"Over the next few days, rainfall totals on the South Island West Coast and over the Southern Alps may approach their one and two-day records,'' he said.
He warned campers near lakes and rivers in Canterbury and Otago that the water could rise rapidly.
It was also likely to be very windy down some valleys, he said.
The first day of 2013 would be a windy day in eastern areas from Southland through to Wairarapa and in Wellington.
"Around central New Zealand on Wednesday, the northwesterlies are likely to be particularly strong,'' Mr Kreft said.
Meanwhile, Tropical Cyclone Freda has struck the Solomon Islands pulling roofs off houses and flooding some areas.
Solomon Star News said there had been no reports of injuries after the category two cyclone made its way through Rennell Island and Makira in the south.
Solomon Island's MetService has downgraded all its tropical warnings now to a watch.
On its current track Cyclone Freda was moving south and away from the Solomon Islands.
Mr Thordarson said it was too early to predict whether New Zealand would be affected by the cyclone.