Severe weather watch for upper North Island

Severe thunderstorms, flash flooding and weak tornadoes are expected to hit parts of the North Island today. Photo / Hawke's Bay Today

Severe thunderstorms, flash flooding and weak tornadoes are expected to hit Northland, Auckland and Great Barrier Island today.

Metservice forecaster Allister Gorman said up to 40mm of rain an hour was predicted for the upper North Island from late morning.

It was likely to cause flash flooding - especially in low-lying areas such as streams, rivers or narrow valleys.

Landslips and weak tornadoes were also possible and drivers should take extra care, Mr Gorman said.

The bad weather was expected to ease north of the Bay of Islands by about mid-afternoon.

- NZPA