Heavy rain and gales are expected to lash parts of the South Island as an active front moves in from tomorrow.
MetService has issued orange heavy rain warnings for Westland and the headwaters of the Canterbury lakes and rivers about and south of Arthur's Pass (SH73).
In Westland, up to 250 millimetres was expected to fall about the ranges, and up to 120mm forecast to hit closer to the coast between tomorrow evening and Friday afternoon.
Peak rates were set to reach 15mm to 25mm an hour about the ranges.
Similar peak rates were expected to fall in Canterbury, where up to 200mm of rain was forecast to hit the main divide, with lesser amounts in the east from 12am on Friday until the afternoon.
MetService said there was a low chance of either being upgraded to a red warning, but warned of possible surface flooding, slips and difficult driving conditions.
Yellow heavy rain watches are in place from tomorrow for parts of Fiordland and from Friday for Tasman northwest of Motueka, and the Buller and Grey Districts.
The watch for Tasman had a high chance of being upgraded to a warning and people should keep up to date with the latest forecasts, MetService said.
Meanwhile, strong wind watches have been issued for Fiordland, the Queenstown Lakes and parts of the Canterbury High Country and Southland tomorrow, with a moderate chance they will be upgraded to warnings.
"Northwest winds may approach severe gale in exposed places," MetService said.
Winds were expected to ease in the Canterbury High Country on Friday morning.
