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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.

Tropical Depression 28W Forms Over the Marianas

Tropical Depression 28W formed over the Mariana Islands on Thursday.  At 5:00 p.m. EDT on Thursday the center of Tropical Depression 28W was located at latitude 14.1°N and longitude 144.8°E which put it about 15 miles (25 km) east-northeast of Guam.  It was moving toward the northwest at 10 m.p.h. (16 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 1002 mb.  Tropical Storm Watches were issued for Rota, Saipan and Tinian.

Tropical Depression 28W was still organizing on Thursday.  A distinct center of circulation formed in an area of thunderstorms near the Marianas.  Bands of showers and thunderstorms developed around the circulation.  The strongest rainbands were forming in the eastern half of the circulation.  Bands of showers and thunderstorms were also forming in the western half of the circulation but there were fewer strong thunderstorms in that half of the tropical depression.  Storm closer to the center of circulation were starting to generate upper level divergence which was pumping mass away from the depression.

Tropical Depression 28W will move through an environment favorable for intensification.  It will move over water where the Sea Surface Temperature is near 30°C.  The tropical depression will move through an area where the upper level winds are weak and there will be little vertical wind shear.  Tropical Depression 28W will intensify during the next few days.  It is likely to strengthen into a tropical storm on Friday and it could intensify into a typhoon during the weekend.

Tropical Depression 28W will move around the southern side of a subtropical ridge over the Western North Pacific Ocean during the next several days.  The ridge will steer the depression in a general west-northwesterly direction.  On its anticipated track the depression could be southeast of Okinawa in four or five days and it is likely to be a typhoon at that time.

Typhoon Mangkhut Brings Wind and Rain to the Marianas

Typhoon Mangkhut brought wind and rain to the Marianas on Sunday night.  At 11:00 p.m. EDT on Sunday the center of Typhoon Mangkhut was located at latitude 14.4°N and longitude 146.6°E which put it about 175 miles (285 km) east-northeast of Guam.  Mangkhut was moving toward the west at 19 m.p.h. (31 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 955 mb.  Typhoon Warnings were in effect for Saipan, Tinian, Rota and Guam.  The airport on Saipan was reporting sustained winds of 41 m.p.h. (66 km/h) and wind gusts to 61 m.p.h. (98 km/h).

Typhoon Mangkhut had a well organized circulation.  There was a circular eye at the center of Mangkhut.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Several bands of showers and thunderstorms were revolving around the core of Typhoon Mangkhut.  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 150 miles (240 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Mangkhut was 13.9.  The Hurricane Size Index (HSI) was 13.5 and the Hurricane Wind Intensity Size Index was 27.4.  Typhoon Mangkhut was capable of causing regional significant damage.

Typhoon Mangkhut will move through an environment favorable for intensification.  Mangkhut will move over water where the Sea Surface Temperature is near 30°C.  An upper level ridge north of Mangkhut will cause 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.  Typhoon Mangkhut could intensify into the equivalent of a major hurricane later this week.

The ridge north of Typhoon Mangkhut will steer the typhoon in a westerly direction.  The core of Typhoon Mangkhut will move over the Marianas during the next few hours.  It will bring strong winds and it will drop locally heavy rain.  On its anticipated track Typhoon Mangkhut could be east of Luzon later this week.

Tropical Storm Mangkhut Causes Typhoon Watch for Marianas

Tropical Storm Mangkhut caused a Typhoon Watch to be issued for the Marianas on Saturday.  A Typhoon Watch was in effect for Guam, Rota, Saipan and Tinian.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Mangkhut was located at latitude 14.9°N and longitude 156.0°E which put it about 760 miles (1225 km) east of Guam.  Mangkhut was moving toward the west at 24 m.p.h. (39 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 983 mb.

The circulation of Tropical Storm Mangkhut became much better organized on Saturday despite its rapid westward movement.  A primary band of thunderstorms wrapped around the southern side of the center of circulation and an eye appeared to be forming.  Winds near the core of Mangkhut were generating upper level divergence which was pumping mass away from the tropical storm.  Several other bands of showers and thunderstorms were revolving around the core of Tropical Storm Mangkhut.  The strongest rainbands were in the western half of the circulation.  Bands in the eastern half of the tropical storm consisted primarily of showers and lower clouds.  An upper level ridge north of Mangkhut was producing easterly winds which were blowing toward the top of the circulation.  Those winds were causing vertical wind shear and they were probably the reason why the strongest rainbands were west of the center of circulation.

Tropical Storm Mangkhut will move through an environment favorable for intensification.  Mangkhut will move over water where the Sea Surface Temperature is near 30°C.  It will move into an area where the upper level winds are weaker and there will be less vertical wind shear.  Tropical Storm Mangkhut will intensify into a typhoon on Sunday and it could intensify rapidly once the inner core and eye are fully formed.

Tropical Storm Mangkhut will move south of a ridge over the Western North Pacific Ocean.  The ridge will steer Mangkhut in a general westerly direction during the next few days.  On its anticipated track Tropical Storm Mangkhut could reach the Marianas in about 36 hours.  It is likely to be a typhoon at that time.  Mangkhut could bring strong winds and locally heavy rain to Guam, Rota, Saipan and Tinian.

Tropical Storm Jebi Forms East of the Marianas

Tropical Storm Jebi formed east of the Marianas on Monday.  At 11:00 p.m. EDT on Monday the center of Tropical Storm Jebi was located at latitude 15.8°N and longitude 156.6°E which put it about 745 miles (1200 km) east of Saipan.  Jebi was moving toward the northwest at 17 m.p.h. (28 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 1004 mb.

A distinct low level center of circulation developed in a cluster of showers and thunderstorms east of the Northern Marianas and the Japan Meteorological Agency designated the system as Tropical Storm Jebi.  The circulation of Jebi was still organizing.  A primary rainband wrapped around the eastern and northern sides of the center of circulation.  Other bands of showers and thunderstorms were developing in the eastern half of the circulation.  Storms near the center started to generate upper level divergence.

Tropical Storm Jebi will move through an environment favorable for intensification during the next several days.  Jebi will move over water where the Sea Surface Temperature is near 29°C.  It will move under the western end of an upper level ridge.  The ridge will produce southerly winds which will cause some vertical wind shear.  Two upper level lows northwest and northeast of Jebi will enhance upper level divergence to the north of the tropical storm.  Tropical Storm Jebi will strengthen and it could become a typhoon later this week.

Tropical Storm Jebi will move southwest of a ridge over the Western North Pacific Ocean.  The ridge is forecast to strengthen and it will steer Jebi in a general west-northwesterly direction during the next several days.  On its anticipated track Tropical Storm Jebi could be near the northernmost Mariana Islands in about three days.  Jebi could be a typhoon by that time.  Jebi could be south of Iwo To by the end of the week.

Typhoon Soulik Moves Toward Ryukyu Islands, Cimaron Approaches Northern Marianas

Typhoon Soulik moved toward the northern Ryukyu Islands on Sunday and Typhoon Cimaron approached the Northern Mariana Islands.  At 11:00 p.m. EDT on Sunday the center of Typhoon Soulik was located at latitude 25.9°N and longitude 135.8°E which put it about 450 miles (730 km) east-southeast of Yaku Shima.  Soulik was moving toward the west at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 105 m.p.h. (170 km/h) and there were wind gusts to 125 m.p.h. (205 km/h).  The minimum surface pressure was 959 mb.

The structure of Typhoon Soulik changed on Sunday.  A large circular eye with a diameter or 45 miles (75 km) developed at the center of circulation.  A circular ring of thunderstorms surrounded the eye.  The ring was thinner on the western side of the eye and there may have been breaks in the ring.  Several bands of thunderstorms were revolving around the core of Typhoon Soulik.  Storms around the core were generating strong upper level divergence which was pumping mass away from the typhoon.  Winds to typhoon force extended out about 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out about 195 miles (315 km) from the center.

Typhoon Soulik will move through an environment that should allow it to maintain its intensity for another day or two.  Soulik will move over water where the Sea Surface Temperature is near 29°C.  An upper level ridge north of Japan will produce easterly winds that will blow toward the top of the typhoon, but the winds will not cause significant vertical wind shear.  Typhoon Soulik could weaken a little, but it is likely to maintain most of its strength for another 24 to 48 hours.

Typhoon Soulik will move around the western end of the ridge north of Japan.  The ridge will steer Soulik toward the northwest for another 36 to 48 hours.  When Soulik reaches the western end of the ridge, it will turn toward the north.  On its anticipated track Typhoon Soulik could reach the northern Ryukyu Islands in about 36 hours.

At 11:00 p.m. EDT on Sunday the center of Typhoon Cimaron was located at latitude 17.3°N and longitude 148.5°E which put it about 240 miles (390 km) east-northeast of Saipan.  Cimaron was moving toward the west-northwest 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 978 mb.  A Typhoon Warning was in effect for Agrihan, Pagan, Almagan.  A Tropical Storm Warning was in effect for Saipan and Tinian.

Typhoon Cimaron will move through an environment that could allow it to intensify during the next several days.  Cimaron will move over water where the Sea Surface Temperature is near 28°C.  Upper level divergence from Typhoon Soulik could inhibit the divergence generated by Cimaron on the northern side of the circulation.  Typhoon Cimaron is likely to intensify during the next day or two,

Typhoon Cimaron will move around the western end of a subtropical ridge.  The ridge will steer Cimaron toward the northwest during the next two or three days.  On its anticipated track Typhoon Cimaron will move over the Northern Marianas during the next 12 to 18 hours.  Cimaron could reach Iwo To within 48 hours and it could be south of Honshu in about three days.

Tropical Storm Cimaron Prompts Warnings for Northern Marianas, Soulik Strengthens West of Iwo To

Tropical Storm Cimaron developed east of the Northern Marianas on Saturday and it prompted Typhoon Warnings for some of the islands, while Typhoon Soulik strengthened west of Iwo To.  At 11:00 p.m. EDT on Saturday the center of Tropical Storm Cimaron was located at latitude 15.5°N and longitude 151.6°E which put it about 420 miles (675 km) east of Saipan.  Cimaron was moving toward the northwest 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 997 mb.  A Typhoon Warning was in effect for Agrihan, Pagan and Almagan.

A distinct center of circulation developed in an area of thunderstorms east of the Northern Marianas on Saturday and the Japan Meteorological Agency designated the system as Tropical Storm Cimaron.  Numerous bands of showers and thunderstorms developed around the circulation of Tropical Storm Cimaron.  The rainbands west and south of the center of circulation were stronger than the bands east and north of the center.  An inner bands of thunderstorms started to wrap around the south side of the center.  Storms near the center began to generate upper level divergence.

Tropical Storm Cimaron will move through an environment favorable for intensification during the next several days.  Cimaron will move over water where the Sea Surface Temperature is near 29°C.  Tropical Storm Cimaron will move through an area where it will be near the upper level divergence from Typhoon Soulik.  Tropical Storm Cimaron is forecast to stay just southeast of the divergence from Soulik.  If it does that, Cimaron will strengthen into a typhoon during the next few days.  However, if Cimaron moves under the upper level divergence from Typhoon Soulik, then the vertical wind shear will keep Cimaron from strengthening.

Typhoon Soulik strengthened into the equivalent of a major hurricane west of Iwo To on Saturday.  At 11:00 p.m. EDT on Saturday the center of Typhoon Soulik was located at latitude 25.2°N and longitude 138.8°E which put it about 145 miles (235 km) west-northwest of Iwo To.  Soulik was moving toward the west-northwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 135 m.p.h. (215 km/h).  The minimum surface pressure was 952 mb.

Typhoon Soulik is well organized.  There is a circular eye at the center of circulation.  The eye is surrounded by a ring of strong thunderstorms and the strongest winds are occurring in that ring of storms.  Several bands of showers and thunderstorms are revolving around the core of Soulik.  Storms near the core are generating strong upper level divergence which is pumping mass away in all directions.  Winds to typhoon force extend out about 50 miles (80 km) from the center of circulation.  Winds to tropical storm force extend out about 170 miles (280 km) from the center.

Typhoon Soulik will move through an area favorable for strong typhoons.  Soulik will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Soulik could maintain its intensity for another 24 to 48 hours.

Typhoon Soulik will move around the western end of a ridge in the middle troposphere.  The ridge will steer Soulik in a general northwesterly direction.  On it anticipated track Typhoon Soulik will move toward the Ryukyu Islands.  Tropical Storm Cimaron will move around the western end of a subtropical ridge over the Western North Pacific Ocean.  On its anticipated track, Cimaron will move near the northern Marianas in 24 to 36 hours.  Tropical Storm Cimaron could approach Iwo To in about three days.