How do you predict the capital's weather?
How do you predict Wellington's weather?OLIVIA WANNAN
Predicting tomorrow's weather in Wellington may be an imperfect art, but measuring today's is a meticulous science.
Figures for rain, wind, sunshine hours and temperature are everyday things, or even every minute with today's technology, but not many people are familiar with the devices used to record them.
But MetService meteorologist Daniel Corbett is well versed and, in his 20 years in weather prediction, has seen the evolution of the gadgets.
"There's so much more information. You can imagine, years ago, you'd be able to get measurements and observations every hour or every couple of hours. Now you can literally see what the weather is doing to make a forecast at any moment of the day."
MetService's weather measurements are gathered from 12 sites around Wellington, including one in the Botanic Gardens, close to the agency's headquarters.
The devices dotted around the lawn resemble poles, bird-houses and metal piping rather than the latest precision technology.
But while a traditional test tube-like gauge remains as a backup, the rainfall gauges of today are slightly more hi-tech.
Instead of a person running out in the rain to check them, the device – a tipping bucket gauge – sends an electronic signal every time it catches 0.2 millilitres of rain in one of its levers.
The electronic thermometers are the latest in weather recording technology, though still housed as they were in the 19th century in a shaded box, a Stevenson screen, out of direct sunlight.
One of the most exciting developments in meteorology is Doppler radar, which can visualise the wind, Mr Corbett says.
"We can literally sit there and tweet to say the southerly is arriving."
Even with such precise data, meteorologists know microclimates, hills and even buildings mean weather can change a few metres down the road, particularly in a country like New Zealand.
"It makes our job difficult, but also fascinating."
- The Dominion Post
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