Tag Archives: Marianas

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.

Tropical Storm Mindulle Forms Northwest of Guam

A smaller center of circulation consolidated within a much larger cyclonic gyre that extends from the Marianas north to Japan and west to China and the system has been designated Tropical Storm Mindulle.  At 11:00 a.m. EDT on Friday the center of Tropical Storm Mindulle was located at latitude 19.5°N and longitude 141.0°E which put it about 410 miles (655 km) south of Iwo To.  Mindule was moving toward the north-northwest at 11 m.p.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 992 mb.

The circulation around Tropical Storm Mindulle is still organizing.  A primary rainband is wrapping about three quarters of the way around the broad center of circulation.  There are few thunderstorms close to the core of tropical storm.  Scattered thunderstorms are forming in broken bands outside the primary rainband.  The thunderstorms in the primary rainband are generating some upper level divergence which is mainly pumping mass to the southwest of the center of circulation.

Tropical Storm Mindulle is in an environment that is favorable for slow intensification.  It is moving over water where the Sea Surface Temperature is near 31°C.  The upper level pattern near Mindulle is quite complex with a number of different features.  A narrow upper level ridge is just north of Mindulle and it is producing northeasterly winds that are blowing across the top of the tropical storm.  The northeasterly winds are contributing to the fact that most of the thunderstorms are west of the center of circulation and they are causing moderate vertical wind shear.  The vertical wind shear is inhibiting intensification.  Tropical Storm Mindulle is expected to extract enough energy from the ocean to intensify.  However, intensification will be slow while the core of the circulation organizes.

Tropical Storm Mindule is moving around the eastern portion of the large cyclonic gyre mentioned above.  That gyre is steering Mindulle toward the north-northwest and a general motion toward the north is expected to continue.  On its anticipated track Tropical Storm Mindulle could pass near Iwo To in about 24 hours.  Mindulle could be near Tokyo, Japan in about three days.

Tropical Storm Omais Forms over the Northern Marianas

A very broad area of low pressure developed enough of the characteristics of a tropical cyclone to be classified as Tropical Storm Omais on Thursday.  At 11:00 p.m. EDT on Thursday the center of Tropical Storm Omais was located at latitude 19.5°N and longitude 146.2°E which put it about 380 miles (615 km) north-northeast of Guam.  Omais was moving toward the north at 3 m.p.h. (5 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 996 mb.

The circulation of Tropical Storm Omais is not well organized.  Several clusters of thunderstorms exist about 100 miles (160 km) east and south of the center of the very broad low pressure system.  No thunderstorms are occurring in the western half of the low or near the center of the circulation.  An inner core does not exist at this time and the strongest winds are occurring in the clusters of thunderstorms well removed from the center.

Tropical Storm Omais is in an environment that is favorable for intensification.  It is moving over water where the Sea Surface Temperature is near 30°C.  The upper level environment is also somewhat favorable for intensification.  An upper level low is northwest of Omais and an upper level ridge is east of the tropical storm.  Those two features are generating southwesterly winds which are blowing over the top of Tropical Storm Omais.  The vertical wind shear is inhibiting the organization and intensification of Omais.

The environment should allow Tropical Storm Omais to intensify, but the large circulation will reduce the rate of intensification.  As the wind field contracts and the strongest winds move closer to the center of circulation, the structure of Tropical Storm Omais will move closely resemble a typical tropical cyclone.  When an inner core forms at the center of circulation, the rate of intensification may increase.

Tropical Storm Omais is near the western end of a subtropical ridge.  The steering currents are weak, but Omais is likely to move slowly toward the north in the short term.  A faster motion is expected over the weekend.  On its anticipated track Tropical Storm Omais will move near the northernmost Marianas and pass east of Iwo To.

In-Fa Intensifies Back Into a Typhoon and a Tropical Storm Warning Is Issued for Guam

In-Fa intensified rapidly back into a typhoon on Thursday and a Tropical Storm Warning was issued for Guam.  At 10:00 p.m. EDT on Thursday the center of Typhoon In-Fa was located at latitude 10.1°N and longitude 148.1°E which put it about 365 miles (590 km) southeast of Guam.  In-Fa was moving toward the west-northwest at 10 m.p.h. (16 km/h).  The maximum sustained wind speed was 105 m.p.h. (170 km/h) and there were gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 954 mb.

After weakening slightly on Wednesday, In-Fa intensified rapidly back into a typhoon on Thursday.  Typhoon In-Fa has a compact tightly wound structure with a small inner core and a tiny pinhole eye.  The strongest winds are contained in the ring of thunderstorms around the pinhole eye.  Many of the strongest thunderstorms outside the eyewall are located southwest of the eye, but there are spiral bands in all quadrants of the storm.  The storms around the core of Typhoon In-Fa are generating upper level divergence in all directions.

Typhoon In-Fa is an environment favorable for intensification.  It is over water where the Sea Surface Temperature is near 29°C.  The upper level winds around In-Fa are light and there is not much vertical wind shear.  In-Fa is likely to intensify more during the next day or two.

A subtropical ridge north of In-Fa is steering the typhoon to the west-northwest and that general motion is expected to continue for another 48 hours.  On its anticipated track the center of In-Fa is likely to pass about 100 miles (160 km) to 150 miles (240 km) south of Guam in about 18 to 24 hours.  The center of Typhoon In-Fa is likely to pass about 200 miles (320 km) northeast of Yap in about 48 hours.

Tropical Storm In-Fa Near Fananu, Watch Issued for Guam

Tropical Storm In-Fa is near Fananu and it is bringing wind and rain to islands around Chuuk.  At 10:00 p.m. EST on Wednesday the center of Tropical Storm In-Fa was located near latitude 8.6°N and longitude 152.0°E which put it about 25 miles (40 km) southeast of Fananu and about 620 miles (1000 km) southeast of Guam.  In-Fa was moving toward the northwest at 15 m.p.h. (24 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 982 mb.

A Tropical Storm Watch has been issued for Guam.  A Typhoon Warning is in effect for Chuuk lagoon, Losap, Ulul and Fananu.

In-Fa was briefly a typhoon earlier on Wednesday when it had a small, but well formed eye.  However, the core of In-Fa weakened slightly and the eye filled with clouds.  A small, but circular, area of thunderstorms has intensified in the core of the tropical storm during the past few hours.  There are signs that In-Fa may be strengthening again.  The environment surrounding Tropical Storm In-Fa is favorable for intensification.  It is over water where the Sea Surface Temperature is near 29.5°C.  The upper level winds are light and the vertical wind shear is modest.  In-Fa could regain typhoon intensity on Thursday and a period of rapid intensification may be possible once the inner core reorganizes.

A subtropical ridge north of In-Fa is steering the tropical storm toward the northwest and that general motion is expected to continue for another two or three days.  On its anticipated track the center of In-Fa will pass near Fananu during the next few hours.  In-Fa could be south of Guam in about 48 hours.

Tropical Storm In-Fa Intensifying, Typhoon Watch for Fananu

Tropical Storm In-Fa intensified quickly on Tuesday and it caused watches and warnings to be issued for the area around Chuuk.  At 10:00 p.m. EST on Tuesday the center of Tropical Storm In-Fa was located at latitude 6.0°N and longitude 156.3°E which put it about 385 miles (620 km) east-southeast of Fananu and about 985 miles (1590 km) east-southeast of Guam.  In-Fa was moving toward the west-northwest 18 m.p.h. (29 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 983 mb.  A Typhoon Watch has been issued for Fananu.

The circulation of Tropical Storm In-Fa organized rapidly on Tuesday.  A tight core formed in the center of circulation and an eyelike feature appeared on satellite images.  A small ring of thunderstorms formed around the eye and a large primary rainband wrapped around the circulation.  The circulation became more symmetrical and upper level outflow began to create divergence in most directions.

Tropical Storm In-Fa remains in an environment favorable for intensification.  It is over water where the Sea Surface Temperature is near 30°C.   The upper level winds are light and the vertical wind shear is modest.  In-Fa is likely to continue to intensify and now that an inner core has developed, it could intensify rapidly.  In-Fa could become a typhoon on Wednesday and it could become the equivalent of a major hurricane later this week.

A subtropical ridge north of In-Fa is steering the tropical storm toward the west-northwest and that general motion is expected to continue for the rest of the week.  On its anticipated track In-Fa will approach Fananu in about 24 hours and it could be a typhoon at that time.  In-Fa could be approaching Guam in about three days as a typhoon.

Tropical Storm Krovanh Organizing Quickly Near Northern Marianas

The circulation around Tropical Storm Krovanh is organizing quickly as it passes near the northern Marianas.  At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Krovanh was located at latitude 19.3°N and longitude 148.1°E which put it about 170 miles (275 km) east-northeast of Agrihan in the northern Mariana Islands.  Krovanh was moving toward the northwest at 11 m.p.h. (18 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.  A Tropical Storm Watch has been issued for Alamagan, Pagan and Agrihan in the northern Marianas.

The circulation near the center of Krovanh organized quickly on Tuesday.  A primary spiral rainband wrapped around the southern side of the center and an eyelike feature has appeared intermittently on visible satellite imagery.  Additional rainbands are developing around the circulation.  The thunderstorms near the core of the tropical storm are producing upper level outflow in all directions which is pumping out mass and is allowing the surface pressure to decrease.

Tropical Storm Krovanh is moving over water where the Sea Surface Temperature is near 30°C.  Upper levels winds are light and there is little vertical wind shear.  The environment is very favorable for further intensification and rapid intensification is likely.  Krovanh could become a typhoon within 24 hours and it could be a strong typhoon within several days.

A subtropical ridge located northeast of Krovanh is steering the tropical storm toward the northwest.  That general steering pattern is expected to continue for the next 48 hours.  After that time Krovanh will reach the western end of the subtropical ridge and it will turn toward the north.  On its anticipated track Krovanh will pass through the extreme northern Marianas on Wednesday and it be approaching Iwo To in about 48 hours.  Krovanh could be a strong typhoon at that time.