Dust storms, diving dam levels, heatwaves and fish kills marked both the start and finish of 2019 for NSW, with the eruption of mega bushfires and incessant smoke haze adding to the year-end’s woes.
For Sydney, 2019 will go also down as the city’s hottest in 161 years of Bureau of Meteorology records. It was also its driest year since 2005 – during the height of the Millennium Drought – said Ben Domensino, a meteorologist at Weatherzone.
“December alone was not a standout month but it came at the end of a very hot year,” Mr Domensino said. He estimates Sydney averaged 24-degree maximums this year topping 2016’s 23.8C record.
Rainfall in December was just 1.6 millimetres at Observatory Hill, beating the record low of 2.8 millimetres recorded for the month in 1979.
The Bureau won’t release its 2019 report until January 9. The main interest may be how much Australia lifted the bar for its hottest year after setting a record pace for January-November daytime temperatures before December’s heatwaves toppled records nationally.
Mr Domensino, though, said 2019 for most of NSW including Sydney has been notable for the prolonged stints of relatively hot and dry weather, disrupted by occasional bursts of thunderstorm activity and cold outbreaks that brought snow at times to northern towns such as Tamworth.
Last January delivered more than a few harbingers of what was to come. Mass fish kills near Menindee in far western NSW hinted at the stresses to come for wildlife and humans alike as rivers turned to puddles, towns began trucking in water and heat sowed misery on farms across the state.
Last summer may be a fading memory but it was NSW’s hottest on record. Average maximums beat the previous high – set in 2016-17 – by more than half a degree, a big margin for such measures, according to the Bureau of Meteorology. January alone smashed the 1939 record by two degrees.
NSW’s summer rainfall was just half the long-run average, exacerbating soil moisture deficits and leading to dust storms that became a regular feature for much of the year.
The heavens, though, did open at times. March was easily Sydney’s wettest month, with the 229.2 millimetres accounting for more than a quarter of the 851.8 millimetres recorded at Observatory Hill for the year as a whole.
Typical annual rainfall for the Harbour City is 1215.7 millimetres, and 2019’s tally will make it Sydney’s driest year since 2005, Mr Domensino said.
The lack, though, of any east coast lows during 2019 for the Sydney region was telling. These intense systems usually bring important top-up falls for the city’s catchment, Mr Domensino said.
Without them, Sydney’s dam levels continued a monthly slide that began in June 2017. As of December 31, storages were 43.7 per cent full, down one-third from a year ago.
Winter rains are crucial for filling rivers and dams and 2019 was another disappointment. Run-off to Sydney’s dams was the second-worst on record, while statewide rain was the least since 1982.
Autumn didn’t get much better, with NSW posting its driest since 2002, the bureau said. That added to the stress on many regional towns, such as Guyra and Bourke, triggering a scramble for new bores or pipelines to keep them supplied.
Winter temperatures were generally mild before warming up rapidly as the days lengthened. Sydney, for instance, collected a record 15 days of at least 20 degrees in July.
The first clear heatwaves began lapping north-eastern NSW by early September with the first major bushfires erupting as temperatures soared to 10 degrees or more above average. Fire danger indices were the highest in data going back to 1950, and 50 fires were active by September 9.
Statewide, October rainfall was just a quarter of the norm. With mostly clear skies and little moisture to provide evaporative cooling, NSW copped its first bursts of 40-degree heat that became regular episodes as the year roasted to a close.
Sydney registered its first catastrophic fire danger warning on November 12, as fires that would consume millions of hectares of forest rapidly expanded to the city’s north-west and south-west.
Not surprisingly, the first 11 months of the year were NSW’s hottest on record for maximum temperatures. The previous two hottest similar periods fell in 2018 and 2017.
Weatherzone’s Mr Domensino said climate change caused by increased emissions of greenhouse gases increased the odds of getting the extreme temperatures that have marked 2019.
“There’s clearly a warming trend,” he said. “You can’t not see it.”
If there’s an upbeat note to end 2019 it’s that the near-term drivers of the unusually warm and dry weather in the Southern Ocean and Indian Ocean are shifting back to neutral conditions.
The tropical monsoon is finally arriving, which should start to break up some of the huge reservoir of heat over central Australia.
“The positive is that we won’t see the air masses quite so hot,” Mr Domensino said.