A severe weather warning remains in place for the Bay of Plenty, but the MetService is expecting heavy rain to ease this evening.

An active trough, which is bringing heavy rain to the upper North Island, is expected to move slowly north-eastwards and clear the North Island later this afternoon and into this evening.

Rain bands are continuing to move across the North Island.

Heavy rain about the ranges of the Eastern Bay of Plenty is expected to ease, and another 100 to 120mm may accumulate on top of what has already fallen.

'In addition, the unstable north-west flow over the South Island is expected to bring another burst of heavy rain and thunderstorms to the south-west of the South Island on Saturday,” says the MetService.

'The heaviest falls are likely about Fiordland and Westland south of Otira, where 90-110mm may accumulate, but up to 140mm is possible about the ranges of southern Westland in an 18-hour period.”

People are advised that streams and rivers may rise rapidly, while surface flooding and slips are possible.

Heavy rain around Waitomo, Taumarunui and Tongariro National Park has eased and the warning for these areas is now lifted.