People in the South Island can expect to wake up to snow and heavy rain this morning.
Metservice says Fiordland and southern Westland should get about 80 millimetres of rain in under 10 hours from this morning.
It says streams and rivers could rise rapidly.
Meteorologist Nick Zachar said further north in both the Lindis and Porters Passes, snow is expected overnight and throughout today.
"Especially in the Homer area, we are expecting snow down to about 500 or 600 metres tonight and into tomorrow morning. Snow of five to 10 centimetres can be expected."
Rain is also forecast to turn to snow about the summit this afternoon along Milford Road.
The snow level there could lower to around 600 metres by the evening.