Holiday weather set to turn ugly - analysts

Motorists make their way through floodwaters in Papamoa after a huge amount of rain fell in the Bay of Plenty early this week. Photo / Alan Gibson

Heavy rain may ruin the Queen's Birthday holiday weekend for some in the North Island as another big low barrels out of the north Tasman Sea, weather analysts say.

And police say arrival of wet weather while holidaymakers are on the road will increase the risks for drivers.

Weatherwatch analyst Philip Duncan said today the long weekend would start off sunny and settled but could end wet and windy for many people.

"This low is going to drag heavy rain over the North Island starting Sunday in the north and moving in to the east on Monday," he said.

The heavy rain may cause serious surface flooding, especially in Northland, Coromandel, Bay of Plenty and Hawke's Bay, where recent drenchings have saturated the soil.

"We're not saying floods are on the way, we're just advising that it won't take much heavy rain to create fairly serious surface flooding."

Conditions for travelling in such areas are likely to be "poor to moderate" for motorists, Mr Duncan said.

"Rain or showers about the North Island's east coast could make driving hazardous," he said.

There would also be gales or strong winds around the lower North Island, and a gale southerly developing in Cook Strait.

MetService weather ambassador Bob McDavitt said the weekend weather could bring holiday drivers some unfamiliar challenges as temperatures plummeted in southern regions.

"High (altitude) roads are likely to freeze overnight, and inland basins are prone to fog, so night drivers need to take extra care," he said.

Senior Sergeant Ian Campion, of the Western Bay of Plenty, said the forecast meant drivers should take special care and reduce speeds, respect following distances, drive to the conditions and be patient, taking extra care during overtaking manoeuvres.

"During wet conditions it's often unsafe to travel at the speed limit so knock 20km/h off and increase following distances to a minimum of four seconds," he said.

Poor weather meant the speed at which a motorist drove was a key factor in crashes: at 100km on a dry road it took 98m to stop - almost the length of a football field - but this distance almost doubled when the road was wet and there was also a higher likelihood of losing control.

Police would prosecute every driver caught travelling more than 4km/h over the speed limit, and drivers caught speeding by more than 40km/h would immediately have their licence suspended, Mr Campion said.

During Queen's Birthday weekend last year, there were six fatal crashes and 114 injury crashes, resulting in 10 deaths, 32 serious injuries and 127 minor injuries.

- NZPA