The Bay of Plenty is bracing for heavy rain to hit this evening, with just under 30mm due between now and midnight as a low moves down the country.
MetService said the Bay and Gisborne could expect between 80mm to 110mm over an 15- to 18-hour period from 9am this morning.
Strong winds are also causing swells of up to 6.6m off the coast of Tauranga, closing the base track at Mauao. Tauranga City Council said those waves would get bigger until high tide at 5.30pm.
Commuter traffic is heavy across Auckland after multiple crashes and breakdowns in the last two hours.
Southbound traffic from the North Shore is congested due to a truck breakdown just before the Onewa Rd offramp and an earlier crash on the Harbour Bridge.
It's also heavy heading south on the Southern Motorway due to a breakdown on the Newmarket Viaduct.
But the city has so far missed out on the worst rain which is landing off the east coast of the upper North Island.
Rain has also eased off in Northland and floodwaters are receding from main highways after the morning's deluge.
A dairy owner resorted to using a tractor to drive through rising floodwaters to open her store as flooding left the main highway to the Far North virtually impassable.
Flooding has caused problems on roads at the top of the country after thundery rain deluged parts of Northland for hours on end.
Two out of three main highways have been left underwater and two schools and a preschool in Kaeo were forced to shut their doors.
SH1 was left virtually impassable for much of the day when the Waihou River breached its banks west of Rangiahua Rd, but the waters have now receded.
Further north flooding has reduced the highway down to one lane between Iwitaua and Mangamuka School Rds.
Pockets of the main eastern highway, SH10, have also been affected by flooding but at this stage are still passable.
The main highway outside Kawakawa is also under water while further south rain is starting to pool on roads outside Whangarei.
While no one has been evacuated one dairy owner had to resort to using a tractor to get through rising waters to reach her shop in a settlement outside Kaitaia this morning.
Bush Fairy Dairy worker Emily Parker said she woke to floodwaters two feet high submerging the backdoor steps of her home this morning.
She said roads surrounding the Peria store east of Kaitaia were under water and the owner needed to use a tractor to open up the businesses this morning.
"She actually got tractored in and tractored out. She got tractored in to open it and tractored out to go home," said Parker.
Surprisingly there had still been customers with those in 4WDs coming in to buy coffees.
Northland Civil Defence spokesman Murray Soljak said the worst of the weather was passing and swollen rivers were starting to drop.
"We're expecting the rain to ease and the rivers to recede," said Soljak.
Many of the worst-affected areas such as Kaeo and Rangiahua were known troublespots that were adversely affected by tides.
He said the flooding, largely concentrated to the region's eastern flank, was expected to drain away as the rain eased this afternoon.
MetService has warned of more rain in this evening from the Gulf north with the heaviest falls likely north of Orewa.
Meanwhile weather severe weather warnings remain in place for Bay of Plenty and northern Gisborne.
Northland, Auckland and Coromandel Peninsula are under weather watches for heavy rain and gales today.
In the South Island motorists are being warned to expect up to 8cm snow on alpine passes today as the second chilly blast in a fortnight hits southern regions.
The Queenstown District Council said snow was falling on the top of Crown Range. It was closely monitoring conditions and warned there could be flooding and rockfalls on the region's roads.