Thunderstorms with hail up to 20mm in diameter are threatening the upper North Island.
MetService said a cluster of active thunderstorms approached southwest Northland this morning, and should move on to western parts of Auckland and Waikato shortly.
Along with hail, they could be accompanied by a burst of heavy rain.
The top half of the North Island had a moderate risk of thunderstorms until early afternoon.
Thunderstorms were possible in north Taranaki and Manawatu later today, while the rest of the North Island had a low risk of thunderstorms into the afternoon.
The storm risk was a result of a very warm and moist airmass moving southeastwards across the North Island, MetService said.
More heavy rain was also expected today in the ranges of eastern Bay of Plenty, with MetService warning streams and rivers in the area could rise quickly.
Between 60mm and 80mm or rain was forecast between 8am and 9pm, with slips and surface flooding also possible.
While heavy rain warnings had been lifted for Tongariro National Park and the Kaimanawa Mountains, a further brief burst of heavy rain was possible in those areas this afternoon, MetService said.
Taranaki Daily News