Tag Archives: 19W

Tropical Storm Leepi Approaches Kyushu

Tropical Storm Leepi approached Kyushu late on Monday.  At 11:00 p.m. EDT on Monday the center of Tropical Storm Leepi was located at latitude 29.8°N and longitude 135.3°E which put it about 335 miles (545 km) east-southeast of Kagoshima, Japan.  Leepi was moving toward the northwest at 17 m.p.h. (28 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 983 mb.

The circulation of Tropical Storm Leepi became much better organized on Monday.  A large circular clear area formed at the center of circulation, which represented the formation of an eye.  A primary band of showers and thunderstorms wrapped most of the way around the formative eye and the strongest winds were occurring in that band of storms.  Several bands of showers and thunderstorms in the eastern half of the circulation were revolving around the core of Tropical Storm Leepi.  Bands northwest of the center consisted mostly of showers and lower clouds.  Winds to tropical storm force extend out about 110 miles (170 km) from the center of circulation.  Storms around the center of Tropical Storm Leepi were generating upper level divergence that was pumping mass away from the tropical storm.

Tropical Storm Leepi will move through an environment that will become less favorable on Tuesday.  Leepi will move over water where the Sea Surface Temperature is near 28°C which means there will be enough energy to support a strong tropical storm.  However, an upper level ridge northwest of Japan will produce northeasterly winds which will cause significant vertical wind shear.  The wind shear will cause Tropical Storm Leepi to start to weaken when it nears Japan.

The ridge northwest of Japan will steer Tropical Storm Leepi toward the northwest on Tuesday.  On its anticipated track the center of Tropical Storm Leepi will reach southeastern Kyushu in about 18 hours.  Leepi will bring gusty winds and locally heavy rain to Kyushu late on Tuesday.  The locally heavy rain could create the potential for flash floods.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Bebinca meandered southwest of Hong Kong and Tropical Storm Hector move westward across the International Date Line.  At 11:00 p.m. EDT on Monday the center of Tropical Storm Bebinca was located at latitude 21.1°N and longitude 113.8°E which put it about 100 miles (160 km) south-southwest of Hong Kong.  Bebinca was moving toward the north-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. (95km/h).  The minimum surface pressure was 989 mb.

At 11:00 p.m. EDT on Monday the center of Tropical Storm Hector was located at latitude 26.2°N and longitude 176.2°E which put it about 760 miles (1225 km) east-northeast of Wake Island.  Hector was moving toward the west at 18 m.p.h. (29 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 1003 mb.

Tropical Storm Yagi Makes Landfall on East Coast of China

Tropical Storm Yagi made landfall on the east coast of China between Wenzhou and Taizhou on Sunday.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Yagi was located at latitude 28.4°N and longitude 121.7°E which put it about 35 miles (55 km) south of Taizhou, China.  Yagi was moving toward the 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 987 mb.

Tropical Storm Yagi was moving steadily inland over Zhejiang province between Wenzhou and Taizhou.  The strongest winds were occurring in bands of thunderstorms east of the center of circulation that were over the coastal waters of the East China Sea.  The wind in those areas will diminish when Yagi moves farther inland.  The greatest risk will be locally heavy rain falling over parts of Zhejiang province.  Rainfall could be enhanced where the wind blows up the slopes of mountains and steep terrain increases the potential for flash floods.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Leepi moved closer to Iwo To and Tropical Depression 20W formed southwest of Hong Kong.  At 11:00 a.m. EDT on Sunday the center of Tropical Storm Leepi was located at latitude 24.1°N and longitude 141.2°E which put it about 85 miles (135 km) south-southeast of Iwo To.  Leepi was moving toward the north-northwest at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 55 m.p.h. (90 km/h) and there were wind gusts to 70 m.p.h. (110 km/h).  The minimum surface pressure was 992 mb.

At 11:00 a.m. EDT on Sunday the center of Tropical Depression 20W was located at latitude 20.7°N and longitude 112.4°E which put it about 85 miles (135 km) southwest of Macao.  It was moving toward the east-southeast at 3 m.p.h. (5 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 996 mb.

Tropical Storm Leepi Forms Southeast of Iwo To

Tropical Storm Leepi formed southeast of Iwo To on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Leepi was located at latitude 21.5°N and longitude 142.7°W which put it about 285 miles (465 km) south-southeast of Iwo To.  Leepi was moving toward the north-northwest at 12 m.p.h. (19 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.

A distinct center of circulation developed within an area of thunderstorms between the Northern Marianas and Iwo To and the Japan Meteorological Agency designated the system as Tropical Storm Leepi.  The distribution of thunderstorms around Tropical Storm Leepi was very asymmetrical.  The stronger thunderstorms were all occurring in bands in the eastern half of the circulation.  The bands in the western half of the circulation consisted of showers and low clouds.  Storms near the center of Leepi were generating upper level divergence which was pumping mass away to the northeast of the tropical storm.

Tropical Storm Leepi will move through an environment somewhat favorable for intensification during the next 12 to 24 hours.  Leepi will move over water where the Sea Surface Temperature is near 29°C.  An upper level trough northeast of the tropical storm was producing southwesterly winds which were causing moderate vertical wind shear.  The wind shear was inhibiting the divergence to the west of Tropical Storm Leepi.  The tropical storm also appeared to be drawing drier air into the western side of the circulation.  Leepi could intensify on Sunday, but it will move into an area of stronger upper level winds in a day or so.  Increased vertical wind shear will likely start to weaken Tropical Storm Leepi after that occurrs.

Tropical Storm Leepi will move near the western end of a ridge in the middle troposphere.  The ridge will Leepi in a general motion toward the northwest.  On its anticipated track Tropical Storm Leepi will move near Iwo To in about 24 hours.  Leepi could approach the northern Ryukyu Islands and Kyushu in about three days.

Elsewhere over the Western North Pacific, Tropical Storm Yagi passed over the southern Ryukyu Islands on Saturday.  At 5:00 p.m. EDT on Saturday the center of Tropical Storm Yagi was located at latitude 25.6°N and longitude 124.8°E which put it about 250 miles (400 km) east of Taipei, Taiwan.  Yagi was moving toward the west 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 993 mb.

Tropical Storm Vamco Forms East of Vietnam

A large area of low pressure east of Vietnam developed enough organization on Sunday to be classified as Tropical Storm Vamco.  At 11:00 p.m. EDT on Sunday the center of Tropical Storm Vamco was located at latitude 14.8°N and longitude 110.0°E which put it about 160 miles (260 km) east-southeast of Da Nang, Vietnam.  Vamco was moving toward the west 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 1000 mb.

Although there is a large area of low pressure, the circulation around Tropical Storm Vamco is not well organized.  Most of the thunderstorms are located in a large rainband about 100 miles (160 km) from the center of circulation that wraps around the northern and western parts of the storm.  There are not many thunderstorms located near the center of the circulation.  Vamco is located over water where the Sea Surface Temperature is near 30°C.  However, an upper level ridge is generating northeasterly winds over the top of the storm and the vertical wind shear is inhibiting development.  Some intensification is possible in the short term, but the lack of a well formed inner core and proximity to land will limit strengthening.

A subtropical ridge north of Vamco is steering the tropical storm toward the west and that steering pattern is expected to continue.  On its anticipated track the center of Vamco will reach the central coast of Vietnam in about 18 hours.  The primary impacts will be locally heavy rainfall and the potential for flooding.