Tag Archives: Usagi

Typhoon Man-yi Intensifies to Equivalent of Cat. 5 Hurricane

Typhoon Man-yi intensified to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Saturday.  At 10:00 a.m. EST on Saturday the center of Typhoon Man-yi was located at latitude 14.2°N and longitude 124.0°E which put the center about 80 miles (130 km) east of Labo, Philippines.  Man-yi was moving toward the northwest at 15 m.p.h. (24 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 Man-yi intensified to the equivalent of a Category 5 hurricane as it approached southeastern Luzon on Saturday.  The southwestern part of Man-yi’s eyewall passed over Catanduanes Island.

Typhoon Man-yi was very impressive on satellite images.  A circular eye with a diameter of 20 miles (32 km) was at the center of Man-yi’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 Man-yi’s circulation.  Storms near the center of Man-yi generated strong upper level divergence that pumped large amounts of mass away from the typhoon in all directions. The removal of large quantities of mass caused the surface pressure to decrease rapidly.

The size of the circulation around Typhoon Man-yi increased when Man-yi intensified.  Winds to typhoon force extended out 45 miles (75 km) from the center of Man-yi’s circulation.  Winds to tropical storm force extended out 150 miles (240 km) from the center of Typhoon Man-yi.

The Hurricane Intensity Index (HII) for Typhoon Man-yi was 35.0.  The Hurricane Size Index (HSI) was 17.6 and the Hurricane Wind Intensity Size Index (HWISI) was 52.6.  Typhoon Man-yi was similar in intensity to Hurricane Michael when Michael hit Northwest Florida in 2018.  Man-yi was bigger than Michael was.

Typhoon Man-yi will move through an environment favorable for intensification during the next few hours.  Man-yi will move over water where where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge over the Western North Pacific Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Typhoon Man-yi could continue to intensify during the next few hours.  However, the fact that the southwestern part of Man-yi’s eyewall passed over Catanduanes Island could halt its intensification.

Typhoon Man-yi will move around the southern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Man-yi toward the northwest during the next 24 hours.  On its anticipated track, Typhoon Man-yi will reach southeastern Luzon in 12 hours.  The center of Man-yi’s circulation could make landfall northeast of Baler.

Typhoon Man-yi is already bringing destructive winds to Catanduanes Island.  Typhoon Man-yi will also bring very strong winds and heavy rain to Luzon.  Heavy rain will cause flash floods and mudslides.  Man-yi could also cause a storm surge of up to 13 feet (4 meters) along the coast of Luzon. Luzon has already been hit by a series of in recent weeks.  Typhoon Man-yi is capable of causing regional catastrophic damage.  Man-yi will seriously set back efforts to recover from the previous typhoons.

Elsewhere over the Western North Pacific Ocean, Tropical Depression Usagi was still dropping heavy rain on parts of Taiwan. At 4:00 a.m. EST on Saturday the center of Tropical Depression Usagi was located at latitude 22.3°N and longitude 120.7°E which put the center about 35 miles (55 km) south of Kaohsiung, Taiwan.  Usagi was moving toward the southeast at 4 m.p.h. (6 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1006 mb.  Continued heavy rain is likely to cause flash floods in Taiwan.

Typhoon Man-Yi Strengthens to Equivalent of a Major Hurricane

Typhoon Man-yi strengthened to the equivalent of a major hurricane as it moved toward the Philippines on Friday.  At 4:00 p.m. EST on Friday the center of Typhoon Man-yi was located at latitude 12.3°N and longitude 127.2°E which put the center about 490 miles (790 km) east-southeast of Manila, Philippines.  Man-yi was moving toward the west-northwest at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 952 mb.

Typhoon Man-yi intensified to the equivalent of a major hurricane on Friday.  A circular eye with a diameter of 25 miles (40 km) was at the center of Man-yi’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 Man-yi’s circulation.  Storms near the center of Man-yi generated strong upper level divergence that pumped mass away from the typhoon in all directions.  The removal of large quantities of mass caused the surface pressure to decrease rapidly.

The circulation around Typhoon Man-yi was very symmetrical.  Winds to typhoon force extended out 30 miles (50 km) from the center of Man-yi’s circulation.  Winds to tropical storm force extended out 125 miles (200 km) from the center of Typhoon Man-yi.

The Hurricane Intensity Index (HII) for Typhoon Man-yi was 23.6.  The Hurricane Size Index (HSI) was 10.3 and the Hurricane Wind Intensity Size Index (HWISI) was 33.9.  Typhoon Man-yi was similar in size and intensity to Hurricane Dennis when Dennis hit Northwest Florida in 2005.

Typhoon Man-yi will move through an environment favorable for intensification during the next 24 hours.  Man-yi will move over water where where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge over the Western North Pacific Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Typhoon Man-yi is likely to continue to intensify during the next 24 hours.

Typhoon Man-yi will move around the southern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Man-yi toward the west-northwest during the next 24 hours.  On its anticipated track, Typhoon Man-yi will reach southeastern Luzon in less than 18 hours.

Typhoon Man-yi will bring very strong winds and heavy rain to Luzon.  Heavy rain will cause flash floods and mudslides.  Man-yi could also cause a storm surge of up to 13 feet (4 meters) along the coast of Luzon.  Luzon has already been hit by a series of in recent weeks.  Typhoon Man-yi is capable of causing regional major damage.  Man-yi will seriously set back efforts to recover from the previous typhoons.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Usagi was bringing wind and rain to Taiwan.  At 4:00 p.m. EST on Friday the center of Tropical Storm Usagi was located at latitude 22.5°N and longitude 120.3°E which put the center about 25 miles (40 km) southwest of Kaohsiung, Taiwan.  Usagi was moving toward the north-northeast at 10 m.p.h. (16 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.  Heavy rain is likely to cause flash floods in Taiwan.

Man-yi Strengthens to a Typhoon East of the Philippines

Former Tropical Storm Man-yi strengthened to a typhoon east of the Philippines on Thursday.  At 10:00 p.m. EST on Thursday the center of Typhoon Man-yi was located at latitude 10.7°N and longitude 131.3°E which put the center about 795 miles (1280 km) east-southeast of Manila, Philippines.  Man-yi was moving toward the west at 18 m.p.h. (30 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.

Former Tropical Storm Man-yi strengthened to a typhoon over the Western North Pacific Ocean east of the Philippines on Thursday.  The inner end of a rainband wrapped around the center of Man-yi’s circulation.  A circular eye with a diameter of 23 miles (37 km) formed at the center of Typhoon Man-yi.  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 Man-yi’s circulation.  Storms near the center of Man-yi generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

Typhoon Man-yi will move through an environment favorable for intensification during the next 24 hours. Man-yi will move over water where where the Sea Surface Temperatures are near 29°C.   It will move under the middle of an upper level ridge over the Western North Pacific Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Typhoon Man-yi will intensify during the next 24 hours.  Man-yi could intensify rapidly.  Typhoon Man-yi is likely to strengthen to the equivalent of a major hurricane.

Typhoon Man-yi will move around the southern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Man-yi toward the west-northwest during the next 24 hours.  On its anticipated track, Typhoon Man-yi will move toward Luzon.  Man-yi could approach Luzon in 36 hours.

Elsewhere over the Western North Pacific Ocean, Typhoon Usagi moved toward Taiwan.  At 10:00 p.m. EST on Thursday the center of Typhoon Usagi was located at latitude 20.2°N and longitude 120.2°E which put the center about 145 miles (235 km) south of Kaohsiung, Taiwan.  Usagi was moving toward the north-northwest at 9 m.p.h. (15 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 977 mb.

Typhoon Usagi Hits Northern Luzon

Typhoon Usagi hit northern Luzon on Wednesday night.  At 10:00 p.m. EST on Wednesday the center of Typhoon Usagi was located at latitude 17.6°N and longitude 122.7°E which put the center about 1205 miles (195 km) southeast of Aparri, Philippines.  Usagi was moving toward the northwest at 14 m.p.h. (22 km/h). The maximum sustained wind speed was 150 m.p.h. (240 km/h) and there were wind gusts to 185 m.p.h. (295 km/h).  The minimum surface pressure was 915 mb.

Typhoon Usagi rapidly intensified to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale east of Luzon on Wednesday.  A small circular eye with a diameter of 5 miles (8 km) was at the center of Usagi’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 revolved around the core of Typhoon Usagi.  Storms near the core of Usagi generated strong upper level divergence that pumped large quantities of mass away from the typhoon in all directions.  The removal of large amounts of mass caused the surface pressure to decrease rapidly.  The inner end of a rainband wrapped around the existing eye and eyewall at the center of Usagi’s circulation during Wednesday evening and concentric eyewalls could be forming.

The circulation around Typhoon Usagi was small.  Winds to typhoon force extended out 30 miles (50 km) from the center of Usagi’s circulation.  Winds to tropical storm force extended out 85 miles (135 km) from the center of Typhoon Usagi.

The Hurricane Intensity Index (HII) for Typhoon Usagi was 31.6.  The Hurricane Size Index (HSI) was 9.4 and the Hurricane Wind Intensity Size Index (HWISI) was 41.0 . Typhoon Usagi was similar in size to Hurricane Ida when Ida hit Louisiana in 2021.  Usagi was not as big as Ida was.

Typhoon Usagi will move around the southern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Usagi toward the northwest during the next 24 hours.  On its anticipated track, the center of Typhoon Usagi will move across northeast Luzon during the next few hours.

Typhoon Usagi will bring strong winds and heavy rain to northern Luzon.  Heavy rain could cause flash floods and mudslides in some locations.  Usagi could cause a storm surge of up to 13 feet ( 4 meters) on the coast of northeastern Luzon.  The area likely to be hit by Usagi was just hit by Typhoon Toraji a few days ago.  Typhoon Usagi will complicate recovery efforts in Luzon.

Elsewhere over the Western North Pacific Ocean, former Tropical Storm Toraji weakened to a tropical depression south of Hong Kong, and Tropical Storm Man-yi was moved north of Yap.

At 10:00 p.m. EST on Wednesday the center of Tropical Depression Toraji was located at latitude 21.0°N and longitude 113.9°E which put the center about 90 miles (145 km) south of Hong Kong.  Toraji was moving toward the west-southwest at 5 m.p.h. (8 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 1005 mb.

At 10:00 p.m. EST on Wednesday the center of Tropical Storm Man-yi was located at latitude 11.1°N and longitude 137.0°E which put the center about 120 miles (195 km) north of Yap. Man-yi was moving toward the west-southwest at 20 m.p.h. (32 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 1000 mb.

Typhoon Usagi Rapidly Intensifies to Equivalent of a Major Hurricane

Typhoon Usagi rapidly intensified to the equivalent of a major hurricane over the Western North Pacific Ocean east of Luzon on Wednesday.  At 10:00 a.m. EST on Wednesday the center of Typhoon Usagi was located at latitude 16.5°N and longitude 124.8°E which put the center about 485 miles (780 km) east-southeast of Aparri, Philippines.  Usagi was moving toward the west-northwest at 15 m.p.h. (24 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 949 mb.

Typhoon Usagi rapidly intensified to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale east of Luzon on Wednesday.  A small circular eye with a diameter of 5 miles (8 km) formed at the center of Usagi’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 revolved around the core of Typhoon Usagi.  Storms near the core of Usagi generated strong upper level divergence that pumped large quantities of mass away from the typhoon in all directions.  The removal of large amounts of mass caused the surface pressure to decrease rapidly.

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

The Hurricane Intensity Index (HII) for Typhoon Usagi was 25.1.  The Hurricane Size Index (HSI) was 9.4 and the Hurricane Wind Intensity Size Index (HWISI) was 34.5.  Typhoon Usagi was similar in size to Hurricane Harvey when Harvey hit Texas in 2017.  Usagi was not as big as Harvey was.

Typhoon Usagi will move through an environment favorable for intensification during the next 24 hours.  Usagi will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the axis of an upper level ridge over the Western North Pacific Ocean.  The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear.  Typhoon Usagi could continue to intensify during the next 24 hours.  However, since the core of Usagi’s circulation is so small, the inner end of a rainband could wrap around the core.  If concentric eyewalls form, an eyewall replacement cycle would halt the intensification of Typhoon Usagi.

Typhoon Usagi will move around the southern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Usagi toward the west-northwest during the next 24 hours.  On its anticipated track, the center of Typhoon Usagi will move near northeast Luzon in 18 hours.

Typhoon Usagi will bring strong winds and heavy rain to northern Luzon.  Heavy rain could cause flash floods and mudslides in some locations.  Usagi could cause a storm surge of up to 13 feet ( 4 meters) on the coast of northeastern Luzon.  The area likely to be hit by Usagi was just hit by Typhoon Toraji a few days ago.  Typhoon Usagi will complicate recovery efforts in Luzon.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Toraji was approaching the coast of China east of Hong Kong, and Tropical Storm Man-yi was moving away from the Marianas.

At 10:00 a.m. EST on Wednesday the center of Tropical Storm Toraji was located at latitude 21.9°N and longitude 114.9°E which put the center about 65 miles (105 km) east-southeast of Hong Kong.  Toraji was moving toward the north at 14 m.p.h. (22 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 995 mb.

At 10:00 a.m. EST on Wednesday the center of Tropical Storm Man-yi was located at latitude 11.7°N and longitude 140.4°E which put the center about 280 miles (450 km) west-southwest of Guam.  Man-yi was moving toward the west-southwest at 16 m.p.h. (26 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 Man-yi Brings Gusty Winds to Guam

Tropical Storm Man-yi brought gusty winds to Guam on Tuesday.  At 4:00 p.m. EST on Tuesday the center of Tropical Storm Man-yi was located at latitude 12.5°N and longitude 144.4°E which put the center about 40 miles (65 km) southeast of Guam.  Man-yi was moving toward the southwest at 18 m.p.h. (30 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 994 mb.

Tropical Storm Warnings were in effect for Guam, Rota, Tinian, and Saipan.

Tropical Storm Man-yi brought gusty wind to Guam and the Marianas on Tuesday.  A weather station at the Guam International Airport reported a sustained wind speed of 30 m.p.h. (50 km/h) and a wind gust of 48 m.p.h. (77 km/h) on Tuesday.

The circulation around Tropical Storm Man-yi was somewhat disorganized.  There were not many thunderstorms near the center of Man-yi’s circulation.  Thunderstorms were occurring in bands in the southern side of the center of Tropical Storm Man-yi.  Bands in the northern side of Man-yi’s circulation consisted primarily of showers and lower clouds.

The circulation around Tropical Storm Man-yi was small.  Winds to tropical storm force extended out 85 miles (135 km) from the center of Man-yi’s circulation.

Tropical Storm Man-yi will move through an environment somewhat favorable for intensification during the next 24 hours.  Man-yi will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the southern side of an upper level ridge over the Western North Pacific Ocean.  The upper level ridge will produce easterly winds that will blow toward the top of Man-yi’s circulation.  Those winds will cause some vertical wind shear. The wind shear will inhibit intensification, but the shear may not be enough to prevent intensification. Tropical Storm Man-yi could intensify during the next 24 hours.

Tropical Storm Man-yi will move around the southern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Man-yi toward the west during the next 24 hours.  On its anticipated track, Tropical Storm Man-yi will move away from the Marianas.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Usagi strengthened east of the Philippines, Tropical Depression Yinxing moved inland over Vietnam, and Tropical Storm Toraji was spinning over the South China Sea southeast of Hong Kong.

At 4:00 p.m. EST on Tuesday the center of Tropical Storm Usagi was located at latitude 15.0°N and longitude 128.3°E which put the center about 530 miles (850 km) east of Manila, Philippines.  Usagi was moving toward the west at 17 m.p.h. (28 km/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 987 mb.

At 10:00 a.m. EST on Tuesday the center of Tropical Depression Yinxing was located at latitude 14.0°N and longitude 108.2°E which put the center about 145 miles (235 km) south of Da Nang, Vietnam.  Yinxing was moving toward the west at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h).  The minimum surface pressure was 1004 mb.

At 4:00 p.m. EST on Tuesday the center of Tropical Storm Toraji was located at latitude 20.1°N and longitude 116.8°E which put the center about 245 miles (395 km) southeast of Hong Kong.  Toraji was moving toward the west-northwest 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 997 mb.

Tropical Storm Usagi Forms East of the Philippines

Tropical Storm Usagi formed over the Western North Pacific Ocean east of the Philippines on Monday.  At 4:00 p.m. EST on Monday the center of Tropical Storm Usagi was located at latitude 13.0°N and longitude 134.2°E which put the center about 945 miles (1525 km) east of Manila, Philippines.  Usagi was moving toward the west at 17 m.p.h. (28 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.

Another tropical storm formed east of the Philippines on Monday.  Former Tropical Depression Twentyseven-W strengthened and the Japan Meteorological Agency designated the system as Tropical Storm Usagi.  More thunderstorms formed near the center of Usagi’s circulation.  However, the distribution of thunderstorms in Tropical Storm Usagi was asymmetrical.  Many of the thunderstorms were occurring in bands in the western half of Usagi’s circulation.  Bands in the eastern half of Tropical Storm Usagi consisted primarily of showers and lower clouds.  Storms near the center of Usagi generated upper level divergence that pumped mass away to the west of the tropical storm.

The circulation around Tropical Storm Usagi was small.  Winds to tropical storm force extended out 50 miles (80 km) from the center of Usagi’s circulation.

Tropical Storm Usagi will move through an environment favorable for intensification during the next 24 hours.  Usagi will move over water where the Sea Surface Temperatures are near 30°C.   It will move under the southern side of an upper level ridge over the Western North Pacific Ocean.  The upper level ridge will produce easterly winds that will blow toward the top of Usagi’s circulation.  Those winds will cause some vertical wind shear.  The wind shear will inhibit intensification, but the shear will not be enough to prevent intensification.  Tropical Storm Usagi will intensify during the next 24 hours.  Usagi could strengthen to a typhoon on Tuesday.

Tropical Storm Usagi will move around the southern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Usagi toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Usagi will move toward the Philippines.

Elsewhere over the Western North Pacific Ocean, former Typhoon Toraji weakened as it moved away from the Philippines, Tropical Storm Yinxing approached the coast of Vietnam, Tropical Storm Watches were issued in the Marianas for Tropical Storm Man-yi.

At 4:00 p.m. EST on Monday the center of Tropical Storm Toraji was located at latitude 18.5°N and longitude 118.7°E which put the center about 420 miles (675 km) southeast of Hong Kong.  Toraji was moving toward the west-northwest at 10 m.p.h. (16 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 985 mb.

At 4:00 p.m. EST on Monday the center of Tropical Storm Yinxing was located at latitude 14.6°N and longitude 109.6°E which put the center about 130 miles (210 km) southeast of Da Nang, Vietnam.  Yinxing was moving toward the south-southwest at 10 m.p.h. (16 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.

At 4:00 p.m. EST on Monday the center of Tropical Storm Man-yi was located at latitude 14.0°N and longitude 150.5°E which put the center about 430 miles (695 km) east of Guam.  Man-yi was moving toward the west-southwest at 8 m.p.h. (13 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 992 mb.

Tropical Storm Watches were in effect for Guam, Rota, Tinian and Saipan.

Tropical Storm Usagi Makes Landfall South of Ho Chi Minh City

Tropical Storm Usagi made landfall south of Ho Chi Minh City, Vietnam on Saturday night.  At 10:00 p.m. EST on Saturday the center of Tropical Storm Usagi was located at latitude 10.2°N and longitude 107.1°E which put it about 60 miles (995 km) south-southeast of Ho Chi Minh City, Vietnam.  Usagi was moving toward the west at 5 m.p.h. (8 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 984 mb.

Former Typhoon Usagi weakened as it approached the coast of southern Vietnam.  Moderate vertical wind shear caused by upper level winds blowing from the east caused Usagi to weaken slowly.  The core of Tropical Storm Usagi was still relatively intact.  A ring of strong thunderstorms surrounded the remnants of the small eye.  The strongest winds were occurring in that ring of storms.  Heavy rain was falling just to the southwest of the center of circulation.  Thunderstorms were also dropping heavy rain in a couple of bands on the northeastern periphery of the circulation.

Tropical Storm Usagi will bring gusty winds to the areas south and west of Ho Chi Minh City.  Some places in southern Vietnam and Cambodia will receive locally heavy rainfall and flash floods could occur in those areas.  Usagi will weaken slowly as it move inland over southern Vietnam.

Elsewhere over the Western North Pacific Ocean, Typhoon Man-yi was meandering slowly southeast of Okinawa.  At 10:00 p.m. EST on Saturday the center of Typhoon Man-yi was located at latitude 18.4°N and longitude 135.8°E which put it about 770 miles (1245 km) southeast of Okinawa.  Man-yi was moving toward the west at 2 m.p.h. (3 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 969 mb.

Usagi Strengthens to a Typhoon East of Southern Vietnam

Former Tropical Storm Usagi strengthened into a typhoon east of southern Vietnam on Friday night.  At 10:00 p.m. EST on Friday the center of Typhoon Usagi was located at latitude 9.6°N and longitude 109.2°E which put it about 205 miles (335 km) east-southeast of Ho Chi Minh City, Vietnam.  Usagi was moving toward the west-southwest at 10 m.p.h. (16 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 977 mb.

A small circular eye was visible at the center of Typhoon Usagi on both conventional and microwave satellite imagery.  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 Usagi.  The strongest rain bands were in the western half of the typhoon.  Storms near the core of Usagi were generating upper level divergence which was pumping mass away from the typhoon.  Winds to typhoon force extended out about 30 miles (50 km) from the center of circulation.  Winds to tropical storm force extended out about 125 miles (200 km) from the center.

Typhoon Usagi will move through an environment favorable for intensification during the next 24 hours.  Usagi will move over water where the Sea Surface Temperature is near 29°C.  It will move south of an upper level ridge.  The ridge will produce easterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear, which will reduce the rate of intensification.  Typhoon Usagi will strengthen on Saturday.

The ridge north of Typhoon Usagi will steer the typhoon a little to the south of due west.  On its anticipated track the center of Typhoon Usagi will approach the Mouths of the Mekong River in about 24 hours.  Usagi will bring strong winds and drop heavy rain on southern Vietnam.  Winds to tropical storm force could affect Ho Chi Minh City.  There could be a storm surge of 6 to 9 feet (2 to 3 meters) along the coast.  Locally heavy rain could cause floods over portions of southern Vietnam and Cambodia.

Elsewhere over the Western North Pacific Typhoon Man-yi started to weaken southeast of Okinawa.  At 10:00 p.m. EST on Friday the center of Typhoon Man-yi was located at latitude 18.1°N and longitude 135.4°E which put it about 760 miles (1230 km) southeast of Okinawa.  Man-yi was moving toward the north at 5 m.p.h. (8 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 969 mb.

Tropical Storm Usagi Forms East of Vietnam

Tropical Storm Usagi formed over the South China Sea east of Vietnam on Thursday.  At 10:00 a.m. EST on Thursday the center of Tropical Storm Usagi was located at latitude 11.2°N and longitude 113.7°E which put it about 350 miles (565 km) east of Lien Huong, Vietnam.  Usagi was moving toward the west at 18 m.p.h. (29 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1001 mb.

More thunderstorms developed near the center of former Tropical Depression 33W and the Japan Meteorological Agency designated the system as Tropical Storm Usagi.  Satellite imagery indicated that the inner end of a rainband was wrapping around the center of circulation.  Several other bands of showers and thunderstorms were in the western half of Tropical Storm Usagi.  Bands in the eastern half of the circulation consisted primarily of showers and low clouds.  An upper level ridge north Usagi was producing southeasterly winds which were blowing toward the top of the circulation.  Those winds were causing moderate vertical wind shear and they were the reason why the stronger thunderstorms were developing west of the center of circulation.  Storms near the center were producing upper level divergence which was pumping mass away to the west of the tropical storm.

Tropical Storm Usagi will move through an environment favorable for intensification during the next 24 to 36 hours.  Usagi will move over water where the Sea Surface Temperature is near 29°C.  It will continue to move south of an upper level ridge and moderate vertical wind shear will continue to affect Tropical Storm Usagi.  The wind shear will slow intensification, but Usagi will strengthen during the next day or so.  It could intensify into a typhoon during the next 36 hours.

The ridge north of Tropical Storm Usagi will steer the tropical storm on a track a little to the south of due west.  On its anticipated track the center of Tropical Storm Usagi will approach the coast of southern Vietnam in about 36 hours.  Usagi could make landfall on the portion of the coast between Cam Ranh and Vung Tau.  Tropical Storm Usagi will bring gusty winds and it could drop locally heavy rain over southern Vietnam and Cambodia.  Heavy rain could cause flash foods in some locations.

Elsewhere over the Western North Pacific, Typhoon Man-yi was moving away from the Marianas after causing power outages in southern Guam.  At 10:00 a.m. EST on Thursday the center of Typhoon Man-yi was located at latitude 13.5°N and longitude 137.8°E which put it about 1155 miles (1860 km) southeast of Okinawa.  Man-yi was moving toward the northwest at 21 m.p.h. (34 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 969 mb.