"The rain will just start to become more steady and persistent,'' Mr Corbett said.
"The drive home in places like Auckland will be just yucky.
"It's a mean low'' which created a risk of flooding and beach erosion, he said.
Poor weather was likely to continue through most of tomorrow, but as the winds are mainly from the tropics, day-time temperatures in the upper half of the North Island should remain around 16C.
"Through Wednesday, the heavy persistent rain starts to become a bit more patchy and showery.
"It will start to wind down as we go through the day on Thursday, and by Friday we can all hang the washing out,'' Mr Corbett said.