A complex low pressure system is moving over the Tasman Sea and is forecast to hit New Zealand today, followed by a second low set to hit the country tomorrow.
A severe weather warning had been issued for the Tararua Range and eastern Otago, and a severe weather watch has been issued for much of the country - including Northland, Auckland, the Coromandel, Bay of Plenty, Gisborne, Hawkes bay, Taranaki, Whanganui, Wellington, Marlborough and Nelson.
Severe west to northwest gales are possible in much of the North Island including Northland, Auckland, Coromandel, and the Bay of Plenty.
The heaviest rain is expected about the Tararua range from midday today.
Rain is likely to persist until tomorrow morning in the area, with possible thunderstorms.
A heavy rain warning has been issued for Dunedin and the eastern parts of North Otago.
"Rain is expected to become steady from mid-morning, and could be heavy at times," a MetService warning read.
"In the 14 hours from 10am to midnight tonight, 40 to 60 millimetres of rain could accumulate with peak intensities of 10mm to 15 mm per hour."
People in affected areas should be aware that this amount of rain could cause rivers and streams to rise rapidly, with slips and surface flooding possible.
A heavy rain warning has been lifted for the Bay of Plenty ranges east of Opotiki.
The low is forecast to cross the upper south island tonight then move away to the southeast tomorrow morning.
Another deep low over the Tasman Sea is expected to move eastwards across the North Island tomorrow, bringing a period of strong west to northwest winds, with severe gales possible for a time from Hawkes Bay and Taranaki northwards, MetService reported.
