Severe weather warnings are in place as a deep low pressure system drags its way across the country.

A big wet weekend will kick in later today with heavy rain expected for the north and west of the South Island while the North Island braces for a drenching on Sunday.

MetService has issued a severe weather outlook, warning of heavy rain over Westland, Buller, Nelson and Marlborough from this afternoon, through to tomorrow night.

Mixed conditions across the North Island will continue today before a front crossing the country will bring heavy rain and windy conditions to some places on Sunday.


"Auckland will see cloud thickening by Saturday afternoon with rain expected at night," MetService analyst Tuporo Marsters said. "On Sunday there will be showers in the morning but these are expected to clear later in the afternoon.

"However the rain will be back at night with a strong northerly ahead of it."

About 20mm of much-needed rain is predicted for Northland tonight, but should clear by Sunday lunchtime.

State Highway 73 between Arthurs Pass and Jacksons will remain closed until at least Monday.

The road was closed due to slips after Thursday's weather bomb.

The New Zealand Transport Agency said more wet weather was expected on the West Coast over the weekend and this could make for dangerous conditions for contractors clearing the slips. But it said "good progress" had been made on clearing the state highway to date.

The NZ Transport Agency will provide a progress report again tomorrow.

On Sunday the wet conditions will continue in most places, possibly heavy at first followed by a few showers, with fine breaks for some.

A deep low crossing the South Island brings gale-force northerlies to exposed places on its eastern side, and will be briefly followed by gale or severe gale southwesterlies over the South Island.

On Monday the rain will ease and the North Island will see cloudy periods in the west, with a few showers from Taranaki to Wellington and also Wairarapa.

"It should be mainly fine elsewhere," Marsters added.