Tag Archives: Tropical Depression 10W

Tropical Storm Bavi Intensifies

Tropical Storm Bavi was intensifying over the Western North Pacific Ocean east of the Marianas on Wednesday night.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Bavi was located at latitude 11.2°N and longitude 159.7°E which put the center about 1050 miles (1690 km) east of Guam.  Bavi was moving toward the west-northwest at 15 m.p.h. (24 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 996 mb.

Former Tropical Depression 09W intensified on Wednesday and the Japan Meteorological Agency designated the system as Tropical Storm Bavi.

The circulation around Tropical Storm Bavi exhibited much more organization on Wednesday evening.  The inner end of a rainband wrapped around the western side of the center of Bavi’s circulation.  Other bands of showers and thunderstorms were revolving around the center of Tropical Storm Bavi.  Storms near the center of Bavi generated more upper level divergence that pumped mass away from the tropical storm.  The removal of more mass caused the surface pressure to decrease.

The distribution of wind speeds in Tropical Storm Bavi became more symmetrical on Wednesday.  Winds to tropical storm force extended out 80 miles (130 km) from the center of Bavi’s circulation.

Tropical Storm Bavi will more through an environment that will be very favorable for intensification during the next 24 hours.  Bavi will move over water where the Sea Surface Temperatures are 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 Bavi is likely to intensify to a typhoon during the next 24 hours.  Bavi could intensify rapidly at times.  Tropical Storm Bavi is likely to strengthen to the equivalent of a major hurricane by the weekend.

Tropical Storm Bavi will move around the southern side of a high pressure system that is over the Western North Pacific Ocean.  The high pressure system will steer Bavi toward the west-northwest during the next 24 hours.  On its anticipated track, Tropical Storm Bavi could reach the Marianas in less than four days.

Tropical Storm Bavi is likely to intensify to the equivalent of a major hurricane before it reaches the Marianas.

Elsewhere over the Western North Pacific Ocean, Tropical Depression 10W formed over the South China Sea.  At 11:00 p.m. EDT on Wednesday the center of Tropical Depression 10W was located at latitude 17.7°N and longitude 112.6°E which put the center about 250 miles (400 km) east-southeast of Sanya, China.  The tropical depression was moving toward the west at 21 m.p.h. (33 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 10W is forecast to strengthen to a tropical storm before it reaches Hainan.  It will bring strong winds and locally heavy rain to Hainan.  Heavy rain could cause flash floods in some locations.

Typhoon Prapiroon Brings Wind and Rain to Kyushu

Typhoon Prapiroon brought wind and rain to Kyushu on Monday night.  At 11:00 p.m. EDT on Monday the center of Typhoon Prapiroon was located at latitude 32.8°N and longitude 128.6°E which put it about 110 miles (180 km) southwest of Sasebo, Japan.  Prapiroon was moving toward the north-northeast at 17 m.p.h. (27 km/h).  The maximum sustained wind speed was 80 m.p.h. (130 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 968 mb.

Rainbands on the eastern side of Typhoon Prapiroon were moving over parts of Kyushu.  Those bands were causing gusty winds and they were dropping locally heavy rain.  The circulation of Typhoon Prapiroon was exhibiting the effects of a more midlatitude environment.  Drier air was wrapping around the western and southern portions of the typhoon.  The bands in those parts of Prapiroon consisted primarily of showers and low clouds.  The western portion of the eyewall was also weakening.  There were still strong thunderstorms in the eastern half of the eyewall and that was where the strongest winds were occurring.  Several bands of showers and thunderstorms on the eastern side of the circulation were revolving around the core of Typhoon Prapiroon.

Typhoon Prapiroon will be moving through an environment that will cause it to weaken.  Prapiroon was moving over water where the Sea Surface Temperature was near 26°C.  However, it will move over water where the Sea Surface Temperature is near 24°C when it moves north of Japan.  An upper level trough west of South Korea will produce southwesterly winds which will cause vertical wind shear.  The combination of cooler water and more vertical wind shear will cause Typhoon Prapiroon to weaken to a tropical storm on Tuesday.  Prapiroon could begin a transition to an extratropical cyclone because of the effects of the midlatitude environment.

Typhoon Prapiroon was being steered toward the north-northeast by the upper level trough.  Stronger westerly winds will steer Prapiroon more toward the northeast when it gets north of Japan.  On its anticipated track the center of Typhoon Prapiroon will pass near the northwestern portion of Kyushu.  The center of Prapiroon is forecast to pass between south Korean and Japan and then to move over the Sea of Japan.  Rainbands on the eastern side of Typhoon Prapiroon will cause gusty winds and drop heavy rain over parts of Kyushu.  Heavy could cause flash floods in some locations.  Prapiroon could also bring wind and rain to southeastern South Korea and parts of northern Honshu.

Elsewhere over the Western North Pacific Ocean Tropical Depression 10W formed southeast of Guam.  At 11:00 p.m. EDT on Monday the center of Tropical Depression 10W was located at latitude 10.6°N and longitude 145.7°E which put it about 205 miles (330 km) south-southeast of Guam.  It was moving toward the north-northwest at 6 m.p.h. (10 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 1003 mb.  A Tropical Storm Warning was issued for Guam.  A Tropical Storm Watch was issued for Tinian and Saipan.