Authorities are warning incoming Tropical Cyclone Gabrielle could be worse than the last storm which battered Auckland, with severe winds likely to down trees and cut power.

Mayor Wayne Brown has told Aucklanders to stock up on torches and batteries as Gabrielle was likely to do more widespread damage when it barrels in from Sunday.

People have been advised to prepare at least three days’ worth of supplies, including medication, water and food.

MetService was forecasting severe gales would affect the country from Northland to Hawke’s Bay with a high degree of certainty.

 “We’re preparing for the worst and hoping for the best,” Brown said.

“It’s not looking good.”

Mayor Wayne Brown has told Aucklanders to stock up on torches and batteries as Cyclone Gabrielle was likely to do more widespread damage when it barrels in from Sunday. Photo / Dean Purcell

Gusts of up to 150km/h were likely - and were expected to blow before the rain hit.

Nearly 300mm of rain was also possible early next week.

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Large waves and a storm surge were expected to affect northern and eastern coastlines from Northland to Gisborne from Sunday, MetService said.

Gabrielle’s full force is expected to thrash the top of the North Island on either Monday or Tuesday.

A large slip on the cliff face under the Ocean Breeze Hotel on Bayswater Ave Bayswater as heavy rain hits Auckland causing widespread flooding. Photo / Brett Phibbs

Auckland Emergency Management (AEM) controller Rachel Kelleher said the strong wind was something the previous storm over Auckland Anniversary weekend didn’t have.

“With the type of wind that could come with an event like this, we expect trees to come down and further slips with heavy rainfall,” Kelleher said.

“If it does come across Auckland it will bring very heavy winds which could bring down power, surface flooding and coastal erosion from sea surges.”

She said people should consider things likely to move around in the wind - trampolines, outdoor umbrellas - things that can lift up and fly away and cause damage to people or properties.

A contractor tries to clear blocked drains on Tamaki Drive as heavy rain hits Auckland causing widespread flooding. Photo / Michael Craig

Kelleher said AEM and weather forecasters should have a clearer picture of what impact the storm would have on Sunday.

She said it was a weather system which could have a potentially significant impact around the top of the North Island.

 “We need to be doing what we can in these intervening days to prepare,” Kelleher said.

This morning the Thames Coromandel district extended its state of emergency for another seven days as Gabrielle was set to hit the flood-ravaged region in three days’ time.

A major slip on Paturoa Rd at Titirangi Beach in Auckland.

Brown was still considering whether to extend Auckland’s already pushed-out state of emergency.

Deputy Mayor Desley Simpson said the big Auckland clean-up has just become that much more urgent.

“It’s very clear that we have to get this kerbside rubbish away before the next storm.”