Parts of the country are in for a stormy end to the week, with heavy rain in the upper North Island, orange warnings for Gisborne and Tasman regions, and widespread wind warnings.
MetService said the rain and gales were due to a deep low and its associated front approaching from the Tasman Sea.
Orange rain warnings are in place for Gisborne north of Tolaga Bay and Tasman west of Motueka, and heavy rain watches have been issued for Coromandel Peninsula, Bay of Plenty and Mt Taranaki.
Strong wind watches were issued for most of the North Island; Northland, Auckland including Great Barrier Island, Coromandel Peninsula, Bay of Plenty, Waikato, aitomo, Gisborne from Tolaga Bay northwards, Taumarunui, Taupo, Taihape, Whanganui, Manawatu, Hawke's Bay and Taranaki.
Metservice said the wind would be especially noticeable on Saturday.
Auckland Harbour Bridge is down to four lanes each way on Friday morning due to the forecast high winds. Waka Kotahi warned commuters to expect delays and take extra care in light or high-sided vehicles.
The weather front was not expected stall, unlike recent heavy rainfall events, and should move quickly to the east of the country by midday, MetService said.
"However, surface flooding and slips are still possible even during this shorter rainfall event, as some areas may see heavy rain fall due to the tropical moisture and thunderstorms involved," MetService meteorologist Peter Little said.
The low-pressure system was expected to track across the central North Island on Saturday, bringing rain or showers to most regions, along with a period of westerly gales and large wave conditions to northern regions.
"A period of westerly gales will also affect northern parts of the country on Saturday as the low moves eastwards across the central North Island," Little said.
"The gusty westerly winds and already sodden soil, means people are advised to be prepared for power outages due to falling trees disrupting power lines."