Batten Down the Hatches - Significant Heavy Rain & Possible Damaging Winds Forecast

With strong winds now upon us and likely turn too extreme gales now would be a good time to secure trampolines, outdoor furniture and make sure outdoor animals are safe.

Major storm expected to hit the South Island with significant heavy rain and strong winds for much of the South Island, also for the lower parts of the North Island.

A front is expected to move onto the lower South Island this afternoon. A major storm (former Tropical Cyclone Fehi) should approach from the north overnight tonight (Wednesday) and cross the South Island during Thursday. It then move away to the southeast on Friday. This storm will bring significant heavy rain and possible damaging winds to much of the South Island and parts of the lower North Island from late Wednesday to early Friday.

The heaviest rain is expected in the South Island (apart from Canterbury Plains and Kaikoura Coast), especially in Westland and Fiordland where 200 to 400mm of rain could accumulate from tonight to early Friday. Heavy rain is also expected for Mt Taranaki and Tararua Range. A Heavy Rain Warning is in force for these areas.

In addition, gale force winds are expected for southern and central New Zealand, initially from the north tonight, then from the northwest about the middle of Thursday, and changing southwesterly Thursday afternoon or evening. Strongest winds will be in Westland, Buller, Canterbury High Country, Nelson, Marlborough , Wellington and southern Taranaki, where a strong wind Warning in force for these areas.

People are strongly advised to keep up to date with the latest forecasts and warnings in case other areas will be added to the Warning.

Heavy Rain Warning

Heavy rain may cause streams and rivers to rise rapidly. Surface flooding and slips are also possible and driving conditions may be hazardous.

Area: Fiordland
Valid: 30 hours from 4:00pm Wednesday to 10:00pm Thursday
Forecast: Rain developing this morning, becoming heavy this afternoon. Expect 200 to 300mm of rain to accumulate north of Doubtful Sound and 160 to 220mm farther south. Peak intensities of 25 to 40mm per hour.

Area: Otago
Valid: 22 hours from 2:00am Thursday to 12:00am Friday
Forecast: Rain developing Wednesday night, with some heavy falls through to Friday morning. Expect 80 to 130mm, or possibly more, but 50 to 80mm about North Otago. Peak intensities 15 to 25mm per hour.

Area: Southland
Valid: 22 hours from 12:00am to 10:00pm Thursday
Forecast: Rain developing Wednesday evening, with some heavy falls through to late Thursday. Expect 90 to 130mm during the period. Peak intensities 10 to 20mm per hour.

Strong Wind Warning

Strong wind gusts could damage trees, powerlines and unsecured structures. Driving may be hazardous, especially for high-sided vehicles and motorcycles.

Area: Southern Taranaki, Wellington, Marlborough, Nelson, Canterbury High Country
Valid: 14 hours from 3:00am to 5:00pm Thursday
Forecast: Northerly gales gusting 130 km/h or more developing overnight tonight, turning northwesterly about midday Thursday, then easing early Thursday evening.

Area: Westland and Buller
Valid: 12 hours from 3:00am to 3:00pm Thursday
Forecast: Northeasterly gales developing Thursday morning, turning northwest about midday, then turning southwest and gradually easing during Thursday afternoon and evening. Expect gales gusting 120 km/h or more in exposed places.

This warning will be updated by: 10:00pm Wednesday 31-Jan-2018

A service provided through a contract with the Crown