Former Tropical Cyclone Gita Speeds Toward New Zealand

After causing flooding in Samoa, significant damage in Tonga, and passing southeast of Vanuatu and New Caledonia, former Tropical Cyclone Gita sped toward New Zealand on Monday.  At 4:00 p.m. EST on Monday the center of former Tropical Cyclone Gita was located at latitude 36.6°S and longitude 168.1°E, which put it about 575 miles (930 km) northwest of Wellington, New Zealand.  Gita was moving toward the southeast at 32 m.p.h. (52 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.

An upper level trough near the east coast of Australia was generating strong northwesterly winds which were blowing across the top of former Tropical Cyclone Gita.  Those winds were causing significant vertical wind shear.  In addition, former Tropical Cyclone Gita has moved over water where the Sea Surface Temperature is near 23°C.  A combination of strong wind shear and colder water caused the structure of former Tropical Cyclone Gita to evolve into a powerful extratropical cyclone.  It has lost its warm core and a cold front appears to have formed.  The low level circulation has elongated in a north to south orientation.  Even though Gita is now an extratropical cyclone, it is still a powerful low pressure system.  The low is producing winds to 65 m.p.h.  (105 km/h).  Winds to tropical storm force extend out about 230 miles (370 km) from the center of circulation.

The upper level trough is steering former Tropical Cyclone Gita quickly toward the southeast.  On its anticipated track the extratropical cyclone will reach the northern end of the South Island of New Zealand in 12 to 18 hours.  It will produce strong gusty winds capable of toppling trees and bringing down power lines.  The extratropical cyclone will also drop locally heavy rain and it could contribute to flash flooding.