Tag Archives: Nuku Alofa

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.

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.

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.

Tropical Cyclone Sarai Moves Toward Tonga

Tropical Cyclone Sarai moved toward Tonga on Sunday.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Sarai was located at latitude 20.7°S and longitude 178.3°E which put it about 220 miles (355 km) west of Nuku Alofa, Tonga.  Sarai was moving toward the east-southeast 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 985 mb.

Tropical Cyclone Sarai weakened on Sunday.  An upper level ridge north of Sarai produced strong westerly winds which blew toward the top of the circulation.  Those winds caused strong vertical wind shear which disturbed the circulation around Tropical Cyclone Sarai.  The inner core became less well organized and there was no evidence of an eye on satellite images.  The stronger thunderstorms were occurring in bands in the eastern half of the circulation.  Bands in the western half of the circulation consisted primarily of showers and lower clouds.  The circulation around Tropical Cyclone Sarai was still large.  Winds to tropical storm force extended out 200 miles (320 km) from the center of circulation.

Tropical Cyclone Sarai will continue to move through an environment unfavorable for intensification during the next several days.  Sarai will move over water where the Sea Surface Temperature is near 28°C.  However, the upper level ridge will continue to produce strong westerly winds and vertical wind shear is likely to cause Tropical Cyclone Sarai to weaken further.

Tropical Cyclone Sarai will move south of a subtropical high pressure system over the South Pacific Ocean.  The high pressure system will steer Sarai toward the east during the next several days.  On its anticipated track Tropical Cyclone Sarai will move across Tonga in about 24 hours.  Although Sarai will weaken, it will bring winds to tropical storm force and heavy rain to parts of Tonga.