Severe weather warnings for the southern, and central regions of the country tomorrow

MetService has issued a heavy rain watch for Tasman, Buller, Westland, and the headwaters of the Canterbury lakes and rivers.

A heavy rain warning's in place for Fiordland, from morning until evening, with Wellington, Canterbury, Otago, and Southland under a strong wind watch.

Meteorologist Alex Holden, says rainfall will start in the west and head south.

He says conditions will worsen as a large low pressure system arrives from the Tasman sea.