Extract from The Guardian
Eastern Australia is sweltering in the second heatwave of 2017, setting the stage for what could be the hottest January on record.
A cool change that brought sudden relief to coastal Sydney on Wednesday after record morning heat failed to flow through to the city’s western fringe, where midday temperatures topped 43C.
Northern New South Wales and southern Queensland are predicted to bear the brunt of unusually high ongoing temperatures in a repeat of last week’s severe to extreme heatwave conditions.
Phil King from the Bureau of Meteorology said the heatwaves were likely driven by warmer sea temperatures combining with the unusual spread of a “reservoir of hot air” that had been building in central Australia over the past several weeks.
A cool front blowing in from the coast south of Sydney saw the mercury drop to below 25C before midday after a near-record overnight low of 28C and record readings of 31C at 6am and 36.9C at 9am.
But west of Sydney, some 60km from the coast, went on to record some of the highest temperatures in the country, with Camden reaching 43.6C, Penrith 43.5C and Richmond 42.8C.
“You can get some incredible differences in temperature, I’ve seen 20C difference from the west to the east [of Sydney],” King said.
Sydney commuters mid-morning took to Twitter to complain about a lack of air-conditioning on trains, one posting a picture of a sweat-soaked seat.
Asked if the conditions were ripe for the hottest start to a year in recorded history, King said: “I suspect that’s pretty likely but January is only halfway through [and] I’m not confident to say.
“But this is the second heatwave [of the summer], it’s likely that parts of Queensland won’t see cooler temperatures and we’re halfway through January with significantly above average maximum and minimum temperatures.”
Hotspots included Grafton on the northern NSW coast, which reached 40C at 2pm.
A staffer at the Grafton Olympic pool said while it was “pretty darn hot at the moment” the numbers of patrons through the gates looking to cool off appeared “regulation, for now”.
It was one of only two publicly owned pools in the town, the other being “on the southside – but it’s heated”, she said.
Moree in NSW was forecast by Weatherzone to remain above 40C until early evening, while Mungindi on the NSW-Queensland border was on track to hit a maximum of 42C, hitting 40C at 1pm.
Cathy North, co-owner of Mungindi’s Two Mile Hotel, said the air-conditioned pub was unlikely to offer any respite to most locals until after 5pm when they finished work. “It’s mainly cotton and grain out this way so there’s a lot of outdoor work,” she said. “[But] they say [42C] is not unusual for out this way.”
Maximum temperatures in most of south-east Queensland were below 40C but the region is predicted to have no break from unusually warm nights and stifling, humid, hot days into the weekend.
Gatton, 90km west of Brisbane, reached 39C on Wednesday.
Some on Twitter poked fun at a “urine chart” advocated by emergency services and health authorities that gives guidance on dehydration levels according to urine colour.
But a death last week underlined warnings by the BoM and health authorities that even fit, healthy adults are at risk of heat-related illness in a heatwave.
A Brisbane man, Matthew Hall, 30, died of heatstroke last Friday while dirt bike riding in the Beerburrum state forest on the Sunshine Coast. His body temperature reportedly climbed to 42C, which caused organ failure.
Amid the soaring heat and dry, gusty conditions, bushfire warnings were current in NSW and the Australian Capital Territory after a large blaze destroyed a home and scorched more than 2,500 hectares of bushland near Canberra on Tuesday.
Also on Tuesday, a fire burned across 51ha in northern South Australia, coming close to a windfarm near Waterloo.
The BoM warned of extreme fire danger across the southern ranges of NSW and severe fire danger in greater Sydney, Illawarra/Shoalhaven, the central ranges and the southern slopes.
King said one driver of the heatwave conditions was the accumulation of heat in Australia’s interior from sinking air caused by persistent high pressure systems. North-westerly winds were pushing this reservoir of heat into eastern coastal areas.
“Every time the wind goes round to the north we drag down that hot air into other areas,” King said. “The other driver of the heat, which is why the climate outlook is suggesting that this will continue, is the warm water surrounding Australia.”
King said the southern states, despite one-off spikes such as 44C in Victoria’s Swan Hill on Tuesday, were being spared the heatwave conditions because of the path high-pressure fronts in the Tasman Sea were taking.
Adelaide reached 26C on Wednesday after a high of 41.1C the day before.
Meanwhile, Western Australia and the Northern Territory were seeing prolonged below-average temperatures and above-average rainfall because of active monsoon conditions, King said.
Those lower temperatures from rainfall in Australia’s north-west would push into NSW from Friday “but not inland Queensland and northern South Australia, so that reservoir of heat will stay there”, he said.
Overnight minimum temperatures were a critical factor on the impact of heatwaves. “If the overnight minimum is high, it’s much harder to recover, cool down, it’s harder to sleep,” he said.
“If you get one hot day and you don’t recover overnight and you get another hot day, I’ve seen [academic] papers that say the impact over the second and third day is compounding.”
The BoM’s measure of a heatwave compares a three-day forecast with average temperatures over the previous 30 days.
Severe to extreme heatwaves feature maximum temperatures of 6C to 10C above the average and minimums of 8C to 12C above the average.
Severe heatwaves can impact the health of elderly people, young children, pregnant women and the ill, while extreme heatwaves have effects on infrastructure, such as railway lines buckling or high demand on electricity networks.
A cool change that brought sudden relief to coastal Sydney on Wednesday after record morning heat failed to flow through to the city’s western fringe, where midday temperatures topped 43C.
Northern New South Wales and southern Queensland are predicted to bear the brunt of unusually high ongoing temperatures in a repeat of last week’s severe to extreme heatwave conditions.
Phil King from the Bureau of Meteorology said the heatwaves were likely driven by warmer sea temperatures combining with the unusual spread of a “reservoir of hot air” that had been building in central Australia over the past several weeks.
A cool front blowing in from the coast south of Sydney saw the mercury drop to below 25C before midday after a near-record overnight low of 28C and record readings of 31C at 6am and 36.9C at 9am.
But west of Sydney, some 60km from the coast, went on to record some of the highest temperatures in the country, with Camden reaching 43.6C, Penrith 43.5C and Richmond 42.8C.
“You can get some incredible differences in temperature, I’ve seen 20C difference from the west to the east [of Sydney],” King said.
Sydney commuters mid-morning took to Twitter to complain about a lack of air-conditioning on trains, one posting a picture of a sweat-soaked seat.
Asked if the conditions were ripe for the hottest start to a year in recorded history, King said: “I suspect that’s pretty likely but January is only halfway through [and] I’m not confident to say.
“But this is the second heatwave [of the summer], it’s likely that parts of Queensland won’t see cooler temperatures and we’re halfway through January with significantly above average maximum and minimum temperatures.”
Hotspots included Grafton on the northern NSW coast, which reached 40C at 2pm.
A staffer at the Grafton Olympic pool said while it was “pretty darn hot at the moment” the numbers of patrons through the gates looking to cool off appeared “regulation, for now”.
It was one of only two publicly owned pools in the town, the other being “on the southside – but it’s heated”, she said.
Moree in NSW was forecast by Weatherzone to remain above 40C until early evening, while Mungindi on the NSW-Queensland border was on track to hit a maximum of 42C, hitting 40C at 1pm.
Cathy North, co-owner of Mungindi’s Two Mile Hotel, said the air-conditioned pub was unlikely to offer any respite to most locals until after 5pm when they finished work. “It’s mainly cotton and grain out this way so there’s a lot of outdoor work,” she said. “[But] they say [42C] is not unusual for out this way.”
Maximum temperatures in most of south-east Queensland were below 40C but the region is predicted to have no break from unusually warm nights and stifling, humid, hot days into the weekend.
Gatton, 90km west of Brisbane, reached 39C on Wednesday.
Some on Twitter poked fun at a “urine chart” advocated by emergency services and health authorities that gives guidance on dehydration levels according to urine colour.
But a death last week underlined warnings by the BoM and health authorities that even fit, healthy adults are at risk of heat-related illness in a heatwave.
A Brisbane man, Matthew Hall, 30, died of heatstroke last Friday while dirt bike riding in the Beerburrum state forest on the Sunshine Coast. His body temperature reportedly climbed to 42C, which caused organ failure.
Amid the soaring heat and dry, gusty conditions, bushfire warnings were current in NSW and the Australian Capital Territory after a large blaze destroyed a home and scorched more than 2,500 hectares of bushland near Canberra on Tuesday.
Also on Tuesday, a fire burned across 51ha in northern South Australia, coming close to a windfarm near Waterloo.
The BoM warned of extreme fire danger across the southern ranges of NSW and severe fire danger in greater Sydney, Illawarra/Shoalhaven, the central ranges and the southern slopes.
King said one driver of the heatwave conditions was the accumulation of heat in Australia’s interior from sinking air caused by persistent high pressure systems. North-westerly winds were pushing this reservoir of heat into eastern coastal areas.
“Every time the wind goes round to the north we drag down that hot air into other areas,” King said. “The other driver of the heat, which is why the climate outlook is suggesting that this will continue, is the warm water surrounding Australia.”
King said the southern states, despite one-off spikes such as 44C in Victoria’s Swan Hill on Tuesday, were being spared the heatwave conditions because of the path high-pressure fronts in the Tasman Sea were taking.
Adelaide reached 26C on Wednesday after a high of 41.1C the day before.
Meanwhile, Western Australia and the Northern Territory were seeing prolonged below-average temperatures and above-average rainfall because of active monsoon conditions, King said.
Those lower temperatures from rainfall in Australia’s north-west would push into NSW from Friday “but not inland Queensland and northern South Australia, so that reservoir of heat will stay there”, he said.
Overnight minimum temperatures were a critical factor on the impact of heatwaves. “If the overnight minimum is high, it’s much harder to recover, cool down, it’s harder to sleep,” he said.
“If you get one hot day and you don’t recover overnight and you get another hot day, I’ve seen [academic] papers that say the impact over the second and third day is compounding.”
The BoM’s measure of a heatwave compares a three-day forecast with average temperatures over the previous 30 days.
Severe to extreme heatwaves feature maximum temperatures of 6C to 10C above the average and minimums of 8C to 12C above the average.
Severe heatwaves can impact the health of elderly people, young children, pregnant women and the ill, while extreme heatwaves have effects on infrastructure, such as railway lines buckling or high demand on electricity networks.
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