Police are warning motorists of strong winds in Central Otago and say they are already dealing with one accident in which high winds blew a car off State Highway 6 between Cromwell and Luggate.
The MetService says a front approaching New Zealand from the Tasman Sea is expected to move onto the lower South Island on Thursday night, then continue moving over the remainder of the South Island overnight and on Friday.
It is expected to bring north-westerly gales to parts of both islands as well as significant heavy rain.
