Tag Archives: Tropical Storm Sanba

Tropical Storm Sanba Drops Heavy Rain on Southern China

Tropical Storm Sanba dropped heavy rain on parts of southern China on Thursday. At 5:00 p.m. EDT on Thursday the center of Tropical Storm Sanba was located at latitude 21.3°N and longitude 109.2°E which put it about 25 miles (40 km) southeast of Beihai China. Sanba was moving toward the north-northeast at 8 m.p.h. (13 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 1001 mb.

Tropical Storm Sanba dropped heavy rain on parts of Guangxi and Guangdong in southern China on Thursday. The center of Sanba’s circulation was still over the northeastern Gulf of Tonkin. Much of the northern half of Tropical Storm Sanba was over southern China. Part of the eastern side of Sanba’s circulation was over Hainan. Winds to tropical storm force extended out 60 miles (95 km) from the center of Tropical Storm Sanba.

An upper level trough over eastern Asia and an upper level ridge centered north of the Philippines were interacting to produce southwesterly winds that were blowing toward the top of Sanba’s circulation. Those winds were causing moderate vertical wind shear and they were also causing the distribution of thunderstorms to be asymmetrical. Thunderstorms were occurring in bands in the northern and eastern parts of Tropical Storm Sanba. Bands in the southern and western parts of Sanba’s circulation consisted primarily of showers and lower clouds.

Tropical Storm Sanba will be in an environment that is mostly unfavorable for intensification during the next 24 hours. Sanba will move over water where the Sea Surface Temperatures are near 28°C. The upper level trough over eastern Asia and the upper level ridge north of the Philippines will continue to cause moderate vertical wind shear. Almost half of Sanba’s circulation will be over land and increased friction will slow the wind in those areas. Tropical Storm Sanba is likely to weaken during the next 24 hours even if the center of circulation does not move over southern China.

The movement of Tropical Storm Sanba during the next 24 hours will depend on how strong the vertical wind shear is. If the wind shear is moderate and the upper and lower parts of Sanba’s circulation remain connected, then southwesterly winds will steer Tropical Storm Sanba toward the north-northeast. If Sanba moves north-northeast it will move inland over southern China. If the vertical wind shear gets stronger, then the upper level winds will push the top part of Sanba’s circulation toward the north-northeast. If the wind shear rips the top off of Tropical Storm Sanba, then the lower part of the circulation could meander over the northeastern Gulf of Tonkin during the next 24 hours.

Tropical Storm Sanba will continue to drop heavy rain over southern China during the next 24 hours. Heavy rain will fall on parts of Guangxi and Guangdong. Prolonged heavy rain will cause floods in some locations.

Tropical Storm Sanba Forms East of Vietnam

Tropical Storm Sanba formed over the Gulf of Tonkin east of Vietnam on Wednesday. At 11:00 a.m. EDT on Wednesday the center of Tropical Storm Sanba was located at latitude 18.9°N and longitude 108.2°E which put it about 180 miles (280 km) southeast of Haiphong, Vietnam. Sanba was moving toward the 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 1003 mb.

A low pressure system over the Gulf of Tonkin east of Vietnam strengthened on Wednesday and the Japan Meteorological Agency designated the system as Tropical Storm Sanba. The distribution of thunderstorms in Tropical Storm Sanba was asymmetrical. Many of the thunderstorms were occurring in bands in the eastern side of Sanba’s circulation. Bands in the western part of Tropical Storm Sanba consisted primarily of showers and lower clouds. Storms near the center of Sanba’s circulation generated upper level divergence that pumped mass away to the west and north of the tropical storm. Winds to tropical storm force extended out 50 miles (80 km) in the eastern side of Tropical Storm Sanba. The winds in the western part of Sanba’s circulation were blowing at less than tropical storm force.

Tropical Storm Sanba will move through an environment somewhat favorable for intensification during the next 24 hours. Sanba 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 centered northwest of the Philippines. The upper level ridge will produce southeasterly winds that will blow toward the top of Sanba’s circulation. Those winds will cause some vertical wind shear but the wind shear will not be strong enough to prevent intensification. Some of the air circulating around the eastern side of Tropical Storm Sanba will flow over Hainan. The additional friction caused by the land will cause the air in that part of Sanba’s circulation to slow down. Tropical Storm Sanba could intensify gradually during the next 24 hours.

Tropical Storm Sanba will move around the western part of a high pressure system over the Western North Pacific Ocean. The high pressure system will steer Sanba toward the north-northwest during the next 24 hours. On its anticipated track the center of Tropical Cyclone Sanba will pass west of Hainan. Sanba will move toward northeastern Vietnam.

Bands in the eastern side of Tropical Storm Sanba are already producing gusty winds and locally heavy rain in parts of Hainan. Bands in the western side of Sanba’s circulation are bringing rain showers to parts of northern Vietnam. Tropical Storm Sanba will continue to produce gusty winds and locally heavy rain in parts of Hainan and northern Vietnam. Heavy rain could cause flash floods in some locations.

Tropical Storm Sanba Brings Rain to the Southern Philippines

Tropical Storm Sanba brought rain to the southern Philippines on Monday.  At 10:00 p.m. EST on Monday the center of Tropical Storm Sanba located at latitude 9.9°N and longitude 125.1°E which put it about 100 miles (160 km) east of Cebu, Philippines.  Sanba was moving toward the west-northwest at 19 m.p.h. (31 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.

Tropical Storm Sanba dropped locally heavy rain on parts of northern Mindanao, Siriagao Island, Dinegat Island, Leyte, southern Samar, Bohol and Cebu on Monday.  The circulation of Tropical Storm Sanba was not well organized.  Bands of showers and thunderstorms were occurring to the north and west of the center of circulation.  There were thin bands of showers and low clouds to the south and east of the center.  An upper level ridge to the north of Sanba was producing easterly winds which were blowing over the top of the circulation.  Those winds were causing moderate vertical wind shear which was the primary reason for the asymmetrical distribution of thunderstorms.

Tropical Storm Sanba will move through an environment marginal for intensification.  Sanba will move over water where the Sea Surface Temperature is near 28°C.  The upper level ridge will continue to produce moderate vertical wind shear, which will inhibit intensification.  In addition, the center of circulation will move across Cebu and Negros.  Increased friction caused by the and could weaken Tropical Storm Sanba.  Sanba could intensify a little when the center moves over the Sulu Sea.

A ridge north of Sanba is steering the tropical storm toward the west.  A general motion toward the west is expected to continue for another 24 to 36 hours.  After that time Sanba could move a little more toward the west-northwest.  On its anticipated track Tropical Storm Sanba is forecast to move over Cebu and Negros during the next 12 to 18 hours.  Sanba will move across the Sulu Sea toward Palawan and over the South China Sea.  Tropical Storm Sanba could drop locally heavy rain over Cebu, Negros, Panay and Palawan.  Prolonged heavy rain could cause flooding in some places.

Tropical Storm Sanba Develops Near Palau

Tropical Storm Sanba developed near Palau on Sunday.  At 10:00 a.m. EST on Sunday the center of Tropical Storm Sanba was located at latitude 7.2°N and longitude 133.5°E which put it about 20 miles (35 km) south-southwest of Koror, Palau.  Sanba was moving toward the west at 19 m.p.h. (31 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.

Thunderstorms developed closer to the center of circulation of former Tropical Depression 02W and the Japan Meteorological Agency classified the system as Tropical Storm Sanba.  The distribution of storms was asymmetrical.  The stronger thunderstorms were occurring in bands west of the center of circulation.  The bands in the eastern half of the circulation consisted primarily of showers and lower clouds.  Sanba is moving south of a strong upper level ridge.  The ridge is producing easterly winds which are causing moderate vertical wind shear.  The wind shear is causing the asymmetrical distribution of thunderstorms.

Tropical Storm Sanba will move through an environment marginally favorable for intensification.  Sanba will move over water where the Sea Surface Temperature is near 29°C.  So, there is sufficient energy in the upper ocean to support intensification.  However, the upper level ridge will continue to generate moderate vertical wind shear which will inhibit intensification.  Tropical Storm Sanba could get a little stronger during the next 24 to 36 hours.

The ridge is steering Tropical Storm Sanba toward the west and a general westerly motion is expected to continue.  On its anticipated track Tropical Storm Sanba could approach Mindanao in the southern Philippines in about 36 hours.  Sanba could bring gusty winds and locally heavy rain to parts of the southern Philippines.  Locally heavy rain could cause flash floods.