A front remains slow-moving over the lower North Island during Sunday afternoon, then starts to move northwards in the evening. Meanwhile, an unstable northwesterly flow persists over southern New Zealand, with an embedded trough moving over Fiordland and southern Westland. This trough also brings a southerly wind change to the southeast of the South Island during the afternoon and evening. There is mostly a low risk of thunderstorms from central Westland to Fiordland, and over Southland and eastern Otago. However about northern Fiordland and southern Westland this morning and early afternoon there is moderate risk of isolated thunderstorms, while over Clutha and Dunedin there is a moderate risk of thunderstorms this afternoon and evening. These thunderstorms if they occur could bring localised heavy rain with intensities of 10 to 20mm per hour and small hail. Further north, apart from a moderate risk of thunderstorms over the waters southwest of Taranaki there is initially a low risk of thunderstorms about the Marlborough Sounds, Wellington, Kapiti Coast, Horowhenua, Tararua Range, Taranaki, Taumarunui and Waitomo. However from late afternoon the risk of thunderstorms increases to moderate about Waitomo, Taumarunui, Taranaki and over the waters south of Taranaki and west of Horowhenua and Kapiti Coast. These thunderstorms will be embedded in bands of rain and boost heavy rainfalls. No thunderstorms or significant convection expected elsewhere in New Zealand during this period.

A front moves slowly north onto northern New Zealand tomorrow morning, bringing a low risk of thunderstorms to Northland, Auckland, Coromandel Peninsula, Waikato, Waitomo, Taupo and Bay of Plenty. Over the South Island an unstable west to southwest flow brings a moderate risk of thunderstorms to Westland, Fiordland, Stewart Island and coastal Southland. These thunderstorms could be accompanied by heavy rain of 10 to 20mm per hour and small hail. A lower risk of thunderstorms covers Nelson, Buller, inland Southland, eastern Otago and coastal Canterbury as far north as Banks Peninsula. No thunderstorms or significant convection expected in other areas.

The front continues to move slowly north over northern New Zealand tomorrow afternoon and evening, bringing an associated low risk of thunderstorms to Northland, Auckland, Coromandel Peninsula, Waikato, Waitomo, Taupo and Bay of Plenty. For the South Island, an unstable west to southwest flow brings a low risk of thunderstorms to western Nelson, Buller, Westland, Fiordland, Southland and eastern parts of Otago and Canterbury as far north as Christchurch. No thunderstorms or significant convection expected in other areas.