Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Typhoon Nolo Passes North of Wake Island

Typhoon Nolo passed north of Wake Island on Tuesday evening.  At 11:00 p.m. EDT on Tuesday the center of Typhoon Nolo was located at latitude 25.5°N and longitude 162.9°E which put the center about 445 miles (720 km) north of Wake Island.  Nolo was moving toward the west at 25 m.p.h. (40 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 977 mb.

Typhoon Nolo weakened on Tuesday.  The eye was no longer visible at the center of Nolo’s circulation.  The distribution of thunderstorms in Typhoon Nolo became more asymmetrical on Tuesday.  Thunderstorms were still occurring in bands in the southern and eastern parts of Nolo’s circulation.  Bands in the northern and western parts of Typhoon Nolo consisted primarily of showers and lower clouds.  Storms near the center of Nolo generated less upper level divergence that pumped less mass away from the typhoon.  The removal of mass in the upper levels was less than the convergence of mass in the lower levels of the atmosphere.  So, the surface pressure increased on Tuesday.

The circulation around Typhoon Nolo was still large.  Winds to typhoon force extended out 75 miles (120 km) from the center of Nolo’s circulation.  Winds to tropical storm force extended out 205 miles (335 km) from the center of Typhoon Nolo.

Typhoon Nolo will move through an environment that will be unfavorable for intensification during the next 24 hours.  Nolo will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the southern part of an upper level ridge that is over the Western North Pacific Ocean.  The upper level ridge will produce easterly winds that will blow toward the top of Nolo’s circulation.  Those winds will cause moderate vertical wind shear.  Typhoon Nolo will continue to weaken gradually on Wednesday because of the moderate vertical wind shear.

Typhoon Nolo will move around the southern side of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Nolo toward the west during the next 24 hours.  On its anticipated track, Typhoon Nolo will move northwest of Wake Island on Wednesday.

Elsewhere over the Western North Pacific Ocean, Typhoon Choi-wan was making a transition to a strong extratropical cyclone east of Japan and Tropical Storm Koguma was gradually intensifying south of Wake Island.

At 5:00 p.m. EDT on Tuesday the center of Typhoon Choi-wan was located at latitude 37.9°N and longitude 151.3°E which put the center about 530 miles (855 km) east-southeast of Misawa, Japan.  Choi-wan was moving toward the northeast at 35 m.p.h. (55 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 959 mb.

At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Koguma was located at latitude 15.5°N and longitude 163.6°E which put the center about 325 miles (525 km) south-southwest of Wake Island.  Koguma was moving toward the northwest at 11 m.p.h. (17 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 996 mb.

Typhoon Nolo Moves Northeast of Wake Island

Typhoon Nolo moved northeast of Wake Island on Monday evening.  At 11:00 p.m. EDT on Monday the center of Typhoon Nolo was located at latitude 25.7°N and longitude 172.0°E which put the center about 600 miles (970 km) northeast of Wake Island.  Nolo was moving toward the west at 17 m.p.h. (28 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 955 mb.

Typhoon Nolo did not change much on Monday.  A circular eye with a diameter of 30 miles (50 km) was at the center of Nolo’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 Nolo.  Storms near the center of Nolo generated upper level divergence that pumped mass away from the typhoon.  The removal of mass in the upper levels was nearly equal to the convergence of mass in the lower levels of the atmosphere.  So, the surface pressure did not change much on Monday.

The distribution of wind speeds around Typhoon Nolo was fairly symmetrical.  Winds to typhoon force extended out 50 miles (80 km) from the center of Nolo’s circulation.  Winds to tropical storm force extended out 155 miles (250 km) from the center of Typhoon Nolo.

The Hurricane Intensity Index (HII) for Typhoon Nolo is 22.1.  The Hurricane Size Index (HSI) is 16.1 and the Hurricane Wind Intensity Size Index (HWISI) is 38.2.  Typhoon Nolo is similar in size and intensity to Hurricane Milton, when Milton hit Florida in 2024.

Typhoon Nolo will move through an environment that will be somewhat unfavorable for intensification during the next 24 hours.  Nolo will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the southern part of an upper level ridge that is over the Western North Pacific Ocean.  The upper level ridge will produce northeasterly winds that will blow toward the top of Nolo’s circulation.  Those winds will cause moderate vertical wind shear.  Typhoon Nolo is likely to weaken gradually on Tuesday because of the moderate vertical wind shear.

Typhoon Nolo will move around the southern side of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Nolo toward the west during the next 24 hours.  On its anticipated track, Typhoon Nolo will pass north of Wake Island on Tuesday.

Elsewhere over the Western North Pacific Ocean, Typhoon Choi-wan weakened gradually northeast of Iwo To and Tropical Storm Koguma strengthened slowly north of Kwajalein.

At 11:00 p.m. EDT on Monday the center of Typhoon Choi-wan was located at latitude 30.8°N and longitude 146.3°E which put the center about 440 miles (710 km) northeast of Iwo To.  Choi-wan was moving toward the north at 16 m.p.h. (26 km/h).  The maximum sustained wind speed was 110 m.p.h. (175 km/h) and there were wind gusts to 130 m.p.h. (210 km/h).  The minimum surface pressure was 945 mb.

At 11:00 p.m. EDT on Monday the center of Tropical Storm Koguma was located at latitude 13.2°N and longitude 166.7°E which put the center about 295 miles (475 km) north of Kwajalein. Koguma was moving toward the northwest at 11 m.p.h. (17 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.

Typhoon Choi-wan Passes East of Iwo To

Typhoon Choi-wan passed east of Iwo To on Sunday.  At 11:00 p.m. EDT on Sunday the center of Typhoon Choi-wan was located at latitude 25.7°N and longitude 146.4°E which put the center about 325 miles (525 km) east of Iwo To.  Choi-wan was moving toward the northwest at 12 m.p.h. (19 km/h).  The maximum sustained wind speed was 150 m.p.h. (240 km/h) and there were wind gusts to 185 m.p.h. (295 km/h).  The minimum surface pressure was 916 mb.

Typhoon Choi-wan intensified to the equivalent of a Category 4 hurricane on the Saffir-Simpson Scale on Sunday.  An eyewall replacement cycle appeared to be starting in Typhoon Choi-wan.  A circular eye with a diameter of 20 miles (32 km) was at the center of Choi-wan’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  The inner end of a rainband wrapped around the existing eye and eyewall.  A larger outer eyewall appeared to be forming around the existing eye and eyewall.  Bands of showers and thunderstorms were revolving around the core of Typhoon Choi-wan.  Storms near the core of Choi-wan generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The circulation around Typhoon Choi-wan was large.  Winds to typhoon force extended out 80 miles (130 km) from the center of Choi-wan’s circulation.  Winds to tropical storm force extended out 355 miles (575 km) from the center of Typhoon Choi-wan.

The Hurricane Intensity Index (HII) for Typhoon Choi-wan is 31.6.  The Hurricane Size Index (HSI) is 27.4 and the Hurricane Wind Intensity Size Index (HWISI) is 59.0.  Typhoon Choi-wan is similar in intensity to Hurricane Laura when Laura hit Southwest Louisiana in 2020.  Typhoon Choi-wan is much larger than Hurricane Laura was.

Typhoon Choi-wan will move through an environment that will be favorable for intensification during the next 24 hours.  Choi-wan will move over water where the Sea Surface Temperatures are near 28°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Even though Typhoon Choi-wan will move through a favorable environment, Choi-wan is likely to weaken during the next 24 hours because of the eyewall replacement cycle.

Typhoon Choi-wan will move around the western end of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Choi-wan toward the north during the next 24 hours.  On its anticipated track, the center of Typhoon Choi-wan will pass east of Japan during the next few days.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Koguma formed north of Kwajalein and former Hurricane Nolo moved west of the International Date Line.  Nolo is now designated as Typhoon Nolo because it is over the Western North Pacific Ocean.

At 11:00 p.m. EDT on Sunday the center of Tropical Storm Koguma was located at latitude 10.8°N and longitude 168.0°E which put the center about 125 miles (200 km) north of Kwajalein. Koguma was moving toward the northeast at 11 m.p.h. (17 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.

At 11:00 p.m. EDT on Sunday the center of Typhoon Nolo was located at latitude 25.0°N and longitude 178.6°W which put the center about 315 miles (510 km) southwest of Midway Island.  Nolo was moving toward the west-northwest at 18 m.p.h. (30 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 955 mb.

Typhoon Choi-wan Intensifies to Equivalent of a Major Hurricane

Typhoon Choi-wan intensified to the equivalent of a major hurricane as it moved east-southeast of Iwo To on Saturday.  At 11:00 p.m. EDT on Saturday the center of Typhoon Choi-wan was located at latitude 22.5°N and longitude 147.1°E which put the center about 410 miles (665 km) east-southeast of Iwo To.  Choi-wan was moving toward the north-northeast at 16 m.p.h. (26 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 942 mb.

Typhoon Choi-wan intensified to the equivalent of a major hurricane on Saturday.  A circular eye with a diameter of 20 miles (32 km) was at the center of Choi-wan’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 Choi-wan.  Storms near the core of Choi-wan generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The circulation around Typhoon Choi-wan was large.  Winds to typhoon force extended out 90 miles (145 km) from the center of Choi-wan’s circulation.  Winds to tropical storm force extended out 355 miles (575 km) from the center of Typhoon Choi-wan.

The Hurricane Intensity Index (HII) for Typhoon Choi-wan is 23.6.  The Hurricane Size Index (HSI) is 28.8 and the Hurricane Wind Intensity Size Index (HWISI) is 52.4.  Typhoon Choi-wan is similar in size and intensity to Hurricane Wilma when Wilma hit South Florida in 2005.

Typhoon Choi-wan will move through an environment that will be favorable for intensification during the next 24 hours.  Choi-wan Choi-wan will move over water where the Sea Surface Temperatures are near 28°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Typhoon Choi-wan is likely to continue to  intensify during the next 24 hours unless an eyewall replacement cycle occurs.

Typhoon Choi-wan will move around the western end of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Choi-wan toward the north during the next 24 hours.  On its anticipated track, the center of Typhoon Choi-wan will pass east of Iwo To on Sunday.

Choi-wan Strengthens to Typhoon West of Northern Marianas

Former Tropical Storm Choi-wan strengthened to a typhoon over the Western North Pacific Ocean west of the Northern Marianas on Friday.  At 11:00 a.m. EDT on Friday the center of Typhoon Choi-wan was located at latitude 18.0°N and longitude 144.7°E which put the center about 80 miles (130 km) west of Alamagan.  Choi-wan was moving toward the north at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 981 mb.

A Typhoon Warning is in effect for Agrihan and Pagan.

A Tropical Storm Warning is in effect for Tinian, Saipan, and Alamagan.

A Typhoon Watch is in effect for Alamagan.

Former Tropical Storm Choi-wan strengthened to a typhoon on Friday.  The inner end of a rainband wrapped around the center of Typhoon Choi-wan.  Other bands of showers and thunderstorms were revolving around the center of Choi-wan’s circulation.  Storms near the center of Choi-wan generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The distribution of wind speeds in Typhoon Choi-wan was asymmetrical.  Winds to typhoon force extended out 110 miles (175 km) in the southern half of Choi-wan’s circulation.  Winds to tropical storm force extended out 50 miles (80 km) in the northern half of Typhoon Choi-wan.  Winds to tropical storm force extended out 250 miles (400 km) in the southern side of Typhoon Choi-wan.  Winds to tropical storm force extended out 175 miles (280 km) in the northern side of Choi-wan’s circulation.

Typhoon Choi-wan will move through an environment that will be favorable for intensification during the next 24 hours.  Choi-wan Choi-wan will move over water where the Sea Surface Temperatures are 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 Choi-wan will intensify during the next 24 hours.  Choi-wan is likely to strengthen to the equivalent of a major hurricane during the weekend.

Tropical Storm Choi-wan will move around the western end of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Choi-wan toward the north during the next 24 hours.  On its anticipated track, Tropical Storm Choi-wan will move away from the Northern Marianas during the weekend.

Tropical Storm Choi-wan will bring strong winds and heavy rain to Alamagan, Agrihan, Pagan, and Anataham.  Heavy rain could cause floods in some locations. Choi-wan could also bring gusty winds and heavy rain to Tinian and Saipan.  Bands in the southern periphery of Typhoon Choi-wan could drop heavy rain over Guam and Rota.

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

Tropical Storm Choi-wan Forms East of Northern Marianas

Tropical Storm Choi-wan formed over the Western North Pacific Ocean east of the Northern Marianas on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Choi-wan was located at latitude 16.3°N and longitude 149.5°E which put the center about 150 miles (240 km) east of Alamagan.  Choi-wan was moving toward the west-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 low pressure system over the Western North Pacific Ocean east of the Northern Marianas strengthened on Wednesday and the Japan Meteorological Agency designated the system as Tropical Storm Choi-wan.

The distribution of thunderstorms in Tropical Storm Choi-wan was asymmetrical.  Thunderstorms were occurring in bands in the western side of Choi-wan’s circulation.  Bands in the eastern side of Tropical Storm Choi-wan consisted primarily of showers and lower clouds.  Storms near the center of Choi-wan generated upper level divergence that pumped mass away to the west of the tropical storm.  The removal of mass caused the surface pressure to decrease.

The strongest winds in Tropical Storm Choi-wan were occurring in the bands of thunderstorms in the western side of Choi-wan.  Winds to tropical storm force extended out 115 miles (185 km) in the western half of Choi-wan’s circulation.  The winds in the eastern side of Tropical Storm Choi-wan were blowing at less than tropical storm force.

Tropical Storm Choi-wan will move through an environment that will be somewhat favorable for intensification during the next 24 hours.  Choi-wan will move over water where the Sea Surface Temperatures are near 30°C.  It will move under the southern part of an upper level ridge that is south of Japan.  The upper level ridge will produce easterly winds that will blow toward the top of Choi-wan’s circulation.  Those winds will cause some vertical wind shear, but the wind shear will not be enough to prevent intensification.  Tropical Storm Choi-wan will intensify during the next 24 hours.  Choi-wan could strengthen to a typhoon by the end of the week.

Tropical Storm Choi-wan will move around the western end of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Choi-wan toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Choi-wan will move over Alamagan, Agrihan, Pagan, and Anatahan on Thursday.

Tropical Storm Choi-wan will bring strong winds and heavy rain to Alamagan, Agrihan, Pagan, and Anataham.  Heavy rain could cause floods in some locations.  Choi-wan could also bring gusty winds and heavy rain to Tinian and Saipan.

A Flash Flood Watch is in effect for Tinian and Saipan.

A Tropical Storm Warning is in effect for Tinian and Saipan. 

A Tropical Storm Warning is in effect for Alamagan and Pagan.

A Typhoon Watch is in effect for Alamagan and Pagan.

A Tropical Storm Watch is in effect for Agrihan.

Typhoon Surigae Intensifies to Equivalent of Major Hurricane

Typhoon Surigae intensified to the equivalent of a major hurricane on Saturday night as it moved over the Western North Pacific Ocean southeast of Okinawa.  At 5:00 a.m. EDT on Sunday the center of Typhoon Surigae was located at latitude 25.7°N and longitude 128.6°E which put the center about 80 miles (130 km) southeast of Okinawa.  Surigae was moving toward the northeast at 11 m.p.h. (17 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 Surigae intensified to the equivalent of a major hurricane on Saturday night.  A circular eye with a diameter of 20 miles (32 km) was at the center of Surigae’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 Surigae.  Storms near the center of Surigae generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The distribution of wind speed around Typhoon Surigae became more symmetrical when Surigae intensified.  Winds to typhoon force extended out 25 miles (40 km) from the center of Surigae’s circulation.  Winds to tropical storm force extended out 90 miles (145 km) from the center of Typhoon Surigae.

The Hurricane Intensity Index (HII) for Typhoon Surigae is 22.1.  The Hurricane Size Index (HSI) is 9.2 and the Hurricane Wind Intensity Size Index (HWISI) is 31.3.  Typhoon Surigae is similar in size and intensity to Hurricane Zeta when Zeta hit Louisiana in 2020.

Typhoon Surigae will move through an environment that will be somewhat favorable for intensification during the next 24 hours.  Surigae will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the southern part of an upper level trough that is northwest of Japan.  The upper level trough will produce southwesterly winds that will blow toward the top of Surigae’s circulation.  Those winds will cause some vertical wind shear, but the wind shear may not be enough to prevent intensification.  Typhoon Surigae could continue to intensify Sunday.  The vertical wind shear will increase on Monday when Surigae moves closer to the upper level westerly winds in the middle latitudes.  Typhoon Surigae will start to weaken when the vertical wind shear increases.

Typhoon Surigae will move around the western end of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Surigae toward the northeast during the next 24 hours.  On its anticipated track, the center of Typhoon Surigae will move away Okinawa on Sunday.

Typhoon Surigae will continue to bring strong winds and locally heavy rain to the Ryukyu Islands including Okinawa on Sunday.  Heavy rain is likely to cause flash floods in some locations.  The strong winds and rain will end gradually as Surigae moves away from the Ryukyu Islands.

Surigae Strengthens to Typhoon South of Okinawa

Former Tropical Storm Surigae strengthened to a typhoon on Friday night as it moved south of Okinawa.  At 5:00 a.m. EDT on Saturday the center of Typhoon Surigae was located at latitude 23.2°N and longitude 126,8°E which put the center about 255 miles (415 km) south-southwest of Okinawa.  Surigae was moving toward the north-northwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 95 m.p.h. (150 km/h).  The minimum surface pressure was 981 mb.

Former Tropical Storm Surigae strengthened to a typhoon on Friday night.  The inner end of a rainband wrapped around the western and southern sides of the center of Typhoon Surigae.  Other bands of showers and thunderstorms were revolving around the center of Surigae’s circulation.  Storms near the center of Surigae generated upper level divergence that pumped mass away from the typhoon.  The removal of mass caused the surface pressure to decrease.

The strongest winds were occurring in the southern side of the center of Typhoon Surigae.  Winds to typhoon force extended out 25 miles (40 km) in the southern side of Surigae’s circulation.  Winds to tropical storm force extended out 90 miles from the center of Typhoon Surigae.

Typhoon Surigae will move through an environment that will be favorable for intensification during the next 24 hours.  Surigae will move over water where the Sea Surface Temperatures are near 28°C.  It will move under the western part of an upper level ridge that is south of Japan.  The upper level ridge will produce southerly winds that will blow toward the top of Surigae’s circulation.  Those winds will cause some vertical wind shear.  The vertical wind shear will inhibit intensification, but the wind shear will not be enough to prevent intensification.  Typhoon Surigae will intensify during the next 24 hours.

Typhoon Surigae will move around the western end of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Surigae toward the north during the next 24 hours.  On its anticipated track, the center of Typhoon Surigae will be just south of Okinawa in 24 hours.

Typhoon Surigae will bring strong winds and locally heavy rain to the Ryukyu Islands including Okinawa.  Heavy rain is likely to cause flash floods in some locations.

Tropical Storm Surigae Forms Southeast of Ryukyu Islands

Tropical Storm Surigae formed over the Western North Pacific Ocean southeast of the Ryukyu Islands on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Surigae was located at latitude 18.4°N and longitude 133,7°E which put the center about 700 miles (1130 km) southeast of Okinawa.  Surigae was moving toward the west-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 1004 mb.

A low pressure system over the Western North Pacific Ocean southeast of the Ryukyu Islands strengthened on Wednesday and the Japan Meteorological Agency designated the system as Tropical Storm Surigae.

More thunderstorms were forming near the center of Tropical Storm Surigae.  Storms were also developing in bands in the northern side of Surigae’s circulation.  The bands in the southern side of Tropical Storm Surigae consisted primarily of showers and lower clouds.  Storms near the center of Surigae generated upper level divergence that pumped mass away from the tropical storm.  The removal of mass caused the surface pressure to decrease.

The strongest winds were occurring in the northern side of Tropical Storm Surigae.  Winds to tropical storm force extended out 80 miles (130 km) in the northern side of Surigae’s circulation.  The winds in the southern side of Tropical Storm Surigae were blowing at less than tropical storm force.

Tropical Storm Surigae will move through an environment that will be favorable for intensification during the next 24 hours.  Surigae will move over water where the Sea Surface Temperatures are 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 Surigae will intensify during the next 24 hours.  Surigae is likely to strengthen to a typhoon by the weekend.

Tropical Storm Surigae will move around the southwestern part of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Surigae toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Surigae will move toward the southern Ryukyu Islands.

Typhoon Dujuan Passes Southeast of Honshu

Typhoon Dujuan passed southeast of Honshu on Monday morning.  At 5:00 a.m. EDT on Monday the center of Typhoon Dujuan was located at latitude 34.3°N and longitude 140.8°E which put the center about 110 miles (175 km) south of Tokyo, Japan.  Dujuan was moving toward the northeast at 18 m.p.h. (30 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 971 mb.

Typhoon Dujuan strengthened a little more on Monday morning as it passed southeast of Honshu.  Bands of showers and thunderstorms were revolving around the center of Dujuan’s circulation.  Storms near the center of Dujuan generated upper level divergence that pumped mass away to the northeast of the typhoon.  The removal of mass caused the surface pressure to decrease.

The strongest winds were occurring in the eastern side of Typhoon Dujuan.  Winds to typhoon force extended out 35 miles (55 km) in the eastern side of Dujuan’s circulation.  Winds to tropical storm force extended out 210 miles (335 km) from the center of Typhoon Dujuan.

Typhoon Dujuan will move through an environment that will be somewhat favorable for intensification during the next 12 hours.   Dujuan will move over water where the Sea Surface Temperatures are near 27°C.  It will move under the eastern part of an upper level trough that is north of Japan.  The upper level trough will produce southwesterly winds that will blow toward the top of Dujuan’s circulation.  Those winds will cause moderate vertical wind shear. The moderate vertical wind shear will inhibit intensification, but the wind shear may not be enough to prevent intensification.  Typhoon Dujuan could intensify a little more during the next 12 hours.  Dujuan will move over cooler Sea Surface Temperatures later on Monday.  Typhoon Dujuan will also into a region where the upper level winds are stronger on Tuesday.  The cooler Sea Surface Temperatures and stronger upper level winds will cause Typhoon Dujuan to weaken.  The cooler water and stronger upper level winds will also cause Dujuan to make a transition to an extratropical cyclone.

The upper level trough that is north of Japan will steer Typhoon Dujuan toward the northeast during the next 24 hours.  On its anticipated track, Typhoon Dujuan will move away from Honshu.