MetService has issued a severe thunderstorm watch for part of the North Island including Northland.

Daytime cloud buildups are expected to produce scattered heavy showers and thunderstorms about northern, central and eastern parts of the North Island.

These thunderstorms are expected to be slow-moving and have the potential to be severe producing localised downpours of 25-40mm per hour and hail.

Rainfall of this intensity can cause surface and/or flash flooding, especially about low-lying areas such as streams, rivers or narrow valleys, and may also lead to slips.