Tropical storms could hit New Zealand on Christmas Day

Tropical storms could put a dampener on Christmas Day barbies. Photo / Andrew Warner /

Don't make too many plans for that Christmas Day barbie on the beach as stormy weather could put a dampener on outdoor celebrations.

At this stage, high pressure coming in from Tasmania indicates a fairly settled December 25 - but a potential tropical storm is also brewing, said WeatherWatch analyst Philip Duncan.

"The law of averages indicate a pretty decent Christmas Day but things could get wild if a tropical storm expected just north of New Zealand moves in.

"The tropics are finally firing up and there could be lots of activity along with that. It is certainly one to watch."

Meanwhile, it might be best to pack a brolly with the sunscreen this weekend as cloudy and wet weather is on the way.

The dry and sunny recent spell will end as a fast-moving front coming in from the Tasman today (Saturday) will sweep the country bringing rain and lower temperatures with it.

It has felt like summer in many places this week but the next few days will get colder in the south and wetter and windier in the north and east.

"Rain will set in for Auckland in the late morning on Saturday which will hit Wellington later in the day," MetService forecaster Tom Adams said. "Unfortunately it could put a bit of a dampener on festive events being staged in both cities but things should start clear up in Auckland by about 4pm, leading to a fine evening."

Despite the downpours, temperatures will still get up to a respectable 23 degrees in Auckland and the Coromandel today (Sat). It will be slightly cooler in the Bay of Islands.

The warmest place to be in the country today will be Napier, where temperatures are expected to top 27 degrees, Adams said.

"Other places in the east such as Masterton will also be pretty hot and in the west, Palmerston North is also looking good ."

By tomorrow (Sunday) temperatures will drop by several degrees in most places as the front from the Tasman continues to clear the warm air.

Wellington is expected to be about 18 degrees on Sunday, with Auckland not much warmer. Napier is again the place to be as temperatures will still be around 23 degrees.

"The South Island will be cooler than the North Island for most of the weekend, with heavy rain expected in Fiordland and parts of Southland," Adams said.

Heading into Christmas, things are expected to be relatively dry with average temperatures.

"The week after Christmas is expected to be slightly cooler and drier than average," Adams added.