Roading authorities are warning travellers to be prepared with heavy rain followed by snow forecast for Central Otago and Queenstown Lakes Districts overnight.
Canterbury and West Coast travellers also need to be prepared for the rain and snow on Friday.
NZ Transport Agency Waka Kotahi journey planner Tresca Forrester said motorists should be ready for winter driving conditions overnight tonight and on Friday.
NZTA crews had been applying CMA de-icing compound yesterday and today, with snow ploughs and grit teams ready for the night shift tonight.
“People may think it is spring now and warming up, but we still need to be prepared for winter driving – carry tyre chains, expect road restrictions or closures, check NZTA’s journey planner before you set off and have blankets and snacks in the car."
The Milford Road (State Highway 94) would be closed all day owing to "heavy rain and significant snow to our avalanche zones above the road".
MetService has a raft of warnings in place, including an orange heavy snow warning for Southland north of Lumsden, and inland Otago from this afternoon into Friday.
In an update to its advisories this morning MetService said those areas could expect 15 to 25 cm of snow to settle above 400 metres, with lesser amounts down to 300m.
The forecaster warned of travel disruption and possible damage to trees and powerlines.
There are also road snow warnings in place for the Lindis Pass (SH8) and the Crown Range Road, heavy rain watches for the headwaters of the Otago lakes and rivers, and for parts of Southland, and an orange heavy rain warning for Fiordland north of Doubtful Sound.
MetService said there could be up to 20cm of snow on the Lindis, above 500m.
Conditions were expected to improve on Friday, but forecasters say there could be more cold, wet weather to come over the weekend.
Road warnings
Snow - Crown Range Road between Wānaka and Queenstown
Rain is forecast to turn to snow Thursday evening and early Friday morning. Three to eight cm of snow may accumulate above 600 metres, with lesser amounts down to about 400 metres.
Snow - Milford Road, SH94
Rain is forecast to turn to snow Thursday evening. One to three cm may accumulate above about 900 metres.
Heavy rain - South Westland/ Haast
A heavy rain warning is in place for South Westland/ Haast (affecting SH6) today into Friday.
Snow – Burkes Pass and Lindis Pass, SH8, (Fairlie to Twizel, Omarama to Wānaka – Canterbury into Otago), and Mt Cook/Aoraki highway, SH80
Rain is forecast to turn to snow Thursday night and early Friday morning. Ten to 15 cm of snow may accumulate above 600 metres, with lesser amounts down to about 300 metres.
Heavy snow Orange Warning – Canterbury High Country south of the Rakaia River
Expect 10 to 20 cm of snow to settle above 400 metres, with lesser amounts down to 300 metres from 3 am Friday to 3 pm Friday.
Heavy rain watch for the Westland District ranges between Haast and Arthur’s Passes
Periods of heavy rain from 3 am Friday to 9 pm Friday, and amounts may approach warning criteria.
Road snowfall warning - Arthur's Pass, SH73
Snow is expected to start falling Friday afternoon. One to three cm may accumulate about the road above 700 metres.
Road snowfall warning - Porters Pass, SH73
Snow is expected to start falling Friday afternoon. Two to five cm may accumulate about the road above 700 metres.