A tornado in the Northland town of Waipu has destroyed caravans and sheds in its path.. Heavy rain has also caused flooding in Whangarei.
Waipu chief fire officer Trevor Vaile says the tornado came off the sea and struck a property half way between Waipu and Waipu Cove at about 4.30pm on Friday.
Mr Vaile says it picked up a caravan and tossed it about 50m, destroying it.
He says the tornado went on to take out a shelter belt of pine trees before picking up another caravan and then destroying a third caravan and a cabin.
Mr Vaile says debris were spread across the nearby road and paddocks.
He says witnesses told him the tornado was an amazing sight.
"They just couldn't believe it, you know, a massive and noise from it as it came across the estuary. The most startling thing I have heard from everybody was how it picked up the swans and was the swans around."
Mr Vaile says fortunately no one was injured.
Heavy rain in the Whangarei area has caused a series of floods.
Whangarei District Council says several traffic problems were reported, including man holes popping open.
The council is advising people to take great care on the district's roads over the next few days and to avoid travelling in flooded areas.
It says the downpours on Friday afternoon also caused a sewage spill at the Hatea Pump Station in Whangarei.
MetService is warning of severe weather in parts of New Zealand this weekend.
It says rivers and streams could rise rapidly as a result of heavy rain in Gisborne and Hawke's Bay.
Further heavy rain is expected in the Hawke's Bay ranges until early Saturday.
MetService says slips and localised surface flooding are possible.
It says strong to gale south easterlies have been affecting exposed areas of Taranaki, Taihape, Wanganui, Manawatu, Nelson and northern Buller.
Meanwhile, snow was expected to develop on Friday night to above 400m in northern Canterbury and the southern Marlborough ranges.
MetService says while snowfalls are likely to remain fairly light, driving conditions may become difficult about the higher roads.
It says farm stock in higher areas may need shelter.