Tag Archives: Guam

Wutip Intensifies Into a Typhoon Southeast of Guam

Former Tropical Storm Wutip intensified into a typhoon southeast of Guam on Wednesday.  At 10:00 p.m. EST on Wednesday the center of Typhoon Wutip was located at latitude 6.5°N and longitude 150.0°E which put it about 640 miles (1035 km) southeast of Guam.  Wutip was moving toward the west-northwest at 13 m.p.h. (20 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 979 mb.

Tropical Storm Watches have been issued for Guam, Rota, Tinian and Saipan.  A Typhoon Warning is in effect for Satawal and Puluwat.  A Tropical Storm Warning and a Typhoon Watch are in effect for Ulul and Faraulep.

Typhoon Wutip continued to exhibit better organization on Wednesday.  A cluster of thunderstorms remained near the center of circulation.  A band of storms wrapped around the southern side of the center, which could indicate the start of the formation of an eyewall.  Other bands of showers and thunderstorms were revolving around the core of Typhoon Wutip.  Storms near the core were generating upper level divergence which was pumping mass away from the typhoon.  Winds to typhoon force extended out about 35 miles (55 km) from the center of circulation.  Winds to tropical storm force extended out about 160 miles (260 km) from the center.

Typhoon Wutip will move through an environment favorable for intensification for several more days.  Wutip will move over water where the Sea Surface Temperature is near 30°C.  Typhoon Wutip will move around the western end of an upper level ridge.  The ridge will produce easterly winds which will blow toward the top of the circulation.  Those winds will create some vertical wind shear, but the wind shear will not be great enough to prevent intensification.  Typhoon Wutip will continue to intensify and it could strengthen into the equivalent of a major hurricane within 36 hours.

The ridge will steer Typhoon Wutip in a northwesterly direction during the next 48 hours.  Wutip is likely to turn more toward the north-northwest when it approaches the western end of the ridge.  On its anticipated track Typhoon Wutip could be south of Guam in 36 to 48 hours.  Wutip could be the equivalent of a major hurricane at that time.

Elsewhere, Tropical Cyclone Oma continued to spin over the Coral Sea between New Caledonia and Australia.  At 10:00 p.m. EST on Wednesday the center of Tropical Cyclone Oma was located at latitude 22.7°S and longitude159.8°E which put it about 560 miles (905 km) northeast of Brisbane, Australia.  Oma was moving toward the southwest at 6 m.p.h. (10 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 981 mb.

Tropical Storm Wutip Forms Southeast of Chuuk

Tropical Storm Wutip formed southeast of Chuuk on Tuesday.  At 4:00 p.m. EST on Tuesday the center of Tropical Storm Wutip was located at latitude 4.6°N and longitude 155.2°E which put it about 295 miles (475 km) southeast of Chuuk.  Wutip was moving toward the west at 15 m.p.h. (24 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.

A Typhoon Watch was issued for Puluwat and Satawal.  A Tropical Storm Warning was in effect for Nukuoro, Losep, and Chuuk.  A Tropical Storm Watch was issued for Fananu and Ulul.

Thunderstorms developed near the center of a low pressure system southeast of Chuuk on Tuesday and the Japan Meteorological Agency designated the system as Tropical Storm Wutip.  Thunderstorms continued to form near the center of Wutip and those storms were starting to generate upper level divergence.  Bands of showers and thunderstorms formed in the northern and western portions of the circulation.  Bands south and east of the center consisted primarily of showers and lower clouds although there were a few thunderstorms in some of those bands.  Winds to tropical storm force extended out about 150 miles (245 km) from the center of circulation in the northern half of Wutip and out about 100 miles (160 km) in the southern half of the tropical storm.

Tropical Storm Wutip will move through an environment favorable for intensification.  Wutip will move over water where the Sea Surface Temperature is near 30°C.  An upper level ridge east of Tropical Storm Wutip will produce easterly winds which will cause some vertical wind shear.  However, the wind shear will not be strong enough to prevent intensification.  Tropical Storm Wutip will intensify during the next several days.  Wutip could strengthen into a typhoon with 24 to 36 hours.  A period of rapid intensification could occur once an inner core becomes more well organized.  Tropical Storm Wutip could strengthen to the equivalent of a major hurricane in three or four days.

Tropical Storm Wutip will move around the western end of a subtropical ridge.  The ridge will steer Wutip toward the northwest during the next few days.  On its anticipated track Tropical Storm Wutip could approach Guam in three days.  Wutip is likely to be a typhoon at that time.

Tropical Storm Pabuk Brings Wind and Rain to Southern Thailand

Tropical Storm Pabuk brought wind and rain to southern Thailand on Friday.  At 5:00 p.m. EST on Friday the center of Tropical Storm Pabuk was located at latitude 8.7°N and longitude 98.5°E which put it about 60 miles (95 km) northeast of Phuket, Thailand.  Pabuk was moving toward the west-northwest at 10 m.p.h. (16 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 997 mb.

Tropical Storm Pabuk made landfall near Sichon in southern Thailand.  Pabuk brought gusty winds to much of the Isthmus of Kra.  It also dropped heavy rain over parts of southern Thailand.  Tropical Storm Pabuk weakened when it crossed the Isthmus of Kra, but the core of the circulation appears to have remained intact.  Pabuk is moving over the Andaman Sea and it still has a well defined low level center of circulation.  Several bands of showers and thunderstorms are revolving around the core of the tropical storm.  Additional bands of showers and thunderstorms are located in the northeastern part of the circulation which is over the Gulf of Thailand.

Tropical Storm Pabuk will move into an environment favorable for intensification during the next 24 to 36 hours.  Pabuk will move over water where the Sea Surface Temperature is near 28°C.  An upper level ridge over the Western North Pacific Ocean will produce southeasterly winds which will blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear, which will inhibit intensification.  However, the wind shear may not be strong enough to prevent Tropical Storm Pabuk from strengthening.

Tropical Storm Pabuk will continue to move around the western end of the ridge over the Western North Pacific Ocean.  The ridge will steer Pabuk toward the west-northwest for another 24 to 36 hours.  Pabuk will turn more toward the north when it reaches the western end of the ridge.  On its anticipated track Tropical Storm Pabuk will reach the Andaman Islands in about 36 hours.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 01W formed southeast of the Marshall Islands.  At 4:00 p.m. EST on Friday the center of Tropical Depression 01W was located at latitude 4.9°N and longitude 174.0°E which put it about 250 miles (400 km) southeast of Majuro, Marshall Islands.  It was moving toward the northwest at 15 m.p.h. (24 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.  Tropical Depression 01W is forecast to move toward the west-northwest and strengthen.  On its anticipated track it could move toward Majuro, Kwajalein, Ujelang, and the Marianas.

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.

Man-yi Strengthens to a Typhoon Southwest of Guam

Former Tropical Storm Man-yi strengthened to a typhoon southwest of Guam on Wednesday.  At 10:00 p.m. EST on Wednesday the center of Typhoon Man-yi was located at latitude 11.1°N and longitude 141.1°E which put it about 300 miles (485 km) southwest of Guam.  Man-yi was moving toward the west-northwest at 27 m.p.h. (44 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 105 m.p.h. (170 km/h).  The minimum surface pressure was 973 mb.

Typhoon Man-yi strengthened quickly on Wednesday.  An inner band of thunderstorms wrapped around the center of circulation.  A small eye appeared intermittently on satellite imagery.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Other bands of showers and thunderstorms were revolving around the core of Typhoon Man-yi.  Storms near the core were generating upper level divergence which was pumping mass away from the typhoon.  Winds to typhoon force extended out about 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out about 145 miles (230 km) from the center.

Typhoon Man-yi will move through an environment somewhat favorable for intensification on Thursday.  Man-yi will move over water where the Sea Surface Temperature is near 29°C.  So, there will be enough energy in the upper ocean to support further intensification.  Typhoon Man-yi will move south of an upper level ridge.  The ridge will produce strong east-southeasterly winds which will blow toward the top of the circulation.  Those winds will produce moderate vertical wind shear.  The wind shear will inhibit upper level outflow to the east of the typhoon and they will slow the rate of intensification.  Despite the moderate vertical wind shear, Typhoon Man-yi is likely to strengthen during the next 24 hours and it could become the equivalent of a major hurricane.

The ridge will steer Typhoon Man-yi rapidly toward the northwest during the next 24 to 36 hours.  On its anticipated track Typhoon Man-yi will move quickly away from Guam and the Marianas.  Man-yi could move southeast of Okinawa this weekend.

Elsewhere over the rest of the Western North Pacific Ocean, Tropical Depression 33W was moving quickly westward over the South China Sea.  At 10:00 p.m. EDT on Wednesday the center of Tropical Depression 33W was located at latitude 11.1°N and longitude 116.2°E which put it about 505 miles (815 km) east of Cam Ranh, Vietnam.  It was moving toward the west at 25 m.p.h. (40 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1004 mb.

Tropical Storm Man-yi Forms Southeast of Chuuk

Tropical Storm Man-yi formed southeast of Chuuk on Tuesday.  At 7:00 a.m. EST on Tuesday the center of Tropical Storm Man-yi was located at latitude 4.8°N and longitude 154.2°E which put it about 245 miles (395 km) southeast of Chuuk.  Man-yi was moving toward the west 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.

A Tropical Storm Watch was issued for Guam and Rota.  Tropical Storm Warnings were in effect for Chuuk Lagoon, Lukunor, Losap, Fananu, Ulul, Pulawat and Satawal.  Typhoon Watches were issued for Faraulep and Pulawat.

Tropical Depression 34W exhibited greater organization on satellite imagery and the Japan Meteorological Agency designated the system as Tropical Storm Man-yi.  More thunderstorms developed near the center of circulation.  The strongest thunderstorms were occurring in a band west of the center.  Other bands of showers and thunderstorms were developing around Tropical Storm Man-yi.  Storms near the center of circulation were generating upper level divergence which was pumping mass away to the west of the tropical storm.

Tropical Storm Man-yi will move through an environment favorable for intensification.  Man-yi 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, but the shear will not be strong enough to prevent intensification.  Tropical Storm Man-yi will intensify and it could strengthen into a typhoon in a day or two.

The upper level ridge will steer Tropical Storm Man-yi toward the west-northwest during the next 12 to 24 hours.  A weakness is forecast to develop in the ridge, which would allow Man-yi to move more toward the northwest.  On its anticipated track Tropical Storm Man-yi will move near Chuuk in 12 to 24 hours.  It will bring gusty winds and drop heavy rain.  Man-yi could be southeast of Guam in 36 to 48 hours.

Elsewhere over the Western North Pacific Ocean Tropical Depression 33W was dropping rain over parts of the central Philippines and Tropical Depression Toraji was moving over the Gulf of Thailand.  At 4:00 a.m. EST on Tuesday the center of Tropical Depression 33W was located at latitude 10.9°N and longitude 126.8°E which put it about 160 miles (260 km) east-southeast of Tacloban, Philippines.  It was moving toward the west-northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 35 m.p.h. (55 km/h) and there were wind gusts to 45 m.p.h. (75 km/h).  The minimum surface pressure was 1004 mb.

At 4:00 a.m. EDT the center of Tropical Depression Toraji was located at latitude 8.1°N and longitude 101.1°E which put it about 100 miles (160 km) east of Hua Sai, Malaysia.  Toraji was moving toward the west-southwest at 5 m.p.h. (8 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 1002 mb.

Dangerous Typhoon Yutu Slams Tinian and Saipan

Dangerous Typhoon Yutu slammed Tinian and Saipan on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Typhoon Yutu was located at latitude 15.5°N and longitude 144.8°E which put it about 35 miles (55 km) west-northwest of Saipan.  Yutu was moving toward the northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 175 m.p.h. (280 km/h) and there were wind gusts to 205 m.p.h. (330 km/h).  The minimum surface pressure was 908 mb.

Typhoon Warnings were in effect for Rota, Tinian and Saipan.  Tropical Storm Warnings were in effect for Guam, Alamagan, Pagan and Agrihan.

The eye of Typhoon Yutu passed directly over Tinian on Wednesday and the northern side of the eyewall moved over Saipan.  So, they would have experienced the strongest parts of Typhoon Yutu.  The Hurricane Intensity Index (HII) for Typhoon Yutu is 40.4.  The Hurricane Size Index (HSI) is 26.7 and the Hurricane Wind Intensity Size Index (HWISI) is 67.1.  Typhoon Yutu was capable of causing widespread catastrophic damage when it passed over Tinian and Saipan.

Yutu is still a very powerful typhoon, but an eyewall replacement cycle appears to have started.  A rainband has wrapped around the original eye and eyewall.  The inner eye and eyewall are still intact and the strongest winds are occurring in the ring of thunderstorms that surround the original eye.  The imminent formation of a second, outer eyewall increased the size of the circulation around Typhoon Yutu.  Winds to typhoon force extend out about 70 miles (110 km) from the center of circulation.  Winds to tropical storm force extend out about 240 miles (390 km) from the center.

Typhoon Yutu will remain in an environment capable of supporting a very strong typhoon for several more days.  Yutu will move over water where the Sea Surface Temperature is near 31°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  The incipient eyewall replacement cycle will cause Typhoon Yutu to weaken when the inner eyewall dissipates.  However, Yutu could strengthen again, if it remains in a favorable environment and the outer eyewall contracts closer to the center of circulation.  Typhoon Yutu is likely to remain a powerful typhoon during the next 48 hours.

Typhoon Yutu will move southwest of a ridge of high pressure over the Western North Pacific Ocean.  The ridge will steer Yutu toward the west-northwest during the next several days.  On its anticipated track Typhoon Yutu will move away from the Northern Marianas, and conditions should gradually improve there.  Yutu could be south of Okinawa in four or five days.

Typhoon Yutu Intensifies Rapidly to Equivalent of Cat. 4 Hurricane, Imminent Threat to Marianas

Typhoon Yutu intensified rapidly on Tuesday into the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale and Yutu posed an imminent threat to the Marianas.  At 11:00 p.m. EDT on Tuesday the center of Typhoon Yutu was located at latitude 13.6°N and longitude 147.5°E which put it about 155 miles (255 km) east-southeast of Rota.  Yutu 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 935 mb.

Typhoon Warnings are in effect for Rota, Saipan and Tinian.  Tropical Storm Warnings are in effect for Guam, Alamagan, Pagan and Agrihan.

Typhoon Yutu intensified rapidly during the past 24 hours.  A circular eye developed at the center of Yutu.  The eye is surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Numerous bands of showers and thunderstorms were revolving around the core of Typhoon Yutu.  Storms near the core were generating strong upper level divergence which was pumping mass away from the typhoon in all directions.  The removal of mass allowed the surface pressure to decrease rapidly.

Typhoon Yutu has a large circulation.  Winds to typhoon force extend out about 65 miles (105 km) from the center of circulation.  Winds to tropical storm force extend out about 210 miles (335 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Yutu is 31.6.  The Hurricane Size Index (HSI) is 20.8 and the Hurricane Wind Intensity Size index (HWISI) is 52.4.  Typhoon Yutu is capable of causing widespread extensive damage.

Typhoon Yutu will move through an environment favorable for further intensification during the next several days.  Yutu will move over water where the Sea Surface Temperature is near 31°C.  It will move through a region where the upper level winds are weak and there is little vertical wind shear.  Typhoon Yutu could intensify into the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale.  At some point a rainband will wrap around the existing eye and eyewall, and an eyewall replacement cycle will occur.  Yutu will weaken during the eyewall replacement cycle, but the typhoon could strengthen afterwards if it remains in an environment favorable for intensification.

Typhoon Yutu will move around the southwestern portion of a ridge of high pressure over the Western North Pacific Ocean.  The ridge will steer Yutu in a general west-northwesterly direction.  On its anticipated track Typhoon Yutu will reach the Northern Marianas in about 12 hours.  The core of Yutu will pass between Rota and Tinian.  Rota, Tinian and Saipan are likly to have winds to typhoon force.  Typhoon Yutu will be capable of causing extensive damage in those locations.  Guam, Alamagan, Pagan and Agrihan are likely to receive winds to tropical storm force.  Wind speeds will be stronger on the northern part of Guam and the damage potential is greater there than it is for the southern part of Guam.

Yutu Strengthens Into a Typhoon East of the Marianas

Former Tropical Storm Yutu strengthened into a typhoon east of the Marianas on Monday evening.  At 11:00 p.m. EDT on Monday the center of Typhoon Yutu was located at latitude 11.8°N and longitude 151.2°E which put it about 475 miles (770 km) east-southeast of Guam.  Yutu 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 975 mb.

A Typhoon Warning was in effect for Tinian and Saipan.  A Tropical Storm Warning was in effect for Rota.  Tropical Storm Watches were in effect for Guam, Alamagan, Pagan and Agrihan.

The circulation around Typhoon Yutu became better organized on Monday.  An inner rainband wrapped around the northern and western sides of the center of circulation.  A partial eyewall appeared to be forming.  Several bands of showers and thunderstorms were revolving around the center of Typhoon Yutu.  The strongest thunderstorms were developing in the bands in the eastern half of the circulation.  There were thunderstorms in bands in the western side of Typhoon Yutu, but those bands consisted primarily of showers and lower clouds.  Winds to typhoon force extended out about 60 miles (95 km) from center center of circulation.  Winds to tropical storm force extended out about 160 miles (260 km) from the center.

Typhoon Yutu will move through an environment favorable for intensification during the next two or three days.  Yutu will move over water where the Sea Surface Temperature is near 30°C.  It will move through an environment where the upper level winds are weak and there will be little vertical wind shear.  Yutu will continue to intensify and it could strengthen into the equivalent of a major hurricane in a day or two.

Typhoon Yutu will move around the southwestern portion of an ridge of high pressure over the Western North Pacific Ocean.  The ridge will steer Typhoon Yutu toward the west-northwest during the next few days.  On its anticipated track Typhoon Yutu will move over the Northern Marianas in about 36 to 48 hours.  Yutu will be a typhoon when it reaches the Marianas.  It will bring strong winds and it could be capable of causing major damage.

Tropical Storm Yutu Forms Southeast of the Marianas

Tropical Storm Yutu formed southeast of the Marianas on Sunday.  At 5:00 p.m. EDT on Sunday the center of Tropical Storm Yutu was located at latitude 8.7°N and longitude 156.4°E which put it about 880 miles (1420 km) east-southeast of Guam.  Yutu was moving toward the west-northwest 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 1002 mb.

A distinct low level center of circulation developed in an area or thunderstorms northeast of Chuuk and the Japan Meteorological Agency designated the system as Tropical Storm Yutu.  The circulation around Yutu was organizing quickly.  An inner band of showers and thunderstorms was wrapping around the center of circulation.  Other bands of showers and thunderstorms were forming and they were starting to revolving around the center.  Storms near the center were producing upper level divergence which was pumping mass away from the tropical storm.

Tropical Storm Yutu will be moving through an environment that is very favorable for intensification.  Yutu will move over water where the Sea Surface Temperature is near 30°C.  It will move through an environment where the upper level winds are weak and there will little vertical wind shear.  Tropical Storm Yutu could strengthen into a typhoon within 36 hours and it could rapidly intensify into the equivalent of a major hurricane within three or four days.

Tropical Storm Yutu will move around the western end of a subtropical ridge over the Western North Pacific Ocean during the next few days.  The ridge will steer Yutu toward the northwest during the next two or three days.  On its anticipated track Yutu will approach the Marianas in about three days.  It will likely be a typhoon by that time.