A Heavy Rain Watch is in place today for Bay of Plenty and Rotorua.

"Periods of heavy rain, with thunderstorms and localised downpours are possible," a MetService spokesperson said.

The Heavy Rain Watch extends for 10 hours from 8am - 6pm today.

Rainfall amounts may approach warning criteria. Note, there is high uncertainty where the largest accumulations will be, and warning amounts may be exceeded in localised areas." MetService said there is a moderate chance of upgrading the Heavy Rain Watch to a Warning.

On Tuesday, MetService is forecasting a strong southerly flow to affect the North Island, while a low pressure system lies to the northeast of the North Island.

"There is low confidence that severe southerly gales will affect exposed parts of Taranaki, Wellington and Wairarapa during the morning; and about eastern Hawke's Bay, Gisborne, and the Bay of Plenty east of Whakatane for much of the day.

"Additionally, there is low confidence for warning amounts of rain in Gisborne and northern Hawke's Bay."

A ridge of high pressure will affect much of New Zealand on Wednesday, while a slow moving pressure system will be lying to the northeast of the North Island.

"There is low confidence for warning amounts of rain in Gisborne and northern Hawke's Bay. Additionally, there is low confidence that southeast winds may be severe in exposed places of Gisborne and Bay of Plenty east of Whakatane."

On Thursday, a low pressure system to the northeast of the North Island will move slowly eastwards. An easterly flow will affect the country. There is minimal risk of severe weather.

On Friday. the easterly flow affecting the country will weaken as another low pressure system develops to the west of New Zealand. MetService said there is minimal risk of severe weather.