Bursts of heavy rain are being forecast for the Bay of Plenty.

A low pressure system and associated fronts are moving east across the country today, bringing periods of heavy rain to the west and upper parts of the South Island, also about the Tararua Ranges, Mount Taranaki and the ranges of Eastern Bay of Plenty.

A heavy rain warning is in force for Westland until this evening.

A watch remains in force for bursts of heavy rain in Buller, the ranges of northwest Nelson, the Bryant and Richmond Ranges and Mount Taranaki, but the rain should ease in these areas today.

'Rain is expected to become persistent and heavy at times from around midday today through to midnight tonight about the Tararua Ranges, and from around midnight tonight through to Saturday evening about the the ranges of eastern Bay of Plenty,” says the MetService.

'This watch includes the possibility of rain reaching warning criteria for these areas during these times.”

Also, the watch for heavy rain in Fiordland for today is lifted, but another front is forecast to move onto Fiordland from the west Saturday morning bringing another period of heavy rain. This watch includes the possibility of rainfall accumulations reaching warning criteria in Fiordland north of Doubtful Sound from Saturday morning through to evening.

People are advised to keep up to date with the latest forecasts in case any parts of this watch are upgraded to a full Warning or further areas are added.

HEAVY RAIN WATCH

Area: The ranges of eastern Bay of Plenty

Valid: 18 hours from 12am to 6pm Saturday

Forecast: Rain is expected to become persistent tonight and heavy at times through to around Saturday evening. During this time, rainfall accumulations may approach warning criteria of 85mm in 18 hours.

Area: Mount Taranaki

Valid: 6 hours from 9am to 3pm Friday

Forecast: Heavy rain should ease around 3pm today.

Area: Buller and the ranges of Nelson west of Riwaka

Valid: 3 hours from 9am to 12pm Friday

Forecast: Heavy rain should ease around midday today.

Area: Tararua Ranges

Valid: 14 hours from 12pm Friday to 2am Saturday

Forecast: Bursts of heavy rain are expected from around midday today to the early hours of Saturday morning, and rainfall accumulations may approach warning amounts, for example 70mm in 12 hours, during this time.

Area: Bryant and Richmond Ranges

Valid: 4 hours from 9am to 1pm Friday

Forecast: Heavy rain should ease early this afternoon.

Area: Fiordland north of Doubtful Sound.

Valid: 9 hours from 9am to 6pm Saturday

Forecast: Rain has eased and the Watch for today is lifted. However, another period of rain is expected from Saturday morning through to evening, and rainfall accumulations may approach warning criteria of 60mm in 9 hours during this time.