened on Sunday as it moved over the Western North Pacific Ocean southeast of Tokyo.  The structure Nari’s circulation changed when it moved under an upper level low south of Japan.  The inner end of a rainband wrapped around the western and southern sides of the center Tropical Storm Nari.  A region of drier air wrapped around the outside of that rainband.  Thunderstorms were occurring near the center of Naria’s circulation.  Thunderstorms were also occurring in bands in the northeastern part of Tropical Storm Nari.

The distribution of winds speeds in Tropical Storm Nari continued to be asymmetrical.  Winds to tropical storm force extended out 180 miles (290 km) in the eastern side of Nari’s circulation. Winds to tropical storm force extended out 65 miles (105 km) in the western side of Tropical Storm Nari.

Tropical Storm Nari will move through an environment that will be marginally favorable for intensification during the next 12 hours.  Nari will move over water where where the Sea Surface Temperatures are near 28°C.  It will move under the northeastern part of an upper level low south of Japan.  The upper level low will produce southerly winds that will blow toward the top of Nari’s circulation. Those winds will cause moderate vertical wind shear.  The vertical wind shear will inhibit intensification.  Tropical Storm Nari could intensify a little during the next 12 hours.  Nari will move over colder water later on Monday.  The colder water will cause Tropical Storm Nari to start to weaken.  The colder water will also cause Nari to start a transition to an extratropical storm.

Tropical Storm Nari will move around the western side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Nari toward the north during the next 24 hours.  On its anticipated track, Tropical Storm Nari will pass east of Honshu.  Nari will be south of Hokkaido in 24 hours.