This will mean increasing cloud, with a spell of rain just about everywhere as the front moves up the country.
There is low confidence of significant heavy rain for Fiordland on Friday and Saturday, and moderate confidence over Westland on Saturday.
There is also low confidence that rainfall accumulations will meet warning criteria in parts of Southland and Otago on Sunday and Monday.
This southerly will also bring strong winds to the whole of the east coast, and snow as low as 600 metres to Southland and Canterbury on Sunday night.
"Spring still has a few tricks up its sleeve and windy, changeable conditions are a big part of that," said MetService meteorologist Tom Adams.
"Although not unusual for the season it certainly will feel like a change from this week. People may have become used to the settled conditions, but next week will not reward complacency so make sure you keep checking the forecast.
"Once this cool southerly comes through the South Island on Sunday and the North Island on Monday, it will be followed by a series of weather features making for a changeable week."
However, WeatherWatch.co.nz head forecaster Philip Duncan said the rain will bode well for farmers in the drier areas.
"It's not going to be instant relief for all that have dry conditions but the rain coming in next week does look, at this stage, to favour falling in places that are the driest," he said.
According to NIWA public soil maps the eastern and upper North Island are the two driest parts of NZ.
Duncan said both of these areas have some relief coming in the next week but that northern regions may miss out on enough to truly soak the ground.
"We're just focused on finding relief where we can before summer officially kicks off on December 1st" he said.
"The fact we have rain and showers in the forecast is a real positive, even if just mentally preparing for the dry months ahead."
