MetService has issued road snow warnings for the Crown Range Road, the Lindis Pass (State Highway 8) and the Milford Road (SH94), and says there could be falls inland from the northern hills of Southland to the Waitaki River.
It said snow was likely above 400 or 500 metres, with heavy falls above 700 metres.
MetService meteorologist Jessie Owen said a low-pressure system from the Tasman Sea and a cold front southwest of New Zealand were both expected reach the country tomorrow.
"This drops temperatures significantly as far north as Kaitaia, and brings further rain and strong winds, as well as snow to low levels.
"Snow is expected to lower to about 400 metres over the South Island on Wednesday, and about 800m over the central North Island on Thursday.
"This colder air is expected to spread right up the country, bringing a distinctly wintry feel.
The snow warnings come as downpours are causing flooding across west Auckland and parts of Northland today, and heavy rain is also falling at the top of the South Island.
Southern road snow warnings
Crown Range Road
Period: 22hrs from 1am - 11pm Wed, 10 May
Snow is expected to develop above 800 metres overnight Tuesday then lower to 500 metres during Wednesday afternoon. Overnight Tuesday and into Wednesday, 1 to 2 cm of snow may accumulate on the road above 900 metres, then a further 2 to 4 cm is possible above 700 metres during Wednesday afternoon and evening.
Milford Road (SH94)
Period: 7hrs from 4am - 11am Wed, 10 May
Snow is expected to develop above 500 metres early Wednesday morning. During Wednesday morning, 2 to 4 cm of snow may accumulate on the road above 700 metres.
Lindis Pass (SH8)
Period: 7hrs from 4pm - 11pm Wed, 10 May
Snow is expected to develop above 600 metres during Wednesday afternoon, and 1 to 3 cm of snow may accumulate above 800 metres late Wednesday afternoon and in the evening.
