Despite Bay of Plenty residents waking to fiery morning sky, a severe weather watch for heavy rain remains in place for the region.

The MetService says a rain band is forecast to travel eastwards across the country, followed by a cold front from the south.

This morning's sun made the sky look like it was on fire. Photo: Jenny Lucey.

'Make the most of your current blues skies,” says meteorologist Emma Blades, 'as you won't be seeing much of them for the next couple of days.”

This is because a moist northerly flow will spread over the country through Friday, bringing rain to much of the country.

With Nelson, Bay of Plenty, Rotorua and Mount Taranaki being particularly vulnerable to a rainy, northerly flow, a watch for heavy rain in those places has been issued.

A period of heavy rain is expected from Friday night through to Saturday night, and possibly early Sunday in eastern Bay of Plenty. Rainfall amounts could approach warning criteria during this time, especially about the ranges (for example over 100mm falling within 24 hours).

Thunderstorms are also forecast as the rainband crosses the Northland region during Friday evening.

'Some of these thunderstorms are likely to produce heavy downpours as they cross Northland,” says Emma.

A cold front then moves northwards over the South Island on Sunday and the North Island on Monday.

'The cold front will bring cooler showery weather, especially for the lower South Island,” says Emma.

'Following this, a ridge of high pressure will build, so we can expect to see those blue skies again once the cold front has passed.”