Strong winds, including potentially severe gales, are being forecast for the South Island and road users are being advised to take extra care in exposed areas.

MetService has a strong wind warning in place from 1am tomorrow for the Canterbury high country, with severe gale northwesterlies predicted to be gusting up to 130km/h in exposed places.

A strong wind watch is in place tomorrow (with winds that may approach severe gales in exposed places) for Christchurch, the Canterbury Plains, Marlborough southeast of the Wairau River and Marlborough Sounds, and inland parts of Otago and Southland.

The winds may make driving difficult, especially for high-sided vehicles and motorcycles, and could also bring down trees and powerlines. Road users are encouraged to plan ahead for the windy conditions, and when driving in strong winds to reduce their speed, ensure a firm grip on the wheel, give other vehicles space and stay alert for debris.   

Heavy rain is also predicted at higher elevations tomorrow, which may cause surface flooding and make driving conditions difficult. Heavy rain warnings are in place for the headwaters of the Canterbury lakes and rivers south of about Lake Marion, the ranges of Westland, the headwaters of the Otago lakes and rivers, and Fiordland north of Doubtful Sound.

MetService is also forecasting (with low confidence) potentially severe gales for coastal Otago, Southland and Stewart Island on Thursday; for part of Fiordland and Stewart Island on Friday; and for much of the South Island on Saturday and Sunday.