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Halong Strengthens to a Typhoon

Former Tropical Storm Halong strengthened to a typhoon west of the Ogasawara Islands south of Japan on Sunday night.  At 5:00 a.m. EDT on Monday the center of Typhoon Halong was located at latitude 25.9°N and longitude 140.5°E which put the center about 665 miles (1075 km) south of Tokyo, Japan.  Halong was moving toward the west at 7 m.p.h. (11 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.

Former Tropical Storm Halong strengthened to a typhoon on Sunday night.  A small circular eye formed at the center of Halong’s circulation.  The eye was surrounded by a broken ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Thunderstorms were also occurring in bands in the eastern side of Typhoon Halong.  Bands in the western side of Halong’s circulation consisted primarily of showers and lower clouds.  Storms near the center of Halong generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The distribution of wind speeds in Typhoon Halong was relatively symmetrical.  Winds to typhoon force extended out 25 miles (40 km) from the center of Halong’s circulation.  Winds to tropical storm force extended out 115 miles (185 km) from the center of Typhoon Halong.

Typhoon Halong will move through an environment that is mostly favorable for intensification during the next 24 hours.  Halong will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the middle of an upper level ridge that is south of Japan.  The upper level winds are weak near the middle of the upper level ridge and there will be little vertical wind shear.  However, Halong will move into a region of drier air.  The drier air will inhibit the formation of thunderstorms in the western part of Halong’s circulation.  Typhoon Halong is likely to intensify during the next 24 hours if the drier air does not get pulled into the core of Halong.

Typhoon Halong will move around the southwestern part of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Halong toward the northwest during the next 24 hours.  On its anticipated track, Typhoon Halong will move a little closer to Japan.

Elsewhere, the center of Tropical Storm Matmo moved over northeastern Vietnam.  At 5:00 a.m. EDT on Monday the center of Tropical Storm Matmo was located at latitude 22.4°N and longitude 106.2°E which put the center about 25 miles (40 km) east of Na Phac, Vietnam.  Matmo was moving toward the west-northwest 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 1000 mb.

Typhoon Matmo Brings Wind and Rain to Southern China

Typhoon Matmo brought wind and rain to southern China on Sunday morning.  At 5:00 a.m. EDT on Sunday the center of Typhoon Matmo was located at latitude 21.1°N and longitude 110.0°E which put the center about 25 miles (40 km) west of Zhanjiang, China.  Matmo was moving toward the west-northwest at 14 m.p.h. (25 km/h).  The maximum sustained wind speed was 105 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 966 mb.

Typhoon Matmo strengthened to the equivalent of a Category 2 hurricane on the Saffir-Simpson Scale before it made landfall on the coast of southern China on Sunday morning.  The center of Matmo made landfall near Zhanjiang.

Typhoon Matmo was a large typhoon at the time of landfall.  Winds to typhoon force extended out 70 miles (110 km) from the center of Matmo’s circulation.  Winds to tropical storm force extended out 175 miles (280 km) from the center of Typhoon Matmo.

The Hurricane Intensity Index (HII) for Typhoon Matmo was 17.8.  The Hurricane Size Index (HSI) was 23.2 and the Hurricane Wind Intensity Size index (HWISI) was 41.0.  Typhoon Matmo was similar in size and intensity to Hurricane Gustav when Gustav hit Louisiana in 2008.

Typhoon Matmo will move around the southern side of a high pressure system that is over southern China.  The high pressure system will steer Matmo toward the west-northwest during the next 24 hours.  On its anticipated track, Typhoon Matmo will move inland near the coast of southern China.

Typhoon Matmo will bring strong winds and heavy rain to southwestern Guangdong, Guangxi, and Hainan.  Heavy rain is likely to cause floods in some locations.  Matmo could also cause a storm surge of up to 10 feet (3 meters) along parts of the coast.  Typhoon Matmo will drop heavy rain on parts of northern Vietnam early next week.

Elsewhere over the Western North Pacific Ocean, former Tropical Depression 28W strengthened to Tropical Storm Halong east of Iwo To.  At 5:00 a.m. EDT on Sunday the center of Tropical Storm Halong was located at latitude 25.0°N and longitude 142.0°E which put the center about 65 miles (105 km) east of Iwo To.   Halong was moving toward the west-northwest at 5 m.p.h. (8 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 994 mb.

Typhoon Matmo Passes South of Hong Kong

Typhoon Matmo passed south of Hong Kong on Saturday.  At 11:00 a.m. EDT on Saturday the center of Typhoon Matmo was located at latitude 19.3°N and longitude 113.4°E which put the center about 225 miles (370 km) south of Hong Kong, Philippines.  Matmo was moving toward the west-northwest at 16 m.p.h. (26 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 984 mb.

Typhoon Matmo strengthened as it passed south of Hong Kong on Saturday.  The inner end of a rainband wrapped around the center of Matmo’s circulation.  A circular eye formed at the center of Typhoon Matmo.  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 Matmo’s circulation.  Storms near the core of Matmo 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 Matmo increased on Saturday.  Winds to typhoon force extended out 35 miles (55 km) from the center of Matmo’s circulation.  Winds to tropical storm force extended out 175 miles (280 km) from the center of Typhoon Matmo.

Typhoon Matmo will move through an environment favorable for intensification during the next 12 hours.  Matmo will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southern part of an upper level ridge that is over China.  The upper level ridge will produce easterly winds that will blow toward the top of Matmo’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Typhoon Matmo will intensify during the next 12 hours. .

Typhoon Matmo will move around the southern side of a high pressure system that is over southern China.  The high pressure system will steer Matmo toward the west-northwest during the next 24 hours.  On its anticipated track, Typhoon Matmo will approach the  southern coast of China in 12 hours.

Typhoon Matmo will bring strong winds and heavy rain to southwestern Guangdong, Guangxi, and Hainan.  Heavy rain is likely to cause floods in some locations.  Matmo also cause a storm surge of up to 10 feet (3 meters) along portions of the coast.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 28W formed east of Iwo To.  At 11:00 a.m. EDT on Saturday the center of Tropical Depression 28W was located at latitude 21.2°N and longitude 63.1°E which put the center about 125 miles (200 km) east of Iwo To.  The tropical depression was moving toward the north at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 55 m.p.h. (90 km/h).  The minimum surface pressure was 1003 mb.

Tropical Storm Matmo Moves over South China Sea

Tropical Storm Matmo moved over the South China Sea on Friday morning after crossing northern Luzon.  At 11:00 a.m. EDT on Friday the center of Tropical Storm Matmo was located at latitude 17.7°N and longitude 118.7°E which put the center about 120 miles (195 km) west of Vigan, Philippines.  Matmo was moving toward the west-northwest 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 993 mb.

Former Typhoon Matmo weakened back to a tropical storm after it moved across northern Luzon.  A circular eye was still visible at the center of Matmo’s circulation on satellite images.  The eye was surrounded by a broken 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 Matmo’s circulation.  Storms near the center of Matmo generated upper level divergence that pumped mass away from the tropical storm.

The circulation around Tropical Storm Matmo was symmetrical.  Winds to tropical storm force extended out 120 miles (195 km) from the center of Matmo’s circulation.

Tropical Storm Matmo will move through an environment favorable for intensification during the next 24 hours.  Matmo will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southern part of an upper level ridge that is over China.  The upper level ridge will produce easterly winds that will blow toward the top of Matmo’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Tropical Storm Matmo will intensify during the next 24hours.  Matmo is likely to strengthen back to a typhoon later today.

Tropical Storm Matmo will move around the southern side of a high pressure system that is over southern China.  The high pressure system will steer Matmo toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Matmo will pass south of Hong Kong in 24 hours. Matmo will be near Hainan in 36 hours.

Typhoon Matmo Brings Wind and Rain to Luzon

Typhoon Matmo brought strong winds and rain to Luzon on Thursday night.  At 11:00 p.m. EDT on Thursday the center of Typhoon Matmo was located at latitude 16.6°N and longitude 119.6°E which put the center about 25 miles (40 km) southeast of Canayan, Philippines.  Matmo was moving toward the west-northwest at 14 m.p.h. (22 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 989 mb.

Former Tropical Storm Matmo strengthened to a typhoon as it approached Luzon on Thursday.  The inner end of a rainband wrapped most of the way around the center of Matmo’s circulation.  An eye started to form at the center of Typhoon Matmo before if made landfall in Luzon.  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 Matmo’s circulation.  Storms near the center of Matmo 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 Matmo was small.  Winds to typhoon force extended out 20 miles (30 km) from the center of Matmo’s circulation.  Winds to tropical storm force extended out 120 miles (195 km) from the center of Typhoon Matmo.

Typhoon Matmo will weaken slightly while it moves across northern Luzon during the next few hours.  Matmo will move into an environment favorable for intensification when it moves over the South China Sea on Friday.  Matmo will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southern part 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 Matmo’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification. Typhoon Matmo will start to intensify again when it moves over the South China Sea.

Typhoon Matmo will move around the southern side of a high pressure system that is south of Japan.  The high pressure system will steer Matmo toward the west-northwest during the next 24 hours.  On its anticipated track, Typhoon Matmo will move across northern Luzon during the next few hours.  Matmo will move over the South China Sea on Friday.

Typhoon Matmo will cause strong winds and heavy rain in northern Luzon.  The strong winds could cause electricity outages.  Heavy rain is likely to cause flash floods in some location. Typhoon Matmo could also cause a storm surge of up to 7 feet (2 meters).

Tropical Storm Matmo Forms East of Luzon

Tropical Storm Matmo formed over the Western North Pacific Ocean east of Luzon on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Matmo was located at latitude 15.4°N and longitude 126.4°E which put the center about 350 miles (565 km) east of Baler Philippines.  Matmo was moving toward the west-northwest at 16 m.p.h. (26 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 1002 mb.

A low pressure system over the Western North Pacific Ocean east of Luzon strengthened on Wednesday and the Japan Meteorological Agency designated the system as Tropical Storm Matmo.

The circulation around Tropical Storm Matmo was exhibiting more organization on Thursday evening.  More thunderstorms developed near the center of Matmo’s circulation.  Bands of showers and thunderstorms were revolving around the center of Tropical Storm Matmo.  Storms near the center of Matmo generated upper level divergence that pumped mass away to the west of the tropical storm.  The removal of mass caused the surface pressure to decrease.

The circulation around Tropical Storm Matmo was relatively symmetrical.  Winds to tropical storm force extended out 150 miles (240 km) from the center of Matmo’s circulation.

Tropical Storm Matmo will move through an environment favorable for intensification during the next 18 hours.  Matmo will move over water where the Sea Surface Temperatures are near 29°C.  It will move under the southern part 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 Matmo’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Tropical Storm Matmo will intensify during the next 18 hours.

Tropical Storm Matmo will move around the southern side of a high pressure system that is south of Japan.  The high pressure system will steer Matmo toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Matmo will hit northern Luzon in 18 hours.

Tropical Storm Matmo will bring strong winds and heavy rain to northern Luzon.  The strong winds could cause electricity outages.  Heavy rain is likely to cause flash floods in some location.  Tropical Storm Matmo could also cause a storm surge of up to 7 feet (2 meters).

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.