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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 Halong Strengthens to Equivalent of a Major Hurricane

Typhoon Halong strengthened to the equivalent of a major hurricane northeast of the Northern Marianas on Monday.  At 4:00 p.m. EST on Monday the center of Typhoon Halong was located at latitude 18.9°N and longitude 152.1°E which put it about 390 miles (630 km) south of Minami Tori Shima, Japan.  Halong was moving toward the northwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 952 mb.

Typhoon Halong continued to strengthen on Monday and it reached the equivalent of a major hurricane.  A small, well formed circular eye was evident on infrared 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 Halong.  Storms near the core were generating strong upper level divergence which was pumping mass away from the typhoon.

The circulation around Typhoon Halong increased in size on Monday.  Winds to typhoon force extended out 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out 160 miles (260 km) from the center.  The Hurricane intensity Index (HII) for Typhoon Halong was 22.0.  The Hurricane Size Index (HSI) was 14.3 and the Hurricane Wind Intensity Size Index was 36.3.  Halong was capable of causing major damage.

Typhoon Halong will remain in an environment favorable for intensification for another 24 hours.  Halong will move over water where the Sea Surface Temperature is near 29°C.  It will move under the northwestern portion of an upper level ridge where the winds are weaker and there will be little vertical wind shear.  An upper level trough southwest of Japan will approach Typhoon Halong in 24 hours.  The trough will produce stronger southwesterly winds which will cause more vertical wind shear.  Halong will start to weaken when the wind shear increases.

Typhoon Halong will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean during the next 36 to 48 hours.  The ridge will steer Halong toward the north-northwest.  Halong will move toward the northeast later this week after if moves around the western end of the high pressure system.  On its anticipated track Typhoon Halong could approach Minami Tori Shima in less than 72 hours.

Halong Strengthens into a Typhoon East of the Northern Marianas

Former Tropical Storm Halong strengthened into a typhoon east of the Northern Marianas on Sunday.  At 4:00 p.m. EDT on Sunday the center of Typhoon Halong was located at latitude 17.0°N and longitude 153.3°E which put it about 520 miles (840 km) east-northeast of Saipan.  Halong was moving toward the northwest at 12 m.p.h. (19 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.

The circulation around former Tropical Storm Halong exhibited much better organization on Sunday.  An eye with a diameter of approximately 12 miles (19 km) formed at the center of Halong.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Typhoon Halong.  The strongest rainbands were north and east of the center of circulation.  Bands in the western half of Halong consisted primarily of showers and lower clouds.  Typhoon Halong may have been pulling sinking, drier air into the western half of the circulation, which may be why the bands were weaker in that part of the typhoon.  Storms around the core of Halong were generating strong upper level divergence which was pumping mass away from the typhoon.  Winds to typhoon force extended out 10 miles (15 km) from the center of circulation.  Winds to tropical storm force extended out 175 miles (280 km) from the center.

Typhoon Halong will move through an environment favorable for intensification during the next 36 to 48 hours.  Halong will move over water where the Sea Surface Temperature is near 29°C.  It will move under the western part of an upper level ridge where the winds are weak.  So, there will not be a lot of vertical wind shear.  Typhoon Halong will continue to intensify and it could strengthen into the equivalent of a major hurricane.

Typhoon Halong will move around the western end of a ridge of high pressure over the Western North Pacific Ocean.  The ridge will steer Halong toward the northwest during the next 24 hours.  After that time Typhoon Halong will move more toward the north while it moves around the western end of the ridge.  Halong will move northeastward after it moves around the end of the ridge.  On its anticipated track Typhoon Halong is forecast to remain northeast of the Northern Marianas.  Halong is expected to pass between Iwo To and Wake Island later next week.

Tropical Storm Halong Develops East of the Marianas

Tropical Storm Halong developed east of the Marianas on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Halong was located at latitude 13.3°N and longitude 156.7°E which put it about 820 miles (1325 km) east of Guam.  Halong was moving toward the northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1000 mb.

A distinct low level center of circulation formed in an area of thunderstorms east of the Marianas on Saturday.  When more thunderstorms formed near the center of circulation, the Japan Meteorological Agency designated the system as Tropical Storm Halong.  The circulation around Halong appeared to be organizing quickly.  New thunderstorms were forming close to the center of circulation.  Bands of showers and thunderstorms were also organizing quickly and the bands were starting to revolve around the center of Tropical Storm Halong.  Storms near the center were generating upper level divergence which was pumping mass away from the tropical storm in all directions.  Winds to tropical storm force extended out 150 miles (240 km) from the center of circulation.

Tropical Storm Halong will move through an environment favorable for intensification during the next two to three days.  Halong will move over water where the Sea Surface Temperature is near 29°C.  It will move under the western end of an upper level ridge over the Western North Pacific Ocean.  The winds will be blowing from the south at all levels and so there will be little vertical wind shear.  Tropical Storm Halong will continue to intensify and it could strengthen rapidly.  Halong is likely to strengthen into a typhoon within 36 hours.

The ridge over the Western North Pacific will steer Tropical Storm Halong toward the northwest during the next several days.  On its anticipated track Halong will be northeast of the Marianas by the end of the weekend.

Typhoon Khanun Makes Landfall in Southern China

Typhoon Khanun made landfall near Zhanjiang in southern China on Sunday.  At 5:00 p.m. EDT on Sunday the center of Typhoon Khanun was located at latitude 20.9°N and longitude 109.3°E which put it about 50 miles (80 km/h) south-southeast of Beihai, China.  Khanun was moving toward the west at 17 m.p.h. (27 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. (150 km/h).  The minimum surface pressure was 969 mb.

Typhoon Khanun brought gusty winds and locally heavy rain over coastal sections of southern China on Sunday.  Khanun has weakened since it made landfall.  An upper level ridge centered over eastern China is producing easterly winds which are blowing over the top of the circulation.  Those winds are causing strong vertical wind shear, which is pushing the upper half of the circulation to the west of low level circulation.  The circulation is pulling drier air from Asia into the western part of Typhoon Khanun and the drier air is wrapping around the southern and eastern sides of the circulation.   Interaction with land and strong vertical wind shear will continue to weaken Khanun on Monday.  Khanun will bring rain to southern China and northern Vietnam as it weakens.

Elsewhere over the western North Pacific Ocean Tropical Depression Twentyfive-W formed west of Yap.  At 5:00 p.m. EDT on Sunday the center of Tropical Depression Twentyfive-W was located at latitude 10.3°N and longitude 136.1°E which put it about 125 miles (200 km) west-northwest of Yap.  It was moving toward the north-northwest at 11 m.p.h. (17 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 999 mb.

The circulation of Tropical Depression Twentyfive-W is still organizing.  Most of the showers and thunderstorms are in a primary rainband that wraps around the eastern side of the circulation.  The depression is moving through an area favorable for intensification.  It is moving over water where the Sea Surface Temperature is near 30°C.  The upper level winds are weak and there is not much vertical wind shear.  Tropical Depression Twentyfive-W is likely to be become a tropical storm during the next 24 hours and it could become a typhoon in a couple of days.  The depression is forecast to move toward the north-northwest as it moves around the western end of a subtropical ridge over the Pacific Ocean.

Khanun Intensifies Into a Typhoon Southeast of Hong Kong

Tropical Storm Khanun intensified into a typhoon southeast of Hong Kong on Saturday.  At 11:00 p.m. EDT on Saturday the center of Typhoon Khanun was located at latitude 20.1°N and longitude 114.2°W which put it about 170 miles (275 km) south-southeast of Hong Kong.  Khanun was moving toward the west-northwest at 18 m.p.h. (29 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 965 mb.

The circulation of Typhoon Khanun became much more well organized on Saturday.  A small circular eye formed at the center of circulation.  A tight ring of strong thunderstorms formed around the eye.  The strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Typhoon Khanun.  There were many more showers and thunderstorms in the western half of the circulation.  The storms in the core of Khanun were generating upper level divergence which was pumping mass away to the west 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 250 miles (400 km) from the center.

Typhoon Khanun will move through an environment favorable for intensification for about another 12 to 18 hours.  Khanun will move over water where the Sea Surface Temperature is near 29°C.  An upper level ridge north of Typhoon Khanun is producing easterly winds which are blowing toward the top of the circulation.  The easterly winds are causing some vertical wind shear, but the shear is not strong enough to prevent intensification.  The circulation of Typhoon Khanun will interact with land in 12 to 18 hours and that interaction should halt further intensification.

The ridge north of Khanun has been steering the typhoon toward the west-northwest.  The ridge is forecast to strengthen on Sunday and it will steer Typhoon Khanun more toward the west.  On its anticipated track the center of Typhoon Khanun will pass south of Hong Kong and Macao on Sunday.  Khanun will approach the south coast of China near Zhanjiang in 12 to 18 hours.  Typhoon Khanun will bring strong gusty winds and locally heavy rain to southern China west of Hong Kong and Macao.  The heavy rain could cause flooding in some locations.  Typhoon Khanun will be weaker when it moves over the Gulf of Tongking in about 24 hours.

Tropical Storm Khanun Forms Near Luzon

Tropical Storm Khanun formed near northern Luzon on Thursday.  At 11:00 p.m. EDT on Thursday the center of Tropical Storm Khanun was located near latitude 18.0°N and longitude 121.6°W which put it about 240 miles (390 km) north of Manila, Philippines.  Khanun was moving toward the west 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 994 mb.

A center of circulation developed near the surface in an area of thunderstorms on Thursday and the Japan Meteorological Agency designated the system as Tropical Storm Khanun.  The circulation of Tropical Storm Khanun was still organizing.  The center of Khanun moved across northern Luzon and the passage over land interrupted the development of the circulation.  Despite the passage over land, a primary rainband wrapped around the western side of the circulation.  Additional bands of showers and thunderstorms developed in the western half of the circulation.  The rainbands were weaker in the eastern half of Khanun, especially in the part of the circulation still over northern Luzon.

Tropical Storm Khanun will move through an environment favorable for intensification when it moves over the South China Sea.  Khanun will move over water where the Sea Surface Temperature is near 30°C.  The tropical storm is moving under the western half of an upper level ridge.  The ridge is producing easterly winds which are blowing toward the top of the circulation.  Those winds are causing moderate vertical wind shear.  The shear will slow the rate of intensification, but it should not be strong enough to prevent Tropical Storm Khanun from intensifying.  Khanun should start to strengthen once the center move farther west of Luzon.  Tropical Storm Khanun is forecast to become a typhoon during the weekend.

Tropical Storm Khanun is moving south of a ridge which is steering the tropical storm toward the west.  A generally westward motion is expected to continue during the next several days.  On its anticipated track Tropical Storm Khanun could approach Hainan Island in about 48 hours.  Khanun is likely to be a typhoon at that time.

Typhoon Sarika Making Landfall on Hainan Island

The center of Typhoon Sarika is making landfall on Hainan Island near Qionghai and Wanning.  At 11:00 p.m. EDT on Monday the center of Typhoon Sarika was located at latitude 19.1°N and longitude 110.4°E which put it near Qionghai, China.  Sarika was moving toward the west-northwest at 11 m.p.h. (18 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 976 mb.

The structure of Typhoon Sarika changed after it moved across the Philippines.  It developed a larger eye and more of the thunderstorms occurred in a primary rainband that wrapped around the western and southern parts of the circulation.  Sarika maintained that structure as it made landfall on Hainan Island, although were some indications in satellite imagery that they eye was contracting just prior to landfall.

Typhoon Sarika will weaken while the center passes over Hainan Island.  Sarika could be a tropical storm by the time the center emerges over the Gulf of Tongking.  The Sea Surface Temperature in the Gulf of Tongking is near 31°C.  So, evaporation could provide another source of energy and moisture while the center is over water.

Typhoon Sarika is being steered toward the west-northwest by a subtropical ridge and that general motion is expected to continue for another day or so.  On its anticipated track Typhoon Sarika will spend the next few hours moving across Hainan Island.  Sarika could make another landfall over northern Vietnam and southern China in about 24 to 30 hours.

The Hurricane Intensity Index (HII) was 11.5 for Typhoon Sarika.  The Hurricane Size Index (HSI) was 13.2 and the Hurricane Wind Intensity Size Index (HWISI) was 24.7.  These indices indicate that Typhoon Sarika is capable of causing regional, minor wind damage.  Sarika will also bring locally heavy which could cause floods over Hainan Island and parts of northern Vietnam and southern China.