Heavy rain and snow in the west, and hot severe gales in the east - tomorrow will be like chalk and cheese in the southern regions.
A MetService spokesman said a cold front, preceded by strong northwesterlies, was expected to approach the South Island from the Tasman Sea tonight.
The front was then expected to move northeast across the South Island during Saturday and the North Island on Sunday.
This front should bring heavy rain to western parts of the South Island, snow in the Milford Road area and severe gale northwesterlies to exposed parts in the east.
"Heavy rain and strong wind warnings and watches are in force for parts of the South Island."
"People are advised to keep up to date with the latest forecasts in case parts of the watches are upgraded to warnings, or further areas are added."
An Orange warning has been issued for the headwaters of the Otago lakes and rivers, which can expect up to 130mm of rain to accumulate near the main divide, between 11pm tonight and 4pm tomorrow.
Up to 100mm of rain may accumulate within 15km east of the divide, and peak rates of up to 20mm per hour and thunderstorms were possible, he said.
Snow showers are forecast for the Lindis Pass (State Highway 8) and the Crown Range Road, linking Queenstown and Wanaka from 7pm tomorrow until 1am on Sunday.
Milford Road closed, snow forecast
An Orange warning has also been issued for Fiordland, which can also expect up to 130mm of rain to accumulate from Milford Sound northwards, and up to 100mm further south, between 10pm tonight and 3pm tomorrow.
Peak rates of up to 20mm per hour and thunderstorms are also possible.
"Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous."
The Milford Road (State Highway 94) has been closed today from 4.30pm from the Lower Hollyford Road turnoff (East Gate) to the Gulliver Bridge (West Gate) due to an increasing risk of avalanche as heavy rain and snow sets in.
A spokesman for Milford Road/NZ Transport Agency said the road would remain closed throughout tomorrow, as more heavy rain and snow to road level was forecast.
MetService said snow was expected to fall from 4pm until 11pm tomorrow. Between 5cm to 10cm of snow was likely to accumulate on the road near the Homer Tunnel, with lesser amounts down to 700 metres.
Snow showers were expected on Sunday but the highway may reopen, depending on avalanche assessment and if there's any control work and snow clearing to do.
Severe gales in eastern Otago
On the other side of the South Island, temperatures are expected to reach 20degC and Orange warnings for severe gales have been issued.
Between 1am and 4pm tomorrow, northwesterly gales were forecast to reach 120kmh in exposed parts of the Southern Lakes, Central Otago, Clutha, Dunedin and North Otago.
The situation would be the same for Southland, Fiordland and Stewart Island between 10pm tonight and 2pm tomorrow, he said.
"Strong wind gusts could damage trees, powerlines and unsecured structures.
"Driving may be hazardous, especially for high-sided vehicles and motorcycles."