A strong cold front is expected to move south to north across the South Island Sunday. This front will be the focus for wind and rain. In some parts of the South Island and lower North Island, the wind could reach severe gale strength and the rain could be intense.
Government forecaster MetService has issued heavy rain warnings for Sunday affecting Fiordland, Ranges of Westland south Otira and the headwaters of the Otago and Canterbury lakes and rivers from Arthurs Pass southward.
Rainfall rates could reach 20 to 25mm an hour with the heaviest falls likely in the late afternoon or early evening.
MetService has also issued strong wind warnings for Sunday affecting Canterbury, Marlborough, Wellington and Wairarapa south of Masterton. In Canterbury, the strongest winds are expected in the late mornings hours on Sunday and then lasting until the late evening hours. Winds could reach gusts of 130km/h in exposed places.
For the lower North Island, the strongest winds are expected Sunday afternoon through early Monday morning. Wind gusts could reach 130 km/h in exposed places.
WeatherWatch.co.nz Analyst Howard Joseph says the wind and rain will overspread the rest of the North Island during the early morning hours of Monday. Pockets of heavy rain and strong winds are possible, but Joseph says widespread severe weather is not likely.
Joseph also says another round of rain and wind will move across the South Island on Monday but severe gales and intense rainfall are not expected.
The weather will settle nationwide as a big ridge of high pressure builds in late on Tuesday.