A warning has been issued for severe thunderstorms over the upper North Island.
Downpours, thunder and lightning are expected to hit Northland, Auckland and the Coromandel until Thursday afternoon.
MetService says there is the potential for localised downpours of up to 40 mm an hour, which cause flash-flooding or slips.
But Met Service spokesman Bob McDavitt told NZ Newswire this should blow over by the weekend.
"It should ease up tonight but then build up again tomorrow.
"There will be some electrical activity during showers as well and then it'll slowly dry out over the weekend.”
He says there will be no rain during the weekend, but it will not be 100 percent sunny.
Mr McDavitt says drivers should be wary during downpours as a lot of rain is expected.
"We're going for a rainfall of 20 to 40mm an hour and the local gutters can only support 25 to30mm an hour so in the centre of these downpours there is likely to be some surface flooding."
NZN/RadioLIVE