Talk about yo-yoing - the weather is seesawing from "shorts and singlets" temperatures to snowy winter woollies and back again this week.
Yesterday, temperatures hit nearly 20degC in Dunedin, but for tomorrow the MetService is forecasting a front with strong, cold southwesterlies to sweep across Otago and Southland.
The front is expected to bring rain to much of the region today and it is set to turn to heavy rain, thunderstorms and snow to 300m tomorrow in Dunedin, Clutha, Alexandra, Wanaka and Te Anau.
A MetService spokeswoman said the snow was likely to affect higher roads in the lower South Island, and she urged drivers to keep an eye on future road snow warnings.
Some 10-15cm of snow is expected on Milford Road (SH94) above 800m, with lesser amounts down to 300m. Some 3-5cm was expected in Arthur's Pass and the Crown Range Road, linking Queenstown and Wanaka, above 800m.
In the far South, it was likely that westerly gales would become severe tomorrow and on Thursday.
As the front moved up the South Island, significant heavy rain was likely to fall in Fiordland, Southland and Clutha on Thursday, and in the Otago and Canterbury headwaters on both Thursday and Friday.
Northwest gales may become severe in Southland on Thursday and in Otago on Thursday and Friday, bringing temperatures back up to the high teens on the coastline again.
"Strong westerlies should affect much of the country on Thursday ahead of another front, followed by cold southwesterlies on Friday, and snow may again affect higher roads and passes of the South Island."
Snow for alpine roads
All alpine roads in the South Island including the Crown Range Road, linking Queenstown and Wanaka, were expected to be affected by snow into tomorrow.
CROWN RANGE ROAD
From 9pm tonight until 10am tomorrow: Showers are expected to turn to snow overnight tonight, affecting the road until late tomorrow morning. Expect 3 to 5cm of snow to settle on the road above 800 metres, with lesser amounts down to lower levels.
MILFORD ROAD (SH94)
The Milford Road from East Gate (Hollyford) to West Gate (Chasm) was closed overnight and was expected to reopen at 9am today.
However, from 6pm tonight until 10am tomorrow snow was expected and should lower to 300 metres overnight. Expect 10cm to 15cm of snow to settle on the road above 800 metres during this time, with lesser amounts down to 300 metres.
Another burst of snow may affect the road tomorrow night, and a warning may be issued closer to the time to cover this possibility. Wednesday would bring showers with snow to 500 metres around the Homer Tunnel area.
ARTHUR'S PASS (State Highway SH73)
From 9pm today until 3am tomorrow: Snow showers are expected to affect higher parts of the road this evening and night and 3cm to 5cm could settle above 800 metres.
LEWIS PASS (SH7)
From 6pm today until 2pm tomorrow: Snow is expected to affect higher parts of the road this evening until overnight tonight. Between 6pm today and 6am tomorrow, expect 3cm to 5cm to settle on the road above 800 metres, with lesser amounts to 600 metres.
Another brief period of snow is possible around midday tomorrow. Between 11am and 2pm, up to 1 cm of snow may settle on the road above 600 metres.
HAAST PASS (SH73)
From 8pm today until 2am tomorrow: Snow is expected to affect the road for a time this evening until overnight tonight. Expect 1 to 3cm of snow to settle on the road near the summit.
PORTERS PASS (SH73)
From 12am until 6am tomorrow: Snow may affect higher parts of the road overnight tonight and 1 or 2 cm of snow may settle on the road near the summit, with lesser amounts to 800 metres.
LINDIS PASS (SH8)
From 10pm today until 10am tomorrow: A few snow showers are expected to affect higher parts of the road tonight through to late tomorrow morning. Expect 1 to 3cm of snow to settle on the road above 700 metres, with lesser amounts down to 400 metres.
