Tropical Storm Vance Meanders Southwest of Mexico

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Tropical Storm Vance meandered slowly over the Eastern North Pacific Ocean southwest of Mexico on Monday.  At 11:00 p.m. EDT on Monday the center of Tropical Storm Vance was located at latitude 15.5°N and longitude 106.3°W which put the center about 275 miles (445 km) south-southwest of Manzanillo, Mexico.  Vance was moving toward the west at 5 m.p.h. (8 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 999 mb.

Tropical Storm Vance continued to weaken on Monday as it meandered southwest of Mexico.  An upper level trough over Baja California continued to produce southwesterly winds that were blowing toward the top of Vance’s circulation.  Those winds caused strong vertical wind shear.  The strong vertical wind shear caused Vance to continue to weaken.

The strong vertical wind shear also continued to cause the distribution of thunderstorms in Tropical Storm Vance to be asymmetrical.  Thunderstorms were still occurring in bands in the eastern part of Vance’s circulation.  Bands in the western part of Tropical Storm Vance consisted primarily of showers and lower clouds.  Storms near the center of Vance generated upper level divergence that pumped mass away to the northeast of the tropical storm.  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 continued to increase on Monday.

The size of the circulation around Tropical Storm Vance decreased on Monday as Vance continued to weaken.  Winds to tropical storm force extended out 105 miles (165 km) from the center of Vance’s circulation.

Tropical Storm Vance will move around the western end of a high pressure system that is over Mexico.  The high pressure system will steer Vance slowly toward the north during the next 24 hours.  On its anticipated track, Tropical Storm Vance will remain southwest of Mexico for the next several days.

Typhoon In-Fa Rapidly Intensifies to Equivalent of a Major Hurricane

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Typhoon In-Fa rapidly intensified to the equivalent of a major hurricane on Monday over the Western North Pacific Ocean east of the Northern Marianas.  At 11:00 a.m. EDT on Monday the center of Typhoon In-Fa was located at latitude 14.1°N and longitude 162.6°E which put the center about 1135 miles (1830 km) east of Saipan.  In-Fa was moving toward the west-northwest at 4 m.p.h. (6 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 946 mb.

Typhoon In-Fa rapidly intensified to the equivalent of a major hurricane on Monday.  A small circular eye with a diameter of 8 miles (13 km) formed at the center of In-Fa’s circulation.  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 Typhoon In-Fa.  Storms near the center of In-Fa generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The circulation around Typhoon In-Fa was small.  Winds to typhoon force extended out 30 miles (50 km) from the center of In-Fa’s circulation.  Winds to tropical storm force extended out 80 miles (130 km) from the center of Typhoon In-Fa.

The Hurricane Intensity Index (HII) for Typhoon In-Fa is 25.1.  The Hurricane Size Index (HSI) is 9.6 and the Hurricane Wind Intensity Size Index (HWISI) is 34.7.  Typhoon In-Fa is similar in size and intensity to Hurricane Harvey when Harvey hit Texas in 2017.

Typhoon In-Fa will move through an environment that will be favorable for intensification during the next 24 hours.  In-Fa 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 In-Fa could continue to intensify during the next 24 hours unless the inner end of a rainband wraps around the existing eye and eyewall.  If concentric eyewalls form, then an eyewall replacement cycle could cause In-Fa to weaken.

Typhoon In-Fa 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 In-Fa toward the west-northwest during the next 24 hours.  On its anticipated track, Typhoon In-Fa will move toward the Northern Marianas.

 

Tropical Cyclone Arnab Develops over Bay of Bengal

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Tropical Cyclone Arnab developed rapidly over the Bay of Bengal on Sunday night.  At 5:00 a.m. EDT on Monday the center of Tropical Cyclone Arnab was located at latitude 15.4°N and longitude 87.8°E which put the center about 500 miles (805 km) east-southeast of Machilipatnam, India.  Arnab was moving toward the west at 5 m.p.h. (8 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 986 mb.

Tropical Cyclone Arnab rapidly intensified to the equivalent of a hurricane/typhoon on Sunday night after it developed over the Bay of Bengal.  The inner end of a rainband wrapped around the center of Arnab’s circulation.  A small circular eye appeared to be forming at the center of Tropical Cyclone Arnab.  The eye was surrounded by a ring of thunderstorms.  Bands of showers and thunderstorms were revolving around the center of Tropical Cyclone Arnab.  Storms near the center of Arnab generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Cyclone Arnab was small.  Winds to hurricane/typhoon force extended out 20 miles (30 km) from the center of Arnab’s circulation.  Winds to tropical storm force extended out 70 miles (110 km) from the center of Tropical Cyclone Arnab.

Tropical Cyclone Arnab will move through an environment favorable for intensification during the next 24 hours.  Arnab will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the western part of an upper level ridge that is over Southeast Asia and the Bay of Bengal.  The upper level ridge will produce southerly winds that will blow toward the top of Arnab’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Tropical Cyclone Arnab will intensify during the next 24 hours.  Arnab could rapidly intensify to the equivalent of a major hurricane.

Tropical Cyclone Arnab will move around the southwestern part of a high pressure system that is over Southeast Asia and the Bay of Bengal.  The high pressure system will steer Arnab toward the west during the next 24 hours.  On its anticipated track, Tropical Cyclone Arnab will move toward southeastern India.

Tropical Cyclone Arnab could approach the coast of Andhra Pradesh in 36 hours.  Arnab is likely to be the equivalent of a hurricane/typhoon when it approaches the coast.  Tropical Cyclone Arnab will bring strong winds and locally heavy rain to Andhra Pradesh.  Heavy rain is likely to cause flash floods in some locations.  Tropical Cyclone Arnab could cause a storm surge of up to 10 feet (3 meters) along parts of the coast of Andhra Pradesh.

Vance Weakens to a Tropical Storm

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Former Hurricane Vance weakened to a tropical storm on Sunday as it moved over the Eastern North Pacific Ocean south of Mexico.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Vance was located at latitude 15.0°N and longitude 104.7°W which put the center about 275 miles (445 km) south of Manzanillo, Mexico.  Vance was moving toward the northwest at 7 m.p.h. (11 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 995 mb.

Former Hurricane Vance weakened to a tropical storm on Sunday.  An upper level trough over Baja California was producing southwesterly winds that were blowing toward the top of Vance’s circulation.  Those winds were causing strong vertical wind shear.  The strong vertical wind shear caused Vance to weaken to a tropical storm.

The strong vertical wind shear also caused the distribution of thunderstorms in Tropical Storm Vance to become asymmetrical.  Thunderstorms were still occurring in bands in the northeastern part of Vance’s circulation.  Bands in the other parts of Tropical Storm Vance consisted primarily of showers and lower clouds.  Storms near the center of Vance generated upper level divergence that pumped mass away to the northeast of the tropical storm.  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 Sunday.

The distribution of wind speeds in Tropical Storm Vance was also asymmetrical.  Winds to tropical storm force extended out 150 miles (240 km) in the northern side of Vance’s circulation.  Winds to tropical storm force extended out 80 miles in the southern side of Tropical Storm Vance.

Tropical Storm Vance will move through an environment that will be unfavorable for intensification during the next 24 hours.  Vance will move over water where the Sea Surface Temperatures are near 29°C.  However, the upper level trough over Baja California will continue to cause strong vertical wind shear.  Tropical Storm Vance is likely to continue to weaken on Monday because of the strong vertical wind shear.

Tropical Storm Vance will move around the western end of a high pressure system that is over Mexico.  The high pressure system will steer Vance slowly toward the northwest during the next 24 hours.  On its anticipated track, Tropical Storm Vance will remain southwest of Mexico for the next several days.

In-Fa Strengthens to a Typhoon

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Former Tropical Storm In-Fa strengthened to a typhoon on Sunday as it moved over the Western North Pacific Ocean northwest of Kwajalein.  At 5:00 p.m. EDT on Sunday the center of Typhoon In-Fa was located at latitude 13.6°N and longitude 163.7°E which put the center about 420 miles (675 km) northwest of Kwajalein.  In-Fa was moving toward the northwest at 9 m.p.h. (15 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.

Former Tropical Storm In-Fa strengthened to a typhoon on Sunday.  The inner end of a rainband wrapped around the center of In-Fa’s circulation.  Bands of showers and thunderstorms were revolving around the center of Typhoon In-Fa.  Storms near the center of In-Fa generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The circulation around Typhoon In-Fa was small.  Winds to typhoon force extended out 20 miles (30 km) from the center of Typhoon In-Fa.  Winds to tropical storm force extended out 80 miles (130 km) from the center of Typhoon In-Fa.

Typhoon In-Fa will move through an environment that will be somewhat favorable for intensification during the next 24 hours.  In-Fa will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southern part of an upper level trough that is over the Western North Pacific Ocean.  The upper level trough will produce westerly winds that will blow toward the top of In-Fa’s circulation.  Those winds will cause moderate vertical wind shear.  The moderate vertical wind shear will inhibit intensification, but the wind shear may not be enough to prevent intensification.  Typhoon In-Fa could intensify during the next 24 hours.  In-Fa could strengthen to the equivalent of a major hurricane during the next several days.

Typhoon In-Fa 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 In-Fa toward the northwest during the next 24 hours.  On its anticipated track, Typhoon In-Fa will move farther away from Kwajalein.

Tropical Storm Olana Forms East of Date Line

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Tropical Storm Olana formed over the Central North Pacific Ocean just to the east of the International Dateline on Sunday.  At 5:00 p.m. EDT on Sunday the center of Tropical Storm Olana was located at latitude 14.8°N and longitude 178.0°W which put the center about 580 miles (935 km) west-southwest of Johnston Atoll.  Olana was moving toward the east-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 1002 mb.

A low pressure system over the Central North Pacific Ocean just to the east of the International Dateline strengthened on Sunday and the U.S. National Hurricane Center designated the system as Tropical Storm Olana.

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

The circulation around Tropical Storm Olana was small.  Winds to tropical storm force extended out 45 miles (75 km) from the center of Olana’s circulation.

Tropical Storm Olana will move through an environment that will be marginally favorable for intensification during the next 24 hours.  Olana will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the southeastern part of an upper level trough that is over the North Pacific Ocean.  The upper level trough will produce southwesterly winds that will blow toward the top of Olana’s circulation.  Those winds will cause moderate vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear may not be enough to prevent intensification.  Tropical Storm Olana could intensify a little during the next 24 hours, if the upper level winds to not get any stronger.

The upper level trough will steer Tropical Storm Olana toward the east-northeast during the next 24 hours.  On its anticipated track, Tropical Storm Olana will move closer to Johnston Atoll.

Typhoon Champi Brings Wind and Rain to Southern Ryukyu Islands

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Typhoon Champi brought wind and rain to the southern Ryukyu Islands and to northeastern Taiwan on Friday.  At 11:00 a.m. EDT on Friday the center of Typhoon Champi was located at latitude 25.3°N and longitude 122.6°E which put the center about 75 miles (120 km) east of Taipei, Taiwan.  Champi was moving toward the north-northwest at 16 m.p.h. (16 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 949 mb.

A weather station on Ishigakijima Island reported a sustained wind speed of 78 m.p.h. (125 km/h).  The weather station also reported 4.94 inches (154.0 mm) of rain.

A weather station in Ohara, Japan reported a sustained wind speed of 75 m.p.h. (121 km/h).

A weather station on Yonagunijima Island reported a sustained wind speed of 66 m.p.h. (107 km/h).  The weather station also reported 8.33 inches (211.5 mm) of rain.

Typhoon Champi was the equivalent of a major hurricane on Friday morning.  Winds to typhoon force extended out 85 miles (135 km) from the center of Champi’s circulation.  Winds to tropical storm force extended out 250 miles (400 km) from the center of Typhoon Champi.

The Hurricane Intensity Index (HII) for Typhoon Champi was 20.6.  The Hurricane Size Index (HSI) was 31.8 and the Hurricane Wind Intensity Size Index (HWISI) was 52.4.  Typhoon Champi was similar in intensity to Hurricane Irma when Irma hit south Florida in 2017.  Champi is larger than Irma was.

Typhoon Champi will move around the western end of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Champi toward the north during the next 24 hours.  On its anticipated track, Typhoon Champi will remain east of China.

Typhoon Champi will move through an environment that will be unfavorable for intensification during the next 24 hours.  Champi will move over water where the Sea Surface Temperatures are near 26°C.  It will move under the eastern side of an upper level trough that is near the east coast of China.  The upper level trough will produce strong southwesterly winds that will blow toward the top of Champi’s circulation.  Those winds will cause strong vertical wind shear.  Champi will also continue to move through a mass of drier air.  Typhoon Champi is likely to weaken steadily during the next 24 hours because of the effects of strong vertical wind shear and drier air.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 30W formed northwest of Kwajalein.  At 11:00 a.m. EDT on Friday the center of Tropical Depression 30W was located at latitude 10.9°N and longitude 166.3°E which put the center about 185 miles (300 km) northwest of Kwajalein.  The tropical depression moving toward the northwest at 2 m.p.h. (3 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 1004 mb.

Vance Strengthens to a Hurricane

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Former Tropical Storm Vance strengthened to a hurricane as it moved over the Eastern North Pacific Ocean south of Mexico on Thursday night.  At 5:00 a.m. EDT on Friday the center of Hurricane Vance was located at latitude 10.9°N and longitude 102.1°W which put the center about 580 miles (930 km) south-southeast of Manzanillo, Mexico.  Vance was moving toward the north-northwest at 6 m.p.h. (10 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 982 mb.

Former Tropical Storm Vance strengthened to a hurricane on Thursday night.

The inner end of a rainband wrapped around the center of Hurricane Vance.  An eye appeared to be forming at the center of Vance’s circulation.  Bands of showers and thunderstorms were revolving around the center of Hurricane Vance.  Storms near the center generated upper level divergence that pumped mass away from the hurricane.  The removal of mass caused the surface pressure to decrease.

The strongest winds were occurring in the northern side of Hurricane Vance.  Winds to hurricane force extended out 35 miles (55 km) in the northern half of Vance’s circulation.  Winds to tropical storm force extended out 200 miles (320 km) from the center of Hurricane Vance.

Hurricane Vance will move through an environment favorable for intensification during the next 24 hours.  Vance 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.  Hurricane Vance will intensify during the next 24 hours.  Vance could intensify rapidly at times.  Vance could strengthen to a major by the weekend.

Hurricane Vance will move around the southwestern part of a high pressure system that is over southern Mexico.  The high pressure system will steer Vance toward the north-northwest during the next 24 hours.  On its anticipated track, Hurricane Vance will gradually move closer to the west coast of Mexico.

Typhoon Champi Approaches Southern Ryukyu Islands

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Typhoon Champi was approaching the southern Ryukyu Islands on Wednesday evening.  At 11:00 p.m. EDT on Wednesday the center of Typhoon Champi was located at latitude 20.6°N and longitude 125.7°E which put the center about 295 miles (475 km) south-southeast of Ishigakijima, Japan.  Champi was moving toward the west-northwest at 11 m.p.h. (17 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 940 mb.

Typhoon Champi weakened on Wednesday.  Even though Champi weakened, it was still a very well organized typhoon.  A circular eye with a diameter of 35 miles (55 km) was at the center of Champi’s circulation.  Bands of showers and thunderstorms were revolving around the the center of Typhoon Champi.  Storms near the center of Champi generated upper level divergence that pumped mass away from the typhoon.  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 Wednesday.

The circulation around Typhoon Champi was large.  Winds to typhoon force extended out 100 miles (160 km) from the center of Champi’s circulation.  Winds to tropical storm force extended out 345 miles (555 km) from the center of Typhoon Champi.

The Hurricane Intensity Index (HII) for Typhoon Champi is 25.1.  The Hurricane Size Index (HSI) is 34.2 and the Hurricane Wind Intensity Size Index (HWISI) is 59.3.  Typhoon Champi is similar in size to Hurricane Ivan when Ivan hit the northern Gulf Coast in 2004.  Champi is stronger than Ivan was.

Typhoon Champi will move through an environment that will be unfavorable for intensification during the next 24 hours.  Champi will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the eastern side of an upper level trough that is near the east coast of China.  The upper level trough will produce southwesterly winds that will blow toward the top of Champi’s circulation.  Those winds will cause the vertical wind shear to increase.   Champi will also move into a region of drier air on Thursday.  Typhoon Champi is likely to weaken during the next 24 hours because of more vertical wind shear and drier air.

Typhoon Champi will move around the western part of a high pressure system that is over the Western North Pacific Ocean. The high pressure system will steer Champi toward the north-northwest during the next 24 hours.  On its anticipated track, the center of Typhoon Champi will be near Ishigakijima in 24 hours.

Typhoon Champi will bring strong winds and heavy rain to the southern Ryukyu Islands.  Heavy rain is likely to cause flash floods in some locations.

Typhoon Champi could also bring strong winds and heavy rain to parts of Taiwan.

Tropical Cyclone Agueda Passes North of Madagascar

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Tropical Cyclone Agueda passed north of Madagascar on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Tropical Cyclone Agueda was located at latitude 6.1°S and longitude 50.7°E which put the center about 400 miles (645 km) north of Antsiranana, Madagascar.  Agueda was moving toward the west-southwest at 11 m.p.h. (17 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 997 mb.

Tropical Cyclone Agueda strengthened on Wednesday.  Thunderstorms were occurring near the center of Agueda’s circulation.  Bands of showers and thunderstorms were revolving  around the center of Tropical Cyclone Agueda.  Storms near the center of Agueda generated upper level divergence that pumped mass away from the tropical cyclone.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Cyclone Agueda was small.  Winds to tropical storm force extended out 40 miles (65 km) from the center of Agueda’s circulation.

Tropical Cyclone Agueda will move through an environment that will become unfavorable for intensification during the next 24 hours.  Agueda will move over water where the Sea Surface Temperatures are near 27°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  However, Agueda will move into a region of drier air on Thursday.  Tropical Cyclone Agueda is likely to weaken when it moves into the region of drier air.

Tropical Cyclone Agueda will move around the northern side of a high pressure system that is over the South Indian Ocean.  The high pressure system will steer Agueda toward the west-southwest during the next 24 hours.  On its anticipated track, Tropical Cyclone Agueda will move northwest of Madagascar on Thursday.