Tag Archives: Choi-wan

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.

Tropical Storm Choi-wan Moves Toward Taiwan

Tropical Storm Choi-wan moved toward Taiwan on Thursday. At 5:00 p.m. EDT on Thursday the center of Tropical Storm Choi-wan was located at latitude 20.0°N and longitude 118.9°E which put it about 185 miles (300 km) south-southwest of Taiwan. Choi-wan was moving toward the north-northeast at 10 m.p.h. (16 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 Choi-wan turned toward the north-northeast on Thursday which put it on a track towards southern Taiwan. The distribution of thunderstorms around Choi-wan was asymmetrical. The strongest thunderstorms were occurring in bands in the southwestern quadrant of Tropical Storm Choi-wan. Bands in the other quadrants of Choi-wan consisted primarily of showers and lower clouds. The distribution of wind speeds around Tropical Storm Choi-wan was also asymmetrical. Winds to tropical storm force extended out 125 miles (200 km) on the western side of Choi-wan. Winds to tropical storm force only extended out 65 miles (105 km) on the eastern side of the circulation.

Tropical Storm Choi-wan will move through an area that is mostly unfavorable for intensification during the next 36 hours. The center of Choi-wan will move over an area where the Sea Surface Temperatures are near 30°C. However, an upper level ridge centered over southern China will produce moderate northeasterly winds that will blow toward the top of the tropical storm. Those winds will cause moderate vertical wind shear and they are already responsible for the asymmetrical distribution of thunderstorms. The moderate vertical wind shear will likely prevent intensification of Tropical Storm Choi-wan.

Tropical Storm Choi-wan will move around the northwestern part of a subtropical high pressure system over the Western North Pacific Ocean. The high pressure system will steer Choi-wan toward the north-northeast during the next 24 hours. On its anticipated track the center of Tropical Storm Choi-wan will reach southern Taiwan in 12 hours. Choi-wan could drop locally heavy rain over parts of southern Taiwan. Flash floods could occur in some locations. Tropical Storm Choi-wan could approach the southern Ryuku Islands in 24 hours. Choi-wan could bring a period of gusty winds to southern Taiwan and the southern Ryukyu Islands.

Tropical Storm Choi-wan Drops Rain on Luzon

Tropical Storm Choi-wan dropped rain on parts of Luzon around Manila on Wednesday. At 5:00 p.m. EDT on Wednesday the center of Tropical Storm Choi-wan was located at latitude 15.5°N and longitude 119.6°E which put it about 85 miles (135 km) west-northwest of Manila, Philippines. Choi-wan was moving toward the 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 1002 mb.

The center of Tropical Storm Choi-wan passed just south of Manila before the tropical storm moved west of Luzon. Bands near the center of Choi-wan dropped rain on parts of Luzon near Manila. Other bands in the southern half of Tropical Storm Choi-wan dropped rain on Mindoro. Choi-wan was still producing a few winds that were blowing at tropical storm force, but Manila did not report any winds that were that strong.

Tropical Storm Choi-wan exhibited an organized circulation on Wednesday afternoon. The inner end of a rainband wrapped around the western, southern and eastern sides of the center of Choi-wan. Other bands of thunderstorms were in the southern half of the tropical storm. Bands in the northern half of Tropical Storm Choi-wan consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 35 miles (55 km) from the center of Choi-wan.

Tropical Storm Choi-wan will move through an area that is marginally favorable for intensification during the next 24 hours. The center of Choi-wan will move over the South China Sea where the Sea Surface Temperatures are near 30°C. However, an upper level ridge centered over southern China will cause moderate vertical wind shear. The wind shear will limit the potential for intensification, but Tropical Storm Choi-wan could get a little stronger during the next 24 hours.

Tropical Storm Choi-wan will move around the western end of a subtropical high pressure system 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 Tropical Storm Choi-wan will move northwest of Luzon during the next 24 hours. Choi-wan will turn toward the northeast on Friday after it moves around the western end of the high pressure system. Tropical Storm Choi-wan could approach the southern end of Taiwan in 36 hours.

Tropical Storm Choi-wan Brings Rain to Philippines

Tropical Storm Choi-wan brought rain to the central Philippines on Tuesday. At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Choi-wan was located at latitude 13.1°N and longitude 121.9°E which put it about 155 miles (250 km) southeast of Manila, Philippines. Choi-wan was moving toward the west-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 1002 mb.

The center of Tropical Storm Choi-wan made an initial landfall on the east coast of Samar and then it moved west-northwest across the central Philippines. Choi-wan moved across the Sibuyan Sea and it was centered southeast of Manila on Tuesday night. The circulation around Tropical Storm Choi-wan weakened when the center passed over Samar, but it was still producing a small area of tropical storm force winds. Winds to tropical storm force extended out 35 miles (55 km) from the center of Choi-wan.

Tropical Storm Choi-wan dropped locally heavy rain over parts of Samar, Masbate, Panay and Mindoro on Tuesday. An upper level ridge centered over southern China was producing northeasterly winds which were blowing toward the top of Choi-wan. Those winds were producing moderate vertical wind shear and they causing the heavier rain to fall in bands in the southern half of Tropical Storm Choi-wan. Bands in the northern half of the tropical storm consisted primarily of showers and lower clouds.

Tropical Storm Choi-wan will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean. The high pressure system will steer Choi-wan toward the north-northwest during the next several days. On its anticipated track the center of Tropical Storm Choi-wan could pass just south of Manila in 12 hours. Choi-wan could drop locally heavy rain on Mindoro and western Luzon. Heavy rain could cause flash floods in some locations.

Tropical Storm Choi-wan will move through an environment that is mostly unfavorable for intensification. Choi-wan will move over water where the Sea Surface Temperatures are near 30°C. However, the upper level ridge center over southern China will continue to cause moderate vertical wind shear. The wind shear will limit the potential for intensification. The eastern side of the circulation around Tropical Storm Choi-wan will be over Luzon during the next 24 hours, which will also be unfavorable for intensification.

Tropical Storm Choi-wan Nears the Philippines

Tropical Storm Choi-wan neared the central Philippines on Monday night. At 11:00 p.m. EDT on Monday the center of Tropical Storm Choi-wan was located at latitude 10.4°N and longitude 126.9°E which put it about 100 miles (160 km) east-southeast of Guiuan, Philippines. Choi-wan was moving toward the west-northwest at 11 m.p.h. (17 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 997 mb.

Tropical Storm Choi-wan was approaching Samar in the central Philippines on Monday night. An upper level ridge centered near Hong Kong was producing northeasterly winds that were blowing toward the top of Choi-wan. Those winds were causing moderate vertical wind shear and they were affecting the structure of the tropical storm. The stronger thunderstorms were occurring bands southwest of the center of Tropical Storm Choi-wan. The bands in the other parts of Choi-wan consisted mainly of showers and lower thunderstorms. Winds to tropical storm force extended out 65 miles (105 km) from the center of circulation.

Tropical Storm Choi-wan will move through an environment only marginally favorable for intensification during the next 12 hours. Choi-wan will move over water where the Sea Surface Temperatures are near 30°C. However, the upper level ridge will continue to cause moderate vertical wind shear. The wind shear will limit the potential for intensification. The center of Tropical Storm Choi-wan will move over land later on Tuesday.

Tropical Storm Choi-wan will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean. The high pressure system will steer Choi-wan during the next 36 hours. On its anticipated track the center of Tropical Storm Choi-wan will reach Samar in 12 hours. Choi-wan will bring gusty winds and locally heavy rain to Samar. Heavy rain could cause flash floods in some locations. The center of Tropical Storm Choi-wan could reach the southeastern part of Luzon in 24 hours.