NZ weather: Significant heavy rain expected for West Coast, could spill over to Canterbury

Parts of the South Island should prepare for heavy rain over the weekend with slips, flooding and road closures possible. 

Forecaster WeatherWatch says a heavy rain event out of Australia is set to "park" itself over parts of the West Coast with central areas close to Hokitika likely to be the heaviest hit.

"Over 200mm is forecast to fall within 3 days," WeatherWatch says. "This is quite a bit, but for the West Coast, it should be mainly manageable if spread over those days. 

"However there is the chance for localised slips, flooding and even road closures and there will also be spillover into Canterbury."

The heavy rain event will also see temperatures tumble on Saturday, with a southerly change moving up the South Island, WeatherWatch says.

The forecaster is also predicting daytime maximums will be more than eight degrees below normal for parts of Canterbury and many other southern and eastern areas.

MetService has warned heavy rain may cause streams and rivers to rise rapidly while surface flooding and slips are also possible meaning driving conditions could be hazardous.

The North Island should miss the heavy rain and are in for a settled weekend with temperatures remaining several degrees warmer than normal.