MetService has issued a warning for significant heavy rain for the headwaters of Otago lakes and rivers over the next few days.
A series of fronts are forecast to move east across the South Island from Sunday morning through into Tuesday afternoon, bringing periods of heavy rain to the west and the south of the South Island, and strong west to northwest winds to parts of southern and central New Zealand.
A MetService spokesman said a heavy rain warning was now in force for Fiordland, Westland and the headwaters of Otago lakes and rivers.
‘‘Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous.’’
He said heavy rain may also affect other parts of Otago and Southland.
On top of what has already fallen in the headwaters of the Otago lakes and rivers, up to 450mm of rain is expected to accumulate near the main divide, and up to 280mm is expected to fall within 15km east of the divide between 10am on Sunday and 1pm on Tuesday.
Peak rates of 25mm per hour are expected to fall, and up to 35mm per hour may fall if there are thunderstorms.
In Fiordland, up to 500mm of rain may accumulate north of Doubtful Sound and up to 300mm may accumulate further south, between 10am today and 10am on Tuesday.
Peak rates of up to 25mm per hour may fall in general, but up to 40mm per hour could fall in possible thunderstorms and in localised downpours, he said.
In Westland (from Harihari southwards), up to 500mm of rain may accumulate about the ranges, and up to 160mm near the coast, from 10am om Sunday until 2pm on Tuesday.
Peak rates of up to 25mm per hour may fall in general, and up to 35mm per hour may fall if there were thunderstorms, he said.
There is also a strong wind watch in place for eastern parts of southern and central New Zealand.
‘‘People are advised to keep up to date with the latest forecasts in case any changes are made.’’
