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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.

Typhoon Toraji Brings Wind and Rain to Luzon

Typhoon Toraji brought wind and rain to Luzon on Sunday night.  At 10:00 p.m. EST on Sunday the center of Typhoon Toraji was located at latitude 16.7°N and longitude 121.8°E which put the center about 25 miles (40 km) east of Echague, Philippines.  Toraji was moving toward the west-northwest at 13 m.p.h. (20 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 970 mb.

The center of Typhoon Toraji made landfall on the coast of Luzon east of Echague on Sunday night.  Toraji was a relatively small typhoon at the time of landfall.  Winds to typhoon force extended out 30 miles (50 km) from the center of Toraji’s circulation.  Winds to tropical storm force extended out 90 miles from the center of Typhoon Toraji.

The Hurricane Intensity Index (HII) for Typhoon Toraji was 13.9. The Hurricane Size Index (HSI) was 7.7. and the Hurricane Wind Intensity Size Index (HWISI) was 21.6. Typhoon Toraji was similar in size and intensity to Hurricane Isaias when Isaias hit North Carolina in 2020.

Typhoon Toraji will move around the southern side of a high pressure system over the Western North Pacific Ocean.  The high pressure system will steer Toraji toward the west-northwest during the next 24 hours.  On its anticipated track, the Typhoon Toraji will move across northern Luzon during the next 12 hours.

Typhoon Toraji will bring strong winds and locally heavy rain to northern Luzon.  Heavy rain is likely to cause flash floods and mudslides.  Toraji will also cause a storm surge of up to 9 feet (2.7 meters) along the coast of northeastern Luzon.  Northern Luzon is trying to recover from the damage caused by two recent typhoons.  Typhoon Toraji will seriously disrupt those recovery activities.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Yinxing continued to weaken over the South China Sea, Tropical Storm Man-yi continued to move toward the Marianas, and a new tropical depression formed west of Guam.

At 10:00 p.m. EST on Sunday the center of Tropical Storm Yinxing was located at latitude 16.7°N and longitude 111.3°E which put the center about 225 miles (365 km) east-northeast of Da Nang, Vietnam.  Yinxing was moving toward the south-southwest at 14 m.p.h. (22 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 993 mb.

At 10:00 p.m. EST on Sunday the center of Tropical Storm Man-yi was located at latitude 15.1°N and longitude 152.2°E which put the center about 460 miles (740 km) east of Saipan.  Man-yi was moving toward the west-southwest at 12 m.p.h. (19 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.

At 10:00 p.m. EST on Sunday the center of Tropical Depression Twentyseven-W was located at latitude 12.7°N and longitude 138.5°E which put the center about 370 miles (595 km) west of Guam.  The tropical depression was moving toward the northwest at 18 m.p.h. (30 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. (60 km/h).  The minimum surface pressure was 999 mb.

Nalgae Strengthens to a Typhoon South-Southeast of Hong Kong

Former Tropical Storm Nalgae strengthened to a typhoon over the South China Sea south-southeast of Hong Kong on Monday. At 11:00 a.m. EDT on Monday the center of Typhoon Nalgae was located at latitude 18.2°N and longitude 116.3°E which put it about 310 miles (500 km) south-southeast of Hong Kong. Nalgae was moving toward the north-northwest at 8 m.p.h. (13 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 981 mb.

Typhoon Nalgae strengthened gradually over the South China Sea south-southeast of Hong Kong on Monday. A large eye with a diameter of 30 miles (50 km) formed at the center of Nalgae’s circulation. A broken ring of thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the center of Typhoon Nalgae. Storms near the center of circulation generated upper level divergence that pumped mass away from the typhoon. Winds to typhoon force extended out 20 miles (30 km) in the western side of Nalgae. Winds to tropical storm force extended out 330 miles (515 km) from the center of circulation.

Typhoon Nalgae will move through an environment mostly favorable for intensification during the next 24 hours. Nalgae will move over water where the Sea Surface Temperatures are near 29˚C. It will move under the western side of an upper level ridge over the Western North Pacific. The upper level ridge will produce southerly winds that will blow toward the top of Nalgae’s circulation. Those winds will cause vertical wind shear, but the wind shear will not be strong enough to prevent intensification. Typhoon Nalgae is likely to intensify during the next 24 hours. Nalgae will move into an environment where there is drier air in the lower levels of the atmosphere when it moves closer to China. Typhoon Nalgae will weaken when the drier air gets pulled into its circulation.

Typhoon Nalgae will move around the western end of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Nalgae toward the northwest during the next 24 hours. On its anticipated track Typhoon Nalgae will move closer to Hong Kong during the next 24 hours. Nalgae will move more toward the west when it encounters the drier environment near China and weakens.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Banyan developed east of the Philippines. At 11:00 a.m. EDT on Monday the center of Tropical Storm Banyan was located at latitude 7.3°N and longitude 131.2°E which put it about 320 miles (515 km) east of Mindanao. Banyan was moving toward the west-northwest at 11 m.p.h. (17 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 Nyatoh Brings Wind and Rain to Iwo To

Typhoon Nyatoh brought wind and rain to Iwo To on Friday. At 10:00 a.m. EST on Friday the center of Typhoon Nyatoh was located at latitude 24.3°N and longitude 142.9°E which put it about 80 miles (130 km) southeast of Iwo To. Nyatoh was moving toward the northeast at 24 m.p.h. (39 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 947 mb.

Bands in the northwestern side of Typhoon Nyatoh brought strong winds and heavy rain to Iwo To on Friday. The core of Nyatoh’s circulation where the strongest winds were occurring passed to the southeast of Iwo To. An upper level trough over Japan was producing strong southwesterly winds that were blowing toward the top of Typhoon Nyatoh’s circulation. Those winds caused strong vertical wind shear and the shear started to weaken Nyatoh when it approached Iwo To. A circular eye was still present at the center of Typhoon Nyatoh, but the distribution of thunderstorms was asymmetrical. The strongest thunderstorms were occurring around the eye and in bands in the northern half of Nyatoh. Bands in the southern half of the typhoon consisted primarily of showers and lower clouds.

Even though Typhoon Nyatoh was weakening, it was still the equivalent of a major hurricane. Winds to typhoon force extended out 60 miles (95 km) from the center of Nyatoh. Winds to tropical storm force extended out 200 miles (320 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Nyatoh was 23.6. The Hurricane Size Index (HSI) was 22.2 and the Hurricane Wind Intensity Size Index (HWISI) was 45.8.

The upper level trough over Japan will steer Typhoon Nyatoh quickly toward the northeast during the next 24 hours. On its anticipated track Nyatoh will move away from Iwo To and the weather conditions should improve. Typhoon Nyatoh will move through an environment that will be unfavorable for a typhoon. Nyatoh will move over water where the Sea Surface Temperatures are near 24.5˚C. The upper level trough will continue to produce strong vertical wind shear. A surface high pressure system over eastern Asia will transport drier air toward the western side of Nyatoh’s circulation. Cooler water, strong vertical wind shear, and drier air will cause Typhoon Nyatoh to weaken rapidly during the next 24 hours.

Typhoon Nyatoh Strengthens to Equivalent of a Major Hurricane

Typhoon Nyatoh strengthened to the equivalent of a major hurricane over the Western North Pacific Ocean southwest of Iwo To on Thursday. At 10:00 a.m. EST on Thursday the center of Typhoon Nyatoh was located at latitude 18.7°N and longitude 137.1°E which put it about 540 miles (875 km) southwest of Iwo To. Nyatoh was moving toward the northeast at 15 m.p.h. (24 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. (230 km/h). The minimum surface pressure was 955 mb.

Typhoon Nyatoh rapidly intensified to the equivalent of a major hurricane on Thursday. A circular eye with a diameter of 35 miles (55 km) formed at the center of Nyatoh. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Typhoon Nyatoh. Storms near the core generated strong upper level divergence that pumped mass away to the northeast of the typhoon.

The circulation around Typhoon Nyatoh increased in size on Thursday. Winds to typhoon force extended out 65 miles (105 km) from the center of Nyatoh. Winds to tropical storm force extended out 220 miles (355 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Nyatoh was 20.6. The Hurricane Size Index (HSI) was 22.1 and the Hurricane Wind Intensity Size Index (HWISI) was 42.7.

Typhoon Nyatoh will move through an environment that will become unfavorable for intensification during the next 24 hours. Nyatoh will move over water where the Sea Surface Temperatures are near 28˚C. An upper level trough near Japan will produce southwesterly winds that will blow toward the top of Nyatoh’s circulation. Those winds will cause the vertical wind shear to increase during the next 24 hours. Clockwise flow around a surface high pressure system centered over eastern Asia will transport drier air toward the northwestern part of Nyatoh’s circulation. The drier air will begin to be pulled into the northwestern part of Typhoon Nyatoh’s circulation during the next 24 hours. The combination of more vertical wind shear and drier air will cause Typhoon Nyatoh to start to weaken.

The upper level trough near Japan will steer Typhoon Nyatoh toward the northeast during the next 24 hours. On its anticipated track Typhoon Nyatoh could approach Iwo To on Friday. Although Nyatoh will weaken, it will bring strong winds and locally heavy rain to Iwo To.

Nyatoh Strengthens to a Typhoon West of the Marianas

Former Tropical Storm Nyatoh strengthened to a typhoon west of the Marianas on Wednesday. At 10:00 a.m. EST on Wednesday the center of Typhoon Nyatoh was located at latitude 15.5°N and longitude 135.6°E which put it about 580 miles (935 km) west-northwest of Guam. Nyatoh was moving toward the north-northwest at 11 m.p.h. (17 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 981 mb.

Former Tropical Storm Nyatoh continued to strengthen over the Western North Pacific Ocean west of the Marianas on Wednesday. The inner end of a rainband wrapped around the center of Typhoon Nyatoh and microwaves satellite images indicated that an eye was forming. The developing 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 core of Nyatoh. Storms near the core generated upper level divergence that pumped mass away from the typhoon. Winds to typhoon force extended out 35 miles (55 km) from the center of Nyatoh. Winds to tropical storm force extended out 150 miles (240 km) from the center of circulation.

Typhoon Nyatoh will move through an environment mostly favorable for intensification during the next 24 hours. Nyatoh will move over water where the Sea Surface Temperatures are near 28˚C. It will move under the western part of the axis of an upper level ridge centered near the Marianas. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Clockwise flow around a high pressure system centered over eastern Asia will transport drier air toward the northwestern part of Nyatoh’s circulation. The drier air is likely to remain northwest of Typhoon Nyatoh during the next 24 hours. Nyatoh could intensify more rapidly once the eye and eyewall become fully formed. Typhoon Nyatoh will continue to strengthen and it could intensify to the equivalent of a major hurricane during the next 24 hours. An upper level trough west of Japan will produce southwesterly winds that will begin to affect Nyatoh later this week. Those winds will create more vertical wind shear and the shear will cause Typhoon Nyatoh to weaken.

Typhoon Nyatoh will move around the western part of a high pressure system over the Western North Pacific Ocean during the next 24 hours. The high pressure system will steer Nyatoh toward the north during the next 24 hours. The upper level trough will steer Typhoon Nyatoh toward the northeast after Nyatoh moves around the western end of the high pressure system. On its anticipated track Tropical Storm Nyatoh will remain west of the Marianas during the next 24 hours. Nyatoh could approach Iwo To in 48 hours.

Tropical Storm Nyatoh Strengthens West of the Marianas

Tropical Storm Nyatoh strengthened over the Western North Pacific Ocean west of the Marianas on Tuesday. At 4:00 p.m. EST on Tuesday the center of Tropical Storm Nyatoh was located at latitude 13.4°N and longitude 136.7°E which put it about 510 miles (825 km) west of Guam. Nyatoh was moving toward the west-northwest at 7 m.p.h. (11 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 991 mb.

Tropical Storm Nyatoh continued to strengthen west of the Marianas on Tuesday. The inner end of a rainband wrapped around the northern and western sides of the center of Nyatoh. Additional bands of showers and thunderstorms were revolving around the center of Tropical Storm Nyatoh. Storms near the center of circulation generated strong upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 130 miles (210 km) from the center of Nyatoh’s circulation.

Tropical Storm Nyatoh will move through an environment mostly favorable for intensification during the next 24 hours. Nyatoh will move over water where the Sea Surface Temperatures are near 29˚C. It will move under the western part of the axis of an upper level ridge centered east of the Marianas. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Clockwise flow around a high pressure system centered over eastern Asia could transport drier air toward the northwestern part of Nyatoh’s circulation. The drier air is likely to remain northwest of Tropical Storm Nyatoh during the next 24 hours. Nyatoh could intensify more rapidly once the inner end of the rainband wraps around the center of circulation and a core with an eye and an eyewall develops. Tropical Storm Nyatoh will continue to strengthen and it will intensify to a typhoon during the next 24 hours.

Tropical Storm Nyatoh will move around the western part of a high pressure system over the Western North Pacific Ocean during the next 24 hours. The high pressure system will steer Nyatoh toward the north during the next 24 hours. Nyatoh could move toward the northeast after it moves around the western end of the high pressure system. On its anticipated track Tropical Storm Nyatoh will remain west of the Marianas during the next 24 hours.

TD 27W Strengthens to Tropical Storm Nyatoh West of Guam

Former Tropical Depression 27W strengthened to Tropical Storm Nyatoh west of Guam on Monday night. At 10:00 p.m. EST on Monday the center of Tropical Storm Nyatoh was located at latitude 13.0°N and longitude 138.7°E which put it about 370 miles (600 km) west of Guam. Nyatoh was moving toward the west at 14 m.p.h. (22 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.

The circulation around former Tropical Depression 27W continued to strengthen on Monday night and the Japan Meteorological Agency upgraded the system to Tropical Storm Nyatoh. More thunderstorms developed near the center of circulation and in the bands revolving around the center of Nyatoh. Storms near the center generated upper level divergence that pumped mass away from the tropical storm. Winds to tropical storm force extended out 125 miles (200 km) from the center of Tropical Storm Nyatoh.

Tropical Storm Nyatoh will move through an environment mostly favorable for intensification during the next 36 hours. Nyatoh will move over water where the Sea Surface Temperatures are near 29˚C. It will move under the western part of the axis of an upper level ridge centered east of the Marianas. The upper level winds are weak near the axis of the ridge and there will be little vertical wind shear. Clockwise flow around a high pressure system centered over eastern Asia could transport drier air toward the northwestern part of Nyatoh’s circulation. The drier air is likely to remain northwest of the core of Tropical Storm Nyatoh during the next 36 hours. Tropical Storm Nyatoh will continue to strengthen and it could intensify to a typhoon during the next 36 hours.

Tropical Storm Nyatoh will move around the southwestern part of a high pressure system over the Western North Pacific Ocean during the next 36 hours. The high pressure system will steer the tropical depression toward the northwest during the next 36 hours. On its anticipated track Tropical Storm Nyatoh will move farther away from the Marianas and Yap.