Keep a jacket handy this weekend, as heavy rain is expected in Fiordland, Westland and the Canterbury and Otago headwaters.
A MetService spokesman said today a front would move north over the South Island during the weekend and was forecast to bring rain to parts of the South Island.
An Orange heavy rainfall warning has been issued for parts of Fiordland and Westland, and there are watches in place for southern Fiordland and the Canterbury and Otago headwaters.
He said up to 200mm was expected to fall about the ranges of Westland, south of Otira, and up to 120mm near the coast south of Ross, between 3am on Sunday and 2am on Monday.
Rainfall intensities of 20mm-30mm per hour were possible during Sunday afternoon and evening.
In Fiordland, about and north of Doubtful Sound, up to 120mm of rain was expected between 8pm on Saturday and 2pm on Sunday, and intensities may reach 15mm-25mm per hour at times.
Heavy rain may cause streams and rivers to rise rapidly, surface flooding and slips were also possible, and driving conditions may be hazardous, the spokesman said.
In Fiordland, south of Doubtful Sound, heavy rain was also expected to approach warning criteria between 6pm on Saturday and 9am on Sunday.
Rainfall accumulations may also approach warning criteria in the Canterbury and Otago headwaters within 15km east of the main divide, between 12.01am on Sunday and 3am on Monday.
He advised people to keep up to date with the latest forecasts and warnings as more areas may be added, or watches could be upgraded to warnings.
