Tag Archives: Puerto Princesa

Typhoon Rai Moves over South China Sea

Typhoon Rai moved over the South China Sea on Friday. At 4:00 p.m. EST on Friday the center of Typhoon Rai was located at latitude 10.9°N and longitude 116.6°E which put it about 175 miles (285 km) west-northwest of Puerto Princesa, Philippines. Rai was moving toward the west-northwest at 14 m.p.h. (22 km/h). The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (230 km/h). The minimum surface pressure was 956 mb.

Typhoon Rai strengthened back to the equivalent of a major hurricane after it moved across Palawan and over the South China Sea. An eye with a diameter of 30 miles (50 km) developed at the center of Rai’s circulation. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Typhoon Rai. Storms near the core generated upper level divergence that pumped mass away to the west and north of the typhoon.

Winds to typhoon force extended out 40 miles (65 km) from the center of Typhoon Rai. Winds to tropical storm force extended out 165 miles (270 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Rai was 20.6. The Hurricane Size Index (HSI) was 16.4 and the Hurricane Wind intensity Size Index (HWISI) was 37.0. Rai was capable of causing regional major damage.

Typhoon Rai will move through an environment favorable for intensification during the next 24 hours. Rai 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 over the Western North Pacific Ocean. The ridge will produce easterly winds that will blow toward the top of Typhoon Rai’s circulation. Those winds will cause some vertical wind shear but the wind shear will be too small to prevent intensification. Typhoon Rai could strengthen again during the next 24 hours.

Typhoon Rai will move south of a surface high pressure system over the Western North Pacific Ocean during the next day or so. The high pressure system will steer Rai toward the west-northwest during the next 24 hours. Rai will move more toward the northwest when it reaches the western end of the high pressure system. On its anticipated track Typhoon Rai could approach the coast of Vietnam in 36 hours.

Typhoon Rai Brings Wind and Rain to the Southern Philippines

Typhoon Rai brought wind and rain to the southern Philippines on Thursday. At 10:00 p.m. EST on Thursday the center of Typhoon Rai was located at latitude 10.0°N and longitude 120.4°E which put it about 140 miles (225 km) east of Puerto Princesa, Philippines. Rai was moving toward the west at 16 m.p.h. (26 km/h). The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (230 km/h). The minimum surface pressure was 956 mb.

Typhoon Rai brought strong winds and heavy rain as it moved across the southern Philippines on Thursday. The core of Typhoon Rai affected Siarago Island, Dinagat Island, northern Mindanao, southern Leyte, Bohol, Cebu, Negros and southern Panay Island. There were reports of wind damage, power outages and flash floods across the southern Philippines.

Typhoon Rai moved over the Sulu Sea on Thursday night and its structure remained well organized. A circular eye was present at the center of Rai’s circulation. The eye was surrounded by a broken 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 Typhoon Rai. Storms near the core of Rai generated upper level divergence that pumped mass away to the west and north of the typhoon.

Winds to typhoon force extended out 45 miles (75 km) from the center of Typhoon Rai. Winds to tropical storm force extended out 155 miles (245 km) from the center of circulation. The Hurricane Intensity Index (HII) for Typhoon Rai was 20.6. The Hurricane Size Index (HSI) was 13.9 and the Hurricane Wind intensity Size Index (HWISI) was 34.5. Rai was capable of causing regional major damage.

Although Typhoon Rai weakened when the center passed over the islands of the southern Philippines, it will move through an environment capable of supporting a strong typhoon as it moves over the Sulu Sea. Rai 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 over the Western North Pacific Ocean. The ridge will produce easterly winds that will blow toward the top of Typhoon Rai’s circulation. Those winds will cause some vertical wind shear but the wind shear will be too small to cause much weakening. Typhoon Rai is likely to maintain its intensity during the next 24 hours. Rai could strengthen when it moves over the South China Sea during the weekend.

Typhoon Rai will move south of a surface high pressure system over the Western North Pacific Ocean. The high pressure system will steer Rai toward the west during the next 24 hours. On its anticipated track the core of Typhoon Rai will move across Palawan during the next 12 hours. Rai will be capable of causing major damage. It will bring strong winds and heavy rain to Palawan on Friday. Typhoon Rai will move over the South China Sea during the weekend. Rai could approach Vietnam by the end of the weekend.

Tropical Storm Kai-tak Weakens Over the Philippines

Tropical Storm Kai-tak weakened as it passed over the Philippines.   Kai-tak dropped heavy rain which caused floods and mudslides before it weakened.  At 10:00 p.m. EST on Sunday the center of Tropical Storm Kai-tak was located at latitude 10.5°N and longitude 119.1°E which put it about 75 miles (120 km) northeast of Puerto Princesa, Philippines.  Kai-tak was moving toward the west-southwest 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.

Moving over islands of the central Philippines disrupted parts of the circulation of Tropical Storm Kai-tak.  In addition an upper level ridge produced strong easterly winds which blew across the top of the circulation.  Those winds caused moderate vertical wind shear.  The strong upper level winds periodically weakened the thunderstorms near the core of the circulation.  The upper level winds slowed at times and more storms developed near the center of Tropical Storm Kai-tak.  The persistent vertical wind shear weakened the low level circulation.

More thunderstorms developed near the center of Tropical Storm Kai-tak during recent hours, but the circulation remains asymmetrical.  The new storms were forming west of the center of circulation.  There were only a few thin bands of showers in the eastern half of the circulation.  The strongest winds were occurring in the thunderstorms west of the center of Tropical Storm Kai-tak.  The Japan Meteorological Agency was maintaining a classification of a tropical storm.

Tropical Storm Kai-tak will move through an environment only marginally favorable for intensification.  Kai-tak will move over water where the Sea Surface Temperature is near 29°C.  The upper level ridge will continue to produce strong easterly winds and there will continue to be moderate vertical wind shear.  Tropical Storm Kai-tak could maintain its intensify, if the wind shear does not increase.  However, if the upper level winds get stronger, then they could blow the top off of the circulation.

Tropical Storm Kai-tak is moving south of a subtropical ridge which is steering the tropical storm toward the west-southwest.  The west-southwesterly motion is forecast to continue for another day or two.  On its anticipated track Tropical Storm Kai-tak will move across Palawan and over the South China Sea.