Much of New Zealand is under weather alerts today and there are fears of flooding as an “atmospheric river” brings heavy rain to both main islands.
Orange heavy rain warnings are in force for Tasman (northwest of Motueka), the Buller District and the Westland ranges, and are set to come in for the Marlborough ranges and Mount Taranaki from 11am onwards.
The heaviest falls were expected to affect the Tasman District, with about 350 to 450 millimetres of rain forecast about the ranges and 150 to 250mm elsewhere. The orange warning in this area had a moderate chance of upgrading to a red warning, according to MetService.
All of the upper North Island is under heavy rain watches.
MetService forecaster Alain Baillie says so far the Tasman region has been heaviest hit, with about 40mm of rain overnight and the downpours expected to intensify later this morning.
"Up to 73mm at Paradise Peak, Collingwood had 50, Takaka 40mm, further west Westport at 28 mm."
Tasman Mayor Tim King said this amount of rain could cause slips, flooded roads and rivers bursting their banks.
"The general advice is to be aware, if you're in an area that is potentially subject to the impacts of heavy rainfall do the normal things; checking gutters, checking stormwater gates, checking your own property," he says.
MetService meteorologist Thapi Makgabutlane says up to 90mm of rain fell overnight, but the bulk of the rain is yet to come.
"The bulk of the rain is expected in the ranges but even away from the ranges quite a lot of rain and of course the flow-on effect from the rain in the ranges, so of course things such as slips, things such as flooding and as well as dangerous driving conditions."
People should plan for a very wet day on the roads, she says.
Makgabutlane says the system is expected to arrive on Tuesday but a high-pressure system to the east of New Zealand has slowed down its movement.
"So it has been tracking very slowly but now that it has arrived its movement is as we're expecting and we'll continue to track it throughout the day and assessing real-time information as it comes in to see how we are looking going forward."
She says it is hoped the rainfall will make a difference in areas which has been very dry, but one system would not fix the problem.
"Up until now what we've been seeing is patchy showers here and there that's not really going to make a difference, what we really need is these large widespread rain bringing systems."
In Buller, up to 300mm of rain was predicted to fall about the Paparoa Range and 160 to 220mm elsewhere.
Buller Mayor Jamie Cleine says sandbags are being given out as a precaution to people in Westport who have previously dealt with surface flooding.
"With those rain intensities particularly later Thursday afternoon and into Friday there could easily be reasonably significant surface flooding around our urban areas."
