Residents from Auckland to Tasman face downpours, with the flood-hit South Island regions bracing for a 'worst-case scenario'.

Thunderstorms are forecast to bring heavy rain to the storm-battered Nelson and Tasman regions.

Thunderstorms are forecast to bring heavy rain to the storm-battered Nelson and Tasman regions.

Downpours are forecast to hit large parts of the country, including Auckland and the already drenched Tasman District.

Downpours are forecast to hit large parts of the country, including Auckland and the already drenched Tasman District.

The top of the South Island is under a second state of emergency in three weeks.

MetService says there's been more rain for the flood-damaged Nelson Tasman district overnight, with more to come.

Civil Defence is warning people whose properties flooded last week to prepare for potentially being inundated again.

Civil Defence is warning people whose properties flooded last week to prepare for potentially being inundated again.

A state of emergency remains in place for the flood-damaged Nelson-Tasman region after much of the country was battered by a barrage of downpours.