Tag Archives: Surigao

Typhoon Ragasa Brings Wind and Rain to Hong Kong

Typhoon Ragasa brought wind and rain to Hong Kong on Tuesday night.  At 11:00 p.m. EDT on Tuesday the center of Typhoon Ragasa was located at latitude 21.3°N and longitude 113.2°E which put the center about 80 miles (130 km) south-southwest of Hong Kong.  Ragasa was moving toward the west at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 944 mb.

The center of Typhoon Ragasa passed south of Hong Kong on Tuesday night.  A weather station at the airport in Hong Kong (VHHH) reported a sustained wind speed of 47 kt (54 m.p.h. or 87 km/h) and a wind gust of 66 kt (76 m.p.h. or 122 km/h).

The inner end of a rainband wrapped around the existing eye and eyewall in Typhoon Ragasa as it was passing south of Hong Kong.  A second outer eyewall appeared to be developing.  The formation of concentric eyewalls could start another eyewall replacement cycle.  Bands of showers and thunderstorms were revolving around the core of Typhoon Ragasa.  Storms near the core generated upper level divergence that pumped mass away from the typhoon.

The circulation around Typhoon Ragasa was large.  Winds to typhoon force extended out 60 miles (95 km) from the center of Ragasa’s circulation.  Winds to tropical storm force extended out 190 miles (305 km) from the center of Typhoon Ragasa.

The Hurricane Intensity Index (HII) for Typhoon Ragasa is 25.1.  The Hurricane Size Index (HSI) is 20.8 and the Hurricane Wind Intensity Size Index (HWISI) is 45.9.  Typhoon Ragasa is similar in intensity to Hurricane Harvey when Harvey hit Texas in 2017.  Ragasa is larger than Harvey was.

Typhoon Ragasa will move through an environment that will be favorable for a powerful typhoon during the next few hours.  Ragasa 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.  Even though Typhoon Ragasa will move through a favorable environment, another eyewall replacement cycle would cause Ragasa to weaken.

Typhoon Ragasa will move around the southern side of a high pressure system over China.  The high pressure system will steer Ragasa toward the west during the next 24 hours.  On its anticipated track, the center of Typhoon Ragasa will make landfall on the coast of southern China west of Macau in 12 hours.

Typhoon Ragasa will bring strong winds and heavy rain to Guangxi and to western Guangdong.  Heavy rain is likely to cause floods in some locations.  Typhoon Ragasa could cause a storm surge of up to 13 feet (4 meters) along portions of the coast.  Ragasa could also drop heavy rain over northern parts of Vietnam and Laos.

Elsewhere over the Western North Pacific Ocean, Tropical Storm Bualoi formed east of the Philippines and former Typhoon Neoguri weakened to a tropical storm far to the east of Japan.

At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Bualoi was located at latitude 9.5°N and longitude 133.4°E which put the center about 535 miles (865 km) east of Surigao, Philippines.  Bualoi was moving toward the west-southwest at 11 m.p.h. (17 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.

At 11:00 p.m. EDT on Tuesday the center of Tropical Storm Neoguri was located at latitude 30.6°N and longitude 154.6°E which put the center about 910 miles (1465 km) east-southeast of Tokyo, Japan.  Neoguri was moving toward the east at 6 m.p.h. (10 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 978 mb.