A front over the Tasman Sea is forecast to move onto Fiordland early Friday morning, preceded by heavy rain in the west and strong north to northwest winds in the east. As a low develops on the front west of the country, the frontal rainband is likely to stall over northern Fiordland and southern Westland from Friday night into Saturday.

A Heavy Rain Warning is now in force for Fiordland, Westland and the Otago headwaters.

This Watch is for a period of significant rain from Friday afternoon into Saturday for inland parts of Southland, the Otago Lakes region across to western parts of Central Otago and also the Mackenzie Basin.

At this stage, amounts in these areas are expected to remain just below warning criteria.

Additionally, northerlies are expected to rise to gale about Fiordland and exposed inland parts of Southland overnight Thursday and Friday morning. This Watch covers the possibility of localised severe gales in these areas during this time. Also, northwesterlies are likely to reach gale force in exposed inland parts of Otago and Canterbury during Friday. While widespread severe gales are unlikely, severe gales are possible in a few places, especially in the high country.

People in all these areas are advised to keep up to date with the latest forecasts, in case any parts of this Watch are upgraded to a full Warning.