MetService forecaster Cameron Coutts said snow was forecast to fall as low as 300m on Sunday, in Dunedin, North Otago, Central Otago, Clutha and Southland.
''It looks like it will be reasonably low on Sunday.
''At this stage, it's too far out to say exactly how much will fall. But I think it will be more than just a dusting.
''It has the potential to disrupt a few roads.''
He said MetService would be watching it closely and advised residents to keep up-to-date with the latest forecasts.
A front was expected to pass over the South Island, turning rain to snow early on Sunday morning.
''We've got a cold southwest change associated with a high over the south Tasman and over the Southern Ocean, which is helping to drag up some cold air.
''And at the same time, we've got a low over the North Island which is bringing down a lot of moisture as well.
''That helps in the making of snow, when you've got a mix of the two coming together.''
Mr Coutts said the snow was likely to clear reasonably quickly.
