Cyclone Cook: Where did this storm come from?

New Zealanders are bracing themselves for a major storm - the biggest in 50 years - but we are only the latest victims of Cyclone Cook.

Cyclone Cook's path:

The category three cyclone formed in the Pacific over Vanuatu on Sunday, bringing rough seas, high winds up to 130km/h and heavy rain. The storm brought down trees, cut power and water supplies to parts of the island nation and its capital Port Vila.

Next on the hit list was New Caledonia where Cook turned fatal. The body of a 73-year-old man was found a day after he went missing, reportedly trying to cross a rising river to get to a friend's home.

The centre of the storm passed around 100km away from the capital Noumea, but it still ripped off roofs, cut power and caused damage to isolated communities.

Eight inmates attempted to use the storm as cover to try and escape from prison, the country's public broadcaster said.

Cook is now barrelling toward New Zealand, expected to hit hardest on Thursday across much of the North Island before moving to south.

MetService has compared its power to Cyclone Giselle which caused one of New Zealand's worst modern maritime disasters  the sinking of the Wahine ferry which killed 52 people.

How do cyclones form?

  • Tropical cyclones go by several other names - hurricanes, typhoons - but they can all bring the same destructive power.
  • They use warm, moist air as their fuel which is why they only form over warm seas near the equator.
  • The warm air rises, causing an area of low air pressure below. Air from areas of higher air pressure is brought into the low pressure area which continues to fuel the cyclone.
  • That warm, moist air rises and cools, the water in the air forms clouds. The system spins and grows further using the warm water and evaporating water from the surface.
  • Tropical cyclones normally weaken once they hit land because they lose the warm ocean as a power source.
  • Their momentum often moves them inland where they let loose a deluge of rain and causing a lot of wind damage before dying out completely.
  • Storms which form north of the equator spin anti-clockwise, while those which are created south of the equator spin clockwise.

Newshub.