Surface flooding and slips are also possible and driving conditions may be hazardous.
Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous.
Strong wind and heavy rain watches are in place for parts of the Canterbury High Country until tomorrow.
Winds reaching gusts of up to 72km/h at Aoraki Mount Cook aerodrome has been reported on Sunday morning, MetService forecaster Dan Corrigan said.
Heavy rain and thunderstorms are possible at the headwaters of the Canterbury lakes and rivers near to and south of Arthur's Pass.
"Expect 130 to 180mm of rain to accumulate about the main divide, and 80 to 120mm within 15km east of the divide," Corrigan said.
"Peak rates of 15 to 25mm/h near the divide."
Corrigan said the wind coming over the Southern Alps would result in warmer than average temperatures for much of the Canterbury region over the next day.
People are advised to keep up to date with the latest forecasts in case any changes are made, or further areas are added.
The weather watch warning extends to Monday morning.