Tag Archives: Marianas

Tropical Storm Trami Develops West of the Marianas

Tropical Storm Trami developed west of the Marianas on Friday.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Trami was located at latitude 16.2°N and longitude 140.8°E which put it about 285 miles (460 km) northwest of Guam.  Trami was moving toward the west-northwest 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 993 mb.

The circulation around former Tropical Depression 28W strengthened on Friday and the Japan Meteorological Agency designated the system as Tropical Storm Trami.  An inner band of thunderstorms wrapped tightly around the northern and western sides of the center of circulation.  Several other bands of showers and thunderstorms in the eastern half of the circulation were revolving around the core of Tropical Storm Trami.  Bands in the western half of the circulation consisted primarily of showers and lower clouds.  Storms near the core of Trami were generating upper level divergence which was pumping mass away from the tropical storm.

Tropical Storm Trami will be moving through an environment favorable for intensification.  Trami will move over water where the Sea Surface Temperature is near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Trami will continue to intensify and it could become a typhoon during the next 24 hours.  A period of rapid intensification is possible once the inner core is fully developed.  Tropical Storm Trami could become the equivalent of a major hurricane during the next few days.

Tropical Storm Trami will continue to move south of a subtropical ridge over the Western North Pacific Ocean.  The ridge will steer Trami in a general west-northwesterly direction.  On its anticipated track Trami could be southeast of Okinawa and the Ryukyu Islands in four or five days.  It could be a powerful typhoon at 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 Strengthens to Equivalent of a Major Hurricane

Typhoon Mangkhut strengthened into the equivalent of a major hurricane as it moved west of Guam on Monday.  At 11:00 p.m. EDT on Monday the center of Typhoon Mangkhut was located at latitude 14.0°N and longitude 140.6°E which put it about 230 miles (375 km) west of Guam.  Mangkhut was moving toward the west at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 140 m.p.h. (225 km/h) and there were wind gusts to 165 m.p.h. (270 km/h).  The minimum surface pressure was 939 mb.  Typhoon Mangkhut was the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale.

Typhoon Mangkhut intensified rapidly on Monday.  A circular eye was at the center of circulation.  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 around the core were generating upper level divergence which was pumping mass away from the typhoon.

Winds to typhoon force extended out about 50 miles (80 km) from the center of circulation.  Winds to tropical storm force extended out about 210 miles (335 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Mangkhut was 28.2.  The Hurricane Size Index (HSI) was 18.9 and the Hurricane Wind Intensity Size Index (HWISI) was 47.1.

Typhoon Mangkhut will move through an environment capable of supporting very strong typhoons during the next two or three days.  Mangkhut will move over water where the Sea Surface Temperature is near 30°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Mangkhut is likely to remain very strong for the next few days.  Eyewall replacement cycles could cause fluctuations in intensity.

Typhoon Mangkhut will move south of a ridge over the Western North Pacific Ocean.  The ridge will steer Mangkhut to the west during the next day or two.  Typhoon Mangkhut will move more toward the west-northwest later this week.  On its anticipated track Typhoon Mangkhut could be near northern Luzon in about four days.

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 Mangkhut Develops Eastof the Marianas

Tropical Storm Mangkhut developed east of the Marianas on Friday.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Mangkhut was located at latitude 13.1°N and longitude 163.2°E which put it about 1275 miles (2060 km) east of Guam.  Mangkhut was moving toward the west at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and three were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 998 mb.

A distinct center of circulation formed in a cluster of thunderstorms east of the Marianas and the Japan Meteorological Agency designated the system as Tropical Storm Mangkhut.  The circulation of Mangkhut was still organizing.  Bands of showers and thunderstorms were developing around Tropical Storm Mangkhut.  There were more thunderstorms on the western side of the circulation.  An upper level ridge north of Mangkhut was producing easterly winds which were blowing toward the top of the circulation.  Those winds were probably the reason why more of the thunderstorms were west of the center of circulation.

Tropical Storm Mangkhut will be moving through an environment favorable for intensification.  Mangkhut will move over water where the Sea Surface Temperature is near 30°C.  It will move south of the upper level ridge, which will cause some vertical wind shear.  However, the shear is not likely to be strong enough to prevent intensification.  Tropical Storm Mangkhut could strengthen into a typhoon by the end of the weekend.

Tropical Storm Mangkhut will move south of a subtropical ridge over the Western North Pacific Ocean.  The ridge will steer Mangkhut in a general westerly direction.  On its anticipated track Mangkhut could approach the Marianas in about 72 hours.  It is likely to be a typhoon at that time.

Typhoon Jebi Intensifies Rapidly East of Northern Marianas

Typhoon Jebi intensified rapidly east of the Northern Marianas on Wednesday.  At 5:00 p.m. EDT on Wednesday the center of Typhoon Jebi was located at latitude 17.5°N and longitude 149.8°E which put it about 270 miles (435 km) east of Pagan.  Jebi 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.  A Typhoon Warning was in effect for Agrihan, Pagan and Alamagan in the Northern Marianas.

The circulation of Typhoon Jebi was very well organized and it was symmetrical.  A small circular eye formed at the center of circulation.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Several bands of thunderstorms were revolving around the core of Typhoon Jebi.  Storms around the core were generating strong upper level divergence which was pumping large quantities of mass away from the typhoon.  Winds to typhoon force extended out about 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out about 100 miles (160 km) from the center.

Typhoon Jebi will be moving through an environment very favorable for further intensification.  Jebi 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.  Jebi is likely to intensify into the equivalent of a major hurricane on Thursday.

Typhoon Jebi will move south of a subtropical ridge over the Western North Pacific for several more days.  The ridge will steer Jebi in a general westerly direction during that time.  Typhoon Jebi will reach the western end of the ridge in about 48 hours.  Jebi will make a gradual turn toward the north when it reaches the end of the ridge.  On its anticipated track Typhoon Jebi will reach the northernmost Mariana Islands within 24 hours.  Jebi will be capable of causing major damage when it arrives.  Jebi is forecast to pass south of Iwo To, but it will turn toward the major islands of Japan during the weekend.

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 Jelawat Strengthens West-Northwest of Guam

Former Tropical Storm Jelawat strengthened into a typhoon as it moved west-northwest of Guam on Thursday.  At 11:00 p.m. EDT on Thursday the center of Typhoon Jelawat was located at latitude 15.9°N and longitude 137.7°E which put it about 520 miles (840 km) west-northwest of Guam.  Jelawat was moving toward the east-northeast at 7 m.p.h. (11 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 972 mb.

Typhoon Jelawat strengthened quickly on Thursday night.  A small eye developed at the center of circulation.  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 Jelawat.  Storms in the core of the circulation were generating upper level divergence which was pumping mass away to the northeast of 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 145 miles (230 km) from the center.

Typhoon Jelawat will move through an area favorable for intensification on Friday.  Jelawat will move over water where the Sea Surface Temperature is near 28°C.  Typhoon Jelawat has moved around the western end of an upper level ridge which is producing southwesterly winds which are blowing toward the top of the circulation.  Those winds are producing some vertical wind shear, but the wind shear is not strong enough to prevent intensification.   Typhoon Jelwat is likely to intensify further on Friday.

The upper level ridge is steering Typhoon Jelawat toward the east-northeast and that general motion is expected to continue for several more days.  On its anticipated track Typhoon Jelawat is expected to pass northwest of Guam.  Jelawat could approach the northernmost islands in the Marianas in about two or three days.

Tropical Storm Chaba Forms East of Guam

A center of circulation developed within an area of thunderstorms east of Guam on Tuesday and the Japan Meteorological Agency designated the system as Tropical Storm Chaba.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Chaba was located at latitude 14.2°N and longitude 147.7°E which put it about 225 miles (360 km) east of Guam.  Chaba was moving toward the west at 17 m.p.h. (27 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 of Tropical Storm Chaba is still organizing.  The distribution of thunderstorms is asymmetrical.  There are more thunderstorms east of the center of circulation.  Additional thunderstorms are forming west of the center of circulation and some rainbands are developing.  The thunderstorms near the center of Tropical Storm Chaba are generating upper level divergence which is pumping mass out in all directions.

Tropical Storm Chaba is moving through an environment that is favorable for intensification.  It is moving over water where the Sea Surface Temperature is near 30°C.  The upper level winds are light and there is not significant vertical wind shear.  Tropical Storm Chaba is likely to continue to intensify as the circulation gets better organized.  Chaba could become a typhoon later this week.

A subtropical ridge to the north of Chaba is steering the tropical storm toward the west and that general motion is expected to continue for another 24 to 36 hours.  When Tropical Storm Chaba moves farther west, it will get closer to the western end of the subtropical ridge and Chaba is likely to turn more toward the west-northwest.  On its anticipated track Tropical Storm Chaba will move through the Marianas between Guam and Saipan and Tinian on Wednesday.  Chaba could be approaching Okinawa in about five days.