A heavy rainstorm which has sparked warnings for holiday makers in Northland, Auckland and Coromandel now has Hamilton and Bay of Plenty in its sights.
Civil Defence is urging holiday makers in the upper North Island to be prepared and check weather forecasts, with a severe weather warning in place for several areas.
MetService has issued a severe weather warning for Auckland, Northland, the Coromandel Peninsula, and Great Barrier Island.
Heavy rain could cause slips and flash flooding, with between 150 and 180mm likely from today through to early on Sunday. Localised downpours were also possible.
Metservice also warned of easterly gales in the affected areas.
The storm's front will pass over Waikato and Bay of Plenty later today.
Marius Rothmann, who co-owns the Takapuna Beach Holiday Park on Auckland's North Shore, said it was definitely an indoor day for most of his guests.
"Today is very wet and windy. At this stage it is just soft rain, but it's consistent - it's an indoor day for them all."
Auckland Civil Defence said more than 50-millimetres of rain fell near Warkworth, in Northland, within four hours this morning.
Meteorologist Angus Hines said other parts of Northland also had a fair amount of rain in the last 12 hours, including Keri Keri which had had more than 30mm.
"The rain that's just kicked off now is expected to last all through today and into tomorrow as well."
Northland Civil Defence said it was on watch for slips and flash flooding that could be caused by downpours, and said the low pressure system was expected to hit hardest this afternoon and tomorrow morning.
Northern Fire Service has attended 12 incidents since this morning, but most have been minor road blockages due to fallen trees, and leaky roofs.
Civil Defence urged holidaymakers to be prepared for the storm, and to continue to check weather forecasts.
Auckland Civil Defence and Emergency Management director John Dragicevich said they were taking a precautionary approach but people needed to be prepared to act quickly if the storm gathered momentum.
"Heavy rain warnings and wind watches mean there is potential for flooding and damage so campers and holiday makers should check and secure their camping and outdoor equipment, and be ready to move quickly if required," he said.
"Boaties should also be prepared, listening to the radio and checking moorings.
Mr Dragicevich said low-lying coastal roads, such as Tamaki Drive, could be affected by wave splash around high tide this afternoon.
"The main effect is going to be north of Whangaparaoa, powerlines may be down," he said.
"I can assure the community that Auckland's utility companies and emergency services are well prepared for these types of events."
Civil Defence was taking a precautionary approach, and so should campers and holiday makers.
Northland Civil Defence spokesperson Shona Morgan said holiday makers should be prepared ahead of the storm, with up to 180mm of rain expected to hit the area's eastern hills during the two days.
"If the rain falls as predicted over the next couple of days, it could cause rivers and streams to rise rapidly, with slips and surface flooding also possible."
Duty Forecaster Heath Gullery said people going outdoors needed to keep an eye on the forecast.
"People, especially holiday makers, those people travelling and trampers etc, should keep aware of the latest watches and warnings because it is likely to impact a lot of outdoor pursuits over the next two or three days."
The rain was predicted to reach the parched upper South Island on Saturday, although it was too early to say where or how much, said MetService meteorologist Angus Hines.