Tag Archives: Marianas

Typhoon Goni Rapidly Intensifies to Equivalent of a Major Hurricane

Typhoon Goni intensified rapidly into the equivalent of a major hurricane east of the Philippines on Thursday. At 11:00 p.m. EDT on Thursday the center of Typhoon Goni was located at latitude 16.2°N and longitude 132.2°E which put it about 690 miles (1115 km) east of Luzon. Goni was moving toward the west at 7 m.p.h. (11 km/h). The maximum sustained wind speed was 145 m.p.h. (230 km/h) and there were wind gusts to 175 m.p.h. (280 km/h). The minimum surface pressure was 934 mb.

Typhoon Goni intensified rapidly on Thursday. A small circular eye with a diameter of 12 miles (19 km) was at the center of Goni. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Typhoon Goni. Storms near the core generated strong upper level divergence which pumped mass away from the typhoon. The removal of mass allowed the surface pressure to decrease quickly which contributed to the rapid increase in wind speed.

The circulation around Typhoon Goni was small. Winds to typhoon force extended out 25 miles (40 km) from the center of Goni. Winds to tropical storm force extended out 100 miles (160 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Goni was 29.9. The Hurricane Size Index (HSI) was 6.3 and the Hurricane Wind Intensity Size Index (HWISI) was 36.2.

Typhoon Goni will move through an environment favorable for intensification during the next 24 hours. Goni 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. Goni could intensify more during the next 24 hours. If the inner end of a rainband wraps around the existing eye and eyewall, then an eyewall replacement cycle could cause Goni to weaken.

Typhoon Goni will move south of a subtropical high pressure system over the Western North Pacific Ocean. The high will steer Goni toward the west. On its anticipated track Typhoon Goni will approach the coast of Luzon in about 48 hours. Goni is likely to be the equivalent of a major hurricane when it approaches Luzon.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Atsani moved south-southeast of the Marianas. At 11:00 p.m. EDT on Thursday the center of Tropical Storm Atsani was located at latitude 10.7°N and longitude 145.3°E which put it about 245 miles (400 km) south-southeast of Guam. Astani was moving toward the northwest at 18 m.p.h. (30 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. Tropical Storm Atsani was forecast to move toward the northwest and to strengthen.

Goni Rapidly Intensifies to a Typhoon, Atsani Forms

Former Tropical Storm Goni intensified rapidly into a typhoon east of the Philippines on Thursday and Tropical Storm Atsani formed south-southeast of the Marianas. At 11:00 a.m. EDT on Thursday the center of Typhoon Goni was located at latitude 16.7°N and longitude 134.1°E which put it about 820 miles (1320 km) east of Luzon. Goni was moving toward the west at 14 m.p.h. (22 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 973 mb.

Typhoon Goni intensified rapidly on Thursday. A small circular eye was at the center of Goni. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Typhoon Goni. Storms near the core generated strong upper level divergence which pumped mass away from the typhoon. The removal of mass allowed the surface pressure to decrease quickly which contributed to the rapid increase in wind speed. The circulation around Typhoon Goni was small. Winds to typhoon force extended out 20 miles (30 km) from the center of Goni. Winds to tropical storm force extended out 80 miles (130 km) from the center of circulation.

Typhoon Goni will move through an environment favorable for intensification during the next several days. Goni 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. Goni could intensify into the equivalent of a major hurricane during the next 24 hours.

Typhoon Goni will move south of a subtropical high pressure system over the Western North Pacific Ocean. The high will steer Goni toward the west. On its anticipated track Typhoon Goni will approach the coast of Luzon in about 72 hours. Goni is likely to be the equivalent of a major hurricane when it approaches Luzon.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Atsani formed south-southeast of the Marianas. At 11:00 a.m. EDT on Thursday the center of Tropical Storm Atsani was located at latitude 8.7°N and longitude 148.0°E which put it about 450 miles (720 km) south-southeast of Guam. Astani was moving toward the north-northwest at 14 m.p.h. (22 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1001 mb. Tropical Storm Atsani was forecast to move toward the northwest and to strengthen.

Tropical Storm Kammuri Forms, Warnings Issued for Marianas

Tropical Storm Kammuri formed on Monday and warnings were issued for the Marianas.  At 10:00 p.m. EST on Monday the center of Tropical Storm Kammuri was located at latitude 10.2°N and longitude 149.0°E which put it about 415 miles (665 km) southeast of Guam.  Kammuri was moving toward the west-northwest at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1000 mb.

Tropical Storm Warnings were in effect for Guam, Rota, Tinian and Saipan.

More thunderstorms formed near the center of a large low pressure system southeast of Guam on Monday and the Japan Meteorological Agency designated the system as Tropical Storm Kammuri.  The circulation around Kammuri was still organizing on Monday night.  Multiple bands of showers and thunderstorms were forming and the bands were starting to revolve around the center of circulation.  Storms near the center began to generate upper level divergence which was pumping mass away from the tropical storm in all directions.

Tropical Storm Kammuri will move through an environment favorable for intensification during the next few days.  Kammuri 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.  Tropical Storm Kammuri will continue to intensify and it could strengthen into a typhoon within 36 hours.  Kammuri could eventually intensify into the equivalent of a major hurricane.

Tropical Storm Kammuri will move south of a subtropical high pressure system over the Western North Pacific Ocean during the next two days.  The high will steer Kammuri toward the west-northwest.  On its anticipated track the center of Tropical Storm Kammuri will pass south of Guam in about 18 to 24 hours.  Kammuri could bring gusty winds and locally heavy rain.  An upper level trough will approach Tropical Storm Kammuri from the northwest in about 48 hours.  The trough will weaken the upper level ridge and the steering currents will weaken.  Kammuri could meander after the steering currents weaken.

Elsewhere, over the South Pacific Ocean Tropical Cyclone Rita was weakening northeast of Vanuatu.  At 10:00 p.m. EST on Monday the center of Tropical Cyclone Rita was located at latitude 14.3°S and longitude 170.0°E which put it about 265 miles (430 km) north-northeast of Port Vila, Vanuatu.  Rita was moving toward the south-southwest at 9 m.p.h. (15 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 990 mb.

Typhoon Fengshen Brings Wind and Rain to Northern Marianas

Typhoon Fengshen brought wind and rain to the Northern Marianas on Thursday.  At 10:00 p.m. EST on Thursday the center of Typhoon Fengshen was located at latitude 19.6°N and longitude 143.3°E which put it about 385 miles (620 km) south-southeast of Iwo To.  Fengshen was moving toward the northwest at 18 m.p.h. (30 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. (165 km/h).  The minimum surface pressure was 974 mb.

Typhoon Fengshen intensified rapidly into a typhoon on Thursday as it moved over the Northern Marianas.  Fengshen brought strong, gusty winds and heavy rain to Alamagan, Agrihan and Pagan.  There was a small circular eye at the center of Typhoon Fengshen.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Fengshen.  Storms near the core were generating upper level divergence which was pumping mass away from the typhoon.  Winds to typhoon force extended out 30 miles from the center of circulation.  Winds to tropical storm force extended out 85 miles (135 km) from the center.

Typhoon Fengshen will move through an environment favorable for intensification during the next day or so.  Fengshen 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.  Typhoon Fengshen could strengthen into the equivalent of a major hurricane on Friday.

Typhoon Fengshen will move around the western end of a ridge of high pressure over the Western North Pacific Ocean.  The ridge will steer Fengshen toward the north during the next 24 hours.  The typhoon will move toward the northeast on Saturday after it moves around the end of the ridge.  On its anticipated track Typhoon Fengshen will be south of Iwo To in about 24 hours.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Kalmaegi move closer to northern Luzon.  At 10:00 p.m. EST on Thursday the center of Tropical Storm Kalmaegi was located at latitude 16.6°N and longitude 125.0°E which put it about 250 miles (400 km) southeast of Aparri, Philippines.  Kalmaegi was moving toward the west-northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1002 mb.

Tropical Storm Fengshen Prompts Typhoon Warning for Northern Marianas

Tropical Storm Fengshen prompted the National Weather Service Office in Guam to issue a Typhoon Warning for portions of the Northern Marianas on Wednesday night.  At 10:00 a.m. EST on Wednesday the center of Tropical Storm Fengshen was located at latitude 17.2°N and longitude 149.0°E which put it about 265 miles (430 km) east of Alamagan.  Fengshen was moving toward west at 18 m.p.h. (30 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. (129 km/h).  The minimum surface pressure was 991 mb.

A Typhoon Warning was in effect for Alamagan, Pagan and Agrihan.

Tropical Storm Fengshen strengthened slowly on Wednesday, although the thunderstorm activity fluctuated during the day.  More thunderstorms developed near the center of circulation on Wednesday night.  Those thunderstorms were generating some upper level divergence which was pumping mass away to the west of the tropical storm.  The strongest rainbands were in the southern and eastern parts of Fengshen.  Bands in the northern wand western parts of the circulations consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out 100 miles (160 km) from the center of circulation.

The circulation around Tropical Storm Fengshen may have pulled drier air into the tropical storm.  The drier air may have mixed into rainbands in the northern and western parts of Fengshen and caused the thunderstorms in those parts of the tropical storm to weaken.  Tropical Storm Fengshen will move through an environment favorable for intensification during the next several days.  Fengshen will move over water where the Sea Surface Temperature is near 29°C.  It will move south of an upper level ridge centered south of Japan.  The ridge will produce northeasterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear.  The wind shear and drier air will slow the rate of intensification.  Tropical Storm Fengshen could strengthen into a typhoon within 24 hours.

The ridge south of Japan will steer Tropical Storm Fengshen toward the west for another 12 to 24 hours.  Fengshen will start to move toward the north when it reaches the western end of the ridge.  On its anticipated track Tropical Storm Fengshen could reach Alamagan, Pagan and Agrihan in about 12 hours.  Fengshen could be a typhoon at that time.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Kalmaegi moved slowly toward northern Luzon.  At 10:00 p.m. EST on Wednesday the center of Tropical Storm Kalmaegi was located at latitude 14.3°N and longitude 127.2°E which put it about 425 miles (685 km) east-southeast of Baler, Philippines.  Kalmaegi was moving toward northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 1002 mb.

Tropical Storm Kalmaegi Forms East of Luzon

Tropical Storm Kalmaegi formed east of Luzon on Tuesday night.  At 10:00 p.m. EST on Tuesday the center of Tropical Storm Kalmaegi was located at latitude 12.9°N and longitude 128.8°E which put it about 350 miles (565 km) east of Legaspi, Philippines.  Kalmaegi was moving toward the west-northwest 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 1002 mb.

The Japan Meteorological Agency determined that former Tropical Depression 27W strengthened into Tropical Storm Kalmaegi on Tuesday night.  The circulation Kalmaegi was not well organized.  There was a large, broad area of low pressure, but there were few thunderstorms near the center of circulation.  Most of the stronger thunderstorms were occurring in bands in the northwestern part of Tropical Storm Kalmaegi.  Bands in the other portions of the circulation consisted primarily of showers and lower clouds.

Tropical Storm Kalmaegi will move through an environment marginally favorable for intensification.  Kalmaegi will move over water where the Sea Surface Temperature is near 29°C.  So, there is plenty of energy in the upper layer of the Western North Pacific Ocean to support intensification.  However, Tropical Storm Kalmaegi will move around the southwestern part of an upper level ridge centered south of Japan on Wednesday.  The ridge will produce northeasterly winds which will blow across the eastern part of the tropical storm.  Those winds will cause moderate vertical wind shear and they will inhibit intensification.  In 12 to 24 hours Kalmaegi will move closer to the western end of the ridge and the upper level winds will blow from the south.  The wind shear could decrease when the wind direction changes, which may allow the tropical storm to strengthen.

The ridge south of Japan will steer Tropical Storm Kalmaegi toward the northwest during the next 48 hours.  On its anticipated track Tropical Storm Kalmaegi could approach northeastern Luzon in 48 to 72 hours.  Since the strongest thunderstorms are in the northwestern part of Kalmaegi, the tropical storm could drop locally heavy rain over Luzon even if the center does not make landfall.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Fengshen continued to organize east of the Northern Marianas.  At 10:00 p.m. EST on Tuesday the center of Tropical Storm Fengshen was located at latitude 17.4°N and longitude 155.3°E which put it about 690 miles (1115 km) east-northeast of Saipan.  Fengshen was moving toward the west-northwest at 21 m.p.h. (34 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 1002 mb.

Tropical Storm Fengshen Forms East of Northern Marianas

Tropical Storm Fengshen formed east of the Northern Marianas on Tuesday.  At 4:00 p.m. EST on Tuesday the center of Tropical Storm Fengshen was located at latitude 17.1°N and longitude 157.1°E which put it about 805 miles (1300 km) east of Saipan.  Fengshen was moving toward the west-northwest at 18 m.p.h. (30 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 1000 mb.

More thunderstorms developed near the center of a cluster of thunderstorms east of the Northern Marianas on Tuesday and the Japan Meteorological Society designated the system as Tropical Storm Fengshen.  The distribution of thunderstorms around Tropical Storm Fengshen was asymmetrical.  Stronger thunderstorms were occurring in bands in the western half of the circulation.  Bands in the eastern half of the tropical storm consisted primarily of showers and lower clouds.  Fengshen was moving south of an upper level ridge over the Western North Pacific Ocean.  The ridge was producing easterly winds which were causing moderate vertical wind shear.  The wind shear was contributing to the asymmetrical distribution of thunderstorms.

Tropical Storm Fenshen will move through an environment favorable for intensification during the next several days.  Fengshen will move over water where the Sea Surface Temperature is near 29°C.  The upper level ridge will continue to cause vertical wind shear.  The wind shear will inhibit intensification, but the shear will not be strong enough to prevent intensification.  Tropical Storm Fengshen will intensify gradually and it could strengthen into a typhoon during the next two to three days.

Tropical Storm Fengshen will move around the western end of the ridge over the Western North Pacific.  The ridge will steer Fengshen toward the west-northwest during the next 24 to 36 hours.  Tropical Storm Fengshen will move more toward the north in about 36 hours when it reaches the western end of the ridge.  On its anticipated track Fengshen will pass northeast of the Northern Marianas.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 27W developed east of Luzon.  At 4:00 p.m. EST on Tuesday the center of Tropical Depression 27W was located at latitude 12.1°N and longitude 130.9°E which put it about 315 miles (510 km) east of Laoang, Philippines.  The depression was moving toward the west at 12 m.p.h. (19 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.

Typhoon Halong Strengthens to Equivalent of a Major Hurricane

Typhoon Halong strengthened to the equivalent of a major hurricane northeast of the Northern Marianas on Monday.  At 4:00 p.m. EST on Monday the center of Typhoon Halong was located at latitude 18.9°N and longitude 152.1°E which put it about 390 miles (630 km) south of Minami Tori Shima, Japan.  Halong was moving toward the northwest at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 120 m.p.h. (195 km/h) and there were wind gusts to 150 m.p.h. (240 km/h).  The minimum surface pressure was 952 mb.

Typhoon Halong continued to strengthen on Monday and it reached the equivalent of a major hurricane.  A small, well formed circular eye was evident on infrared satellite images.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Typhoon Halong.  Storms near the core were generating strong upper level divergence which was pumping mass away from the typhoon.

The circulation around Typhoon Halong increased in size on Monday.  Winds to typhoon force extended out 45 miles (75 km) from the center of circulation.  Winds to tropical storm force extended out 160 miles (260 km) from the center.  The Hurricane intensity Index (HII) for Typhoon Halong was 22.0.  The Hurricane Size Index (HSI) was 14.3 and the Hurricane Wind Intensity Size Index was 36.3.  Halong was capable of causing major damage.

Typhoon Halong will remain in an environment favorable for intensification for another 24 hours.  Halong will move over water where the Sea Surface Temperature is near 29°C.  It will move under the northwestern portion of an upper level ridge where the winds are weaker and there will be little vertical wind shear.  An upper level trough southwest of Japan will approach Typhoon Halong in 24 hours.  The trough will produce stronger southwesterly winds which will cause more vertical wind shear.  Halong will start to weaken when the wind shear increases.

Typhoon Halong will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean during the next 36 to 48 hours.  The ridge will steer Halong toward the north-northwest.  Halong will move toward the northeast later this week after if moves around the western end of the high pressure system.  On its anticipated track Typhoon Halong could approach Minami Tori Shima in less than 72 hours.

Halong Strengthens into a Typhoon East of the Northern Marianas

Former Tropical Storm Halong strengthened into a typhoon east of the Northern Marianas on Sunday.  At 4:00 p.m. EDT on Sunday the center of Typhoon Halong was located at latitude 17.0°N and longitude 153.3°E which put it about 520 miles (840 km) east-northeast of Saipan.  Halong was moving toward the northwest at 12 m.p.h. (19 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.

The circulation around former Tropical Storm Halong exhibited much better organization on Sunday.  An eye with a diameter of approximately 12 miles (19 km) formed at the center of Halong.  A ring of strong thunderstorms surrounded the eye and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Typhoon Halong.  The strongest rainbands were north and east of the center of circulation.  Bands in the western half of Halong consisted primarily of showers and lower clouds.  Typhoon Halong may have been pulling sinking, drier air into the western half of the circulation, which may be why the bands were weaker in that part of the typhoon.  Storms around the core of Halong were generating strong upper level divergence which was pumping mass away from the typhoon.  Winds to typhoon force extended out 10 miles (15 km) from the center of circulation.  Winds to tropical storm force extended out 175 miles (280 km) from the center.

Typhoon Halong will move through an environment favorable for intensification during the next 36 to 48 hours.  Halong will move over water where the Sea Surface Temperature is near 29°C.  It will move under the western part of an upper level ridge where the winds are weak.  So, there will not be a lot of vertical wind shear.  Typhoon Halong will continue to intensify and it could strengthen into the equivalent of a major hurricane.

Typhoon Halong will move around the western end of a ridge of high pressure over the Western North Pacific Ocean.  The ridge will steer Halong toward the northwest during the next 24 hours.  After that time Typhoon Halong will move more toward the north while it moves around the western end of the ridge.  Halong will move northeastward after it moves around the end of the ridge.  On its anticipated track Typhoon Halong is forecast to remain northeast of the Northern Marianas.  Halong is expected to pass between Iwo To and Wake Island later next week.

Tropical Storm Halong Develops East of the Marianas

Tropical Storm Halong developed east of the Marianas on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Halong was located at latitude 13.3°N and longitude 156.7°E which put it about 820 miles (1325 km) east of Guam.  Halong was moving toward the northwest at 9 m.p.h. (15 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 distinct low level center of circulation formed in an area of thunderstorms east of the Marianas on Saturday.  When more thunderstorms formed near the center of circulation, the Japan Meteorological Agency designated the system as Tropical Storm Halong.  The circulation around Halong appeared to be organizing quickly.  New thunderstorms were forming close to the center of circulation.  Bands of showers and thunderstorms were also organizing quickly and the bands were starting to revolve around the center of Tropical Storm Halong.  Storms near the center were generating upper level divergence which was pumping mass away from the tropical storm in all directions.  Winds to tropical storm force extended out 150 miles (240 km) from the center of circulation.

Tropical Storm Halong will move through an environment favorable for intensification during the next two to three days.  Halong 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 over the Western North Pacific Ocean.  The winds will be blowing from the south at all levels and so there will be little vertical wind shear.  Tropical Storm Halong will continue to intensify and it could strengthen rapidly.  Halong is likely to strengthen into a typhoon within 36 hours.

The ridge over the Western North Pacific will steer Tropical Storm Halong toward the northwest during the next several days.  On its anticipated track Halong will be northeast of the Marianas by the end of the weekend.