Weather warnings remain in place as storm moves north

Christchurch is expected to reach 21 degrees today but change is coming for the city and large areas of the South Island as heavy rain and strong winds remain the forecast for overnight.

MetService updated its forecast this morning to pull back the times for when it expects the wind and rain to abate, with the South Island all clear by 1am Sunday and the lower North Island by 5am Sunday.

Already the rain is having an impact on the West Coast, with flooding forcing the closure of State Highway 6 between Haast and Makarora.

A slip has also closed the state highway between Rapahoe and Nine Mile in the Grey District.

These follow an earlier MetService warning that flooding and slips were possible and that rivers and streams could rise rapidly.

All warnings are expected to lift by the early hours of Sunday, with the MetService forecasting only scattered rainfall for the Winter Solstice.

A front preceded by a strong northwest flow is the culprit. MetService expects it to move over southern and central New Zealand today and into Sunday.

Parts of the South Island covered by an orange heavy rain warning include:

Coastal ranges of the districts of Buller and Grey from 11am Saturday until 1am Sunday

The ranges of Westland from 9am until 7pm Saturday

Headwaters of the Canterbury lakes and rivers south of the Hurunui River from 9am until 7pm Saturday

Headwaters of the Otago lakes and rivers from 9am until 2pm Saturday

Fiordland from 9am until noon Saturday

Areas covered by an orange strong wind warning are:

Canterbury High Country from 9am until 5pm Saturday

Canterbury Plains from 1pm until 5pm Saturday

Heavy rain watches are in place for:

The Tararua Range from 9pm Saturday until 7am Sunday

Inland ranges of the Buller District and the Nelson Lakes from 11am Saturday until 1am Sunday

Strong wind watches are in place for:

Wellington and Wairarapa, south of Carterton, from 3pm Saturday until 3am Sunday

Wairarapa north of Carterton from 5am Saturday until 5am Sunday

Marlborough Sounds and inland ranges of Marlborough from 11am until 10pm Saturday