Always take the weather with you

By MARK STORY

They have the bedside manner of a game-show host, are rarer than brain surgeons, and despite being highly-qualified scientists can regularly make mistakes - but still remain gainfully employed.

Who? Weather forecasters. They are to meteorology what the turf guide is to horse racing.

Whether you're talking form, rider and track or atmospheric conditions like temperature, pressure and wind, it all comes down to numbers.

But with numbers only revealing so much, veteran meteorologist, Bob McDavitt believes successful weather forecasting is as much science as it is art and communication - with a smidgen of good old-fashioned luck.

One of the MetService's 65 weather forecasters, McDavitt saw meteorology as an interesting way to combine his interest in both science and computers after completing a bachelor of science in maths and information science from Victoria University in the early 1970s.

"As a school boy, I was so fascinated by live radio weather forecasts, presented in monotonic drawl. I thought to myself, here's a job that I could add some spark to," says McDavitt.

Since then he's covered cyclones in Fiji, two America's Cups, worked as a television weather presenter and is now MetService's "weather ambassador".

McDavitt spends a lot of time explaining why weather forecasters don't get it wrong. Before people can appreciate the explanation, he says, they need to understand what forecasters do.

Weather forecasting is just one part of meteorology. It's a desk-bound job that applies numerical weather prediction techniques to the problem of calculating weather.

After collecting and analysing data from land, sea and air, by balloons, satellite and radar, forecasters compile maps that show weather patterns.

"Using computer models based on the mathematics of the physics of the air, we develop weather maps for the next several days," says McDavitt. "We then turn these weather maps back into words and write forecasts, highlighting changes significant to various users."

To appreciate why accurate forecasting is hard, argues McDavitt, it means understanding the nature of weather patterns, which only ever offer five-day snapshots.

"Weather is a mix of pattern and chaos. We work with the pattern, but can't work with the chaos. One jiggle has a kaleidoscope affect, and everything can change."

So how should we treat weather forecasts? McDavitt says they should be viewed as the best idea possible from the patterned world of isobar-land. "It will only be an estimate of the real world that you can fine-tune using your own local knowledge."

History suggests the world can be unkind to this fraternity. In fact, the world's first forecaster, New Zealand Governor of the 1840s, Robert FitzRoy, was so berated by the London Times for false weather alarms, he committed suicide.

So what sort of qualifications do weather forecasters need? Owing to the highly intuitive nature of this job, McDavitt says a bachelor's degree in either maths or physics is only ever a minimum entry point.

"Not even top mathematicians will make good forecasters if they can't communicate," says McDavitt. "A lot of what meteorologists do is technical, but it also involves working closely with customers and colleagues. You must maintain excellent relationships, communicate well, and not be overly sensitive to criticism."

In addition to a working knowledge of equations, and a predisposition for deadlines and shift work, they also need a love of the weather and willingness to work in Wellington at the National Forecasting Centre.

What's the demand like for weather forecasters? Deregulation in the early 1990s meant weather forecasting was no longer the exclusive domain of government. Like the America's Cup syndicates, all ski fields hire their own weather forecasters. But 95 per cent of career opportunities for this profession are with MetService. With people relocating offshore, changing careers or retiring, McDavitt suspects the MetService requires around seven new weather forecasters annually.

Most of MetService's resources are allocated to areas where disruptive weather has the biggest impact. Not surprisingly, transport sectors like aviation and marine are the prime focus of rookies after two years of training. Those with more experience progress to "lead forecasting", where intuition plays a major part in successfully interpreting weather patterns.

So what weather are we in store for this winter? Expect a bit of everything, says McDavitt. "The El Nino [westerlies] we had last winter have faded away. With another La Nina [rain and cloud] looking unlikely, we're currently in neutral territory."

But that doesn't necessarily mean average weather. He says the field's wide open for all weather patterns to come our way. Remember, the colour of the sky is a useful indicator for predicting rain, and don't forget the brolly, sweater and shades when stepping out.