The MetService has issued an Orange heavy rain warning for the headwaters of Lake Wānaka and Lake Hāwea from 1am-midday Thursday (October 23).

An active front, associated with a significant deep low to the south, moves over southern and central New Zealand on Thursday.

Between 140 to 200mm of rain is expected about the main divide, and 80 to 150mm within 40km farther east.

Peak rates of 30 to 40mm/h expected about the divide Thursday morning. Thunderstorms are possible.

Severe gale northwesterlies gusting 130 km/h are expected in exposed places.

Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous.

Anyone heading into Mt Aspiring National Park is advised to take extra care or delay travel.

Read more: Heavy rain warning for lake headwaters - strong winds