The top half of the North Island is due to be battered by heavy rain, hail and thunder this afternoon.
Isolated heavy showers were forecast to move in to the Auckland area between 1.30pm and 2.30pm, WeatherWatch.co.nz head analyst Philip Duncan said.
"Heaviest showers may contain isolated hail and a rumble of thunder."
The front was "pretty narrow", but it did open up the gates for more showers across the upper North Island for this afternoon, Mr Duncan said.
Motorists were advised to drive with care during sudden downpours and watch for very localised surface flooding.
