A severe weather warning has been issued for the South Island's West Coast, with a metre of rain expected to fall in parts of the region over the next two days - which could cause significant flooding and landslips.
MetService has issued a severe red weather warning for Westland, with between 600 and 800mm of rain expected to fall in the ranges between 9am on Thursday and 8am on Saturday.
Between 100 and 200mm of rainfall is also expected along the coast.
West Coast Emergency Management is warning Kiwis in the Westland and Grey districts and is "mobilising staff" in preparation for heavy rain.
"Agencies and first responders will be meeting this afternoon," Civil Defence said on Thursday. "There is a high level of concern about possible impacts of the weather, particularly south of Hokitika.
"Slips and floodwaters are likely to disrupt travel, making some roads impassable and possible isolating communities."
MetService warns the rain is likely to cause "dangerous river conditions and significant flooding".
"Slips and floodwaters are likely to disrupt travel, making some roads impassable and possibly isolating communities," the forecaster said.
A heavy rain warning has also been declared for the Grey District and Civil Defence said it is watching the area closely.
Between 200 and 300mm of rain is expected about the ranges and 75 to 125mm along the coast, along with the threat of possible thunderstorms.
NZ Transport Agency Waka Kotahi (NZTA) is urging motorists to plan and check the latest conditions before driving on the West Coast.
The heavy rain "may impact parts of the state highway network, including the possibility of surface flooding and debris on road surfaces", the agency warned.
NZTA said unsafe driving conditions could result in closures of some parts of the highway overnight on Friday.
