Tag Archives: Auckland

Tropical Cyclone Gabrielle Transitions to an Extratropical Cyclone

Former Tropical Cyclone Gabrielle made a transition to an extratropical cyclone northwest of New Zealand on Friday. At 4:00 p.m. EST on Friday the center of former Tropical Cyclone Gabrielle was located at latitude 27.2°S and longitude 165.3°E which put it about 670 miles (1080 km) northwest of Auckland, New Zealand. Gabrielle was moving toward the southeast at 29 m.p.h. (46 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 979 mb.

Former Tropical Cyclone Gabrielle made a transition to an extratropical cyclone on Friday. Gabrielle moved over water where the Sea Surface Temperatures are near 24˚C. An upper level trough east of Australia produced northwesterly winds that blew toward the top of Gabrielle’s circulation. Those winds cause strong vertical wind shear. A combination of cooler water and strong vertical wind shear caused former Tropical Cyclone Gabrielle to make a transition to a strong extratropical cyclone. Strong thunderstorms were still occurring in bands in the southern half of the extratropical cyclone. Bands in the northern half of the circulation consisted primarily of showers and lower clouds. The transition to an extratropical cyclone caused the size of the low pressure system to expand. Winds to tropical storm force extended out 330 miles (530 km) from the center of circulation.

The upper level trough east of Australia will steer the extratropical cyclone quickly toward the southeast. On its anticipated track, former Tropical Cyclone Gabrielle could affect northern New Zealand during the weekend. The extratropical cyclone will bring strong winds and locally heavy rain to northern New Zealand. Heavy rain could cause flash floods in some locations.

Tropical Cyclone Dovi Moves Toward New Zealand

Tropical Cyclone Dovi moved toward New Zealand on Friday morning. At 10:00 a.m. EST on Friday the center of Tropical Cyclone Dovi was located at latitude 30.0°S and longitude 166.3°E which put it about 780 miles (1200 km) northwest of Auckland, New Zealand. Dovi was moving toward the south at 24 m.p.h. (39 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 969 mb.

Tropical Cyclone Dovi was located between New Caledonia and New Zealand on Friday morning. There was an eye with a diameter of 25 miles (40 km) at the center of Dovi’s circulation. The eye was surrounded by a broken ring of thunderstorms. The strongest thunderstorms were occurring in the eastern half of the ring. There were breaks in the northwestern part of the ring of storms. Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Dovi. Storms near the core generated upper level divergence that pumped mass away to the southeast of the tropical cyclone. Winds to hurricane/typhoon force extended out 50 miles (80 km) from the center of Dovi. Winds to tropical storm force extended out 250 miles (400 km) from the center of circulation.

Tropical Cyclone Dovi will move into an environment that is unfavorable for a tropical cyclone. Dovi will move over water where the Sea Surface Temperatures are near 23˚C. An upper level trough centered east of Australia will produce strong northwesterly winds that will blow toward the top of Dovi’s circulation. Those winds will cause strong vertical wind shear. The combination of colder water and strong vertical wind shear will cause Tropical Cyclone Dovi to make a transition to a strong extratropical cyclone.

The upper level trough east of Australia will steer Tropical Cyclone Dovi toward the southeast during the next 36 hours. On its anticipated track Dovi will move across New Zealand during the weekend. Tropical Cyclone Dovi will be a strong extratropical cyclone when it crosses New Zealand. Dovi will bring strong winds and locally heavy rain to parts of New Zealand. The strongest winds and heaviest rain will occur in northern New Zealand.

Tropical Cyclone Gretel Speeds By New Caledonia

Tropical Cyclone Gretel sped by New Caledonia on Sunday.  At 5:00 p.m. EDT on Sunday the center of Tropical Cyclone Gretel was located at latitude 25.9°S and longitude 169.4°E which put it about 750 miles (1210 km) north-northwest of Auckland, New Zealand.  Gretel was moving toward the southeast at 37 m.p.h. (60 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 983 mb.

Tropical Cyclone Gretel moved around the western end of high pressure system over the South Pacific Ocean.  The high steered Gretel rapidly toward the southeast and the tropical cyclone sped over the Coral Sea west of New Caledonia.  Rainbands on the eastern side of Tropical Cyclone Gretel brought wind and rain to portions of New Caledonia on Sunday.

An upper level ridge produced strong northwesterly winds which created strong vertical wind shear.  The wind shear tilted the circulation around Tropical Cyclone Gretel toward the southeast and Gretel began to weaken.  The stronger thunderstorms were occurring in bands south and east of the center of Gretel.  Bands in other parts of the tropical cyclone consisted primarily of showers and lower clouds.  The wind field around Gretel expanded when the tropical cyclone started to weaken.  Winds to tropical storm force extended out 250 miles (400 km) from the center of circulation.

Tropical Cyclone Gretel will continue to move rapidly toward the southeast during the next several days.  On its anticipated track Gretel could pass north of New Zealand in 24 to 36 hours.

Elsewhere, over the South Indian Ocean Tropical Cyclone Herold strengthened east of Madagascar.  At 5:00 p.m EDT on Sunday the center of Tropical Cyclone Herold was located at latitude 15.5°S and longitude 53.2°E which put it about 405 miles (655 km) west-northwest of Port Louis, Mauritius.  Herold was moving toward the east-southeast at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 972 mb.  Tropical Cyclone Herold could reach Rodrigues in about 48 hours.