A Severe Weather Watch has been issued by MetService for parts of New Zealand.

Westerly gales are forecast for parts of southern and central New Zealand, and heavy rain for Northland.

"A strong west to southwest flow covers the southern and central New Zealand," says a MetService spokesperson.

"A Strong Wind Warning remains in force for coastal parts of Clutha and Southland, also Stewart Island.

"A Strong Wind Watch covers the Canterbury High Country, and remaining parts of Otago
except North Otago, and Southland not covered by the Strong Wind Warning."

On Monday, a low pressure system is forecast to move onto the upper North Island, bringing a period of heavy rain and strong to gale northeasterlies. A Heavy Rain Watch is in place for Northland.

People are advised to keep up to date with forecasts in case any changes are made or more areas are added.

A Heavy Rain Watch is in place for the north and east of Northland. This is valid for nine hours from 8am to 5pm on Monday. A period of heavy rain, and amounts may approach warning criteria.

A Strong Wind Watch is in place for Canterbury High Country, Queenstown Lakes, Central Otago,
Dunedin, and inland parts of Clutha and Southland. This is valid for 11 hours from 6am to 5pm Sunday. Westerly winds may approach severe gale in exposed places.