Auckland’s ageing rain radar needs to survive another year before it can be replaced with a new model.
The radar on Mount Tamahunga was commissioned in 1989 and regular upgrades have kept it running well beyond its typical 20-year lifespan.
MetService’s general manager of observing systems Kevin Alder told Nine to Noon the radar was a critical piece of infrastructure.
“Its job is to provide information on current weather conditions, so where precipitation is actually falling, and it does this by scanning every seven and a half minutes,” he explained.
“It has a range of 300 kilometres so it can see weather coming in off the Tasman Sea or in from the north-east coming into Auckland so it’s critical for forecasting services and also for Auckland Council and how they manage severe weather events.”
MetService was in the process of replacing its weather radars up and down the country, starting with Wellington and Canterbury.
“We’ve been funded through the Ministry of Transport to replace it in this current four-year period, and in that agreement in 2023 we were also funded to replace to the Canterbury and Wellington radars; those two were prioritised because their structures had seismic risks,” Alder said.
Alder was confident that MetService had the right equipment and spare parts to keep the old radar running until it could be replaced around the end of 2026 or start of 2027.
“The current radar is 36 years old, it’s done its time, but we have the ability to keep it running until the replacement technology is installed,” he said.
“We’ve been maintaining it throughout its life, it had quite a significant mid-life upgrade in around 2007 or 2008. We’ve done subsequent upgrades to its power supplies and communications infrastructure, most recently in the last three years.”
The new radar would be worth the wait, he said, promising new technology to give more accurate weather warnings.
“We have a technology called dual polarisation which allows us to see much more clearly the shape and size of the raindrops, we can tell whether the precipitation is frozen, whether it’s hail, and how quickly [the rain is] falling, and from that we get much better estimates of rainfall intensity.”
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