Tag Archives: Tonga

Tropical Cyclone Yasa Passes West of Tonga

Tropical Cyclone Tonga passed west of Tonga on Friday. At 4:00 p.m. EST on Friday the center of Tropical Cyclone Yasa was located at latitude 20.6°S and longitude 178.0°W which put it about 280 miles (305 km) west of Nuku’Alofa, Tonga. Yasa was moving toward the south at 9 m.p.h. (15 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 974 mb.

After making a direct hit on Vanua Levu, Tropical Cyclone Yasa moved over the Fiji islands in the Lau Group. There were reports of damage and casualties from Fiji. Tropical Cyclone Yasa weakened after it made landfall on Vanua Levu. The eye and eyewall were disrupted by passage over land. An upper level low centered north of New Zealand produced northerly winds which blew toward the top of Yasa’s circulation on Friday. Those winds caused moderate vertical wind shear and the shear caused the tropical cyclone to weaken steadily on Friday.

The circulation around Tropical Cyclone Yasa exhibited less organization on Friday. The strongest thunderstorms were occurring in a band in the southern half of the circulation. Bands in the northern half of Yasa consisted primarily of showers and lower clouds. The circulation around Tropical Cyclone Yasa was still large. Winds to tropical storm force extended out 200 miles (320 km) from the center of circulation.

Tropical Cyclone Yasa will move through an environment that is mostly unfavorable for intensification during the next several days. Yasa will move over water where the Sea Surface Temperature is near 27°C. However, the upper level low centered north of New Zealand will continue to cause moderate vertical wind shear. The shear is likely to be strong enough to cause Tropical Cyclone Yasa to continue to weaken.

Tropical Cyclone Yasa will move around the eastern side of the upper level low. The low will steer Yasa toward the southwest during the next 48 hours. On its anticipated track Tropical Cyclone Yasa will pass west of Tonga and it will remain north of New Zealand.

Tropical Cyclone Zazu Brings Wind and Rain to Northern Tonga

Tropical Cyclone Zazu brought wind and rain to northern Tonga on Monday. At 10:00 a.m. EST on Monday the center of Tropical Cyclone Zazu was located at latitude 18.9°S and longitude 174.4°W which put it about 40 miles (65 km) west of Neiafu, Tonga. Zazu was moving toward the south-southwest at 6 m.p.h. (10 km/h). The maximum sustained wind speed was 50 m.p.h. (80 km/h) and there were wind gusts to 65 m.p.h. (105 km/h). The minimum surface pressure was 991 mb.

Tropical Cyclone Zazu brought wind and rain to the Vava’u Group of islands in northern Tonga on Monday. The circulation around Zazu was intensifying. The inner end of a rainband wrapped partly around the eastern side of the center of circulation. Storms near the center generated upper level divergence which pumped mass away from the tropical cyclone. Thunderstorms were occurring in bands in the eastern half of Tropical Cyclone Zazu. Bands in the western half of the circulation consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 150 miles (240 km) on the eastern side of Zazu. Winds to tropical storm force extended out 75 miles (120 km) in the western half of the circulation.

Tropical Cyclone Zazu will move through an environment favorable for intensification during the next 24 hours. Zazu will move over water where the Sea Surface Temperature is near 29°C. It will move south of an upper level trough over the South Pacific Ocean. The trough will produce westerly winds which will blow toward the top of Zazu. Those winds will cause some vertical wind shear and they are contributing to the asymmetrical distribution of thunderstorms. The shear will inhibit intensification of Tropical Cyclone Zazu, but the shear will not be strong enough to prevent Zazu from intensifying. Tropical Cyclone Zazu could strengthen into the equivalent of a hurricane/typhoon during the next 24 hours. The vertical wind shear will increase in a day or so, and Zazu will start to weaken when that happens.

The upper level trough will start to steer Tropical Cyclone Zazu toward the southeast during the next 24 hours. On its anticipated track Zazu will move between Tonga and Niue. Tropical Cyclone Zazu will continue to cause gusty winds and heavy rain over parts of Tonga during the next 24 hours. Rainbands on the eastern side of Zazu could affect Niue on Tuesday.

Elsewhere over the South Pacific Ocean, Tropical Cyclone Yasa strengthened to the equivalent of a hurricane/typhoon west-northwest of Fiji. At 10:00 a.m. EST on Monday the center of Tropical Cyclone Yasa was located at latitude 15.5°S and longitude 171.6°E which put it about 400 miles (640 km) west-northwest of Nadi, Fiji. Yasa was moving toward the north-northwest at 3 m.p.h. (5 km/h). The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h). The minimum surface pressure was 976 mb. Tropical Cyclone Yasa is forecast to move toward Fiji and to intensify into the equivalent of a major hurricane.

Tropical Cyclone Yasa Strengthens between Fiji and Vanuatu

Tropical Cyclone Yasa strengthened between Fiji and Vanuatu on Sunday. At 4:00 p.m. EST on Sunday the center of Tropical Cyclone Yasa was located at latitude 15.7°S and longitude 172.1°E which put it about 380 miles (610 km) west-northwest of Nadi, Fiji. Yasa was moving toward the west-southwest at 4 m.p.h. (6 km/h). The maximum sustained wind speed was 65 m.p.h. (105 km/h) and there were wind gusts to 80 m.p.h. (130 km/h). The minimum surface pressure was 982 mb.

Tropical Cyclone Yasa strengthened on Sunday after the circulation of former Tropical Cyclone 04P was absorbed by the larger circulation around Yasa. The inner end of a rainband wrapped around the eastern side of the center of circulation. Other bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Yasa. Storms near the center generated upper level divergence which pumped mass away from the tropical cyclone. Winds to tropical storm force extended out 120 miles (195 km) from the center of circulation.

Tropical Cyclone Yasa will be in an environment favorable for intensification during the next several days. Yasa will be over water where the Sea Surface Temperature is near 29°C. It will be in a region where the upper level winds are weak and there will be little vertical wind shear. Tropical Cyclone Yasa will likely intensify into the equivalent of a hurricane/typhoon during the next 18 hours. It could strengthen to the equivalent of a major hurricane in about three days.

Tropical Cyclone Yasa will be in an area where the steering winds are weak during the next 24 hours. Yasa is forecast to make a slow clockwise loop during the next 24 to 36 hours. Eventually, a high pressure system over the South Pacific Ocean will start to steer Tropical Cyclone Yasa toward the southeast. On its anticipated track Tropical Cyclone Yasa could approach Fiji in about four days.

Elsewhere over the South Pacific Ocean, Tropical Cyclone 06P developed north of Tonga. At 4:00 p.m. EST on Sunday the center of Tropical Cyclone 06P was located at latitude 17.8°S and longitude 173.9°W which put it about 60 miles (95 km) north of Neiafu, Tonga. It was moving toward the south-southwest 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 997 mb.

Tropical Cyclone Harold Brings Wind and Rain to Tonga

Tropical Cyclone Harold brought wind and rain to Tonga on Wednesday.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Harold was located at latitude 23.8°S and longitude 172.1°W which put it about 250 miles (400 km) southeast of Nuku Alofa, Tonga.  Harold was moving toward the east-southeast at 30 m.p.h. (50 km/h).  The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 945 mb.

After forming near the Solomon Islands and causing damage in Vanuatu and Fiji, Tropical Cyclone Harold brought gusty winds and locally heavy rain to portions of Tonga on Wednesday.  The core of Harold with the strongest winds passed about 60 miles (95 km)  southwest of Tongatapu.  However, winds to hurricane/typhoon force extended out 60 miles (95 km) from the center of Tropical Cyclone Harold.  Winds to tropical storm force extended out 200 miles (320 km) from the center of circulation.  An airport at Fua’amotu, Tonga reported a sustained wind speed of 58 m.p.h. (93 km/h) when Harold passed southwest of its location.  The airport also reported a wind gust of 89 m.p.h. (143 km/h).

Tropical Cyclone Harold moved quickly away from Tonga on Wednesday night.  Weather conditions were improving.  A high pressure system over the South Pacific Ocean will continue to steer Harold rapidly toward the east-southeast during the next several days.  On its anticipated track Tropical Cyclone Harold will pass well to the south of Niue.

Tropical Cyclone Harold will move into a less favorable environment.  Harold will move under the southwestern part of an upper level ridge over the South Pacific Ocean.  The ridge will produce northwesterly winds which will blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear.  Harold will also move over cooler water.  Moderate vertical wind shear and cooler water will cause Tropical Cyclone Harold to weaken.  Harold could eventually make a transition to an extratropical cyclone when it moves out of the tropics.

Powerful Tropical Cyclone Harold Brings Wind and Rain to Fiji

Powerful Tropical Cyclone Harold brought strong wind and heavy rain to parts of Fiji on Tuesday night.  At 11:00 p.m. EDT on Tuesday the center of Tropical Cyclone Harold was located at latitude 19.4°S and longitude 178.7°E which put it about 30 miles (50 km) southeast of Tavuki, Fiji.  Harold was moving toward the east-southeast at 22 m.p.h (35 km/h).  The maximum sustained wind speed was 140 m.p.h. (225 km/h) and there were wind gusts to 165 m.p.h. (270 km/h).  The minimum surface pressure was 930 mb.

The eye of Tropical Cyclone Harold passed directly over Kadavu Island, Fiji on Tuesday night.  The Hurricane Intensity Index (HII) for Harold was 28.3.  The Hurricane Size Index (HSI) was 19.7 and the Hurricane Wind Intensity Size Index (HWISI) was 48.0.  Tropical Cyclone Harold probably caused significant damage to Kadavu.  Harold also brought gusty winds and heavy rain to Viti Levu.  Flash floods were likely to have occurred in areas that received heavy rain.

Tropical Cyclone Harold strengthened on Tuesday after it moved away from Vanuatu where it caused significant damage.  The eye became evident on satellite imagery again and a solid ring of thunderstorms formed a strong eyewall.  The strongest winds were occurring in that ring of storms.  Storms around the core of Harold generated strong upper level divergence which pumped mass away from the tropical cyclone.  The size of the circulation around Tropical Cyclone Harold continued to increase in size.  Winds to hurricane/typhoon force extended out 65 miles (105 km) from the center of circulation.  Winds to tropical storm force extended out 250 miles (400 km) from the center.

Tropical Cyclone Harold will move into an area less favorable for intensification during the next 24 hours.  Harold will move over water where the Sea Surface Temperature is near 28°C.  It will move under the southwestern part of an upper level ridge over the South Pacific Ocean.  The ridge will produce northwesterly winds which will blow toward the top of the circulation.  Those winds will increase in speed during the next 48 hours and the increased vertical wind shear will cause Tropical Cyclone Harold to weaken.  Harold could weaken slowly during the next 12 to 24 hours.

Tropical Cyclone Harold will move around the southwestern part of a high pressure system over the South Pacific Ocean.  The high will steer Harold quickly toward the east-southeast.  On its anticipated track the center of Tropical Cyclone Harold could reach Tonga within 12 to 18 hours.  Harold will be the equivalent of a major hurricane when it reaches Tonga.

Tropical Cyclone Harold Approaches Fiji

Tropical Cyclone Harold approached Fiji on Tuesday morning.  At 5:00 a.m. EDT on Tuesday the center of Tropical Cyclone Harold was located at latitude 17.4°S and longitude 173.4°E which put it about 270 miles (435 km) west of Nadi, Fiji.  Harold was moving toward the east-southeast at 17 m.p.h. (28 km/h).  The maximum sustained wind speed was 125 m.p.h. (200 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 943 mb.

Although the maximum sustained wind speed in Tropical Cyclone Harold decreased, the area of stronger winds increased.  Winds to hurricane/typhoon force extended out 70 miles (110 km) from the center of Harold.  Winds to tropical storm force extended out 200 miles (320 km) from the center of circulation.  The Hurricane Intensity Index (HII) for Tropical Cyclone Harold was 23.6.  The Hurricane Size Index (HSI) was 22.1 and the Hurricane Wind Intensity Size Index (HWISI) was 45.7.  Tropical Cyclone Harold was capable of causing major damage.

The circulation around Tropical Cyclone Harold increased in size on Tuesday.  The previous small eye was no longer visible on satellite imagery, but the most recent images suggested that a larger eye could be developing that the center of circulation.  The newly forming eye was surround 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 center of Harold.  Storms near the center were generating upper level divergence which was pumping mass away from the tropical cyclone.

Tropical Cyclone Harold will move through an environment favorable for intensification during the next 12 to 24 hours.  Harold will move over water where the Sea Surface Temperature is near 30°C.  It will move under the southwestern part of an upper level ridge over the South Pacific Ocean.  The ridge will produce northwesterly winds which will blow toward the top of the circulation.  Those winds will cause some vertical wind shear, but they will not be strong enough to prevent intensification.  Tropical Cyclone Harold could strengthen during the next 12 to 24 hours.

Tropical Cyclone Harold will move around the southwestern part of a high pressure system over the South Pacific Ocean.  The high will steer Harold toward the east-southeast during the next several days.  On its anticipated track Tropical Cyclone Harold could reach Fiji within 12 hours.  Harold will be capable of causing major wind damage.  It will drop heavy rain and flash floods are likely.  Tropical Cyclone Harold could reach Tonga within 36 hours.

Tropical Cyclone Tino Speeds Across Tonga

Tropical Cyclone Tino sped quickly across Tonga on Saturday.  The core of Tino passed northeast of Nuku Alofa and the most populated island of Tonga.  At 4:00 p.m. EST on Saturday the center of Tropical Cyclone Tino was located at latitude 24.0°S and longitude 170.6°E which put it about 370 miles (595 km) east-southeast of Nuku Alofa, Tonga.  Tino was moving toward the southeast at 26 m.p.h. (42 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 970 mb.

The strongest part of Tropical Cyclone Tino passed northeast of the more populated Tongatapu Group of islands in Tonga.  The core of Tino passed closer to the Vava’u Group and Ha’apai Group of islands in Tonga.  Winds to tropical storm force extended out 350 miles (565 km) from the center of Tino.  Tropical Cyclone Tino brought gusty winds and heavy rain to parts of Tonga.

Tropical Cyclone Tino began to weaken after it passed across Tonga.  Tino moved over water where the Sea Surface Temperature was cooler than 26°C.  Tropical Cyclone Tino moved southwest of an upper level ridge over the South Pacific Ocean.  The ridge caused moderate vertical wind shear and the wind shear contributed to the weakening of Tino.  Colder Sea Surface Temperatures and moderate vertical wind shear will cause Tropical Cyclone Tino to make a transition to an extratropical cyclone during the next two days.

Tropical Cyclone Tino Brings Wind, Rain to Eastern Fiji

Tropical Cyclone Tino brought wind and rain to eastern Fiji on Friday.  The core of Tino moved east of Vanua Levu but the large circulation around the tropical cyclone brought wind and rain across eastern Fiji.  There were reports of flash floods in some parts of Fiji.  At 4:00 p.m. EST on Friday the center of Tropical Cyclone Tino was located at latitude 18.6°S and longitude 176.7°W which put it about 190 miles (305 km) north-northwest of Nuku Alofa, Tonga.  Tino was moving toward the southeast at 27 m.p.h. (45 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 964 mb.

Tropical Cyclone Tino intensified into the equivalent of a hurricane/typhoon as it moved over eastern Fiji.  The inner end of a rainband wrapped around the center of circulation and a possible eye was seen on some infrared satellite images.  The strongest winds were occurring in a ring of thunderstorms around the center of circulation.  Bands of showers and thunderstorms were revolving around the core of the tropical cyclone.  There was a large circulation around Tropical Cyclone Tino.  Winds to hurricane/typhoon force extended out 60 miles (95 km) from the center of circulation.  Winds to tropical storm force extended out 400 miles (645 km) from the center.

The Hurricane Intensity Index (HII) for Tropical Cyclone Tino was 11.5.  The Hurricane Size Index (HSI) was 22.6 and the Hurricane Wind Intensity Size Index (HWISI) was 34.1.  Tropical Cyclone Tino was capable of causing widespread mostly minor damage and smaller areas of more significant damage.

Tropical Cyclone Tino will move through an environment favorable for intensification during the next 12 hours.  Tino will move over water where the Sea Surface Temperature is near 28°C.  It will move around the southwestern portion of an upper level ridge over the South Pacific Ocean.  The ridge will produce northwesterly winds which will blow toward the top of the circulation.  Those winds will cause moderate vertical wind shear, but the shear will not be strong enough during the next 12 hours to prevent intensification.   The wind speed will increase in about a day or so and more vertical wind shear will cause Tropical Cyclone Tino to weaken when that occurs.

Tropical Cyclone Tino will around the southwestern end of a high pressure system over the South Pacific Ocean.  The high will steer Tino toward the southeast.  On its anticipated track the center of Tropical Cyclone Tino could affect Tonga within 12 hours.  Tino will be the equivalent of a hurricane/typhoon when it moves over Tonga.  It will bring strong winds and rain.  Locally heavy rain could cause flash floods.

Tropical Cyclone Tino Forms North of Fiji

Tropical Cyclone Tino formed north of Fiji on Thursday.  At 4:00 p.m. EST on Thursday the center of Tropical Cyclone Tino was located at latitude 14.3°S and longitude 178.3°E which put it about 155 miles (250 km) west-northwest of Labasa, Fiji.  Tino was moving toward the southeast at 13 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 985 mb.

The circulation around a large area of low pressure north of Fiji consolidated around a distinct low level center of circulation on Thursday and the Fiji Meteorological Service designated the system as Tropical Cyclone Tino.  The circulation around Tino was still organizing.  A primary band of showers and thunderstorms wrapped around the northern, eastern and southern sides of the circulation.  Other bands of showers and thunderstorms were forming around Tropical Cyclone Tino.  Winds to tropical storm force extended out 400 miles (645 km) north of the center of circulation.  Winds to tropical storm force extended out 150 miles (240 km) from the center in the southern half of the tropical cyclone.

Tropical Cyclone Tino will move through an environment favorable for intensification during the next 24 to 36 hours.  Tino will move over water where the Sea Surface Temperature is near 28°C.  It will move around the southwestern part of an upper level ridge.  The ridge will produce northwesterly winds which will blow toward the top of the circulation.  Those winds will generate moderate vertical wind shear.  The wind shear will slow the rate of intensification, but the shear will not be strong enough to keep Tropical Cyclone Tino from getting stronger.  Tino could intensify into the equivalent of a hurricane/typhoon during the next 24 to 36 hours.

Tropical Cyclone Tino will move southwest of a high pressure system over the South Pacific Ocean.  The high will steer Tino toward the southeast during the next few days.  On its anticipated track the center of Tropical Cyclone Tino could be near the eastern end of Vanua Levu in about 12 hours.  Tino could approach Tonga in about 36 hours.  Tropical Cyclone Tino will bring gusty winds and locally heavy rain to Vanua Levu, Taveuni and many of the smaller islands in eastern Fiji.  Locally heavy rain  could cause flash floods in some locations.

Weakened Tropical Cyclone Sarai Moves Across Tonga

A weakened Tropical Cyclone Sarai moved across Tonga on Monday.  At 10:00 p.m. EST on Monday the center of Tropical Cyclone Sarai was located at latitude 20.6°S and longitude 174.9°W which put it about 30 miles (50 km) northeast of Nuku Alofa, Tonga.  Sarai was moving toward the 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 989 mb.

Tropical Cyclone Sarai moved south of an upper level ridge on Monday.  The upper level ridge produced strong westerly winds which blew across the top of Sarai.  Those winds caused strong vertical wind shear and they blew the tops off of thunderstorms in Tropical Cyclone Sarai.  The circulation in the lower levels of Sarai remained intact, but it consisted of showers and lower clouds.  The wind speed gradually decreased during Monday.

The center of Tropical Cyclone Sarai passed just north of the Tongatapu Group of islands.  Sarai passed over the Ha’apai Group of islands.  Tropical Cyclone Sarai brought winds to tropical storm force and squally weather to parts of Tonga.  Rainfall amounts were relatively light because the wind sheared the tops off of any thunderstorms which started to form.

Tropical Cyclone Sarai will move through an environment unfavorable for intensification.  Sarai will move over water where the Sea Surface Temperature is near 27°C.  The upper level ridge will continue to cause strong vertical winds shear.  The wind shear will make it very difficult for new thunderstorms to form.  Tropical Cyclone Sarai is likely to weaken slowly as the circulation in the lower levels spins down.

Tropical Cyclone Sarai will move south of a subtropical high pressure system over the South Pacific Ocean.  The high will steer Sarai toward the east during the next several days.  On its anticipated track Tropical Cyclone Sarai will move south of the Vava’u Group of Islands during the next 24 hours.  Sarai could reach Niue in less than 30 hours.