On Monday an active front is expected to move northeast over the lower and central South Island bringing strong northwesterly winds and heavy rain to some areas, says MetService.

Watches and warnings have already been issued for heavy rain and severe gales for Monday and some of these extend into Tuesday and early Wednesday.

On Tuesday an intense low is expected to move northeast just east of the South Island directing a strong southerly flow over the Island.

A front is expected to move north over central New Zealand. There is then a high confidence in rainfall accumulations reaching warning amounts for Westland, Southland, Otago and Canterbury as indicated on the chart. There is a low confidence in warning amounts of rain for Buller, Nelson, Marlborough and the North Island south of Waikato and Banks Peninsula apart from coastal Gisborne, Hawkes Bay and Marlborough.

On Tuesday there is also a high confidence that southwesterly gales will be severe for North Otago and Canterbury, especially the Banks Peninsula. There is a moderate confidence in severe southerly gales about the Southern Alps north of Fiordland and for the south of Nelson and Marlborough as indicated. There is a moderate confidence in severe northwest gales about the Cook Strait affecting the Marlborough Sounds and Wellington.

A ridge of high pressure is expected to bring settled weather to much of the country on Wednesday and Thursday.

On Friday a front may bring rain to the south of Westland and to Fiordland and there is a low confidence that rainfall accumulations will reach warning amounts.