Heavy rain and severe gales are set to batter Auckland this weekend, raising concerns about already weakened trees and potential power cuts.

MetService has issued a heavy rain and wind watch for the region from tomorrow morning to Sunday as a front moves over the upper North Island.

The front is forecast to be preceded by heavy rain and easterly gales.

Up to 70mm of rain may fall in Auckland from 9am to 9pm tomorrow, with potential for more heavy rain on Sunday. East to northeast winds could also reach gale force, and potentially severe gale force in exposed places, from 8am tomorrow to 1am Sunday.


Northland is also under a heavy rain watch, with up to 75mm of rain forecast from 3am to 6pm tomorrow, and more on Sunday. Winds there may reach gale from 8am to 6pm tomorrow.

A heavy rainfall warning is in force for Coromandel Peninsula and western Bay of Plenty, with potential for 100-120mm of rain over a 24-hour period from 1pm tomorrow.

WeatherWatch NZ analyst Philip Duncan said following the April 10 storm in Auckland, which brought winds over 200km/h, even fairly low end gusty winds from the opposing direction could cause further complications on Saturday.

"The storm a few Tuesdays ago in Auckland blew in from the west to southwest. The gusty winds on Saturday will be coming in from the opposite direction and this may loosen or break already damaged branches and trees.

"This could lead to a couple of isolated power cuts on Saturday, otherwise for the most part these winds very much look below the damaging and power cut threshold and certainly much, much, lighter than the winds a couple weeks ago."

Auckland energy distributor Vector said the previous storm of April 10 had damaged hundreds of trees in the region.

"While repairing damage to the network in the days after the storm, Vector field crews reported hundreds of damaged or weakened trees on a lean, or large branches which are barely attached," a Vector spokeswoman said.

The strong winds coming in this storm could loosen or break the already-damaged branches and trees.

"Our advice is to maintain a safe distance from damaged or weakened trees, and where safe to do so, keep cars away from areas of concern."

Damaged trees directly on or very close to power lines should be reported to Vector through the call centre on 0508 832 867.

Concerns about weakened or damaged trees on public land should be directed to Auckland Council on 09 301 0101.

People concerned by weakened or damaged trees on their own properties should contact an arborist as soon as possible.

Another front moving over the South Island today and on Saturday will also bring a period of heavy rain in western and eastern areas.

In Westland up to 85mm could fall from 6pm tonight to 6pm Saturday, and heavy rain is forecast most of Saturday in Dunedin and North Otago.

Tips to stay safe in a storm:

β€’ Check weather updates.

β€’ Stay clear of fallen power lines or damaged electrical equipment and treat them as live at all times.

β€’ Stay well clear of damaged or weakened trees.

β€’ Watch out for falling tree branches as these can cause damage to power lines.

β€’ Avoid possible damage to electrical appliances (in the unlikely event there is a power surge when the power is restored) by switching off appliances at the wall.

β€’ Keep a torch and spare batteries, and mobile phone handy.

. Ensure an alternate fuel is always available for cooking (e.g. gas for BBQ)

β€’ People using medical equipment that relies on electricity should ensure they are prepared for power disruptions and if there is an immediate health threat, contact their health provider or call 111.

β€’ Check gutters and drains, secure large outdoor items and move any loose outdoor equipment or furniture inside.

β€’ Have a supply of food and provisions.

β€’ Check in on neighbours to see if they need any assistance.