The sub-tropical low that cut power, created slips and flooded roads in Northland yesterday remains centred near the region for Tuesday but heavy rain and strong winds are heading south.

WeatherWatch.co.nz says eastern areas of the North Island, from Wellington to Gisborne, will be most exposed to the heavy rain while the strongest winds will affect central New Zealand.

The low has weakened a little but will get a shot in the arm from the sub-tropics on Wednesday – bringing a return to gales and heavy rain for the upper North Island.

For the most part the South Island is settled thanks to a large high – it’s this same high that is helping create the strong winds over the the North Island between the high pressure in the south and the low pressure at the centre of the low near Northland.

Gale force south easterlies are expected to blast though Cook Strait today and affect some surrounding coastal communities.  The wind tunnel effect caused by Cook Strait will see the worst of the winds out at at sea to the west but some exposed coastal areas in Taranaki, the Marlborough Sounds and Kapiti/Horowhenua may also have some strong wind gusts across Tuesday, as will Wellington, Wairarapa and exposed parts of the Nelson region.

Generally speaking the winds on Wednesday will be lighter across the entire North Island – easing in the south but building again in the north as the sub-tropical low energises up once more.

Rain in the upper North Island on Tuesday will ease to patchy showers with winds easing slowly as the day progresses – while the lower South Island remains sunny, warm and settled underneath the large high.

– WeatherWatch.co.nz