Dunedin faces hailstorms, thunderstorms and lightning flashes, while there are rainy snow and rain warnings for some areas of Otago and Southland as the weather worsens in the South.
A large compound vessel is expected to cover the country next week until Thursday, with built-in low centers.
MetService has issued a very nice watch for Fiordland and coastal Otago.
"The cold southerners are expected to affect the south of the southern island from afternoon until late Tuesday, bringing winter conditions to the south of the southern island."
The snow is projected to fall as low as 400 meters with a significant accumulation at 800 meters. Inland Inland, Central Otago and Clutha.
"This watch is about the possibility that the accumulation of snow is approaching the warning amounts for the eastern Fiordland, the southern lakes and the inland of Dunedin."
The weather clock is also in effect due to the possibility that the accumulation of rainfall can reach the warning amounts for the coastal Otago.
Meteorologist MetService Andrew James said the change will be felt in the South Island today.
"Very cold and winter weather is down to the south," he said.
"Tonight, Queenstown and Wanaka look like they're approaching about 2C, which is cold for this time period."
"It will be a cold and stormy week."
Rainy events and even hail are expected in much of the country during this period, with the most persistent rainfall in some eastern parts of the southern island.
James warned that South African drivers need to track down on roads such as Pass Arthur, Porters Pass and Lindis Pass in the next few days.
MetService warned that snow periods for Pass Lindis, Crown Range Rd and Milford Rd are expected.
Snow was expected for the eastern parts of the southern island over 400 to 500 meters, and probably for the tall country of the northern island over 1000 meters.