Weather: 750mm of rain possible on West Coast, caution urged

MetService has issued a red warning for parts of the west coast of the South Island as a deluge of rain is set to hit this week.

The heaviest rain is expected in Westland and Buller, both of which are now covered by a red warning. A spokesperson for the forecaster said this signals the likelihood of significant impacts.

🔴 RED HEAVY RAIN WARNING ISSUED FOR WESTLAND AND BULLER 🔴

Act now!

◾ Dangerous river conditions
◾ Significant flooding and slips
◾ Travel disruptions
◾ Communities may become isolated

Full details: https://t.co/qHyE5zzql5 pic.twitter.com/hm7bqkfAxk

— MetService (@MetService) January 31, 2022

"An active front, preceded by a strong and very moist north to northwesterly flow, is forecast to move slowly northwards over the South Island from Wednesday to Friday, bringing significant heavy rain to western areas," they said.

In Westland, MetService is predicting between 550 and 750mm of rain will accumulate near the ranges and 150 to 250mm near the coast.

Meanwhile, orange warnings cover the headwaters of the Otago and Canterbury lakes and rivers, and also Fiordland and Tasman.

"This is likely to be a significant heavy rain event."

A watch for possible severe northwest gales has also been issued for the Canterbury High Country.

The spokesperson said heavy rain can cause streams and rivers to rise rapidly.

"Widespread flooding and slips are possible and driving conditions could be hazardous during the event. People are strongly advised to keep up to date with the latest forecasts."