The weather gods delivered a king-hit of heavy rains and high winds over the country yesterday, causing flash flooding and closing off roads due to slips.

Things are looking better for many parts of New Zealand today.

However, another weather system is forecast to head our way tomorrow, again bringing heavy rain to the South Island and strong gusts south of the North Island.

State Highway 73 through Arthur's Pass was closed off because of substantial slips.

One of the landslides spilled into the Taramakau River; blocking access to Jacksons and Aickens .

In nearby Otira, a woman and her son had a lucky escape after a slip spilled onto their house.

The landslide moved a shed, ruined a car and diverted a creek into the house but the pair were uninjured.

On Wednesday night, a Swedish couple were swept down a flooded Canterbury river while out tramping.

The man was able to get to the water's edge of Hawdon River, but his partner became stranded on an island in the middle of the river.

Authorities credited an emergency locator beacon with saving her life.

MetService recorded wind gusts of up to 154km/h at Rimutaka Summit, 118km/h at Wellington Airport, 172km/h near Mt Hutt and 124km/h in Banks Peninsula.

More than 250mm of rain fell at Arthur's Pass and up to 209 lightning strikes have been recorded over Westland since Wednesday evening.

MetService said another significant low pressure system would move eastwards across the South Island on Sunday.

"During Saturday, there is moderate confidence of significant heavy rain from Marlborough Sounds to South Westland, rising to high on Sunday.''

There was the possibility of significant spillover into the headwaters of the Canterbury lakes and rivers on Sunday.

Many places, including eastern Otago, the Tararua Range and the North Island high country from Mt Taranaki to the ranges of eastern Bay of Plenty, could all be in for rainfall amounts that would meet warning criteria, MetService said.

Severe gale warnings were also likely in the Wairarapa, Wellington and Marlborough on Sunday.

In Auckland today, some isolated morning showers are forecast. After that, however, the skies are looking fine and there is a temperature high of 21C.

Tauranga has similar conditions, with a high of 23C and an overnight low of 12C.

Gisborne will get fine spells today - but also a few showers and southerly winds will be developing.

There is a bit of a mixed bag in the South Island. Nelson is looking mainly fine today and a high of 17C. There is a chance of showers later in the day.

There will be some cloudy periods and a possibility of showers for those in Blenheim, while people in Christchurch will get a high of 17C and a chilly 7C low overnight.

In Dunedin, the sun will be out too, but there will also be some cloudy. Queenstown is mainly fine, with light winds, and a high of 16C and overnight low of 4C.

FORECAST TODAY: • Auckland: 21C temperature high. Isolated morning showers, otherwise fine.
• Hamilton: 21C. Isolated morning showers, otherwise fine.
• Tauranga: 23C. Fine. Westerlies dying out.
• Gisborne: 21C. Fine spells, a few showers. Southerlies developing.
• Wellington: 17C. Fine spells, a few morning showers.
• Blenheim: 18C. Fine, but some cloud and chance of showers later.
• Christchurch: 17C. Mainly fine, chance of evening shower.
• Dunedin: 15C. Fine, but some cloud and odd shower. Light winds.
• Queenstown: 16C. Mainly fine, chance of shower.