A severe thunderstorm watch has been issued across most of the North Island for Tuesday afternoon.
The combination of a warm humid day and light winds is set to produce scattered heavy showers and thunderstorms in the afternoon.
MetService says showers in Auckland are expected to "supercharge" into thunderstorms around midday, with surface flooding and heavy rain impacting driving conditions.
In the central North Island, rainfall is likely to reach 20 to 50mm per hour.
By Tuesday evening, the storms are expected to move towards the northern South Island.
MetService says to "keep an eye on [thunderstorm] progression by looking out the window".