Flood warning for Northland

Photo / File

Northlanders are being warned to brace themselves for a sub-tropical low which could deliver a month's worth of rain in 24 hours.

The weather warning predicts heavy rain, gales and likely flooding for the region.

MetService forecasters today issued a heavy rain warning predicting the rain will become heavy about 9pm today with 100mm to 150mm expected in the 24 hours from then.

They say some areas near the east coast may get even more rain - 180 to 200mm - over that same period and warn heaviest falls may reach 25 to 30mm per hour.

Graeme MacDonald, spokesman for the Northland Civil Defence Emergency Management (CDEM) Group, says if the rain arrives in the amount forecast, there will be flooding and possible slips along the parts of the east coast that are usually susceptible to it.

"Essentially, that's a month's worth of rain in just 24 hours - including some very heavy hourly rainfall rates - so we're urging people to make sure they take the usual precautions and stay off the roads unless absolutely necessary."

He says rivers could rise quickly, with a predicted 2.5m high tide due just before 6am tomorrow likely to put even more stress on rain-swollen rivers.

"The rain is also expected to be accompanied by gale force winds from the south-east, which again could be an issue for those in exposed parts of the region."

Mr MacDonald says Civil Defence officials will monitor the situation overnight and the usual warnings apply for farmers with stock in low-lying areas to move them to higher ground and boaties to make sure vessels are secure.

He says the warning to stay off the roads is particularly important as in previous storms some Northland motorists have put themselves and others at risk by driving through floodwaters unnecessarily.

"Floodwaters can wash out roads or carry logs and other debris which can cause serious risks to drivers and the force of the floodwaters can also wash vehicles from roads altogether.

"We're also advising people to keep an eye out for the latest weather forecasts."