Violent electrical storms are rumbling across the North Island with rain set to drench the top half in coming hours.

MetService has today issued heavy rain watches for the central North Island with a threat of downpours during the thunderstorms.

Rain is expected to fall over the upper North Island for much of the day.

An intense band of rain packed with lightning is bearing down on the North Island’s western coastline.

The latest heavy rain watch has been issued for Waikato just as the delayed annual Fieldays gets underway at Mystery Creek Events Centre.

Waitomo, Taumarunui, Taupo north of Turangi and the ranges of eastern Bay of Plenty are also all under heavy rain watches.

The rain alerts are in place until 3pm for all areas except the ranges of Bay of Plenty which remains in force until 7pm.

MetService says heavy rainfall in these areas may approach warning criteria and thunderstorms are possible.

“[A] front is expected to deliver a period of heavy rain and thunderstorms to some places, and a heavy rain watch remains in force for central areas.

“People are advised to keep up to date with forecasts in case any changes are made.”

• NZ’s ‘disjointed December’: When will summer weather arrive?
• Bad weather rolls into new week with a forecast of showers, heavy rain and thunder

In the South Island, areas from Christchurch to Dunedin could get thunderstorms and hail this afternoon and this evening.

The bad weather will be settling in as the Blackcaps v India third ODI is due to kick off at 2.30pm in Christchurch at Hagley Oval.

On Thursday parts of both islands will get a few showers.

Areas between Wellington and Wairarapa, and Canterbury to Kaikoura, will start Friday off with rain.

The start to the weekend will also be rainy for eastern and southern regions of the North Island while in the South Island it was expected to be mostly fine.