MetService is warning the south to brace for the possibility of severe gales and heavy rain later this week.
A MetService spokeswoman said a strong and moist northwest flow was expected to spread over the South Island, ahead of a front that was forecast to move on to the far south late Thursday.
``There is high confidence of warning amounts of rain for Fiordland and southern Westland, with significant spill-over rain falling into the headwaters of the southern Canterbury and Otago lakes and rivers.
``There is also low confidence of severe gale northwesterlies affecting Canterbury High Country and western parts of Otago and Southland.''
Later on Friday, a trough was forecast to move past the far southeast of the South Island, and there was a low confidence of severe gale southwesterlies affecting eastern parts of Otago for a time.
The front was then expected to move on to the North Island and weaken, she said.
