It's highly likely that Auckland's Harbour Bridge will be closed due to Cyclone Cook later this afternoon.
MetService is warning ex-Tropical Cyclone Cook is a "very significant event" on Thursday and likely to bring widespread flooding, slips and wind damage. Gusts are expected to reach 150km/h as it moves down to Wellington by Friday morning.
The Far North is temporarily inaccessible. SH10 is closed due to flooding near Kaeo, as well as SH1, NZTA says.
Auckland Civil Defence is warning people to postpone travel on Thursday afternoon. Cook is expected to hit between noon and 6pm.
NZTA warns the Harbour Bridge may close if winds get too dangerous.
A state of emergency has been declared by the Thames-Coromandel District Council, and evacuations are underway in low-lying areas. There's been some sandbagging has taken place in Whangamata and Paihia.
Slips have closed SH25 between Thames and Coromandel. Flooding in the Karangahake Gorge, SH2, has partially blocked the eastbound lane.
Coromandel, eastern Bay of Plenty, Franklin, Great Barrier and Waiheke Island schools (94 in total) and early learning centres (130) are closed on Thursday.
SH2 at Edgecumbe is closed because of flooding. Whakatāne district residents are ready to evacuate if it gets worse in the area.
8:45am: Thames Valley Civil Defence Controller Garry Towler has advised Coromandel residents to self-evacuate all low-lying areas on the peninsula that were prone to flooding in the last two storms. These include Whitianga and Mercury Bay.
The Defence Force is sending four Unimogs to Coromandel, to help Civil Defence staff around the area.
"We're asking people to self-evacuate - we're not dictating," Mr Towler said.
"At noon we will reassess the situation and look to see how many vulnerable situations we have on the peninsula."
It was too hard to give an estimate on how many people have been affected across Coromandel by flooding or self-evacuations, he said.
Fifty campervans and caravans have left the area.
Civil Defence centres are open for anyone needing to find a safe haven.