Motorists in Auckland are being told to expect delays as wet weather continues to hit the region.
Much of the upper North Island can expect thunder and lightning this afternoon as a warm, moist front blankets the region.
Northland, Auckland, the Coromandel Peninsula, Waikato, the Bay of Plenty and Great Barrier Island are all under a severe thunderstorm watch issued by MetService.
Motorists on Auckland's southwestern motorway travelling north are being told to expect delays after a vehicle collision.
Waka Kotahi NZ Transport Agency said both left northbound lanes are blocked. A police spokesperson said there are no injuries.
The watch will remain in place until midnight on Sunday and residents are urged to take care, as the intense thunderstorms could produce torrential rain which carries the risk of slips and flash flooding alongside it.
Residents in Whenuapai have also reported an unplanned power outage. Vector said the power outage was reported at 3.40pm and a crew is being sent to the area.
Localised downpours could produce up to 40mm of rain, which MetService warns could lead to hazardous driving conditions. Surface flooding could also occur in places hit by these downpours.
The weather will remain wet into Monday and possibly even Tuesday as a low-pressure system moves from the Tasman over Aotearoa. Further into the week the system will deepen and move southeast, bringing "significant rain and strong winds".
"During Tuesday and Wednesday, there is moderate confidence of warning amounts of rain for the north and west of the North Island from Northland to the ranges of Gisborne, and to Wellington, also northern Marlborough and Tasman."
Wellington also experienced winter-like conditions on Sunday with rain and strong winds hitting the capital.
The weather has caused a tree and powerlines to fall in the suburb of Wadestown, closing Mairangi Rd shortly before 2pm.