Tag Archives: 04W

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.

TD 04W Strengthens to Tropical Storm Choi-wan East of Mindanao

Tropical Depression 04W strengthened to Tropical Storm Choi-wan east of Mindanao on Sunday. At 11:00 p.m. EDT on Sunday the center of Tropical Storm Choi-wan was located at latitude 8.2°N and longitude 130.4°E which put it about 260 miles (420 km) east of Mindanao. Choi-wan was moving toward the northwest at 9 m.p.h. (15 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.

The circulation around former Tropical Depression 04W exhibited more organization on Sunday night and the Japan Meteorological Agency named the system as Tropical Storm Choi-wan. Although the circulation around Choi-wan exhibited more organization, the distribution of thunderstorms was asymmetrical. The strongest thunderstorms were occurring in bands in the western side of Tropical Storm Choi-wan. Bands in the eastern half of the tropical storm consisted of showers and lower clouds. Storms west of the center of Choi-wan generated upper level divergence that pumped mass away to the west and south of the tropical storm. Winds to tropical storm force extended out 85 miles (135 km) from the center of circulation.

Tropical Storm Choi-wan will move through an environment 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 southeastern part of an upper level ridge centered northeast of the Philippines. The ridge will produce easterly winds which will blow toward the top of the tropical storm. Those winds are the reason for the asymmetrical distribution of thunderstorms and they will continue to cause vertical wind shear. The wind shear will not be enough to prevent intensification, but the shear will limit the rate of intensification. Tropical Storm Choi-wan will likely intensify during the next 24 hours.

Tropical Storm Choi-wan will move around the western side of a subtropical high pressure system over the Western North Pacific Ocean. The high will steer Choi-wan toward the northwest during the next 36 hours. On its anticipated track Tropical Storm Choi-wan could approach the central Philippines in 36 hours.

Tropical Depression 04W Forms Southwest of Palau

Tropical Depression 04W formed southwest of Palau on Saturday. At 11:00 p.m. EDT on Saturday the center of Tropical Depression 04W was located at latitude 6.8°N and longitude 133.5°E which put it about 75 miles (120 km) southwest of Palau. It was moving toward the west-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.

The circulation around Tropical Depression 04W was still organizing on Saturday night. Bands of thunderstorms were revolving around the center of the depression. The strongest rainbands were in the western half of the circulation. Bands on the eastern side of the tropical depression consisted mainly of showers and lower clouds. Storms near the center of circulation began to generate upper level divergence that pumped mass away to the west and north of the depression.

Tropical Depression 04W will move through an environment favorable for intensification during the next 24 hours. The tropical depression will move over water where the Sea Surface Temperatures are near 30°C. It will move under the southern side of an upper level ridge east of the Philippines. The ridge will produce easterly winds which will blow toward the top of the depression. Those winds will cause vertical wind shear. The wind shear will not be enough to prevent intensification, but the shear will limit the rate of intensification. Tropical Depression 04W will likely intensify into a tropical storm during the next 24 hours.

Tropical Depression 04W will move around the western side of a subtropical high pressure system over the Western North Pacific Ocean. The high will steer the tropical depression toward the northwest during the next 48 hours. On its anticipated track Tropical Depression 04W will move farther away from Palau. The tropical depression is forecast to pass east of the Philippines.

Tropical Storm Hagupit Almost a Typhoon

Tropical Storm Hagupit intensified to almost typhoon strength east of Taiwan on Sunday.  At 11:00 p.m. EDT on Sunday the center of Typhoon Hagupit was located at latitude 25.4°N and longitude 123.2°E which put it about 130 miles (215 km) east of Taipei, Taiwan.  Hagupit was moving toward the north-northwest at 10 m.p.h. (16 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 circulation around Tropical Storm Hagupit exhibited much greater organization on Sunday night.  The inner end of a rainband wrapped around the center of circulation and an eye emerged on visible satellite imagery.  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 Hagupit.  The strongest rainbands were in the eastern half of the circulation.  Bands in the western half of the tropical storm consisted primarily of showers and lower clouds.  Winds to tropical storm force extended out 115 miles (185 km) from the center of circulation.

Tropical Storm Hagupit will move through an environment favorable for intensification during the next 24 hours.  Hagupit will move over water where the Sea Surface Temperature is near 29°C.  It will move through a region where the upper level winds are weak and there will be little vertical wind shear.  Tropical Storm Hagupit will intensify into a typhoon during the next 6 to 12 hours.

Tropical Storm Hagupit will move around the western end of a subtropical high pressure system over the Western North Pacific Ocean.  The high will steer Hagupit toward the north-northwest during the next 24 to 36 hours.  On its anticipated track Hagupit will approach the coast of China south of Shanghai near Wenzhou in about 24 hours.  It will bring gusty winds and locally heavy rain to the east coast of China.  Heavy rain could cause flash floods in some locations.

Elsewhere, former Tropical Storm Sinlaku dropped locally heavy rain on northern Vietnam and Laos.  At 2:00 p.m. EDT on Sunday the center of Tropical Depression Sinlaku was located at latitude 19.7°N and longitude 103.6°E which put it about 150 miles (240 km) north of Vientiane, Laos.  Sinlaku was moving toward the west at 10 m.p.h. (16 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 Storms Sinlaku & Hagupit Form over West Pacific

Tropical Storms Sinlaku and Hagupit formed over the Western North Pacific Ocean on Saturday.  At 11:00 a.m. EDT on Saturday the center of Tropical Storm Sinlaku was located at latitude 19.4°N and longitude 107.1°E which put it about 90 miles (145 km) southeast of Nam Dinh, Vietnam.  Sinlaku was moving toward the northwest at 12 m.p.h. (19 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.

The circulation around a low pressure system near Vietnam exhibited greater organization on Saturday and the Japan Meteorological Agency designated the system as Tropical Storm Sinlaku.  Bands of showers and thunderstorms were revolving around the center of Sinlaku.  There were more thunderstorms in the bands on the western side of the circulation.  Winds to tropical storm force extended out 110 miles (185 km) from the center of circulation.

Tropical Storm Sinlaku has about 12 hours to strengthen before it makes landfall in northern Vietnam.  Sinlaku will move over water where the Sea Surface Temperature is near 30°.  It will move under the southeast part of an upper level ridge over Asia.  The ridge will produce easterly winds which will blow toward the top of Sinlaku.  Those winds will cause moderate vertical wind shear and the shear will limit intensification.  Tropical Storm Sinlaku will bring gusty winds and rain to northern Vietnam on Sunday.

The circulation around a second low pressure system east of Taiwan also exhibited more organization on Saturday and the Japan Meteorological Agency designated that system as Tropical Storm Hagupit.  At 11:00 a.m. EDT on Saturday the center of Tropical Storm Hagupit was located at latitude 21.8°N and longitude 126.5°W which put it about 220 miles (350 km) southeast of Ishigaki, Japan.  Hagupit was moving toward the northwest 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 1003 mb.

The circulation around Tropical Storm Hagupit was still organizing on Saturday.  Thunderstorms were developing in bands in the eastern half of Hagupit.  Bands in the western side of the circulation consisted primarily of showers and lower clouds.  Storms near the center of Hagupit were generating upper level divergence which was pumping mass away to the east of the tropical storm.

Tropical Storm Hagupit will move through an environment favorable for intensification.  Hagupit will move over water where the Sea Surface Temperature is near 30°C.  Hagupit will move into a region where the upper level winds are weaker and there will not be a lot of vertical wind shear.  Tropical Storm Hagupit is likely to intensify during the next 24 to 36 hours.

Tropical Storm Hagupit will move around the western end of a high pressure system over the Western North Pacific Ocean.  The high will steer Hagupit toward the northwest during the next several days.  On its anticipated track the center of Tropical Storm Hagupit will pass near Ishigaki, Japan in about 24 hours.  Hagupit will approach the coast of China south of Shanghai in about 48 hours.

Tropical Depression 04W Forms East of the Northern Marianas

Tropical Depression 04W formed east of the Northern Marianas very late on Friday.  At 11:00 p.m. EDT on Friday the center of Tropical Depression 04W was located at latitude 18.8°N and longitude 148.5°E which put it about 185 miles (300 km) east of Agrihan.  It was moving toward the northwest at 11 m.p.h. (17 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.

An area of showers and thunderstorms persisted for much of the past week east of the Northern Marianas.  Several smaller centers of circulation formed within the area of showers and storms, but those centers ran into strong upper level winds and weakened because strong vertical wind shear and they dissipated.  Another center formed on Friday, but the upper level winds were a little weaker and the center persisted.  An upper level trough south of Japan was still producing southwesterly winds which were blowing toward the top of the circulation.  Those winds were producing moderate vertical wind shear, but the center of circulation persisted.  Most of the thunderstorms were occurring in bands east of the center of circulation.  The bands west of the center consisted primarily of low clouds and showers.

Tropical Depression will move through an area marginally favorable for intensification during the next 24 hours.  it will move over water where the Sea Surface Temperatures are near 28°C.  So, there will be enough energy in the upper ocean to support some intensification.  The upper level trough south of Japan will continue to cause moderate vertical wind shear, but the upper level winds could be weak enough to allow for further intensification.  Tropical Depression 04W could strengthen into a tropical storm on Saturday.

Tropical Depression 04W is moving near the southwestern part of a ridge over the North Pacific Ocean.  The ridge is steering the depression toward the northwest and that general motion is expected to continue for another day or two.  On its anticipated track Tropical Depression 04W is expected to pass near the northernmost Mariana Islands.  It could pass near Asuncion Island, the Maug Islands, Supply Reef and Farallon de Pajaros.  Tropical Depression 04W could bring gust winds, locally heavy rain and higher waves to those places.

Tropical Storm Merbok Makes Landfall Near Hong Kong

Tropical Storm Merbok made landfall near Hong Kong on Monday.  At 5:00 p.m. EDT on Monday the center of Tropical Storm Merbok was located at latitude 23.5°N and longitude 114.9°E which put it about 55 miles (85 km) north-northeast of Hong Kong.  Merbok was moving toward the north 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 1005 mb.

Tropical Storm Merbok intensified before it made landfall and the maximum sustained wind speed was around 55 m.p.h. (85 km/h) at the time of landfall.  Merbok began to weaken after landfall and the strongest winds are now occurring in bands over the the open water.  Merbok is producing locally heavy rain in bands east of the center if circulation.  The heavy rains represent the greatest risk and flooding is possible over parts of eastern China.  Merbok is a fairly small tropical storm and the heavier rain will fall primarily to the east of the track of Merbok.  Merbok should gradually spin down as it moves farther inland.