MetService has this evening issued heavy snow warnings for parts of the South over the weekend.
The forecaster says heavy snow is possible in Otago south of a line from Queenstown to Alexandra and Mosgiel, and also in Southland and Stewart Island.
The warning covers a period of 41 hours from 4pm on Saturday to 9am on Monday.
MetService says to expect periods of heavy snow above about 300 metres, with some falls down to near sea level.
"The heaviest snow is expected from Saturday evening through to Sunday evening, where 20 to 35cm of snow is expected above about 300m, with lesser amounts down to near sea level."
Another heavy snow warning has been issued for Fiordland about and south of Doubtful Sound, from noon tomorrow to 4am on Monday.
The forecaster previously had heavy snow watches in place for the southern regions.
There are road snow warnings for some southern highways: Lindis Pass (State Highway 8), Haast Pass (SH6), the Milford Road (SH94) and the Crown Range Road.
There is also a strong wind watch in place for Dunedin, Clutha and Southland south of Lumsden, including Stewart Island, from Saturday afternoon till about noon on Sunday. MetService says west to southwest winds may approach severe gale in exposed places.
Earlier today, authorities were warning drivers to be ready for challenging conditions on busy southern roads at the weekend.
Waka Kotahi says the start of the school holidays will mean more traffic on southern roads, including a likely influx of Australian visitors.
Travellers, particularly those driving through alpine passes and the Crown Range Road between Wānaka and Queenstown should check the MetService website for road snow warnings and with Waka Kotahi for road closures and advice.
NIWA Weather has released a video showing the predicted accumulations as a cold southwest flow spreads onto the southern South Island today, then persists through the weekend.
"Snow falling to low-levels is likely to be impactful, even where accumulations do not meet warning criteria," MetService says.
Elsewhere in the Lakes District, Cardrona Valley Road was "wet and very cold" with black ice likely.
