A severe thunderstorm outlook is being issued for the upper North Island this afternoon including the Bay of Plenty.

MetService issued the warning earlier today reporting a moderate risk of thunderstorms, heavy rain and gusts in the Bay of Plenty, Northland, Auckland, Coromandel Peninsula, Waikato, Waitomo, Taranaki, northern Gisborne, Buller and Nelson.

MetService issued a severe thunderstorm outlook for Tauranga and wider Bay of Plenty.

Communications and media meteorologist Dan Corbett says tornadoes are possible, but unlikely.

'The main risk is for heavy downpours and hail, but we can't completely rule out the risk of a tornado.”

Some tornadic systems such as funnel clouds, waterspouts and small land-based tornadoes are possible with thunderstorms, he says.

At least two waterspouts have already been seen in the Maukau Harbour this afternoon. The waterspouts – or tornados over water – passed over the harbour earlier today.