Australia notches fourth-warmest year amid frequent extreme events: weather bureau
Australia posted its fourth-hottest year in 2016, driven by record sea-surface temperatures around the nation, in a period marked by frequent extreme events, the Bureau of Meteorology says.
Mean temperatures, which average day- and night-time conditions, were 0.87 degrees above the 1961-90 norm.
Only 2013, 2005 and 2014 were hotter, Karl Braganza, head of climate monitoring at the bureau, said.
Sydney and Darwin were among the cities posting record years for maximum, mean and minimum temperatures.
Brisbane and Hobart had their hottest years for mean temperatures.
Sea-surface temperatures were well above previous records, coming in at 0.73 degrees above the average, easily eclipsing the 0.64 degree anomaly set in 2010.
That warmth around the nation’s shores contributed to extreme rainfall and heat events, notably the huge east coast low that swept down the eastern seaboard in June and the tropical low that brought record rains to inland Australia and the south-east in December.
“It was a warm and wet year,” Dr Braganza said. “We had frequent extreme events.”
A breakdown of the big El Nino in the Pacific – one of the three largest on record – saw Australia transition from drier than average to wetter than average conditions by midway through the year.
Internationally, 2016 is expected to be declared as the hottest year on record, pipping 2015 for the title, and making it three years in a row of new highs.
Averaged across Australia, rainfall was 544.99 mm, or 17 per cent above the 1961-’90 average, leading to the 15th wettest year on record.
The Murray-Darling Basin had its record wettest May to September period, filling reservoirs and helping produce what is likely to be Australia’s biggest wheat crop.
Dr Braganza said the El Nino influence came on top of background warming from climate change.
In the past year, conditions favoured the dominant influence of warm oceans, leading to unusually – at times record – levels of atmospheric moisture over Australia.
The bureau’s near-term forecast is for a warmer-than-average January-March period for eastern Australia, but also a drying out.
Fire authorities are particularly concerned about grass fires, given the strong growth in vegetation since the spring.
A fresh burst of heat is also heading across the country, with temperatures set to soar progressively through the week across the south. Adelaide is forecast to reach 39 degrees on Friday and Saturday, while Melbourne will see 36 degrees on Saturday.
For Sydney, the mercury should reach the 30s by the weekend and nudge towards 40 degrees in the city’s west by the middle of next week.
Wyndham in the Kimberley set a new high mark for Australian temperatures, with an average daily maximum through the year of 37.5 degrees, Blair Trewin, the bureau’s chief climatologist, said.
Among the hot cities, Sydney was notably warm through 2016, with each month beating mean maximum temperature averages by at least one degree, the bureau said.
Some 151 days reached at least 25 degrees, the most on record and not far short of double the average of 89 such days.
Only 50 nights fell below 10 degrees at its Observatory Hill site, the second fewest on record, and well short of the 88 such nights of a typical year in records going back to 1858.
It was also Sydney’s wettest year since 2007 thanks in part to several east coast lows bringing heavy falls.
For Melbourne, rainfall was close to average and all three temperatures measures – mean, minimum and maximum, were very much above average at most site across the city.
Brisbane broke its mean temperature records for both its current site and an older one at Ann Street.
Western Australia split between a mild year in the south and record heat in the north, while Perth was generally cooler than average.
Hobart beat its mean temperature record, previously set in 2014, by 0.2 degrees, while the state as a whole had its hottest year.
Big wet spots
2016 was also Tasmania’s second-wettest year on record, trailing only 1956. That result came despite a very dry start to the year, which also included bushfires in regions usually spared such blazes.
Rain was South Australia’s notable feature, with several severe storms, including one that led to widespread blackouts in September. 2016 was the state’s fourth wettest and Adelaide’s second-wettest year.
Overall, the hottest national temperature readings came in the Pilbara, with 47.8 degrees set in consecutive days in February.
Coramba on the NSW mid-north coast, posted the highest 24-hour rainfall total, collecting 430 mm in June.
Another notable wet spot was the Australian territory of Christmas Island, which posted its wettest year on record with 5120.8 mm, exceeding the previous record set in 1978 by more than one metre.
Across the Top End, the wet season was relatively dry and the dry season unusually wet. Northern Australia also had its lowest number of tropical cyclones on record, with just three in the 2015-16 summer.
The coldest reading of minus-10.4 degrees, recorded at Thredbo Top in August, was unusually high for the year’s lowest temperature, Dr Trewin said.
The story Australia notches fourth-warmest year amid frequent extreme events: weather bureau first appeared on The Sydney Morning Herald.