The MetService has issued an Orange heavy rain warning for the headwaters of Lake Wānaka and Lake Hāwea from midnight tonight (November 17) until 2pm Tuesday.

A front over the Tasman Sea is moving towards New Zealand. It is expected to bring strong winds and heavy rain overnight.

Between 100 to 140mm of rain is expected about the main divide, and 70 to 100mm within 15km farther east.

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.