Rain was also starting to reach Gisbourne tonight but Metservice was not expecting it to become heavy until tomorrow.
Flynn said Auckland drivers should take care and drive to the conditions.
No severe weather warnings had been issued for the rain although MetService had noted moderate risk on their thunderstorm chart.
A large low-pressure system from the Tasman Sea moving slowly across northern New Zealand over the next few days will spread a band of rain and southeast gales over the North Island and upper South Island.
As the low crosses the upper North Island tomorrow, a high is forecast to build over southern parts of the country, directing southeast gales and rain across central and northern regions.
Fire services said trees and power lines were brought down in high winds about 4pm today in Rawhiti and Wainui in the north of the North Island. They could not confirm how many were down or whether any roads had been blocked.
A MetService spokeswoman said the closest weather station to both locations was in Kerikeri, where gusts had reached about 56km/h - which was not unusually strong. However, Wainui and Rahwiti were a "bit more exposed". At the very tip of the North Island, in Cape Reinga, winds reached 113km/h.
Southeast gales are likely to become severe for a time about parts of northern Westland, Buller, the Marlborough Sounds and central North Island high country tomorrow.
There is a risk that rainfall accumulations will reach warning level in Auckland, Coromandel Peninsula, eastern Waikato and Bay of Plenty this morning, with the heaviest rain expected about the ranges of northern Hawke's Bay and Gisborne tomorrow afternoon and evening.
MetService warned of the possibility of raised river levels and surface flooding making driving dangerous.
Rain was likely to be briefly heavy about the upper North Island early tomorrow, becoming more persistent in Gisborne and Hawke's Bay through till Saturday morning.
As the low moved northeast of the North Island, there was a moderate chance that south to southeast gales could become severe for a time from Waikato to Wellington, including Bay of Plenty and the central North Island high country, also the Marlborough Sounds, Nelson, Buller and Westland, MetService said.
The southerly flow would also spread cooler air over the country and was likely to bring snow about the ranges from Marlborough to Hawke's Bay.
A large ridge of high pressure was then forecast to spread across New Zealand during Sunday and Monday, with frosts likely.
Tomorrow's forecast
• Whangarei: Sunny spells with a chance of showers. High 18 Low 12
• Auckland: Showers, chance heavy at first, clears evening. Southeasterly developing. High 17 Low 11
• Hamilton: Showers, heavy at first, clears afternoon. High 16 Low 9
• Taupo: Rain clearing by afternoon. Strong southeast, gusts up to100km/h. High 13 Low 7
• Nelson: Few early showers, then mostly fine. Strong, gusty southeasterly. High 12 Low 5
• Wellington: Morning rain, then cloudy periods. Southerly rises to gale. High 11 Low 8
- Additional reporting by NZ Herald
