Tag Archives: Tropical Storm Nepartak

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.

Tropical Storm In-Fa Makes Landfall near Shanghai

Tropical Storm In-Fa made landfall on the east coast of China near Shanghai on Sunday. At 5:00 p.m. EDT on Sunday the center of Tropical Storm In-Fa was located at latitude 30.6°N and longitude 121.4°E which put it about 50 miles (80 km) south of Shanghai, China. In-Fa was moving toward the northwest at 6 m.p.h. (10 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 In-Fa weakened slowly as it approached the east coast of China. The circulation around In-Fa pulled drier air from Asia into the western side of the former typhoon. The drier air caused thunderstorms in the western half of Tropical Storm In-Fa to weaken. The strongest thunderstorms were occurring in bands on the eastern side of In-Fa. Bands in the western half of the tropical storm consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 165 miles (270 km) on the eastern side of In-Fa. The strongest winds were occurring over the waters of the East China Sea. Winds to tropical storm force extended out 80 miles on the western side of the circulation.

Tropical Storm In-Fa will move slowly toward the northwest, which will take it farther inland over eastern China. The circulation around In-Fa will weaken gradually as the tropical storm moves farther inland. Tropical Storm In-Fa will bring gusty winds and locally heavy rain to the region around Shanghai and Ningbo. Heavy rain could cause flash floods in some locations.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Nepartak swirled southwest of Japan. At 5:00 p.m. EDT on Sunday the center of Tropical Storm Nepartak was located at latitude 33.4°N and longitude 149.7°E which put it about 630 miles (1015 km) east-southeast of Tokyo, Japan. Nepartak was moving toward the north at 13 m.p.h. (20 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 998 mb.

Weakened Tropical Storm Nepartak Still Bringing Rain to Parts of China and Taiwan

Although Tropical Storm Nepartak was weakened significantly during its passage over the mountains on Taiwan, it is still producing heavy rain over portions of eastern China and Taiwan.  At 5:00 p.m. EDT on Friday the center of Tropical Storm Nepartak was located at latitude 24.0°N and longitude 119.0°E which put it about 100 miles (160 km) east-southeast of Xiamen, China.  Nepartak was moving toward the northwest at 5 m.p.h. (8 km/h).  The maximum sustained wind speed was 70 m.p.h. (115 km/h) and there were wind gusts to 85 m.p.h. (140 km/h).  The minimum surface pressure was 978 mb.

Typhoon Nepartak brought damaging winds and heavy rainfall to Taiwan when the core of the tropical cyclone passed over that area.  The mountains on Taiwan significantly disrupted the lower levels of the circulation.  There are some indications on satellite imagery that the upper portion of the circulation is located northwest of the surface center.  When a typhoon crosses Taiwan, the mountains can cause the original center of circulation to weaken and a new center can sometimes form over the water on the downstream side of the island.

In any case, crossing over Taiwan caused Nepartak to weaken to a tropical storm and the circulation no longer exhibits a tight inner core.  However, there are still rainbands that are producing heavy rain and wind speeds to almost typhoon force.   Because Nepartak no longer has a tight inner core, it is unlikely to intensify significantly before the centers moves into eastern China.

A ridge northeast of Nepartak is steering the tropical storm toward the northwest and that general motion is expected to continue for the next 12 to 24 hours.  After that time Nepartak is expected to turn toward the north.  On its anticipated track Tropical Storm Nepartak will make landfall in China between Xiamen and Fuqing on Saturday.

Tropical Storm Nepartak could produce locally heavy rainfall over portions of eastern China.  Some of that region has already received a lot of rain from other weather systems.  So, the potential for additional flooding is high in some areas.

Tropical Storm Nepartak Develops South of Guam

A center of circulation organized within an area of thunderstorms south of Guam and the system was designated Tropical Storm Nepartak.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Nepartak was located at latitude 12.2°N and longitude 141.4°E which put it about 215 miles (345 km) west-southwest of Guam.  Nepartak was moving northwest at 16 m.p.h. (26 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 989 mb.

The circulation of Tropical Storm Nepartak is still organizing.  A primary rainband wrapped around the center and a circular area of thunderstorms formed at the core of the circulation.  The area of thunderstorms is generating upper level divergence which is pumping out mass and allowing the surface pressure to decrease.  Winds to tropical storm force extend our about 100 miles (160 km) from the center of circulation.

An upper level low located north of Nepartak is producing southwesterly winds which area blowing over the top of the tropical storm.  Those winds are creating some vertical wind shear, which is slowing the intensification of Nepartak.  However, the upper low is also enhancing upper level divergence to the northeast of the tropical storm.  Nepartak is moving over water where the Sea Surface Temperature is near 30°C.  The environment is favorable for intensification and Nepartak could become a hurricane during the next several days.

A subtropical ridge located northeast of Nepartak is steering the tropical storm toward the northwest.  That general motion is expected to continue during the next few days.  On its anticipated track, Nepartak could be approaching the southernmost islands of Japan in three or four days.  It is likely to be a typhoon at that time.