Severe easterly gales and significant heavy rain for parts of the North Island and upper South Island

Cyclone Tam northwest of New Zealand is moving slowly into the Tasman Sea where it becomes slow moving late Thursday. Associated fronts are expected to move southwards over the country through into Saturday, bringing sustained heavy rain and severe easterly gales to many areas of the North Island and upper South Island. Large waves are also expected to affect eastern coastlines of the upper North Island.

Warnings and Watches for heavy rain and strong winds are in force.

Please keep up to date with the latest forecasts.

Area: Northland

Period: 25hrs from 8pm Wed, 16 Apr - 9pm Thu, 17 Apr

Forecast: Expect 90 to 130 mm of rain on top of what has already fallen. Peaks rates of 15 to 25 mm/h likely on Thursday with thunderstorms possible. Low chance of upgrading to a Red Warning.

Impact: Streams and rivers may rise rapidly. Surface flooding, slips, and difficult driving conditions possible.

Action: Clear your drains and gutters to prepare for heavy rain. Avoid low-lying areas and drive cautiously. Preparedness advice.

Area: Coromandel Peninsula

Period: 36hrs from midnight Wed, 16 Apr - noon Fri, 18 Apr

Forecast: Expect 150 to 250 mm of rain about the ranges, and lesser amounts nearer the coast. Peak rates of 15 to 25 mm/h about the ranges. Thunderstorms possible Thursday evening and Friday. Low chance of upgrading to a Red Warning.

Impact: Streams and rivers may rise rapidly. Surface flooding, slips, and difficult driving conditions possible.

Action: Clear your drains and gutters to prepare for heavy rain. Avoid low-lying areas and drive cautiously. Preparedness advice.

Area: Bay of Plenty west of Kawerau, including Rotorua and the Kaimai Range

Period: 36hrs from 10am Thu, 17 Apr - 10pm Fri, 18 Apr

Forecast: Expect 120 to 200 mm of rain inland, and lesser amounts nearer the coast. Peak rates of 10 to 20 mm/h expected Thursday evening and Friday morning. Low chance of upgrading to a Red Warning.

Impact: Streams and rivers may rise rapidly. Surface flooding, slips, and difficult driving conditions possible.

Action: Clear your drains and gutters to prepare for heavy rain. Avoid low-lying areas and drive cautiously. Preparedness advice.

Area: Gisborne/Tairawhiti north of Tokomaru Bay

Period: 27hrs from 9pm Thu, 17 Apr - midnight Fri, 18 Apr

Forecast: Expect 110 to 150 mm of rain. Peak rates of 10 to 20 mm/h expected Friday. Note, further periods of heavy rain are expected on Saturday. Minimal chance of upgrading to a Red Warning.

Impact: Streams and rivers may rise rapidly. Surface flooding, slips, and difficult driving conditions possible.

Action: Clear your drains and gutters to prepare for heavy rain. Avoid low-lying areas and drive cautiously. Preparedness advice.

Area: Tasman northwest of Motueka

Period: 54hrs from 6pm Thu, 17 Apr - midnight Sat, 19 Apr

Forecast: Expect 250 to 350 mm of rain about the ranges, and lesser amounts nearer the coast. Peak rates of 10 to 20 mm/h expected about the ranges. Note, further periods of heavy rain are expected on Sunday. Low chance of upgrading to a Red Warning.

Impact: Streams and rivers may rise rapidly. Surface flooding, slips, and difficult driving conditions possible.

Action: Clear your drains and gutters to prepare for heavy rain. Avoid low-lying areas and drive cautiously. Preparedness advice.

Area: Northland

Period: 24hrs from 8pm Wed, 16 Apr - 8pm Thu, 17 Apr

Forecast: Severe gale easterlies gusting 120 km/h in exposed places, with damaging gusts of 140 km/h possible tonight and Thursday morning, especially in the north. Moderate chance of upgrading to a Red Warning.

Impact: Damage to trees, powerlines, and unsecured structures possible. Driving may be difficult, especially for high-sided vehicles and motorcycles.

Action: Prepare your property by securing items that can be picked up by strong winds. Drive cautiously. Preparedness advice.

Area: Auckland and Great Barrier Island

Period: 28hrs from 8pm Wed, 16 Apr - midnight Thu, 17 Apr

Forecast: Severe gale easterlies gusting 120 km/h in exposed places. Low chance of upgrading to a Red Warning.

Impact: Damage to trees, powerlines, and unsecured structures possible. Driving may be difficult, especially for high-sided vehicles and motorcycles.

Action: Prepare your property by securing items that can be picked up by strong winds. Drive cautiously. Preparedness advice.

Issued: 8:07pm Wed, 16 Apr
Next update: 10am Thu, 17 Apr
Action advice supplied by the National Emergency Management Agency.