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Typhoon Sinlaku Still Bringing Wind and Rain to Northern Marianas

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Typhoon Sinlaku was still bringing wind and rain to the Northern Marianas on Thursday.  At 5:00 a.m. EDT on Thursday the center of Typhoon Sinlaku was located at latitude 18.0°N and longitude 144.6°E which put the center about 90 miles (145 km) west of Alamagan.   Sinlaku was moving toward the north 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 145 m.p.h. (235 km/h).  The minimum surface pressure was 953 mb.

Typhoon Warnings remain in effect for Rota, Tinian, Saipan, Pagan, Alamagan, and Agrihan.

Typhoon Sinlaku was weakening gradually as it moved just to the west of the Northern Marianas.  The circulation around Sinlaku was pulling drier air into the typhoon.  There were fewer clouds in the regions between the rainbands.  Typhoon Sinlaku also appeared to be in the going through another eyewall replacement cycle.

The circulation around Typhoon Sinlaku was still well organized even though Sinlaku was weakening.  A circular eye with a diameter of 35 miles (55 km) was still visible at the center of Sinlaku’s circulation.  Bands of showers and thunderstorms were revolving around the center of Typhoon Sinlaku.  Storms near the center of Sinlaku generated upper level divergence that pumped mass away from the typhoon.  The removal of mass in the upper levels of the atmosphere was less than the convergence of mass in the lower levels.  So, the surface pressure was continuing to increase gradually.

The circulation around Typhoon Sinlaku was large.  Winds to typhoon force extended out 90 miles (145 km) from the center of Sinlaku’s circulation.  Winds to tropical storm force extended out 290 miles (470 km) from the center of Typhoon Sinlaku.

The Hurricane Intensity Index (HII) for Typhoon Sinlaku is 20.6.  The Hurricane Size Index (HSI) is 32.7 and the Hurricane Wind Intensity Size Index (HWISI) is 53.2.  Typhoon Sinlaku is similar in intensity to Hurricane Irma when Irma hit Southwest Florida in 2017.  Sinlaku is bigger than Irma was.

Typhoon Sinlaku will move around the western part of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Sinlaku toward the north-northeast during the next 24 hours.  On its anticipated track, the center of Typhoon Sinlaku will move over the northernmost islands in the Northern Marianas during the nest 24 hours.  Sinlaku will start to move away from the Marianas on Friday.

Typhoon Sinlaku will move through an environment that will become more unfavorable for a strong typhoon during the next 24 hours.  Sinlaku will move over water where the Sea Surface Temperatures are near 26°C.  It will move under the southeastern part of an upper level trough that is southeast of Japan.  The upper level trough will produce southwesterly winds that will blow toward the top of Sinlalu’s circulation.  Those winds will cause the vertical wind shear to increase.  Typhoon Sinlaku will also continue to pull drier air into its circulation.  The drier air will continue to to inhibit the development of new thunderstorms in the rainbands revolving around the center of Sinlaku’s circulation.  The cooler Sea Surface Temperatures, more vertical wind shear and drier air will cause Typhoon Sinlaku to continue to weaken during the next 24 hours.

Typhoon Sinlaku will continue to bring strong winds and heavy rain to the Northern Marianas during the next 24 hours.  Heavy rain is likely to cause flash floods in some locations.

Flood Watches remain in effect for Guam, Rota, Tinian, and Saipan.

Typhoon Sinlaku could also cause a storm surge of up to 10 feet (3 meters).

Typhoon Sinlaku Continues to Bring Wind and Rain to Northern Marianas

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Typhoon Sinlaku continued to bring strong winds and heavy rain to the Northern Marianas on Wednesday.  At 5:00 a.m. EDT on Wednesday the center of Typhoon Sinlaku was located at latitude 16.2°N and longitude 144.8°E which put the center about 80 miles (130 km) northwest of Saipan.  Sinlaku was moving toward the northwest at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 944 mb.

Typhoon Warnings remain in effect for Rota, Tinian, Saipan, Pagan, Alamagan, and Agrihan.

A Tropical Storm Warning remains in effect for Guam.

A Typhoon Watch also remains in effect for Guam.

Typhoon Sinlaku completed an eyewall replacement cycle on Wednesday.  A circular eye with a diameter of 35 miles (55 km) was present at the  center of Sinlaku’s circulation.  Bands of showers and thunderstorms were revolving around the core of Typhoon Sinlaku.  Storms near the core of Sinlaku generated upper level divergence that pumped mass away from the typhoon.  The removal of mass in the upper levels of the atmosphere was less than the convergence of mass in the lower levels.  So, the surface pressure was continuing to increase gradually.

The circulation around Typhoon Sinlaku was large.  Winds to typhoon force extended out 75 miles (120 km) from the center of Sinlaku’s circulation.  Winds to tropical storm force extended out 275 miles (445 km) from the center of Typhoon Sinlaku.

The Hurricane Intensity Index (HII) for Typhoon Sinlaku is 23.6.  The Hurricane Size Index (HSI) is 28.3 and the Hurricane Wind Intensity Size Index (HWISI) is 51.9.  Typhoon Sinlaku is similar in size and intensity to Hurricane Wilma when Wilma hit South Florida in 2005.

A weather station at the Guam International Airport recently reported a sustained wind speed of 28 m.p.h. (45 km/h) and a wind gust of 45 m.p.h. (73 km/h).  There were no recent reports from weather stations on Rota, Tinian, or Saipan.

Typhoon Sinlaku was moving slowly west of the Northern Marianas.  The slow movement was prolonging the period destructive wind and rain in Tinian and Saipan.  Sinlaku was capable of causing major damage.  Prolonged heavy rain is likely to cause flash floods.

Flood Watches remain in effect for Guam, Rota, Tinian, and Saipan.

Typhoon Sinlaku could cause a storm surge of up to 10 feet (3 meters).

Typhoon Sinlaku will move around the western part of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Sinlaku toward the north-northwest during the next 24 hours.  On its anticipated track, the center of Typhoon Sinlaku will move very slowly away from Tinian and Saipan.  Sinlaku will move parallel of the Northern Marianas on Wednesday.

Typhoon Sinlaku will move through an environment that will be marginally favorable for a strong typhoon during the next 24 hours.  Sinlaku will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the middle of an upper level ridge that is over the Western North Pacific Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Typhoon Sinlaku will move into a region where the air is drier.  The drier air is likely to inhibit the development of thunderstorms in the northern and western parts of Sinlaku’s circulation.  Typhoon Sinlaku is likely to continue to weaken gradually during the next 24 hours because of the recently completed eyewall replacement cycle and the drier air.

Typhoon Sinlaku Batters Tinian and Saipan

Typhoon Sinlaku battered Tinian and Saipan on Tuesday.  At 11:00 a.m. EDT on Tuesday the center of Typhoon Sinlaku was located at latitude 15.1°N and longitude 145.7°E which put the center about 20 miles (30 km) south of Saipan.   Sinlaku was moving toward the northwest at 5 m.p.h. (8 km/h).   The maximum sustained wind speed was 145 m.p.h. (235 km/h) and there were wind gusts to 175 m.p.h. (285 km/h).  The minimum surface pressure was 930 mb.

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

A Tropical Storm Warning is in effect for Guam.

A Typhoon Watch is also in effect for Guam.

A weather station at the international airport in Saipan reported a sustained wind speed of 82 m.p.h. (132 km) and a wind gust of 130 m.p.h. (210 km/h) as the eyewall of Typhoon Sinlaku passed over it.

Typhoon Sinlaku began an eyewall replacement cycle just before it reached Tinian and Saipan.  A larger, outer eyewall formed around the smaller, original eyewall.  The low level convergence began to be intercepted by the outer eyewall and the original inner eyewall began to weaken.  The weakening of the inner eyewall caused the strongest winds in Typhoon Sinlaku to diminish very gradually.

The remnant of the original inner eyewall was still visible on satellite and radar images of Typhoon Sinlaku.  The larger outer eyewall appeared to be becoming the predominant feature in the core of Sinlaku’s circulation.  Bands of showers and thunderstorms were revolving around the core of Typhoon Sinlaku.  Storms near the core of Sinlaku generated upper level divergence that pumped mass away from the typhoon.  The removal of mass in the upper levels of the atmosphere was less than the strong convergence of mass in the lower levels.  So, the surface pressure was increasing gradually.

The circulation around Typhoon Sinlaku was large.  Winds to typhoon force extended out 75 miles (120 km) from the center of Sinlaku’s circulation.  Winds to tropical storm force extended out 265 miles (425 km) from the center of Typhoon Sinlaku.

The Hurricane Intensity Index (HII) for Typhoon Sinlaku is 29.9.  The Hurricane Size Index (HSI) is 27.4 and the Hurricane Wind Intensity Size Index (HWISI) is 57.3. Typhoon Sinlaku is similar in size and intensity to Hurricane Helene when Helene hit Florida in 2024.

Typhoon Sinlaku started to move more slowly as it began the eyewall replacement cycle.  The slower movement was prolonging the period destructive wind and rain in Tinian and Saipan.  Sinlaku was capable of causing severe damage.  Prolonged heavy rain is likely to cause flash floods.

Flood Watches are in effect for Guam, Rota, Tinian, and Saipan.

Typhoon Sinlaku could cause a storm surge of up to 13 feet (4 meters).

Typhoon Sinlaku will move around the western part of a high pressure system that is over the Western North Pacific Ocean. The high pressure system will steer Sinlaku toward the north-northwest during the next 24 hours.  On its anticipated track, the center of Typhoon Sinlaku will move very slowly away from Tinian and Saipan.  Sinlaku will be west of the Marianas on Wednesday.

Typhoon Sinlaku will move into an environment that will be marginally favorable for a strong typhoon during the next 24 hours.  Sinlaku will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the middle of an upper level ridge that is over the Western North Pacific Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Typhoon Sinlaku will move into a region where the air is drier.  The drier air is likely to inhibit the development of thunderstorms in the northern and western parts of Sinlaku’s circulation.  Typhoon Sinlaku is likely to continue to weaken gradually during the next 24 hours because of the eyewall replacement cycle and the drier air.

Typhoon Sinlaku Nears Tinian and Saipan

The center of Typhoon Sinlaku was nearing Tinian and Saipan on Monday evening.  At 11:00 p.m. EDT on Monday the center of Typhoon Sinlaku was located at latitude 14.5°N and longitude 146.3°E which put the center about 75 miles (120 km) southeast of Saipan.  Sinlaku was moving toward the northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 155 m.p.h. (250 km/h) and there were wind gusts to 190 m.p.h. (305 km/h).  The minimum surface pressure was 919 mb.

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

A Tropical Storm Warning is in effect for Guam.

A Typhoon Watch is also in effect for Guam.

Typhoon Sinlaku weakened just slightly as it neared Tinian and Saipan on Monday evening.  A circular eye with a diameter of 20 miles (32 km) was visible at the center of Sinlaku’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Typhoon Sinlaku.  Storms near the center of Sinlaku generated upper level divergence that pumped mass away from the typhoon.  The removal of mass in the upper levels of the atmosphere was less than the strong convergence of mass in the lower levels.  So, the surface pressure was increasing gradually.

The circulation around Typhoon Sinlaku was large.  Winds to typhoon force extended out 75 miles (120 km) from the center of Sinlaku’s circulation.  Winds to tropical storm force extended out 265 miles (425 km) from the center of Typhoon Sinlaku.

The Hurricane Intensity Index (HII) for Typhoon Sinlaku is 33.3.  The Hurricane Size Index (HSI) is 29.6 and the Hurricane Wind Intensity Size Index (HWISI) is 62.9.  Typhoon Sinlaku is similar in intensity to Hurricane Ian when Ian hit Southwest Florida in 2022.  Sinlaku is bigger than Ian was.

Typhoon Sinlaku will move into an environment that will become a little less favorable for a strong typhoon during the next 24 hours.  Sinlaku will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the middle of an upper level ridge that is over the Western North Pacific Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Typhoon Sinlaku will move into a region where the air is drier.  The drier air is likely to inhibit the development of thunderstorms in the northern and western parts of Sinlaku’s circulation.  Typhoon Sinlaku is likely to continue to weaken gradually during the next 24 hours because of the drier air.

Typhoon Sinlaku will move around the western part of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Sinlaku toward the northwest during the next 24 hours.  On its anticipated track, the center of Typhoon Sinlaku will reach Tinian and Saipan in a few hours.

Typhoon Sinlaku will be the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale when it reaches Tinian and Saipan.  Sinlaku will be capable of causing severe damage in Tinian and Saipan.  Typhoon Sinlaku will bring also strong winds and locally heavy rain to Guam, Rota, Pagan, Alamagan, and Agrihan. Heavy rain is likely to cause flash floods in some locations.

A Flash Flood Warning is in effect for Guam.

Flood Watches are in effect for  Rota, Tinian, and Saipan.

Typhoon Sinlaku could also cause a storm surge of up to 15 feet (4.5 meters) along parts of the coasts of the Marianas.

Typhoon Sinlaku Bears Down on the Marianas

Typhoon Sinlaku was bearing down on the Marianas on Monday morning.  At 11:00 a.m. EDT on Monday the center of Typhoon Sinlaku was located at latitude 13.3°N and longitude 147.2°E which put the center about 190 miles (335 km) east of Guam.  Sinlaku was moving toward the northwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 175 m.p.h. (285 km/h) and there were wind gusts to 205 m.p.h. (335 km/h).  The minimum surface pressure was 903 mb.

Typhoon Warnings are in effect for Rota, Tinian, and Saipan.

Tropical Storm Warnings are in effect for Guam, Pagan, and Alamagan.

A Typhoon Watch is in effect for Guam.

A Tropical Storm Watch is in effect for Agrihan.

Typhoon Sinlaku was maintaining its intensity as it was bearing down on the Mariana’s on Monday morning.  Sinlaku was the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale.  A circular eye with a diameter of 17 miles (28 km) was as the center of Sinlaku’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Typhoon Sinlaku.  Storms near the center of Sinlaku generated upper level divergence that pumped mass away from the typhoon.  The removal of mass in the upper levels of the atmosphere was nearly equal to the convergence of mass in the lower levels.  So, the surface pressure was nearly constant.

The circulation around Typhoon Sinlaku was large.  Winds to typhoon force extended out 80 miles (130 km) from the center of Sinlaku’s circulation.  Winds to tropical storm force extended out 290 miles (465 km) from the center of Typhoon Sinlaku.

The Hurricane Intensity Index (HII) for Typhoon Sinlaku is 40.4.  The Hurricane Size Index (HSI) is 28.4 and the Hurricane Wind Intensity Size Index (HWISI) is 68.8.  Typhoon Sinlaku is similar in intensity to Hurricane Maria when Maria was at its peak strength in 2017.  Sinlaku is bigger than Maria was.

Typhoon Sinlaku will move through an environment favorable for a very powerful typhoon during the next 24 hours.  Sinlaku will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the middle of an upper level ridge that is over the Western North Pacific Ocean.  The upper level winds are weak near the middle of the ridge and there will be little vertical wind shear.  Typhoon Sinlaku is likely to maintain its intensity during the next 24 hours unless an eyewall replacement cycle occurs.  Sinlaku could weaken if the inner end of a rainband wraps around the existing eye and eyewall.  If concentric eyewalls form, then an eyewall replacement cycle would cause Typhoon Sinlaku to weaken.

Typhoon Sinlaku will move around the western part of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Sinlaku toward the northwest during the next 24 hours.  On its anticipated track, the center of Typhoon Sinlaku will be near Tinian and Saipan in less than 24 hours.

Typhoon Sinlaku could be the equivalent of a Category 5 hurricane when it reaches Tinian and Saipan.  Sinlaku will be capable of causing catastrophic damage in Tinian and Saipan.  Typhoon Sinlaku will bring also strong winds and locally heavy rain to Guam, Rota, Pagan, and Alamagan. Heavy rain is likely to cause flash floods in some locations.

Flood Watches are in effect for Guam, Rota, Tinian, and Saipan.

Typhoon Sinlaku could also cause a storm surge of up to 17 feet (5.1 meters) along parts of the coasts of the Marianas.

Typhoon Bolaven Rapidly Intensifies to Equivalent of Cat. 5 Hurricane

Typhoon Bolaven rapidly intensified to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale on Tuesday evening. At 11:00 p.m. EDT on Tuesday the center of Typhoon Bolaven was located at latitude 17.5°N and longitude 143.8°E which put it about 245 miles (390 km) north-northwest of Guam. Bolaven was moving toward the north-northwest at 14 m.p.h. (22 km/h). The maximum sustained wind speed was 160 m.p.h. (260 km/h) and there were wind gusts to 185 m.p.h. (295 km/h). The minimum surface pressure was 920 mb.

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

Typhoon Bolaven rapidly intensified to the equivalent of a Category 5 hurricane west of the Marianas on Tuesday evening. A small circular eye with a diameter of 14 miles (22 km) was at the center of Bolaven’s circulation. The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Typhoon Bolaven. Storms near the core generated upper level divergence that pumped mass away from the typhoon.

The circulation around Typhoon Bolaven was very symmetrical. Winds to typhoon force extended out 25 miles (40 km) from the center of Bolaven’s circulation. Winds to tropical storm force extended out 185 miles (295 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Bolaven was 35.0. The Hurricane Size Index (HSI) was 11.5 and the Hurricane Wind Intensity Size Index (HWISI) was 46.5.

Typhoon Bolaven will move through an environment favorable for intensification during the next 24 hours. Bolaven will move over water where the Sea Surface Temperatures are 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 Bolaven could continue to intensify during the next 24 hours. If the inner end of a rainband wraps around the existing eye and eyewall, then concentric eyewalls could form. If concentric eyewalls form, then an eyewall replacement cycle could cause Typhoon Bolaven to weaken.

Typhoon Bolaven will move around the western part of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Bolaven toward the north-northwest during the next 24 hours. On its anticipated track, the Typhoon Bolaven will stay west of the Marianas during the next 24 hours.

Tropical Storm Lionrock Drops Heavy Rain on Northern Vietnam

Tropical Storm Lionrock dropped heavy rain on parts of northern Vietnam on Saturday night. At 11:00 p.m. EDT on Saturday the center of Tropical Storm Lionrock was located at latitude 20.4°N and longitude 107.1°E which put it about 25 miles (40 km) southeast of Haiphong, Vietnam. Lionrock 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 995 mb.

Tropical Storm Lionrock dropped heavy rain over the part of northern Vietnam between Hanoi and Haiphong on Saturday night. The heaviest rain was falling in bands in the western half of Tropical Storm Lionrock. Bands in the eastern side of Lionrock consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 120 miles (195 km) from the center of Lionrock’s circulation.

Tropical Storm Lionrock will move south of a high pressure system over China during the next 24 hours. The high pressure system will steer Lionrock toward the west during the next day or so. On its anticipated track Tropical Storm Lionrock will move across northern Vietnam and northern Laos. Lionrock will bring gusty winds and locally heavy rain to parts of northern Vietnam and northern Laos. Heavy rain could cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Kompasu was spinning east of Luzon and Tropical Storm Namtheun formed east of the northern Marianas. At 11:00 p.m. EDT on Saturday the center of Tropical Storm Kompasu was located at latitude 15.9°N and longitude 129.8°E which put it about 470 miles (760 km) east of Luzon. Kompasu was moving toward the northwest at 9 m.p.h. (15 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 990 mb. Kompasu is forecast to move toward the west-northwest and to strengthen.

At 11:00 p.m. EDT on Saturday the center of Tropical Storm Namtheun was located at latitude 17.0°N and longitude 160.3°E which put it about 980 miles (1580 km) east of Alamagan. Namtheun was moving toward the west at 8 m.p.h. (13 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. Namtheun was forecast to move toward the northwest and to strengthen.

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.

Typhoon Bualoi Strengthens as it Approaches the Marianas

Typhoon Bualoi strengthened as it approached the Marianas on Sunday.  At 11:00 p.m. EDT on Sunday the center of Typhoon Bualoi was located at latitude 14.5°N and longitude 147.8°E which put it about 175 miles (285 km) east-southeast of Saipan.  Bualoi was moving toward the northwest at 13 m.p.h. (20 km/h).  The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h).  The minimum surface pressure was 967 mb.

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

Typhoon Bualoi strengthened quickly on Sunday.  A small circular eye developed at the center of Bualoi.  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 the typhoon.  Storms near the core were generating upper level divergence which was pumping mass away from Bualoi in all directions.

The circulation around Typhoon Bualoi was relatively small.  Winds to typhoon force extended out 35 miles (55 km) from the center of circulation.  Winds to tropical storm force extended out 130 miles (215 km) from the center.  The Hurricane Intensity Index (HII) for Typhoon Bualoi was 16.5.  The Hurricane Size Index (HSI) was 9.8 and the Hurricane Wind Intensity Size Index (HWISI) was 26.3.  Bualoi was capable of causing localized serious damage.

Typhoon Bualoi will move through an environment favorable for intensification for another 36 to 48 hours.  Bualoi 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 Bualoi will continue to intensify and it could strengthen into the equivalent of a major hurricane during the next 12 to 24 hours.

Typhoon Bualoi will move around the western end of a high pressure system over the Western North Pacific.  The high will steer Bualoi toward the northwest during the next 48 hours.  The typhoon will move more toward the north when it reaches the western end of the high pressure system.  On its anticipated track the center of Typhoon Bualoi could pass near Saipan in about 12 hours.  If the center passes near or over Saipan, then there will be winds of typhoon force.  However, since the circulation around Bualoi is fairly small, if the typhoon passes north of Saipan, it will receive much weaker winds.  Typhoon Bualoi could be near Iwo To in less than three days.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Neoguri was moving toward Honshu.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Neoguri was located at latitude 29.5°N and longitude 133.6°E which put it about 600 miles (965 km) southwest of Tokyo, Japan.  Neoguri was moving toward the north-northeast at 22 m.p.h. (35 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 989 mb.  Tropical Storm Neoguri could pass close to the coast of Honshu near Tokyo in about 24 hours.