Thunderstorms, hail and tornado risk as North Island braces for stormy start to week

The upper half of the country is bracing for a day plagued by thunderstorms, hail and even tornadoes, and the eastern regions will be inundated.

A heavy rain watch and watch has been issued for the eastern regions as MetService warns of a volatile start to the week with a large swath of the North Island being hit by thunderstorms today.

MetService says heavy rains and thunderstorms are expected to affect the northern half of the North Island, with a moderate risk of thunderstorms north of Taupō after lunch.

And the forecaster warns that the storms will bring heavy rain and localized hail, along with a low risk of a small tornado or two.

The eastern regions, from southern Gisborne to the Tararua district, have 24 hours of rain, and people are told to prepare for torrential downpours during thunderstorms.

A heavy rain warning and alert have been issued. MetService warns that they are expected to fall as much as 140mm today with up to 140mm of rain in the ranges.

The strongest drops would occur from morning to night, where intense flooding was forecast that could lead to rapidly rising streams and rivers. Flash flooding and slipping were also possible and motorists are cautioned that driving conditions can be extremely dangerous.

Wet weather is expected to move slowly east towards the Bay of Plenty on Tuesday before good weather returns on Wednesday.