MetService says former Cyclone Gita is expected to have a significant impact on much of central New Zealand over the next 24 hours.
The official forecaster said heavy rain was already falling from Taranaki southwards to the Marlborough Sounds, and was expected to spread over Buller, Nelson and the rest of Marlborough over the next few hours.
Strong winds were expected for the entire country from early this afternoon into this evening, with the potential for damaging wind gusts from Taranaki and Taihape south to Westland and Banks Peninsula, including Wellington.
Niwa is predicting gusts up to between 130 and 150km/h will peak around 10.30pm.
It said the wind will start to rise rapidly from about 4pm and should drop significantly by 4am tomorrow.
Tides, strong winds and heavy rain could bring storm surges and waves up to 6m high.
At this stage no flights or ferry sailings in and out of the capital have been cancelled. Metlink said trains and buses were running as scheduled but an ongoing signalling issue could cause peak-time delays.
Nelson and Tasman are still recovering from the previous storm, while trampers boaties and campers in Marlborough Sounds have been advised to leave the area.