Wind blast on the way

A blast of powerful wind is on the way for the east of the South Island and lower North Island, while the west of the South Island is likely to get only a brief respite from torrential rain.

MetService said 200mm of rain fell at Milford Sound in the 36 hours to this morning, with 150mm at Franz Josef Glacier.

Today rain had eased in Fiordland and Westland south of the glaciers, but further significant heavy rain was expected to set in tomorrow ahead of a strengthening northwest flow. As much as 200mm could fall from tomorrow afternoon to noon Friday.

"People are advised that driving conditions may be hazardous, rivers and streams may rise rapidly, surface flooding and slips are possible," MetService said.

Heavy rain also looked set to return late tomorrow for Westland between the glaciers and Otira.

Rain had eased this morning about the headwaters of the Otago lakes and rivers but was expected to return to the area late tomorrow into Friday morning.

Northwest winds were expect to strengthen tomorrow, and could reach 110kmh in some parts of the east of the South Island and lower North Island, MetService said.

The strongest wind in the South Island was likely in some inland parts of Canterbury and Otago in the lee of the Southern Alps, MetService communications meteorologist John Law said.

The worst of the wind could reach Otago late tomorrow and Canterbury on Friday morning. Winds were expected to peak in Wellington and Wairarapa through Friday.