NIWA has unveiled its new state of the art super-computer - worth $20 million.

It's the fourth the agency's bought since 1999, with up to three times more power than its predecessor.

Rob Murdoch, NIWA's deputy chief executive, says the technology will help model potential weather disasters.

"Which is important when you have to think about things like Cyclone Gabrielle, for example - where it's very isolated and the hills can have a massive impact on the amount of rainfall."

LISTEN ABOVE