Tag Archives: Marianas

Typhoon Bavi Moves Away from the Marianas

Typhoon Bavi moved away from the Marianas on Monday.  At 5:00 p.m. EDT on Monday the center of Typhoon Bavi was located at latitude 16.0°N and longitude 140.4°E which put the center about 300 miles (480 km) west-northwest of Guam.  Bavi was moving toward the west-northwest at 18 m.p.h. (30 km/h).  The maximum sustained wind speed was 155 m.p.h. (250 km/h) and there were wind gusts to 190 m.p.h. (305 km/h).  The minimum surface pressure was 921 mb.

Typhoon Bavi was in the middle of another eyewall replacement cycle on Monday afternoon.  An inner eye with a diameter of 25 miles (40 km) was at the center of Bavi’s circulation.  The inner eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  The inner end of a rainband wrapped around the inner eye and eyewall.  A larger, outer eyewall surrounded those features.

Bands of showers and thunderstorms revolved around the concentric eyewalls in the middle of Typhoon Bavi.  Storms near the center of Bavi generated upper level divergence that pumped mass away from the typhoon.  However, the removal of mass in the upper levels was less that the convergence of mass in the lower levels of the atmosphere.  So, the surface pressure increased on Monday.

The circulation around Typhoon Bavi grew even larger on Monday as the eyewall replacement cycle was underway.  Winds to typhoon force extended out 115 miles (185 km) from the center of Bavi’s circulation.  Winds to tropical storm force extended out 300 miles (480 km) from the center of Typhoon Bavi.

The Hurricane Intensity Index (HII) for Typhoon Bavi is 33.3.  The Hurricane Size Index (HSI) is 36.4 and the Hurricane Wind Intensity Size Index (HWISI) is 69.7. Typhoon Bavi is similar in intensity to Hurricane Ian when Ian hit Southwest Florida in 2022.  Typhoon Bavi is much larger than Ian was.

Typhoon Bavi will more through an environment that will be favorable for a powerful typhoon during the next 24 hours.  Bavi will move over water where the Sea Surface Temperatures are near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  The eyewall replacement cycle currently underway will cause Typhoon Bavi to weaken during the next few hours.  Bavi could strengthen again after the eyewall replacement cycle is completed.

Typhoon Bavi will move around the southern side of a high pressure system that is over the Western North Pacific Ocean. The high pressure system will steer Bavi toward the west-northwest during the next 24 hours.  On its anticipated track, Typhoon Bavi will approach the southern Ryukyu Islands and Taiwan in less than four days.

Typhoon Bavi Batters the Marianas

Typhoon Bavi battered the Marianas on Sunday night.  The eye of Typhoon Bavi passed over Rota.  At 11:00 p.m. EDT on Sunday the center of Typhoon Bavi was located at latitude 14.5°N and longitude 144.4°E which put the center about 20 miles (30 km) northwest of Rota and about 45 miles (75 km) north of Guam.  Bavi was moving toward the west-northwest at 13 m.p.h. (21 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. (335 km/h).  The minimum surface pressure was 906 mb.

Typhoon Warnings are in effect for Guam, Rota, Tinian, and Saipan.

Tropical Storm Warnings are in effect for Alamagan.

Tropical Storm Watches are in effect for Pagan and Agrihan.

The eye of Typhoon Bavi passed directly over Rota.  There have been no recent reports from the weather station on Rota.  The most recent observation from Andersen Air Force Base on Guam (PGUA) reported a sustained wind speed of 74 m.p.h. (119 km/h) and a wind gust of 92 m.p.h. (148 km/h).

Typhoon Bavi was the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale.

A circular eye with a diameter of 25 miles (40 km) was at the center of Typhoon Bavi.  The eye was surrounded by a 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 Bavi’s circulation.  Storms near the core of Bavi generated strong upper level divergence that pumped large quantities of mass away from typhoon.  The removal of large quantities of mass caused the surface pressure to decrease.

The size of the circulation around Typhoon Bavi increased on Sunday.  Winds to typhoon force extended out 70 miles (110 km) from the center of Bavi’s circulation.  Winds to tropical storm force extended out 310 miles (500 km) from the center of Typhoon Bavi.

The Hurricane Intensity Index (HII) for Typhoon Bavi is 40.4.  The Hurricane Size Index (HSI) is 26.8 and the Hurricane Wind Intensity Size Index (HWISI) is 67.2. Typhoon Bavi is similar in intensity to Hurricane Maria when Maria was at its maximum intensity in 2017.  Typhoon Bavi is bigger than Maria was.

Typhoon Bavi will more through an environment that will be favorable for a powerful typhoon during the next 24 hours.  Bavi will move over water where the Sea Surface Temperatures are near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Bavi could maintain its intensity during the next 24 hours unless another eyewall replacement cycle occurs.  If the inner end of a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle would cause Bavi to weaken temporarily again.

Typhoon Bavi will move around the southern side of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Bavi toward the west-northwest during the next 24 hours.  On its anticipated track, Typhoon Bavi will move to the west of the Marianas during the next 24 hours.

Typhoon Bavi will continue to bring strong winds and heavy rain to the Marianas on Monday.  Bavi could be capable of causing catastrophic damage.  Heavy rain will cause flash floods in some locations.

Flood Warnings are in effect for Guam, Rota, Tinian, and Saipan.

Typhoon Bavi could also cause a storm surge of up to 16 feet (5 meters) along the coast of the Marianas.

Typhoon Bavi Bears Down on the Marianas

Typhoon Bavi was bearing down on the Marianas on Sunday morning.  At 5:00 a.m. EDT on Sunday the center of Typhoon Bavi was located at latitude 13.6°N and longitude 147.6°E which put the center about 215 miles (350 km) east of Guam.  Bavi was moving toward the west-northwest at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 165 m.p.h. (265 km/h) and there were wind gusts to 200 m.p.h. (325 km/h).  The minimum surface pressure was 911 mb.

Typhoon Warnings are in effect for Guam, Rota, Tinian, and Saipan.

Tropical Storm Warnings are in effect for Alamagan.

Tropical Storm Watches are in effect for Pagan and Agrihan.

Typhoon Bavi went through a complete eyewall replacement cycle on Saturday.  Bavi strengthened back to its previous intensify after it completed the eyewall replacement cycle.

A new circular eye with a diameter of 25 miles (40 km) was at the center of Typhoon Bavi.  The eye was surrounded by a 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 Bavi’s circulation.  Storms near the core of Bavi generated strong upper level divergence that pumped large quantities of mass away from typhoon.  The removal of large quantities of mass caused the surface pressure to decrease.

The size of the circulation around Typhoon Bavi increased after the eyewall replacement cycle.  Winds to typhoon force extended out 60 miles (95 km) from the center of Bavi’s circulation. Winds to tropical storm force extended out 195 miles (315 km) from the center of Typhoon Bavi.

The Hurricane Intensity Index (HII) for Typhoon Bavi is 36.8.  The Hurricane Size Index (HSI) is 19.1 and the Hurricane Wind Intensity Size Index (HWISI) is 55.9.  Typhoon Bavi is similar in size and intensity to Hurricane Maria when Maria hit Puerto Rico in 2017.

Typhoon Bavi will more through an environment that will be favorable for a powerful typhoon during the next 24 hours.  Bavi will move over water where the Sea Surface Temperatures are near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Bavi could intensify a little more during the next 24 hours unless another eyewall replacement cycle occurs.  If the inner end of a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle would cause Bavi to weaken temporarily again.

Typhoon Bavi will move around the southern side of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Bavi toward the west-northwest during the next 24 hours.  On its anticipated track, the center of Typhoon Bavi will reach the Marianas in 12 hours.

Typhoon Bavi will bring very strong winds and heavy rain to the Marianas.  Bavi could be capable of causing catastrophic damage.  Heavy rain will cause flash floods in some locations.

Flood Watches are in effect for Guam, Rota, Tinian, and Saipan.

Typhoon Bavi could also cause a storm surge of up to 16 feet (5 meters) along the coast of the Marianas.

Elsewhere, Tropical Storm Maysak continued to move inland over southern China.  At 5:00 a.m. EDT on Sunday the center of Tropical Storm Maysak was located at latitude 23.3°N and longitude 108.8°E which put the center about 110 miles (175 km) south-southwest of Liuzhou, China.  Maysak was moving toward the north-northeast at 8 m.p.h. (13 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.

 

Bavi Causes Typhoon Warnings for Marianas

The risk posed by Typhoon Bavi caused Typhoon Warnings to be issued for the Marianas.  At 5:00 a.m. EDT on Saturday the center of Typhoon Bavi was located at latitude 12.6°N and longitude 150.5°E which put the center about 405 miles (650 km) east of Guam.  Bavi was moving toward the west at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 165 m.p.h. (265 km/h) and there were wind gusts to 200 m.p.h. (325 km/h).  The minimum surface pressure was 913 mb.

Typhoon Warnings are in effect for Guam, Rota, Tinian, and Saipan.

Tropical Storm Warnings are in effect for Alamagan, Pagan, and Agrihan.

A circular eye with a diameter of 20 miles (32 km) was at the center of Typhoon Bavi.  The eye was surrounded by a 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 Bavi’s circulation.  Storms near the core of Bavi generated strong upper level divergence that pumped large quantities of mass away from typhoon.  The removal of large quantities of mass caused the surface pressure to continue to decrease.

The circulation around Typhoon Bavi was fairly symmetrical.  Winds to typhoon force extended out 50 miles (80 km) from the center of Bavi’s circulation.  Winds to tropical storm force extended out 160 miles (260 km) from the center of Typhoon Bavi.

The Hurricane Intensity Index (HII) for Typhoon Bavi is 36.8.  The Hurricane Size Index (HSI) is 19.2 and the Hurricane Wind Intensity Size Index (HWISI) is 56.0.  Typhoon Bavi is similar in size and intensity to Hurricane Maria when Maria hit Puerto Rico in 2017.

Typhoon Bavi will more through an environment that will be favorable for a powerful typhoon during the next 24 hours.  Bavi will move over water where the Sea Surface Temperatures are near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Bavi could intensify a little more during the next 24 hours unless an eyewall replacement cycle occurs.  If the inner end of a rainband wraps around the existing eye and eyewall and concentric eyewalls form, then an eyewall replacement cycle would cause  Bavi to weaken temporarily.

Typhoon Bavi will move around the southern side of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Bavi toward the west-northwest during the next 24 hours.  On its anticipated track, Typhoon Bavi will reach the Marianas in 36 hours.

Typhoon Bavi will bring very strong winds and heavy rain to the Marianas.  Bavi could be capable of causing catastrophic damage.  Heavy rain will cause flash floods in some locations.

Flood Watches are in effect for Guam, Rota, Tinian, and Saipan.

Typhoon Bavi could also cause a storm surge of up to 16 feet (5 meters) along the coast of the Marianas.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Maysak was moving toward northeast Vietnam.  At 5:00 a.m. EDT on Saturday the center of Tropical Storm Maysak was located at latitude 20.9°N and longitude 107.7°E which put the center about 50 miles (80 km) east of Haiphong, Vietnam.  Maysak was moving toward the northwest 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 991 mb.

Typhoon Bavi Rapidly Intensifies to Equivalent of Cat. 5 Hurricane

Typhoon Bavi rapidly intensified to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Friday.  At 5:00 p.m. EDT on Friday the center of Typhoon Bavi was located at latitude 12.7°N and longitude 151.9°E which put the center about 500 miles (805 km) east of Guam.  Bavi was moving toward the west at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 160 m.p.h. (260 km/h) and there were wind gusts to 195 m.p.h. (315 km/h).  The minimum surface pressure was 921 mb.

Typhoon Watches are in effect for Guam, Rota, Tinian, and Saipan.

Tropical Storm Watches are in effect for Alamagan, Pagan, and Agrihan.

A circular eye with a diameter of 20 miles (32 km) was at the center of Typhoon Bavi.  The eye was surrounded by a 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 Bavi’s circulation.  Storms near the core of Bavi generated strong upper level divergence that pumped large quantities of mass away from typhoon.  The removal of large quantities of mass caused the surface pressure to decrease rapidly.

The circulation around Typhoon Bavi was fairly symmetrical.  Winds to typhoon force extended out 50 miles (80 km) from the center of Bavi’s circulation.  Winds to tropical storm force extended out 150 miles (240 km) from the center of Typhoon Bavi.

The Hurricane Intensity Index (HII) for Typhoon Bavi is 35.0.  The Hurricane Size Index (HSI) is 18.6 and the Hurricane Wind Intensity Size Index (HWISI) is 53.6.  Typhoon Bavi is similar in size and intensity to Hurricane Maria when Maria hit Puerto Rico in 2017.

Typhoon Bavi will more through an environment that will be favorable for intensification during the next 24 hours.  Bavi will move over water where the Sea Surface Temperatures are near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Bavi could continue to intensify during the next 24 hours unless an eyewall replacement cycle occurs.  If the inner end of a rainband wraps around the existing eye and eyewall and concentric eyewalls form, then an eyewall replacement cycle would cause  Bavi to weaken.

Typhoon Bavi will move around the southern side of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Bavi toward the west during the next 24 hours.  On its anticipated track, Typhoon Bavi will reach the Marianas in 48 hours.

Typhoon Bavi will bring very strong winds and heavy rain to the Marianas.  Bavi could be capable of causing catastrophic damage.  Heavy rain will cause flash floods in some locations.

Flood Watches are in effect for Guam, Rota, Tinian, and Saipan.

Typhoon Bavi could also cause a storm surge of up to 16 feet (5 meters) along the coast of the Marianas.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Maysak was moving toward the coast of Southern China.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Maysak was located at latitude 20.2°N and longitude 108.5°E which put the center about 115 miles (185 km) south of Qinzhou, China.  Maysak was moving toward the north-northwest at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1000 mb.

Typhoon Bavi Intensifies to Equivalent of a Major Hurricane

Typhoon Bavi intensified to the equivalent of a major hurricane on Thursday night.  The threat posed by Bavi prompted the issuance of Typhoon Watches and Tropical Storm Watches for the Marianas.  At 5:00 a.m. EDT on Friday the center of Typhoon Bavi was located at latitude 12.9°N and longitude 153.8°E which put the center about 625 miles (1010 km) east of Guam.  Bavi was moving toward the west at 13 m.p.h. (21 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 955 mb.

Typhoon Watches are in effect for Guam, Rota, Tinian, and Saipan.

Tropical Storm Watches are in effect for Alamagan, Pagan, and Agrihan.

A circular eye with a diameter of 21 miles (33 km) was at the center of Typhoon Bavi.  The eye was surrounded by a 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 Bavi’s circulation.  Storms near the core of Bavi generated strong upper level divergence that pumped large quantities of mass away from typhoon.  The removal of large quantities of mass caused the surface pressure to decrease rapidly.

The circulation around Typhoon Bavi was fairly symmetrical.  Winds to typhoon force extended out 50 miles (80 km) from the center of Bavi’s circulation.  Winds to tropical storm force extended out 150 miles (240 km) from the center of Typhoon Bavi.

The Hurricane Intensity Index (HII) for Typhoon Bavi is 22.1.  The Hurricane Size Index (HSI) is 18.6 and the Hurricane Wind Intensity Size Index (HWISI) is 40.7.  Typhoon Bavi is similar in intensity to Hurricane Jeanne when Jeanne hit South Florida in 2004.  Bavi is not quite as large as Jeanne was.

Typhoon Bavi will more through an environment that will be very favorable for intensification during the next 24 hours.  Bavi will move over water where the Sea Surface Temperatures are near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Bavi will intensify during the next 24 hours.  Bavi could intensify rapidly at times.  Typhoon Bavi could strengthen to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale during the next 24 hours.

Typhoon Bavi will move around the southern side of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Bavi toward the west during the next 24 hours.  On its anticipated track, Typhoon Bavi could reach the Marianas in less than 60 hours.

Typhoon Bavi will bring strong winds and heavy rain to the Marianas.  Bavi could be capable of causing catastrophic damage.  Heavy rain will cause flash floods in some locations.

Flood Watches are in effect for Guam, Rota, Tinian, and Saipan.

Typhoon Bavi could cause a storm surge of up to 16 feet (5 meters) along the coast of the Marianas.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Maysak was bringing gusty winds and locally heavy rain to Hainan.  At 5:00 a.m. EDT on Friday the center of Tropical Storm Maysak was located at latitude 17.9°N and longitude 109.4°E which put the center about 25 miles (40 km) south of Sanya, China.  Maysak was moving toward the northwest at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 999 mb.

Bavi Strengthens to a Typhoon

Former Tropical Storm Bavi strengthened to a typhoon over the Western North Pacific Ocean east of the Marianas on Thursday.  At 5:00 p.m. EDT on Thursday the center of Typhoon Bavi was located at latitude 12.7°N and longitude 156.1°E which put the center about 790 miles (1275 km) east of Guam.  Bavi was moving toward the west-northwest at 14 m.p.h. (22 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 982 mb.

Former Tropical Storm Bavi strengthened to a typhoon on Thursday.  The inner end of a rainband wrapped around the center of Bavi’s circulation.  A circular eye formed at the center of Typhoon Bavi.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Bavi’s circulation.  Storms near the center of Bavi generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The size of the circulation around Typhoon Bavi increased on Thursday as Bavi intensified.  Winds to typhoon force extended out 50 miles (80 km) from the center of Bavi’s circulation.  Winds to tropical storm force extended out 160 miles (260 km) from the center of Typhoon Bavi.

Typhoon Bavi will more through an environment that will be very favorable for intensification during the next 24 hours.  Bavi will move over water where the Sea Surface Temperatures are near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Bavi will intensify during the next 24 hours.  Bavi could intensify rapidly at times. Typhoon Bavi could strengthen to the equivalent of a major hurricane during the next 24 hours.

Typhoon Bavi will move around the southern side of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Bavi toward the west-northwest during the next 24 hours.  On its anticipated track, Typhoon Bavi could reach the Marianas in less than 72 hours.

Typhoon Bavi will bring strong winds and heavy rain to the Marianas.  Bavi could be capable of causing catastrophic damage.  Heavy rain will cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, former Tropical Depression 10W strengthened to Tropical Storm Maysak southeast of Hainan.  At 5:00 p.m. EDT on Thursday the center of Tropical Storm Maysak was located at latitude 17.6°N and longitude 110.2°E which put the center about 50 miles (80 km) southeast of Sanya, China.  Maysak was moving toward the west at 7 m.p.h. (11 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 Bavi Intensifies

Tropical Storm Bavi was intensifying over the Western North Pacific Ocean east of the Marianas on Wednesday night.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Bavi was located at latitude 11.2°N and longitude 159.7°E which put the center about 1050 miles (1690 km) east of Guam.  Bavi was moving toward the west-northwest at 15 m.p.h. (24 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 996 mb.

Former Tropical Depression 09W intensified on Wednesday and the Japan Meteorological Agency designated the system as Tropical Storm Bavi.

The circulation around Tropical Storm Bavi exhibited much more organization on Wednesday evening.  The inner end of a rainband wrapped around the western side of the center of Bavi’s circulation.  Other bands of showers and thunderstorms were revolving around the center of Tropical Storm Bavi.  Storms near the center of Bavi generated more upper level divergence that pumped mass away from the tropical storm.  The removal of more mass caused the surface pressure to decrease.

The distribution of wind speeds in Tropical Storm Bavi became more symmetrical on Wednesday.  Winds to tropical storm force extended out 80 miles (130 km) from the center of Bavi’s circulation.

Tropical Storm Bavi will more through an environment that will be very favorable for intensification during the next 24 hours.  Bavi will move over water where the Sea Surface Temperatures are near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Bavi is likely to intensify to a typhoon during the next 24 hours.  Bavi could intensify rapidly at times.  Tropical Storm Bavi is likely to strengthen to the equivalent of a major hurricane by the weekend.

Tropical Storm Bavi will move around the southern side of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Bavi toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Bavi could reach the Marianas in less than four days.

Tropical Storm Bavi is likely to intensify to the equivalent of a major hurricane before it reaches the Marianas.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 10W formed over the South China Sea.  At 11:00 p.m. EDT on Wednesday the center of Tropical Depression 10W was located at latitude 17.7°N and longitude 112.6°E which put the center about 250 miles (400 km) east-southeast of Sanya, China.  The tropical depression was moving toward the west at 21 m.p.h. (33 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 1003 mb.

Tropical Depression 10W is forecast to strengthen to a tropical storm before it reaches Hainan.  It will bring strong winds and locally heavy rain to Hainan.  Heavy rain could cause flash floods in some locations.

Tropical Depression Forms East-southeast of Marianas

Tropical Depression 09W formed over the Western North Pacific Ocean east-southeast of the Marianas on Tuesday evening.  At 11:00 p.m. EDT on Tuesday the center of Tropical Depression 09W was located at latitude 8.9°N and longitude 162.9°E which put the center about 175 miles (280 km) east-southeast of Ujelang.  The tropical depression was moving toward the west 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 1003 mb.

A low pressure system over the Western North Pacific Ocean east-southeast of the Marianas strengthened on Tuesday evening.  Both the Japan Meteorological Agency and the U.S. Joint Typhoon Warning Center classified the system as a tropical depression.

More thunderstorms formed near the center of Tropical Depression 09W on Tuesday evening.  Thunderstorms were also developing in bands in the northern and western parts of the tropical depression.  Bands in the southern and eastern parts of Tropical Depression consisted primarily of showers and lower clouds.  Storms near the center of circulation began to generate upper level divergence that pumped mass away to the west of the tropical depression.  The removal of mass caused the surface pressure to start to decrease.

Tropical Depression 09W will move through an environment favorable for intensification during the next 24 hours.  The tropical depression will move over water where the Sea Surface Temperatures are near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Depression 09W will intensify to a tropical storm during the next 24 hours.  It is likely to strengthen to a typhoon by the end of the week.

Tropical Depression 09W will move around the southern part of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer the tropical depression toward the west-northwest during the next 24 hours.  On its anticipated track, the center of Tropical Depression 09W will pass near Ujelang in 12 hours.  Tropical Depression 09W could approach the Marianas in four days.  It is likely to be a typhoon when it approaches the Marianas.

Tropical Depression 09W will bring gusty winds and heavy rain to Ujelang.  Heavy rain could cause flash floods.

Typhoon Mekkhala Weakens

Typhoon Mekkhala weakened on Tuesday as it moved toward the southern Ryukyu Islands.  At 11:00 p.m. EDT on Tuesday the center of Typhoon Mekkhala was located at latitude 21.3°N and longitude 124.7°E which put the center about 235 miles (380 km) south of Miyakojima, Japan.  Mekkhala was moving toward the north 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 974 mb.

Typhoon Mekkhala weakened on Tuesday.  An upper level ridge over China produced northeasterly winds that blew toward the top of Mekkhala’s circulation.  Those winds caused strong vertical wind shear.  The strong vertical wind shear caused Typhoon Mekkhala to weaken.

The northeasterly winds in the upper levels also blew the tops off of many of the thunderstorms in the northern half of Typhoon Mekkhala.  Thunderstorms were still occurring in bands in the southern half of Mekkhala’s circulation.  Bands in the northern half of Typhoon Mekkhala consisted primarily of showers and lower clouds.  Storms near the center of Mekkhala generated upper level divergence that pumped mass away to the south and west of the typhoon.  However, the removal of mass in the upper levels was less than the convergence of mass in the lower levels of the atmosphere.  So, the surface pressure increased on Tuesday.

Even though Typhoon Mekkhala weakened on Tuesday, the size of Mekkhala’s circulation did not change much.  Winds to typhoon force extended out 65 miles (105 km) from the center of Typhoon Mekkhala.  Winds to tropical storm force extended out 140 miles (225 km) from the center of Mekkhala’s circulation.

Typhoon Mekkhala will move through an environment that will be unfavorable for intensification during the next 24 hours.  Mekkhala will move over water where the Sea Surface Temperatures are near 28°C.  However, the upper level ridge over China will continue to cause strong vertical wind shear.  Typhoon Mekkhala will continue to weaken during the next 24 hours because of the strong vertical wind shear.

Typhoon Mekkhala will move around the western end of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Mekkhala toward the north during the next 24 hours.  On its anticipated track, Typhoon Mekkhala will reach the southern Ryukyu Islands in less than 24 hours.

Typhoon Mekkhala will bring strong winds and locally heavy rain to the southern Ryukyu Islands including Ishigakijima and Miyakojima.  Heavy rain could cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, former Tropical Storm Higos weakened to a tropical depression as it moved west of the Marianas.  At 11:00 p.m. EDT on Tuesday the center of Tropical Depression Higos was located at latitude 15.4°N and longitude 141.3°E which put the center about 225 miles (360 km) west-northwest of Guam.  Higos was moving toward the west-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 1002 mb.