Category Archives: Western North Pacific

Western Pacific Typhoons and Tropical Storms

Typhoon Chanthu Strengthens to Equivalent of Cat. 5 Hurricane

Typhoon Chanthu intensified to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale east of northern Luzon on Wednesday. At 5:00 a.m. EDT on Wednesday the center of Typhoon Chanthu was located at latitude 15.5°N and longitude 130.8°E which put it about 630 miles (1015 km) east-southeast of Aparri, Philippines. Chanthu was moving toward the west-southwest at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 160 m.p.h. (260 km/h) and there were wind gusts to 195 m.p.h. (315 km/h). The minimum surface pressure was 915 mb.

Typhoon Chanthu intensified to the equivalent of a Category 5 hurricane on Wednesday morning. A small eye was at the center of Typhoon Chanthu. 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 revolved around the core of Chanthu. Storms near the core generated strong upper level divergence that pumped mass away from the typhoon. The inner end of a rainband wrapped part of the way around the core of Typhoon Chanthu. Concentric eyewalls might be developing, which would indicate the start of an eyewall replacement cycle.

The circulation around Typhoon Chanthu was small. Winds to typhoon force extended out 20 miles (30 km) from the center of Chanthu. Winds to tropical storm force extended out 80 miles (130 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Chanthu was 35.0. The Hurricane Size Index (HSI) was 7.1 and the Hurricane Wind Intensity Size Index (HWISI) was 42.1. Typhoon Chanthu was capable of causing localized catastrophic damage.

Typhoon Chanthu will move through an environment capable of maintaining a strong typhoon during the next 48 hours. Chanthu 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. If an eyewall replacement cycle occurs, Typhoon Chanthu will weaken when the inner eyewall weakens. An eyewall replacement cycle would increase the size of the circulation around Chanthu when the outer eyewall forms.

Typhoon Chanthu will move south of a high pressure system over the Western North Pacific Ocean. The high will steer Chanthu toward the west during the next several days. On its anticipated track Typhoon Chanthu could approach northeastern Luzon in 48 hours. Chanthu will likely still be a powerful typhoon when it approaches Luzon.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Conson continued to bring wind and rain to parts of Luzon. At 5:00 a.m. EDT on Wednesday the center of Tropical Storm Conson was located at latitude 14.3°N and longitude 120.5°E which put it about 35 miles (55 km) south-southwest of Manila, Philippines. Conson was moving toward the northwest at 8 m.p.h. (13 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 988 mb.

Typhoon Chanthu Rapidly Intensifies to Equivalent of Major Hurricane

Typhoon Chanthu rapidly intensified to the equivalent of a major hurricane over the Western North Pacific Ocean on Tuesday. At 5:00 p.m. EDT on Tuesday the center of Typhoon Chanthu was located at latitude 16.3°N and longitude 133.0°E which put it about 915 miles (1475 km) east-southeast of Taiwan. Chanthu was moving toward the west at 13 m.p.h. (20 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 929 mb.

Former Tropical Storm Chanthu rapidly intensified from a minimal tropical storm to the equivalent of a major hurricane during the past 24 hours. A small eye quickly developed at the center of Typhoon Chanthu. 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 Chanthu. Storms near the core generated strong upper level divergence that pumped mass away from the typhoon.

The circulation around Typhoon Chanthu was small. Winds to typhoon force extended out 20 miles (30 km) from the center of Chanthu. Winds to tropical storm force extended out 85 miles (135 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Chanthu was 30.0. The Hurricane Size Index (HSI) was 7.4 and the Hurricane Wind Intensity Size Index (HWISI) was 37.4. Typhoon Chanthu was capable of causing localized severe damage.

Typhoon Chanthu will move through an environment favorable for intensification during the next 24 hours. Chanthu 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. Typhoon Chanthu could continue to intensify during the next 24 hours and there is a chance it could strengthen to the equivalent of a Category 5 hurricane on the Saffir-Simpson Scale.

Typhoon Chanthu will move south of a high pressure system over the Western North Pacific Ocean. The high will steer Chanthu toward the west during the next several days. On its anticipated track Typhoon Chanthu could approach northeastern Luzon in 60 hours. Chanthu could be near Taiwan in less than four days.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Conson brought wind and rain to Luzon. At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Conson was located at latitude 13.5°N and longitude 121.7°E which put it about 110 miles (175 km) southeast of Manila, Philippines. Conson was moving toward the west-northwest at 9 m.p.h. (15 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 988 mb.

Tropical Storm Conson Brings Wind and Rain to Central Philippines

Tropical Storm Conson brought wind and rain to the central Philippines on Monday. At 5:00 p.m. EDT on Monday the center of Tropical Storm Conson was located at latitude 11.7°N and longitude 124.6°E which put it about 50 miles (80 km) south-southeast of Calbayog, Philippines. Conson was moving toward the west-northwest at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h). The minimum surface pressure was 985 mb.

The center of Tropical Storm Conson made landfall on the east coast of Samar near Borongan on Monday. Conson was nearly a typhoon at the time of landfall. A small eye was visible at the center of Tropical Storm Conson on both radar and microwave satellite images. Conson produced gusty winds as it passed over Samar. Winds to tropical storm force extended out 45 miles (75 km) from the center of circulation. Tropical Storm Conson dropped heavy rain on Samar, Leyte, northern Cebu and northeastern Panay. Heavy rain could result in flash floods in some locations.

Tropical Storm Conson will move around the southern side of a high pressure system over the Western North Pacific Ocean. The high will steer Conson toward the northwest during the next 36 hours. On its anticipated track Tropical Storm Conson will pass over the Visayan Sea and the Sibuyan Sea. The center of Conson could pass over Masbate during the next 12 hours. Tropical Storm Conson could reach southern Luzon in a day or so. Conson could be be near Manila in 48 hours. Tropical Storm Conson will bring gusty winds and locally heavy rain to parts of Masbate, Mindoro and southern Luzon.

Tropical Storm Conson will move through an environment mostly favorable for intensification during the next 24 hours. Conson 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. Since the circulation around Tropical Storm Conson is small, it is likely to weaken each time the center passes over land. The intensity of Conson could fluctuate when it moves over islands and water surfaces.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 19W was organizing quickly and it appeared to be on the verge of strengthening to a tropical storm. At 5:00 p.m. EDT on Monday the center of Tropical Depression 19W was located at latitude 15.5°N and longitude 137.1°E which put it about 1170 miles (1890 km) east-southeast of Taiwan. The tropical depression was moving toward the northwest at 8 m.p.h. (13 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 1003 mb. Tropical Depression 19W is forecast to move toward the west-northwest and to intensify.

Tropical Storm Conson Develops Quickly near the Philippines

Tropical Storm Conson developed quickly near the Philippines on Monday morning. At 5:00 a.m. EDT on Monday the center of Tropical Storm Conson was located at latitude 11.0°N and longitude 126.6°E which put it about 120 miles (195 km) east-southeast of Dolores, Philippines. Conson was moving toward the west-northwest at 8 m.p.h. (13 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 991 mb.

The circulation around Tropical Storm Conson organized quickly on Monday morning, The inner end of a primary rainband wrapped around the center of circulation. A small circular eye was at the center of Conson on microwave satellite images. Storms near the center of circulation generated upper level divergence that pumped mass away from the tropical storm. The circulation around Tropical Storm Conson was small. Winds to tropical storm force extended out 35 miles (55 km) from the center of Conson.

Tropical Storm Conson will move through an environment favorable for intensification during the next 12 hours. Conson 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. Tropical Storm Conson is likely to intensify during the next 12 hours and it could strengthen to a typhoon.

Tropical Storm Conson will move around the southern side of a high pressure system over the Western North Pacific Ocean. The high will steer Conson toward the northwest during the next 24 hours. On its anticipated track Tropical Storm Conson will reach northeastern Samar in 12 hours. Conson could be a typhoon when it reaches Samar. It will bring strong winds and locally heavy rain to Samar. Heavy rain could cause flash floods in some locations. Conson will weaken when the center passes over northeastern Samar. Since the circulation of Tropical Storm Conson is small, it could weaken quickly over land. The center of Tropical Storm Conson could move back over water when it moves north of Samar. The circulation could strengthen again when that happens. Conson could reach southeastern Luzon in a day or so.

Elsewhere over the Western North Pacific, Tropical Depression 19W formed north of Yap. At 5:00 a.m. EDT on Monday the center of Tropical Depression 19W was located at latitude 14.3°N and longitude 138.1°E which put it about 310 miles (500 km) north of Yap. The tropical depression was moving toward the north at 7 m.p.h. (11 km/h). The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 km/h). The minimum surface pressure was 1006 mb. Tropical Depression 19W is forecast to move toward the west-northwest and to strengthen.

Tropical Storm Lupit Brings Rain to Japan

Tropical Storm Lupit brought rain to Japan on Sunday. At 11:00 a.m. EDT on Sunday the center of Tropical Storm Lupit was located at latitude 32.3°N and longitude 131.6°E which put it about 20 miles (30 km) southwest of Miyazaki, Japan. Lupit was moving toward the east-northeast at 26 m.p.h. (42 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 990 mb.

Tropical Storm Lupit made landfall on the coast of Kyushu near Kagoshima on Sunday. Lupit was being steered quickly toward the east-northeast by an upper level trough near the Korean Peninsula. The trough was producing strong southwesterly winds that were blowing toward the top of Lupit’s circulation. Those winds were causing strong vertical wind shear and they were affecting the distribution of rain in Tropical Storm Lupit. Most of the heavier rain was falling in bands north and east of the center of Lupit. The heavier rain was falling over Shikoku, northern Kyushu and southwestern Honshu. Bands south and west of the center of circulation consisted primarily of showers and lower clouds. The strongest winds were occurring in the southern half of Tropical Storm Lupit. Winds to tropical storm force extended out 160 miles (260 km) on the south side of Lupit. The winds in the northern half of the circulation were blowing at less than tropical storm force.

The trough near the Korean Peninsula will steer Tropical Storm Lupit quickly toward the northeast during the next 36 hours. On its anticipated track the center of Lupit will move over the southern Sea of Japan. The center of Tropcial Storm Lupit could be near northern Honshu in 36 hours. Rain will spread over the rest of Honshu and Hokkaido during the next two days. Locally heavy rain could cause flash floods in some locations.

Tropical Storm Lupit will move through an environment only marginally favorable for intensification. Lupit will move over water in the Sea of Japan where the Sea Surface Temperatures are near 28°C. However, the upper level trough will continue to cause strong vertical wind shear. The lower part of Lupit’s circulation will also be disrupted while it passes over land. Tropical Storm Lupit is not likely to strengthen significantly and it could weaken if the center does not move over the Sea of Japan.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Mirinae was moving eastward away from Japan. At 11:00 a.m. EDT on Sunday the center of Tropical Storm Mirinae was located at latitude 36.6°N and longitude 144.7°E which put it about 230 miles (370 km) east-northeast of Tokyo, Japan. Mirinae was moving toward the northeast at 18 m.p.h. (30 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.

Tropical Storm Lupit Drops Very Heavy Rain on Taiwan

Tropical Storm Lupit dropped very heavy rain on Taiwan on Friday. At 5:00 p.m. EDT on Friday the center of Tropical Storm Lupit was located at latitude 25.1°N and longitude 120.5°E which put it about 100 miles (160 km) west of Taipei, Taiwan. Lupit was moving toward the east at 7 m.p.h. (11 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 990 mb.

Bands of rain on the eastern side of Tropical Storm Lupit dropped very heavy rain over much of Taiwan on Friday. Radar estimates of the rainfall by Taiwan’s Central Weather Bureau were as high as two feet (0.6 meters) in some locations. Southerly and southeasterly winds on the eastern side of Tropical Storm Lupit were pushing air up the slopes of mountains on Taiwan. The enhanced rising motion was contributing to prolonged periods of very heavy rain. The very heavy rainfall was creating a very high danger of widespread flash floods.

Tropical Storm Lupit began to strengthen slowly after the center of circulation moved over the Taiwan Strait. The circulation around Lupit was asymmetrical. The strongest thunderstorms and highest wind speeds were in bands on the eastern side of Tropical Storm Lupit. Bands in the western half of Lupit consisted primarily of showers and lower clouds. Northerly winds circulating around the western side of the tropical storm were transporting drier air into the western half of Lupit. Winds to tropical storm force extended out 80 miles on the eastern side of Lupit. The in the western side of the circulation were blowing at less than tropical storm force.

Tropical Storm Lupit will move around the northwestern part of a high pressure system over the Western North Pacific Ocean. The high will steer Lupit toward the east during the next 12 hours. On its anticipated track the center of Tropical Storm Lupit could be near Taipei in six hours. Lupit will continue to drop very heavy rain over Taiwan during the next 12 hours and the risk of flash floods will be very high. The high pressure system will steer Tropical Storm Lupit toward the northeast during the weekend. Lupit could also bring gusty winds and heavy rain to portions of the Ryukyu Islands.

Tropical Storm Lupit will move through an environment somewhat favorable for intensification during the next several days. Lupit will move over water where the Sea Surface Temperatures are near 28°C. It will move under the northeastern part of an upper level ridge. The upper level winds are weaker in that part of the ridge and there will be little vertical wind shear. Tropical Storm Lupit is likely to intensify during the weekend unless the center passes over northern Taiwan. If the center crosses northern Taiwan, then mountains will disrupt the low level circulation.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Mirinae was spinning south of Japan and Tropical Storm Nida was speeding away to the east of Japan. At 5:00 p.m. EDT on Friday the center of Tropical Storm Mirinae was located at latitude 29.0°N and longitude 137.3°E which put it about 480 miles (775 km) south-southwest of Tokyo, Japan. Mirinae was moving toward the east-northeast at 21 m.p.h. (33 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 993 mb.

At 5:00 p.m. EDT on Friday the center of Tropical Storm Nide was located at latitude 38.1°N and longitude 156.6°E which put it about 775 miles (1250 km) east-southeast of Misawa, Japan. Nida was moving toward the east-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 980 mb.

Tropical Storms Lupit, Mirinae and Nida Spin over Active West Pacific

Tropical Storms Lupit, Mirinae and Nida were spinning over an active Western North Pacific Ocean on Thursday. At 11:00 a.m. EDT on Thursday the center of Tropical Storm Lupit was located at latitude 23.8°N and longitude 117.3°E which put it about 25 miles (40 km) southeast of Yunxiao, China. Lupit was moving toward the northeast at 5 m.p.h. (8 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 990 mb.

Tropical Storm Lupit was dropping heavy rain along the coast of Fujian province. A band of heavy rain on the eastern periphery of Lupit was just west of Taiwan. Tropical Storm Lupit is forecast to move northeast along the east coast of China during the next 24 hours. Lupit is likely to weaken slowly while the center is near the coast. Tropical Storm Lupit could strengthen during the weekend if the center moves farther over the ocean.

At 11:00 a.m. EDT on Thursday the center of Tropical Storm Mirinae was located at latitude 27.1°N and longitude 129.1°E which put it about 70 miles (110 km) east-northeast of Okinawa. Mirinae was moving toward the east-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 996 mb.

Tropical Storm Mirinae is forecast to move toward the northeast and to strengthen. Mirinae could be south of Japan by this weekend. Weather conditions in Okinawa and the other Ryukyu Islands should improve when Tropical Storm Mirinae moves farther away.

At 11:00 a.m. EDT on Thursday the center of Tropical Storm Nida was located at latitude 33.9°N and longitude 148.2°E which put it about 490 miles (790 km) east-southeast of Tokyo. Nida was moving toward the north-northeast at 12 m.p.h. (19 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 992 mb. Westerly winds in the middle latitudes are forecast to carry Tropical Storm Nida farther away from Japan during the next few days.

Tropical Storm Lupit Makes Landfall in Eastern China

Tropical Storm Lupit made landfall on the coast of eastern China just to the south of Shantou on Wednesday night. At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Lupit was located at latitude 23.3°N and longitude 116.9°E which put it about 25 miles (40 km) south-southeast of Shantou, China. Lupit was moving toward the north at 8 m.p.h. (13 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 987 mb.

Tropical Storm Lupit made landfall on the northeastern part of the coast of Guangdong province south of Shantou and east of Chaoyang. Lupit strengthened before landfall and the maximum sustained wind speed was 50 m.p.h. (80 km/h). Winds to tropical storm force extended out 80 miles (130 km) from the center of Tropical Storm Lupit. The strongest winds were occurring in the parts of Lupit’s circulation that were over water. Strong thunderstorms developed recently near the center of Tropical Storm Lupit. Those thunderstorms were producing gusty winds and they were dropping locally heavy rain.

Tropical Storm Lupit will move around the western end of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Lupit toward the northwest during the next several days. On its anticipated track Tropical Storm Lupit will move along the east coast of China. The center of Lupit could pass near Xiamen in about 24 hours. Tropical Storm Lupit will weaken while the center is over land. However, Lupit could strengthen again if the center moves over the East China Sea. Tropical Storm Lupit will continue to bring gusty winds and locally heavy rain to the northeast coast of Guangdong province and the coastal part of Fujian province.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 14W was passing west of Okinawa and Tropical Storm 15W developed southeast of Japan. At 11:00 p.m. EDT on Wednesday the center of Tropical Depression 14W was located at latitude 26.5°N and longitude 126.5°E which put it about 90 miles (145 km) west of Okinawa. The depression was moving toward the northwest at 7 m.p.h. (11 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 998 mb.

At 11:00 p.m. EDT on Wednesday the center of Tropical Storm 15W was located at latitude 32.1°N and longitude 147.4°E which put it about 510 miles (825 km) southeast of Tokyo,, Japan. The tropical storm was moving toward the north at 16 m.p.h. (26 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 992 mb.

Tropical Storm Lupit Forms Southeast of Hong Kong

Tropical Storm Lupit formed southeast of Hong Kong on Tuesday night. At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Lupit was located at latitude 21.5°N and longitude 115.9°E which put it about 115 miles (185 km) southeast of Hong Kong. Lupit was moving toward the east-northeast 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 994 mb.

The circulation around a low pressure system southeast of Hong Kong exhibited more organization on Tuesday night and the Japan Meteorological Agency designated the system as Tropical Storm Lupit. Winds to tropical storm force extended out 35 miles (55 km) from the center of Lupit. The distribution of thunderstorms around Tropical Storm Lupit was asymmetrical. Most of the thunderstorms were occurring in bands in the southern half of Lupit. Bands on the northern side of the circulation consisted primarily of showers and lower clouds. Tropical Storm Lupit was under the southern part of an upper level ridge over eastern China. The ridge was producing northeasterly winds that were blowing toward the top of Lupit’s circulation. Those winds were causing moderate vertical wind shear and they were the reason for the asymmetrical distribution of thunderstorms.

Tropical Storm Lupit will move through an environment somewhat favorable for intensification during the next 24 hours. Lupit will move over water where the Sea Surface Temperatures are near 29°C. The upper level ridge over eastern China will continue to cause moderate vertical wind shear which will inhibit intensification. The wind shear may not be strong enough to prevent intensification and Tropical Storm Lupit could strengthen during the next 24 hours.

Tropical Storm Lupit will move around the western end of a high pressure system over the Western North Pacific Ocean. The high will steer Lupit toward the northeast during the next 24 hours. On its anticipated track Tropical Storm Lupit could be over the southern Taiwan Strait southeast of Shantou, China in 24 hours. Lupit could produce gusty winds and locally heavy rain over portions of the coast of Eastern China.

Elsewhere over the Western North Pacific Ocean, a tropical depression formed east of Taiwan. At 11:00 p.m. EDT on Tuesday the center of the tropical depression was located at latitude 24.0°N and longitude 125.9°E which put it about 190 miles (305 km) southwest of Okinawa. The tropical depression was moving toward the east-northeast at 4 m.p.h. (6 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 998 mb. The depression is forecast to move toward the northeast and to strengthen. It could bring gusty winds and locally heavy rain to some of the Ryukyu Islands.

Tropical Storm Nepartak Strengthens East of Tokyo

Tropical Storm Nepartak strengthened east of Tokyo on Monday night. At 11:00 p.m. EDT on Monday the center of Tropical Storm Nepartak was located at latitude 35.4°N and longitude 142.3°E which put it about 160 miles (260 km) east of Tokyo, Japan. Nepartak was moving toward the north-northwest at 5 m.p.h. (8 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 992 mb.

Tropical Storm Nepartak exhibited a structure a little more like a tropical cyclone on Monday night. Nepartak was embedded in the center of an upper level low. The center of Tropical Storm Nepartak was under the center of the upper level low and the circulation assumed a more circular shape. Bands of showers and thunderstorms were revolving around the center of Nepartak. Winds to tropical storm force extended out 160 miles (260 km) in the eastern side of the circulation. Winds to tropical storm force extended out 100 miles (160 km) in the western side of Nepartak.

Tropical Storm Nepartak will move through an environment capable of supporting a tropical storm during the next 18 hours. Nepartak will move over water where the Sea Surface Temperatures are near 26°C. Since Tropical Storm Nepartak is embedded at the center of an upper level low, the winds are blowing from the same direction at all levels in the troposphere. So, there will be little vertical wind shear. Tropical Storm Nepartak will likely maintain its intensity during the next 18 hours and it could strengthen a little more.

The upper level low and Tropical Storm Nepartak are forecast to drift toward the northwest during the next 24 hours. On its anticipated track the center of Nepartak could make landfall on the northern coast of Honshu near Sendai in about 18 hours. Tropical Storm Nepartak will bring gusty winds and locally heavy rain to parts of northern Honshu. Nepartak already generated waves along the coast of Honshu and some Olympic events at coastal sites were postponed.

Elsewhere, Tropical Storm In-Fa continued to drop heavy rain over parts of eastern China. At 11:00 p.m. EDT on Monday the center of Tropical Storm In-Fa was located at latitude 31.2°N and longitude 119.5°E which put it about 100 miles (160 km) west of Shanghai, China. In-Fa was moving toward the west-northwest at 4 m.p.h. (6 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 982 mb.