Severe weather warning: Flooding and slips possible

Eastern parts of the North Island are in store for a soaking wet day and the rest of us won't escape showers either as a low makes its way down the country this weekend.

A severe weather warning is in place until midnight tonight for the Bay of Plenty and northern Gisborne, and MetService warned of possible surface flooding and slips.

The big wet brought flooding to Northland yesterday, causing hundreds of children to miss school and creating a "cow island" in Hokianga as cattle scrambled to higher ground.

A herd of cows appear stranded on an island as heavy rain brings localised flooding to Hokianga Photo/ Csilla Janovski, My Little Eye Photography

In Auckland this morning, Gulf Harbour ferries had been replaced by buses because of the weather and commuters could expect a "large blob" of rain to hit just in time for the journey to work this morning.

Buses will replace Gulf Harbour ferries today due to current weather conditions. Buses depart city from 152 Quay St opposite Queens Wharf. pic.twitter.com/YSWIjNKkFm

— Auckland Transport (@AklTransport) June 22, 2017

MetService meteorologist Sarah Haddon said rain was heaviest in the Raukumara Ranges in the west of Gisborne.

"We're seeing 130mm of rain, which is quite a lot."

In lower, more populated parts of the city rainfall was between 30 and 40mm and it was the same story in the Bay of Plenty as well.

The regions could expect continuous rain today followed by showers tomorrow.

"There won't be overly strong winds in those areas, there's just going to be continuous periods of rain throughout the day."

In Auckland, a "large blob of rain" was about to move over the city shortly before 7am, Haddon said.

"We'll definitely get a big burst over the next few hours."

A complex low that arrived from the north Tasman sea was making its way down the North Island today and tomorrow, bringing "quite a few troughs and fronts".

Persistent rain would accompany the slow-moving weather system and a weather watch was in place for Northland, Auckland, Great Barrier Island and the Coromandel peninsula.

The top of the South Island was also forecast to get rain, and Christchurch could expect a wet couple of days as well.

Today's forecast

WHANGAREI: Showers, chance heavy​/​thundery early morning. Northerlies, turning strong southwesterly evening. H 19C L 12C

AUCKLAND: Rain with some heavy and possibly thundery falls, turning to showers, some heavy, this afternoon. Northeast, dying out evening. H 18C L 12C

HAMILTON: Showers, some heavy. Northeasterlies, dying out in the evening. H 18C L 11C

TAURANGA: Rain at times, some heavy and possibly thundery falls. Northeasterlies dying out afternoon. H 18C L 12C

WELLINGTON: Periods of rain. Southerlies. H 13C L 9C

NELSON: Periods of rain. Southeasterlies, dying out. H 15C L 8C

CHRISTCHURCH: Drizzle, turning to rain morning, easing evening. Southwesterlies. H 8C L 5C

QUEENSTOWN: Fine, with variable high cloud. Southwesterlies developing. H 9C L 0C

INVERCARGILL: Fine, with variable high cloud. Easterlies. H 8C L -1C