Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Typhoon Vamco Brings Wind and Rain to Vietnam

Typhoon Vamco brought wind and rain to Vietnam on Saturday night. At 10:00 p.m. EST on Saturday the center of Typhoon Vamco was located at latitude 17.3°N and longitude 107.5°E which put it about 40 miles (65 km) east of Vinh Linh, Vietnam. Vamco was moving toward the northwest at 8 m.p.h. (13 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 979 mb.

The center of Typhoon Vamco was about to make landfall on the coast of Vietnam between Vinh Linh and Dong Hoi on Saturday night. Bands on the western side of Vamco were already bringing wind and rain to Vietnam. A flow of drier air from eastern Asia into the western part of the circulation around Vamco caused the typhoon to weaken as it approached Vietnam. Even though it was weaker, Typhoon Vamco was still capable of causing serious damage. Winds to typhoon force extended out 30 miles (50 km) from the center of Vamco. Winds to tropical storm force extended out 130 miles (210 km from the center.

Typhoon Vamco will bring strong winds to the coast of central Vietnam during the next few hours. Wind blowing water toward the coast will cause a storm surge north of Vinh Linh. The winds blwoing around Vamco will weaken when it moves inland. However, Typhoon Vamco will drop heavy rain over parts of central Vietnam, southern Laos and northeastern Thailand. Heavy rain will fall on saturated ground and significant flooding is likely to occur.

Typhoon Vamco Strengthens to Equivalent of Major Hurricane

Typhoon Vamco strengthened to the equivalent of a major hurricane east of Vietnam on Friday. At 4:00 p.m. EST on Friday the center of Typhoon Vamco was located at latitude 15.7°N and longitude 111.9°E which put it about 275 miles (440 km) east of Da Nang, Vietnam. Vamco was moving toward the west at 12 m.p.h. (19 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 954 mb.

Typhoon Vamco rapidly intensified into the equivalent of a major hurricane over the East China east of Vietnam on Friday. The circulation contracted around a small clear eye. 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 Vamco. Storms near the core were generating strong upper level divergence which was pumping mass away fro the typhoon. The removal of mass allowed the pressure to decrease rapidly which contributed to the rabid intensification.

Winds to typhoon force extended out 40 miles (65 km) from the center of Typhoon Vamco. Winds to tropical storm force extended out 200 miles (320 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Vamco was 25.1. The Hurricane Size Index (HSI) was 16.7 and the Hurricane Wind Intensity Size Index (HWISI) was 41.8. Vamco was capable of causing significant damage.

Typhoon Vamco will move through an environment that will become less favorable for intensification during the next day or so. Vamco will move over water where the Sea Surface Temperature is near 28°C. So, there will be enough energy in the upper ocean to support an intense typhoon. However, northeasterly winds will transport drier air over eastern Asia toward the western side of Typhoon Vamco. Vamco is likely to start to weaken when the drier air is pulled into the core of the circulation.

Typhoon Vamco will move south of a high pressure system over the eastern Asia. The high will steer Vamco toward the west during the next several days. On its anticipated track Typhoon Vamco will approach the coast of Vietnam north of Da Nang in about 24 hours. Vamco is likely to still be a typhoon when it reaches Vietnam. Typhoon Vamco will drop heavy rain over Vietnam, Laos and northeastern Thailand. The rain will fall on saturated surfaces and floods will occur in those areas.

Typhoon Vamco Moves Toward Vietnam

Typhoon Vamco moved toward Vietnam on Thursday. At 10:00 p.m. EST on Thursday the center of Typhoon Vamco was located at latitude 15.5°N and longitude 115.0°E which put it about 480 miles (775 km) east of Da Nang, Vietnam. Vamco was moving toward the west-northwest at 9 m.p.h. (15 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. (165 km/h). The minimum surface pressure was 972 mb.

One day after causing widespread damage on Luzon, Typhoon Vamco moved across the South China Sea toward Vietnam. An eye was present at the center of Vamco, but there were clouds in the eye. The eye was surrounded by a broken ring of thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Typhoon Vamco. The size of the circulation around Vamco increased after it crossed Luzon. Winds to typhoon force extended out 75 miles (120 km) from the center of circulation. Winds to tropical storm force extended out 230 miles (370 km) from the center.

Typhoon Vamco will move through an environment that could allow it to maintain its intensity for another 24 to 36 hours. Vamco will move over water where the Sea Surface Temperature is near 28°C. It will move under the southern portion of an upper level ridge over eastern Asia. The ridge will produce easterly winds which will blow toward the top of the Typhoon Vamco. Those winds will cause some vertical wind shear, but the shear will not be too strong. Northeasterly winds will transport drier air toward the western side of Typhoon Vamco when it moves closer to land in 24 to 36 hours. Vamco could start to weaken if the drier air is pulled into the core of the typhoon.

Typhoon Vamco will move south of a high pressure system over the eastern Asia. The high will steer Vamco toward the west-northwest during the next several days. On its anticipated track Typhoon Vamco will approach the center coast of Vietnam in about 36 hours.

Typhoon Vamco Makes Landfall Northeast of Manila

Typhoon Vamco made landfall on Luzon northeast of Manila on Wednesday. At 4:00 p.m. EST on Wednesday the center of Typhoon Vamco was located at latitude 15.0°N and longitude 120.6°E which put it about 35 miles (55 km) northeast of Manila, Philippines. Vamco was moving toward the west at 17 m.p.h. (28 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.

Typhoon Vamco was strengthening when it made landfall on Luzon. Vamco was nearly the equivalent of a major hurricane at the time of landfall. The circulation around Typhoon Vamco also increased in size prior to landfall. Winds to typhoon force extended out 100 miles (160 km) on the northern side of Vamco. Winds to force extended out 40 miles (65 km) on the southern side of the typhoon. Winds to tropical storm force extended out 350 miles in the northern half of the circulation. Winds to tropical storm force extended out 150 miles in the southern half of Vamco. The Hurricane Intensity Index (HII) for Typhoon Vamco was 19.2. The Hurricane Size Index (HSI) was 28.4 and the Hurricane Wind intensity Size Index (HWISI) was 47.6. Typhoon Vamco was capable of causing widespread serious damage to Luzon.

The center of Typhoon Vamco passed over the Polillo Islands before it reached Luzon. The center of Vamco will pass just north Manila, but it will be close enough to cause strong winds. The center will pass near San Fernando and Olongapo before it moves over the South China Sea. Typhoon Vamco will drop very heavy rain over Luzon and significant floods could occur. There will also be widespread power outages.

Typhoon Vamco will weaken as it passes over Luzon, but Vamco could still be a typhoon when it reaches the South China Sea. A high pressure system over eastern Asia will steer Typhoon Vamco toward the west. On its anticipated track Vamco could approach Vietnam in two or three days.

Vamco Rapidly Intensifies to Typhoon East of Luzon

Former Tropical Storm Vamco rapidly intensified into a typhoon east of Luzon on Tuesday. At 10:00 p.m. EST on Tuesday the center of Typhoon Vamco was located at latitude 14.9°N and longitude 124.0°E which put it about 230 miles (375 km) east of Manila, Philippines. Vamco was moving toward the west at 16 m.p.h. (26 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. (165 km/h). The minimum surface pressure was 973 mb.

Typhoon Vamco intensified rapidly on Tuesday. A circular eye was visible on satellite images. 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 Vamco. Storms near the center were generating upper level divergence which was pumping mass away from the typhoon. Winds to typhoon force extended out 30 miles (50 km) from the center of Vamco. Winds to tropical storm force extended out 175 miles (280 km) from the center of circulation.

Typhoon Vamco will move through an environment that will be favorable for intensification during the next 12 hours. Vamco will move over water where the Sea Surface Temperature is near 28°C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. Typhoon Vamco will continue to intensify rapidly and it could strengthen to the equivalent of a major hurricane.

Typhoon Vamco will move south of a high pressure system over the Western North Pacific Ocean. The high will steer Vamco toward the west during the next several days. On its anticipated track Typhoon Vamco will make landfall on the east coast of Luzon in about 12 hours. The center of Vamco will pass north of Manila and the core of Typhoon Vamco could come close to San Francisco.

Typhoon Vamco will bring strong winds and heavy rain to Luzon. Vamco will be capable of causing major damage. The heavy rain will cause flash floods in part of Luzon. Typhoon Vamco could cause a storm surge of up to 10 feet (3 meters) on the east coast of Luzon. Vamco will weaken when the center passes over Luzon, but it is likely to still be a typhoon when it passes north of Manila. Typhoon Vamco is also likely to cause widespread power outages on Luzon.

Elsewhere over the Western North Pacific Ocean, Tropical Depression Etau was dropping heavy rain over Cambodia. At 10:00 p.m. EST on Tuesday the center of Tropical Depression Etau was located at latitude 12.5°N and longitude 105.5°E which put it about 100 miles (160 km) northeast of Phnom Penh, Cambodia. Etau was moving toward the west at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 25 m.p.h. (40 km/h) and there were wind gusts to 30 m.p.h. (50 km/h). The minimum surface pressure was 1006 mb.

Tropical Storm Etau Nears Vietnam, Vamco Threatens Philippines

Tropical Storm Etau neared Vietnam on Monday and newly formed Tropical Storm Vamco threatened the Philippines. At 4:00 a.m. EST on Monday the center of Tropical Storm Etau was located at latitude 12.8°N and longitude 111.6°E which put it about 170 miles (280 km) east of Tuy Hoa, Vietnam. Etau was moving toward the west at 15 m.p.h. (24 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 995 mb.

The distribution of thunderstorms around Tropical Storm Etau was asymmetrical. Etau was moving under the southern part of an upper level ridge over eastern Asia. The ridge was producing easterly winds which were blowing toward the top of Etau. Those winds were causing moderate vertical wind shear. The shear was causing the stronger thunderstorms to occur in bands on the western side of Tropical Storm Etau. The bands in the eastern side of Etau consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 150 miles (240 km) in the northern half of Tropical Storm Etau. Winds to tropical storm force only extended out 50 miles in the southern half of Etau.

Tropical Storm Etau will move south of a high pressure system over eastern Asia. The high will steer Etau toward the west during the next two days. On its anticipated track the center of Etau will make landfall in Vietnam near Tuy Hoa in about 12 hours.

Tropical Storm Etau will move through an environment that should allow it to maintain its intensity until it makes landfall in Vietnam. Etau will move over water where the Sea Surface Temperature is near 28°C. The upper level ridge over eastern Asia will continue to cause moderate vertical wind shear which will limit intensification.

Since the stronger thunderstorms are in the western half of Tropical Storm Etau, heavy rain will fall over central Vietnam before the center of Etau makes landfall. Etau will drop locally heavy rain over central Vietnam, northern Cambodia, southern Laos and northeastern Thailand. The ground is already saturated in that region and flash floods are likely.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Vamco developed east of the Philippines. At 4:00 a.m. EST on Monday the center of Tropical Storm Vamco was located at latitude 12.8°N and longitude 130.6°E which put it about 370 miles (605 km) east of Laoang, Philippines. Vamco was moving toward the northwest at 13 m.p.h. (20 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 1002 mb. Tropical Storm Vamco is forecast to move toward Luzon and to strengthen into a typhoon.

Tropical Storm Atsani Passes Just South of Taiwan

Tropical Storm Atsani passed just south of Taiwan early on Friday. At 4:00 a.m. EST on Friday the center of Tropical Storm Atsani was located at latitude 21.5°N and longitude 120.7°E which put it about 30 miles (50 km) south of Taiwan. Atsani was moving toward the west-northwest at 12 m.p.h. (19 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 995 mb.

The center of Tropical Storm Atsani passed just to the south of the southern tip of Taiwan early on Friday. Radar images from the Taiwan Central Weather Bureau showed the well organized structure of Tropical Storm Atsani.

There was a small, tight center of circulation. The center was surrounded by a partial eyewall and the strongest winds were occurring in eyewall. Multiple bands of showers and thunderstorms were revolving around the core of Tropical Storm Atsani. Bands in the northern half of Atsani were dropping heavy rain over the southern half of Taiwan. The heaviest rain was falling in parts of southeastern Taiwan where the wind was pushing air up the eastern slopes of mountains. Flash floods are possible in those areas. Winds to tropical storm force extended out 100 miles (160 km) from the center of Atsani.

Tropical Storm Atsani will be in an environment favorable for intensification during the next 12 to 24 hours. Atsani will move over water where the Sea Surface Temperature is near 28°C. It will be in an area where the upper level winds are weaker and there will be little vertical wind shear. Tropical Storm Atsani could intensify during the next 24 hours and there is a chance it could strengthen into a typhoon. An upper level trough over eastern Asia will approach Atsani during the weekend. The trough will produce stronger southwesterly winds which will cause more vertical wind shear. Tropical Storm Atsani will weaken when the wind shear increases. If the shear is strong enough, the upper level winds could blow the top half of Atsani northeast of the low level circulation.

Tropical Storm Atsani will move south of a ridge of high pressure over the Western North Pacific Ocean. The high will steer Atsani toward the west during the next day or so. If the wind shear blows the top half of Tropical Storm Atsani northeast of the lower level circulation, then a surface high pressure system over eastern Asia could push the lower half of Atsani toward the southeast. On its anticipated track Tropical Storm Atsani will pass southeast of Hong Kong and it could eventually move toward Vietnam.

Elsewhere over the Western North Pacific Ocean, the remnants of former Typhoon Goni were dropping heavy rain over parts of Vietnam. At 4:00 a.m. EST on Friday the center of Tropical Depression Goni was located at latitude 13.8°N and longitude 108.3°E which put it about 50 miles (80 km) west of Quy Nhon, Vietnam. Goni was moving toward the west at 7 m.p.h. (11 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 1003 mb. Tropical Depression Goni is dropping heavy rain over ground that is already saturated and the rain will make ongoing floods worse.

Dangerous Typhoon Goni Hits Catanduanes

Extremely dangerous Typhoon Goni hit Catanduanes Island on Saturday. At 5:00 p.m. EDT on Saturday the center of Typhoon Goni was located at latitude 13.7°N and longitude 124.4°E which put it about 25 miles (40 km) northeast of Virac, Philippines. Goni was moving toward the west-southwest at 16 m.p.h. (26 km/h). The maximum sustained wind speed was 195 m.p.h. (315 km/h) and there were wind gusts to 235 m.p.h. (380 km/h). The minimum surface pressure was 884 mb.

The eye of Typhoon Goni moved over the southern part of Catanduanes Island on Saturday. Despite the development of concentric eyewalls and the occurrence of an eyewall replacement cycle, Goni actually strengthened on Saturday. The original inner eyewall weakened and the outer eyewall contracted around the center of Typhoon Goni. Goni exhibited an eye with a diameter of 14 miles (22 km) when it made landfall on Catanduanes Island.

The circulation around Typhoon Goni increased in size during the eyewall replacement cycle. Winds to typhoon force extended out 60 miles (95 km) from the center of Goni. Winds to tropical storm force extended out 130 miles (210 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Goni was 48.0. The Hurricane Size Index (HSI) was 16.0 and the Hurricane Wind Intensity Size Index (HWISI) was 64.0. Typhoon Goni was capable of causing catastrophic damage on a regional scale.

Typhoon Goni will also generate a storm surge of up to 20 feet (6 meters) along the coasts of Catanduanes Island and southeastern Luzon. Typhoon Goni will move west across the Philippines. Goni will weaken as the core passes over land. The center of Goni will make landfall in southeastern Luzon near Tabaco. The southern eyewall of Goni will produce strong winds in Legaspi. The northern eyewall will bring strong winds to Naga. Typhoon Goni could be near Manila in 18 hours and it could still be the equivalent of a major hurricane at that time. Goni will also drop locally heavy rain over southern Luzon and flash floods are likely.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Atsani was organizing slowly east of the Philippines. At 5:00 p.m. EDT on Saturday the center of Tropical Storm Atsani was located at latitude 15.2°N and longitude 135.8°E which put it about 900 miles (1450 km) east of Luzon. Atsani was moving toward the west-northwest at 11 m.p.h. (17 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. Tropical Storm Atsani was forecast to move toward the west and to strengthen.

Potentially Catastrophic Typhoon Goni Nears Luzon

Potentially catastrophic Typhoon Goni neared Luzon on Saturday morning. At 5:00 a.m. EDT on Saturday the center of Typhoon Goni was located at latitude 14.6°N and longitude 126.9°E which put it about 300 miles (485 km) east-northeast of Labo, Philippines. Goni was moving toward the west-southwest at 15 m.p.h. (24 km/h). The maximum sustained wind speed was 180 m.p.h. (290 km/h) and there were wind gusts to 220 m.p.h. (355 km/h). The minimum surface pressure was 898 mb.

Typhoon Goni exhibited a double eyewall structure sometimes seen in very intense tropical cyclones. There was a small inner eye with a diameter of 6 miles (10 km). That eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that inner eyewall. A second, outer eyewall with a diameter of 35 miles (56 km) surrounded the inner core of Typhoon Goni. Storms near the core of Gone generated strong upper level divergence which pumped large quantities of mass away from the typhoon. The removal of so much mass allowed the surface pressure to remain very low. Bands of showers and thunderstorms were revolving around the core of the typhoon.

The circulation around Typhoon Goni increased in size when the double eyewalls formed. Winds to typhoon force extended out 35 miles (55 km) from the center of Goni. Winds to tropical storm force extended out 130 miles (210 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Goni was 42.2. The Hurricane Size Index (HSI) was 13.6 and the Hurricane Wind Intensity Size Index (HWISI) was 55.8. Typhoon Goni was capable of causing catastrophic damage.

Typhoon Goni will move through an environment favorable for a strong typhoon during the next 12 hours. Goni will move over water where the Sea Surface Temperature is near 30°C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. An eyewall replacement cycle could cause Typhoon Goni to start to weaken. If the original inner eyewall dissipates and convergence becomes concentrated into the new outer eyewall, then the wind speed will decrease. However, Goni is likely to maintain much of its intensity until it reaches Luzon.

Typhoon Goni will move south of a subtropical high pressure system over the Western North Pacific Ocean. The high will steer Goni toward the west. On its anticipated track Typhoon Goni will be near Cataduanes Island in 12 48 hours. Goni could be near Manila in 24 hours. Typhoon Goni is capable of causing catastrophic damage to Luzon. Goni could generate a storm surge of up to 20 feet (6 meters) along the coast of southeastern Luzon. Typhoon Goni will drop heavy rain over parts of Luzon and flash floods are likely.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Atsani moved north of Yap. At 5:00 a.m. EDT on Saturday the center of Tropical Storm Atsani was located at latitude 14.6°N and longitude 138.2°E which put it about 1060 miles (1705 km) east of Luzon. Astani was moving toward the west 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 1001 mb. Tropical Storm Atsani was forecast to move toward the northwest and to strengthen.

Typhoon Goni Rapidly Intensifies Into Equivalent of Cat. 5 Hurricane

Typhoon Goni intensified rapidly into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale east of the Philippines on Thursday night. At 5:00 a.m. EDT on Friday the center of Typhoon Goni was located at latitude 16.2°N and longitude 131.2°E which put it about 620 miles (1000 km) east of Luzon. Goni was moving toward the west at 13 m.p.h. (20 km/h). The maximum sustained wind speed was 175 m.p.h. (280 km/h) and there were wind gusts to 205 m.p.h. (330 km/h). The minimum surface pressure was 912 mb. Typhoon Goni is capable of causing catastrophic damage.

Typhoon Goni continued to intensify rapidly on Thursday night. A small circular eye with a diameter of 10 miles (16 km) was at the center of Goni. 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 tight core of Typhoon Goni. Storms near the core generated strong upper level divergence which pumped mass away from the typhoon. The removal of mass allowed the surface pressure to decrease quickly which contributed to the rapid increase in wind speed.

Typhoon Goni will move through an environment favorable for a strong typhoon during the next 36 to 48 hours. Goni will move over water where the Sea Surface Temperature is near 30°C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. If the inner end of a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could occur. The cycle would cause Goni to weaken when the original inner eyewall dissipates and convergence becomes concentrated into a new outer eyewall. An eyewall replacement cycle would also cause the size of the circulation around Goni to Increase.

Typhoon Goni will move south of a subtropical high pressure system over the Western North Pacific Ocean. The high will steer Goni toward the west. On its anticipated track Typhoon Goni will approach the coast of Luzon in about 48 hours. Goni is likely to be the equivalent of a major hurricane when it approaches Luzon.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Atsani moved south of the Marianas. At 5:00 a.m. EDT on Friday the center of Tropical Storm Atsani was located at latitude 11.6°N and longitude 142.6°E which put it about 170 miles (275 km) south-southwest of Guam. Astani was moving toward the west-northwest at 30 m.p.h. (48 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. Tropical Storm Atsani was forecast to move toward the northwest and to strengthen.