Heavy rain forecast for parts of North Island, upper South Island

Already-sodden areas of Nelson and Tasman are once again forecast to be hit with heavy rain from this afternoon into Friday, according to MetService.

The forecaster issued yellow heavy rain watches, including one over part of the Tasman District north-west of Motueka from 1pm today, as a front brings a period of heavy northerly rain for the upper South Island from Wednesday afternoon until early Thursday morning.

It said another more intense front would then move east across the country on Friday, bringing heavy northerly rain and strong winds to many areas.

Many of the watches were likely to be upgraded to a warning level as the rain was forecast to hit areas already flooded during last week's deluge.

1News meteorologist Dan Corbett said last night that there was “a lot more wet weather to come” as there were two rain weather systems coming in the next few days.

He said the first would sweep through the upper South Island on Wednesday, before the next hit late Thursday and early Friday with "more juice".

"That is one to certainly watch," he said.

"We're talking in particular Tasman, north and west of Motueka, yes you’ve heard this before. Late Wednesday into early Thursday a rain watch means 20mm to potentially 60mm of rain."

He said that rainfall amount would be similar to last week’s storms, but the second one coming late Thursday into Friday could bring an additional 50mm to 100mm.

Heavy Rain Watch

Northland and Auckland apart from Great Barrier Island - 16 hours from 6am Friday.

Great Barrier Island, Coromandel Peninsula and Waikato - 17 hours from 9am Friday.

Bay of Plenty including Rotorua - 16 hours from 1pm Friday.

Taranaki about and north of the Maunga - 13 hours from 11am Friday.

Tasman District northwest of Motueka - 57 hours from 3pm Wednesday.

Nelson about and southeast of Motueka and north of Lake Rotoroa, also Marlborough northwest of the Awatere Valley - 13 hours from 1pm Friday.