Mike Bergin "stumbled" into a career with the Bureau of Meteorology (BOM) at the age of 18 and is retiring after five decades, having witnessed firsthand the monumental changes not only in forecasting technology, but also Australia's climate.

Key points: Mike Bergin has most recently been the BOM's state manager in Western Australia

Mike Bergin has most recently been the BOM's state manager in Western Australia He says extreme weather events are more frequent than they were in the 1970s

He says extreme weather events are more frequent than they were in the 1970s Mr Bergin says sitting in a room predicting a potential catastrophe is "quite stressful"

The digital age has transformed the way the public is kept informed about weather, which can lead to an inflated perception of how common extreme weather events are.

But Mr Bergin said since joining BOM in 1970, such events had become more frequent.

"People are more aware of significant weather events because of social media, but in reality we are getting more severe weather events," he said.

"Australia-wide we continue to see the warming of the atmosphere — 2018 was the third-warmest year on record.

"The continual warming of not just the atmosphere, but more importantly the oceans, is a trend that has been going pretty strongly for the 40-odd years that I've been with the bureau."

Mr Bergin says heatwaves and fires are closely linked. ( AAP/DFES )

Heatwaves, fires on the rise

Mr Bergin said the most dramatic changes had been observed in fires and heatwaves.

"Heatwaves have become far more frequent, particularly over the last 10 to 20 years, so we're seeing extremes in temperature and protracted periods of heat to become heatwaves, and associated with that has been fire," he said.

"With the fires here in WA we've seen small numbers of fatalities, but nonetheless fatalities … then in the south-east of Australia we've seen these huge fire events. Black Saturday [in Victoria] being the stand-out where more than 170 people perished."

It was around the time that Mr Bergin joined BOM that rainfall in south-western parts of Western Australia started to significantly decline.

"If you look at the averages of rainfall in the decades leading up to the 70s rainfall was much, much higher here in the south-west," he said.

"And there's no doubt that the change in the rainfall has led to great changes in the fuel availability here in the south-west of WA, and has exacerbated the fire risks significantly."

Mr Bergin says the most dramatic changes have been seen in fires and heatwaves. ( ABC News: Hugh Sando )

Beautiful, majestic, destructive cyclones

Mr Bergin has spent the past 49 years working with BOM as a forecaster around Australia and overseas, and most recently as the state manager of Western Australia.

He was in charge of the forecasting centre the morning Tropical Cyclone Larry — one of Australia's fiercest storms — crossed the north Queensland Coast in March 2006, and when just a month later TC Monica arrived, reaching Category 5 — the highest intensity possible.

"If you look at the satellite imagery of Monica and the radar imagery of it, it's the most amazing example of nature at its most awesome I believe, but also its most destructive," he said.

Even after almost 50 years in the job, the novelty of tracking a cyclone has not worn off, but neither has the immense pressure to get it right.

"Cyclones are, I describe them as beautiful, they are majestic and quite something to look at but obviously they're incredibly destructive," he said.

"While you're looking at this system and you're tracking it, you're aware that right then and there, seas are being generated which are huge, and as it comes to the coast you know it will cause damage and potentially people's lives are at risk, so you feel that.

Mr Bergin describes cyclones as both beautiful and destructive. ( Bureau of Meteorology )

'Should we have done better?'

Mr Bergin describes the feeling of sitting in the comfort of a quiet, air-conditioned room while forecasting for a potential catastrophe as "surreal".

"It is quite stressful. Black Saturday for example, more than 170 people perished in those fires and some of our forecasters really struggled with that afterwards thinking 'should I have done more? What else could I have done that would have helped those people and emergency services? Should we have done better?'" he said.

"I feel that too. Fire to me is one of the most difficult things from a forecasting point of view but also from a response point of view.

"We've had a number of fires here in WA in the last 10 years and unfortunately there's been fatalities associated with them."

Mr Bergin says he sometimes thinks the hand-drawn maps are solely for his benefit. ( ABC News: Hugh Sando )

Technology's role in improving accuracy

The role of a forecaster has also greatly evolved from a job that was almost entirely manual when Mr Bergin started — with computer modelling and satellite imagery in its infancy — to one that is largely reliant on technology.

"Easily the biggest changes have been in satellite imagery … now we can get imagery every two-and-a-half minutes and … we get a whole range of remotely sensed data about the atmosphere," Mr Bergin said.

"The other huge change has been in computer modelling. When I first began, we had computer models trying to predict what the atmosphere would look like in one, two, three days but the skill was really quite poor.

"Now the power and the accuracy of the computer models is really quite something, particularly in the last 10 years it has changed dramatically, so now we can forecast quite accurately out to seven days, and we continue to push those boundaries to forecast to even longer time scales."

Mr Bergin says there is immense pressure to get it right when tracking cyclones. ( www.sxc.hu: sebadanon )

BOM forecasters in Perth still hand-draw weather charts, although Mr Bergin joked that perhaps the custom has survived for his sake only.

"I sometimes think that surface chart that's drawn is for my benefit, I'm not quite sure," he laughed.

"But many of our forecasts now are not actually written by our forecasters. They edit grids of data and then automatic-text formatters generate the text forecasts that you see on our website, [but] we still write the warnings."

Staying with the same organisation for 49 years is no ordinary feat, but Mr Bergin said he was not particularly fussed about making it to 50.