Thunderstorms to rattle north, heavy rain in south

More thunderstorms are lining up to roll across the North Island today while southern regions cop more heavy rain.

Intense thundery showers are set to track from Northland to northern Waikato early this morning while coastal Hawke's Bay is also under threat of morning storms.

MetService is warning the thunderstorms were likely to be accompanied by heavy rain and small hail.

After midday the thunderstorms would rattle eastern and central regions and the top of the South Island.

Isolated heavy showers and thunderstorms were expected to develop from cloud build-ups during this afternoon and early evening.

The most likely area for thunderstorms included Waikato, Waitomo, Taumarunui, Taupo, Bay of Plenty and Rotorua, and also parts of Manawatu, Horowhenua, Kapiti, the Marlborough Sounds and eastern Nelson.

Heavy rain falling on the Kaikoura Ranges and inland parts of Canterbury was expected to ease today but a rain warning remained in place.

Accumulated rainfall by 6pm tomorrow night. The Kaikoura Ranges and foothills about the Canterbury High Country the areas most affected ^KL pic.twitter.com/e29sNITMEt

— MetService (@MetService) September 18, 2017

Yesterday parts of Otago were hit again by flooding with the Taieri swamped after waterways breached banks spilling into roads and properties.

A number of roads were closed but river levels had since dropped and roads re-opened.

Further north the Inland Route 70 from Mt Lyford to Kaikoura remained closed this morning due to flooding.