MetService meteorologist Braydon White said a very cold south-to-southeast flow would spread northwards over the South Island behind another front, bringing the possibility of warning amounts of rain for Dunedin, South Otago and Southland.
He said heavy snow was also possible above 400m in inland parts of Southland, Clutha and southern parts of the Queenstown Lakes District and Central Otago, and lesser amounts at lower levels.
It was ‘‘very likely’’ to affect roads around the region, and road snowfall warnings would be issued today, he said.
The snow was expected to continue into Monday, and could stretch towards Dunedin where higher areas like Swampy Summit may get a dusting.
‘‘It’s a little bit tricky to say exactly how low it will get.
‘‘There’s a little bit of uncertainty in the models, but we do have a risk of heavy snow above 400m.
‘‘There is the potential some could get lower than that — just not as heavy.’’
‘‘By the time the rain and wind sort of sets in for Dunedin, the coldest air has been pushed a bit further south, so we’re not expecting snow there.’’
In inland parts of Otago and Southland, the weather was expected to clear on Tuesday, and would remain that way for the rest of the working week.
He said the clear skies would probably bring a risk of hard frosts and black ice, and drivers should take extra care on inland roads for the whole week.
‘‘Some of those overnight minimums are dropping into the negatives through that area — sort of in the -1˚C to -2˚C range mostly — and there’s definitely still the risk of some of that black ice or heavy frosts forming.’’
At this stage, the skies across all of Otago and Southland appear to clear on Friday, just in time for Matariki celebrations.
