What you need to know: How to prepare for an emergency

Explainer - As Cyclone Gabrielle heads towards Aotearoa, those in the upper North Island are being urged to get ready for heavy rain and damaging winds. So how best to prepare for the latest emergency? RNZ has compiled this advice.

The threat

MetService said it was looking "more and more likely that Cyclone Gabrielle will bring severe weather to our shores".

Cyclone Gabrielle has strengthened to category 3, according to Australia's bureau of meteorology which upgraded the storm on Friday morning. The weather system is off the coast of Australia and may start delivering rain to Northland from Sunday.

The worst period is likely to be in the 24 hours from Monday morning when Northland and Auckland north of Whangaparaoa could see 150 - 200mm of rainfall. For Coromandel the worst will occur from around noon on Monday for 24 hours when the region could receive 200-300mm.

MetService forecaster David Miller said it was comparable to Auckland's recent floods, when 250mm of rain fell in one day, but this time the rain was expected to be over a longer period rather than crashing down in one day.

Gale force easterlies, possibly going up to 120km/h or higher, were also expected.

In addition, wet grounds from the heavy rain in late January was likely to contribute to tree falls, he said.

Impacts from the significant weather system would also reach eastern parts of the North Island, including Gisborne and Hawke's Bay, and possibly Wellington too, he said.

"Some models are indicating some pretty significant rainfall amounts in Gisborne as well ... but Gisborne is a little bit later so Monday and into Tuesday."

It was likely orange or red warnings would be posted in the next couple of days, MetService said.

The state of emergency in Auckland and Thames-Coromandel from the recent flooding was extended yesterday due to the risks from the upcoming cyclone.

Acting director of Civil Defence Emergency Management Roger Ball told RNZ's The Panel on Thursday: "We are going to have a severe and impactful event for parts of New Zealand."

He urged people to think about how they would keep their households going without power for 24 - 48 hours.

He said the social media channels of local Civil Defence authorities and utility providers, such as electricity companies, provided reliable and timely information relating to particular areas.

Bell said it was also sensible to arrange in advance a possible place to go, such as a friend or relative, in case of evacuation, although Civil Defence also opens up emergency facilities.

Far North mayor Moko Tepania said an emergency operation centre was being set up on Friday in preparation.

"Twenty of our communities here in the Far North alone have got local Civil Defence groups that have community response plans."

Auckland Emergency Management deputy controller Rachel Kelleher said they were working on preparing a large number of evacuation centres as well as community hubs as a precaution, and their details would later be published as needed.

Residents should make a plan

The mayors of Whangārei, Auckland and Thames-Coromandel District have all urged residents to start their preparations now.

With that advice in mind, it is a good idea to sit down with your family or flatmates and make a household emergency plan, the National Emergency Management Agency says.

It should cover topics such as contact details, a meeting place if you cannot get home, plans to pick up children from school, daycare etc and how to cope without water or power.

There is a template that can be downloaded here. Once it is finalised it can be printed out for sharing or emailed.

People should also have "a grab bag" packed with clothes, medications, phone chargers, cash, copies of important documents and photo ID and other items in case of evacuation.

Far North mayor Moko Tepania urged people, in particular those in coastal and known flooding areas, to pay attention to the high tide times, which could cause flooding and road closures.

For Aucklanders, the emergency management agency asked that residents hold off on putting flood-damaged property out on berms.

"We still have 15 transfer stations open that people can take that waste to," said deputy controller Rachel Kelleher. "We really encourage people if they're able, to use that method of getting rid of waste over the next couple of days, just so that we don't have things sitting out and posing more of a risk to our streams and road networks."

Insurance advice was also available at community hubs. "The advice I'd be giving is take a lot of photos and also video imagery if you can, if there's serious damage caused by this next event, because they may be treated as separate events [to the recent Auckland flooding," Kelleher said.

Tips when at home:

• Check your drains and spouting to ensure they are not blocked
• Have water for three days or more - make sure you have at least nine litres of water for every person. This will be enough for drinking and basic hygiene
• Have some long-lasting food that doesn't need cooking (unless you have a camping stove or gas barbecue) and food for babies and pets
• Have toilet paper and large plastic buckets for an emergency toilet
• Secure, or move inside, anything that could cause damage in strong winds
• Close windows and doors, close curtains to prevent injury from breaking windows
• Stay inside and bring your pets inside. If you have to leave, take them with you
• Check on your neighbours
• Listen to the radio and follow the instructions of emergency services
• Keep up to date with MetService weather forecasts

For possible travel

• Make sure your vehicle has fuel and have some emergency supplies in it too such as water, snacks and a change of clothes
• Avoid non-essential travel during severe weather and never drive through floodwaters
• If you do need to travel plan your route with live traffic and travel information from the Waka Kotahi website

At work

• Make sure you have supplies at work including sturdy walking shoes, a waterproof jacket, a torch, snack food and water
• Connect with those who live in the same area and see if you can join together to get home during an emergency
• For business owners or managers: find out what the risks are and how they can impact on your business - risks include natural hazards, health emergencies and utility failures
• If you have staff, talk to them about the risks they think are most relevant to your business
• Have a plan in place covering emergency procedures for each hazard, assembly points, and contact details for staff, suppliers, clients and insurance providers
• Plan for and talk to any disabled staff
• Study advice from Civil Defence that helps businesses plan for emergencies

The Get Ready website has comprehensive advice on helping households and businesses be as well prepared for adverse weather events as possible.

Local Civil Defence information will be issued by your local Civil Defence Emergency Management Group. To find yours, see here.

In an emergency, always call 111.

- RNZ with additional informational drawn from the Civil Defence, NEMA and MBIE websites