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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 Nakri Brings Wind, Rain to Vietnam and Cambodia

Tropical Storm Nakri brought wind and rain to Vietnam and Cambodia on Sunday.  At 4:00 p.m. EST on Sunday the center of Tropical Storm Nakri was located at latitude 13.0°N and longitude 108.9°E which put it about 20 miles (35 km) west of Tuy Hoa, Vietnam.  Nakri was moving toward the west at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h).  The minimum surface pressure was 992 mb.

The center of Tropical Storm Nakri made landfall on the coast of Vietnam near Tuy Hoa on Sunday.  The maximum sustained wind speed at the time of landfall was 65 m.p.h. (105 km/h).  Nakri moved slowly toward the west after it made landfall.  Tropical Storm Nakri has been weakening slowly since the center moved over land.  The heaviest rain was falling in bands in the western half of the circulation.  Heavy rain was falling over portions of southern Vietnam and northeastern Cambodia.  The strongest winds were occurring in the eastern half of Nakri which was still over the South China Sea.  Winds to tropical storm force extended out 60 miles (95 km) from the center of circulation.

Tropical Storm Nakri will move south of a ridge over high pressure over the South China Sea and southeast Asia.  The ridge will steer Nakri toward the west-northwest during the next 24 to 36 hours.  Tropical Storm Nakri will continue to weaken as it moves farther inland.  On its anticipated track Nakri will drop locally heavy rain over parts of southern Vietnam, northern Cambodia, southern Laos and eastern Thailand.  Heavy rain could cause flash floods in some locations.

Nakri Strengthens to a Typhoon and Moves Toward Vietnam

Former Tropical Storm Nakri strengthened into a typhoon and started to move toward Vietnam on Friday.  At 4:00 p.m. EST on Friday the center of Typhoon Nakri was located at latitude 12.9°N and longitude 114.9°E which put it about 395 miles (635 km) east of Quy Nhon, Vietnam.  Nakri was moving toward the west at 13 m.p.h. (20 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 977 mb.

The distribution of thunderstorms around Typhoon Nakri was asymmetrical.  A broken ring of showers and thunderstorms surrounded the center of Nakri.  The strongest thunderstorms were in the southern portion of the ring.  Most of the strongest rainbands were in the southern half of the typhoon, although there was one strong rainband along the northern periphery of the circulation.  Many of the other bands on the eastern and northern sides of Typhoon Nakri consisted primarily of showers and lower clouds.  It appeared that sinking, drier air was limiting the development of thunderstorms in the northern half of the circulation.

In spite of the effects of the drier air, the size of the circulation around Typhoon Nakri increased on Friday.  Winds to typhoon force extended out 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out 175 miles (280 km) from the center.

Typhoon Nakri will be moving through an environment marginally favorable for intensification during the next 12 to 24 hours.  Nakri will move over water where the Sea Surface Temperature is near 28°C.  It will move around the southern side of an upper level ridge over southeast Asia and the South China Sea.  The ridge will produce easterly winds which will blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear which will inhibit intensification.  Drier air to the north of Typhoon Nakri will also inhibit intensification.  Nakri is likely to maintain its intensity during the next day or so, but it could start to weaken if the wind shear increases or more drier air sinks over the circulation.

The ridge over southeast Asia and the South China Sea will steer Typhoon Nakri toward the west during the next two to three days.  On its anticipated track Typhoon Nakri could approach the coast of Vietnam in about 48 hours.  Typhoon Nakri could bring gusty winds and a storm surge for the central coast of Vietnam.  Nakri could drop locally heavy rainfall when it moves inland and flash floods could occur in some locations.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Halong was speeding away from Miami Tori Shima, Japan.  At 4:00 p.m. EDT on Friday the center of Tropical Storm Halong was located at latitude 30.9°N and longitude 161.1°E which put it about 580 miles (935 km) northeast of Minami Tori Shima, Japan.  Halong was moving toward the northeast at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h).  The minimum surface pressure was 983 mb.

Tropical Storm Nakri Stalls West of the Philippines

Tropical Storm Nakri stalled west of the Philippines on Thursday.  At 10:00 p.m. EST on Thursday the center of Tropical Storm Nakri was located at latitude 12.8°N and longitude 116.8°E which put it about 290 miles (465 km) west-southwest of Manila, Philippines.  Nakri was moving toward the south at 2 m.p.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.

Tropical Storm Nakri meandered slowly west of the Philippines on Thursday.  The structure of Nakri did not change a lot during the day.  There was a distinct low level center center of circulation.  Thunderstorms were forming on the south side of the center and the strongest winds were occurring in those thunderstorms.  Thunderstorms were also developing in bands in the southern half of Tropical Storm Nakri.  Bands in the northern half of the circulation consisted primarily of showers and lower clouds.  Storms south of the center generated upper level divergence that pumped mass away to the west of the tropical storm.  Winds to tropical storm force extended out 175 miles (280 km) from the center of circulation.

Tropical Storm Nakri will move through an environment favorable for intensification during the next 24 to 36 hours.  Nakri mixed cooler water to the surface during the period when it meandered west of the Philippines, but it will move over water where the Sea Surface Temperature is near 29°C when it starts moving.  Tropical Storm Nakri will move southeast of an upper level ridge over southeast Asia.  The ridge will produce easterly winds which will cause moderate vertical wind shear.  The wind shear will inhibit intensification, but it will not be strong enough to prevent Tropical Storm Nakri from strengthening.  Nakri will likely become a typhoon on Friday or Saturday.

Tropical Storm Nakri has been in an area where the steering winds have been weak and it has moved little during the past 24 hours.  The ridge over southeast Asia will strengthen and it will steer Nakri toward the east during the next 72 hours.  On its anticipated track Tropical Storm Nakri could approach the coast of Vietnam in less than 72 hours.  Nakri is likely to be a typhoon when it approaches the coast of Vietnam.

Elsewhere over the Western North Pacific Ocean, Typhoon Halong was passing north of Minami Tori Shima, Japan.  At 10:00 p.m. EST on Thursday the center of Typhoon Halong was located at latitude 27.2°N and longitude 154.4°E which put it about 175 miles (280 km) north of Minami Tori Shima, Japan.  Halong was moving toward the northeast at 16 m.p.h. (26 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 968 mb.

Typhoon Halong Intensifies into Equivalent of Cat. 5 Hurricane

Typhoon Halong intensified into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Tuesday.  At 4:00 p.m. EST on Tuesday the center of Typhoon Halong was located at latitude 20.4°N and longitude 150.6°E which put it about 345 miles (560 km) southwest of Minami Tori Shima, Japan.  Halong was moving toward the north-northwest at 5 m.p.h. (8 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 900 mb.

Typhoon Halong intensified into one of the strongest tropical cyclones of 2019 over the Western North Pacific Ocean on Tuesday.  There was a circular eye with a diameter of 15 miles (24 km) at the center of Halong.  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 Halong.  Storm near the core were generating strong upper level divergence which was pumping mass away to the northeast of the typhoon.

The circulation around Typhoon along was compact and symmetrical.  Winds to typhoon force extended out 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out 115 miles (185 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Halong was 42.2.  The Hurricane Size Index (HSI) was 9.4 and the Hurricane Wind Intensity Size Index (HWISI) was 51.6.

Typhoon Halong has probably reached its peak intensity.  Halong will move over water where the Sea Surface Temperature is near 29°C.  However, an upper level trough near Japan will approach Typhoon Halong from the northwest.  The trough will produce strong southwesterly winds which will start to increase the vertical wind shear.  More wind shear will cause Halong to weaken.

The upper level trough will start to steer Typhoon Halong toward the northeast in 12 to 24 hours.  On its anticipated track Typhoon Halong will pass northwest of Minami Tori Shima on Thursday.  Even though it will weaken, Halong will bring strong, gusty winds and heavy rain.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Nakri developed over the South China Sea between the Philippines and Vietnam on Tuesday.  At 4:00 p.m. EST on Tuesday the center of Tropical Storm Nakri was located at latitude 13.8°N and longitude 116.0°E which put it about 380 miles (615 km) west of Manila, Philippines.  Nakri was moving toward the northeast at 5 m.p.h. (8 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 998 mb.

Although Tropical Storm Nakri is currently moving toward the northeast, it is forecast to move back toward the west later this week.  Nakri will move through an environment favorable for intensification.  It will move over water where the Sea Surface Temperature is near 28°C.  Tropical Storm Nakri could strengthen into a typhoon before it reaches the coast of Vietnam.

Typhoon Jebi Brings Wind and Rain to Japan

Typhoon Jebi brought wind and rain to Japan on Monday night.  At 11:00 p.m. EDT on Monday the center of Typhoon Jebi was located at latitude 33.9°N and longitude 134.4°E which put it about 15 miles (25 km) southwest of Tokushima.  Jebi was moving toward the north-northeast at 25 m.p.h. (40 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 105 m.p.h. (170 km/h).  The minimum surface pressure was 945 mb.

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

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

Typhoon Jebi Moves Closer to Japan

Typhoon Jebi moved closer to Japan on Sunday.  At 11:00 p.m. EDT on Sunday the center of Typhoon Jebi was located at latitude 26.7°N and longitude 133.0°E which put it about 620 miles (1000 km) south of Kyoto, Japan.  Jebi was moving toward the northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (235 km/h).  The minimum surface pressure was 940 mb.

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

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

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

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

Typhoon Jebi Turns Toward Japan

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

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

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

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

Typhoon Jebi Strengthens to Equivalent of Cat. 5 Hurricane

Powerful Typhoon Jebi strengthened into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Friday.  At 11:00 a.m. EDT on Friday the center of Typhoon Jebi was located at latitude 18.8°N and longitude 141.0°E which put it about 400 miles (645 km) south of Iwo To.  Jebi was moving toward the west-northwest at 14 m.p.h. (22 km/h).  The maximum sustained wind speed was 175 m.p.h. (280 km/h) and there were wind gusts to 210 m.p.h. (335 km/h).  The minimum surface pressure was 907 mb.

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

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

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

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

Typhoon Jebi Hits Northern Marianas

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

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

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

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

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