A severe weather watch for strong wind is in force for the Bay of Plenty.

Strong south to southeast winds continue to cover the east of the North Island as ex-tropical cyclone Gretel passes east over waters to the northeast of New Zealand, says the MetService.

"There is moderate confidence of southeast winds approaching severe gale about exposed parts of eastern Bay of Plenty and Gisborne early Wednesday.

"A ridge covers much of the country on Wednesday. A weakening front should move northeast over the South Island on Thursday, then across the North Island on Friday.

"There is low confidence of warning amounts of rain in Fiordland on Thursday.

"On Saturday, another cold front is expected to cross the South Island from the south Tasman Sea, bringing a period of rain to the west and south of the South Island. There is low confidence of heavy rain in Westland during Saturday."