West Coast authorities are already preparing for the ex-tropical cyclone Gita to hit, despite not being sure exactly what it could bring.
Mayors and council chairs in the region met on Sunday to discuss how to prepare for the storm, and would meet later again today to get an update from MetService.
West Coast Regional Council chief executive Mike Meehan said there were a "few things" they could get under way already, but today would provide a better picture of how the storm was likely to hit.
"The key part of the modelling for us is what's going to be the impact on those coastal communities with potential storm surge, also mindful of the rain that could come with it ... then of course the wind is obviously of concern as well, and how all those things interact with each other."
TC #Gita will bring strong winds to the lower North Island and upper South Island on Tuesday and Tuesday night.— NIWA Weather (@NiwaWeather) February 18, 2018
The highest gusts may exceed 110 km/h across Taranaki, Wellington, Tasman, Nelson, Marlborough, and northern Canterbury.
Secure any loose items in your yard! pic.twitter.com/b08YQjlKFf
Once a clearer picture was found decisions would be made around moving people, and whether sandbags were needed.
Mr Meehan told Morning Report it was possible a state of emergency would be declared, and it would be discussed today.
In the meantime people should check their emergency kit, fill up on gas and tie down or remove outside furniture, he said.
All schools and early childhood centres in the Buller District will be closed tomorrow and Wednesday as a safety precaution, said Civil Defence.
Authorities were conscious some communities had already been hit by cyclone Fehi, and some people just starting to rebuild might be hit again.
Nelson mayor Rachel Reese said the council would constantly be in touch with residents, and the best thing they could do was be prepared.
"They should have their emergency kits and their evac plans ready and we're really asking people to be neighbourly and look out for vulnerable people on your street, [and] make sure older people have got some support.
The storm has been predicted to hit Tuesday night or Wednesday morning.
MetService said on Sunday a heavy rain watch had been issued for the lower North Island from Horowhenua to Wellington, and including Wairarapa and the Tararua Range.
Heavy rain was likely to fall over the South Island from Westland and Canterbury north.
The storm was also likely to bring severe gales to those areas.
Cold air being dragged northwards could cause unseasonably low levels of snow in the Canterbury High Country on Tuesday.