Australian Bureau of Meteorology
Australian Bureau of Meteorology
News Article | April 27, 2017
Tropical Storm Frances has formed in the Beagle Gulf, east of the Timor Sea near Darwin, Australia, and NASA's Aqua satellite captured a clear image of the storm. On April 27 at 04:50 UTC (12:50 a.m. EDT), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA's Aqua satellite captured a visible image of Tropical Cyclone Frances. Frances appeared somewhat elongated. At 04:47 UTC (12:47 a.m. EDT), the Atmospheric Infrared Sounder or AIRS instrument aboard NASA's Aqua satellite gathered temperature data on Frances by viewing the storm in infrared light. The image showed thunderstorms with very cold cloud top temperatures near minus 60 degrees Fahrenheit / minus 53 degrees Celsius over the Tiwi Islands, Darwin and Garig Gunak Bariu National Park in the Northern Territory of Australia. Storms with cloud top temperatures have been found to produce heavy rain. The Australian Bureau of Meteorology or ABM has posted a warning from Kuri Bay to Wyndham, not including Wyndham. In addition, ABM noted that tides between Kalumburu and Wyndham are likely to rise above normal high tide mark with very rough seas and flooding of low-lying coastal areas. At 9:45 a.m. EST/U.S. or 11:15 p.m. ACST local time on Thursday April 27, Frances had maximum sustained winds near 53 mph /85 kilometers per hour with higher wind gusts. Frances was centered near 11.0 degrees south latitude and 128.3 degrees east longitude, about 146 miles/235 kilometers west of Pirlangimpi and 410 kilometers north northeast of Kalumburu. Frances was moving to the west-southwest at ~12 mph/19 kilometers per hour. ABM said "Tropical Cyclone Frances is expected to intensify as it moves southwest through the Timor Sea tonight, possibly developing into a Category 2 system early on Friday, [April 28]. The cyclone is expected to remain over water as it heads towards the Indian Ocean, however If it takes a more southerly track peripheral gales may affect the north Kimberley coast later on Friday." The Joint Typhoon Warning Center noted that as Frances tracks to the west vertical wind shear is forecast to increase and the storm may dissipate in three days by April 30.
News Article | April 17, 2017
The remnant clouds and showers associated with Ex-Tropical Cyclone Debbie were slowly moving off the coasts of Queensland and New South Wales as NASA's Terra satellite passed overhead on March 31. On March 31 at 01:30 p.m. AEST/Queensland (March 30 at 11:30 p.m. / U.S.), the Moderate Resolution Imaging Spectroradiometer aboard NASA's Terra satellite captured a visible image of Debbie's remnants. The remnant clouds and showers were blanketing southeastern Queensland and northeastern New South Wales, Australia. The system appeared frontal in nature, stretching from north to south over the eastern Australian coast. On March 31, Debbie's remnants were still generating rough surf along coastal areas, as the heavy rainfall the storm generated continued to trigger warnings for rivers. At 11 p.m. AEST/Queensland local time (9 a.m. EST/U.S.) the Australian Bureau of Meteorology noted that Ex-Tropical Cyclone Debbie was located 500 km to the east of the Gold Coast. Debbie's remnants are forecast to slowly move away from the east coast over the next few days. Although dangerous surf and abnormally high tides are no longer expected over Southeast Queensland, the surf is expected to be rough for several into the next week. Several river flood warning remain in effect. There is currently a major Flood Warning for the Logan and Albert Rivers in Queensland, and for the Bremer River and Warrill Creeks River. There was also a Minor Flood Warning in effect for the Lockyer and Laidley Creeks and Lower Brisbane River. Further south, in New South Wales, large waves are forecast for the North Coast. ABM noted "Damaging surf conditions are expected along the Northern Rivers coast tonight and early Saturday. Waves exceeding 5 meters in the surf zone may produce significant beach erosion, especially on this evening's high tide. South-facing parts of coast are more likely to be affected. High tide is expected around midnight, and may exceed the highest astronomical tide of the year in some localities." Coastal areas north of Seal Rocks are expected to experience dangerous surf conditions Friday, March 31 and Saturday, April 1. Locations which may be affected by beach erosion include Wooli, Evans Head and Ballina. The Australian Bureau of Meteorology noted that Tropical Cyclone Debbie established some records. According to ABM, "Severe tropical cyclone Debbie is the first tropical cyclone to reach severe status (category 3 or higher) since the Australian 2014-15 cyclone season. Debbie attained a maximum intensity of category 4 and made landfall on the central Queensland coast, near Airlie Beach, around mid-day on March 28. An unofficial wind gust of 263 kph was recorded at Hamilton Island airport on the morning of 28 March as Debbie made a direct impact on the site; if this observation is verified it would be the highest wind gust on record for Queensland. Heavy rainfall was also a feature in the Central Coast region with daily rainfall observations at multiple locations above 200 mm and a peak recording of 470 mm at Mount William, west of Mackay." For more warnings and watches in Queensland, visit: http://www.
News Article | February 3, 2016
One spring day in 2004, Qiang Fu was poring over atmospheric data collected from satellites when he noticed an unusual and seemingly inexplicable pattern. In two belts on either side of the equator, the lower atmosphere was warming more than anywhere else on Earth. Fu, an atmospheric scientist at the University of Washington in Seattle, was puzzled. It wasn't until a year later that he realized what he had discovered: evidence of a rapid expansion of the tropics, the region that encircles Earth's waist like a green belt. The heart of the tropics is lush, but the northern and southern edges are dry. And these parched borders are growing — expanding into the subtropics and pushing them towards the poles. Cities that currently sit just outside the tropics could soon be smack in the middle of the dry tropical edge. That's bad news for places like San Diego, California. “A shift of just one degree of latitude in southern California — that's enough to have a huge impact on those communities in terms of how much rain they will get,” explains climate modeller Thomas Reichler of the University of Utah in Salt Lake City. Since Fu and his colleagues announced their discovery1 in 2006, many scientists have investigated the tropical bloating and tried to decipher its cause. Explanations range from global warming to ozone depletion or natural cycles that will reverse in the future. And there is little agreement on how quickly the border of the tropics is shifting: estimates run from less than half a degree of latitude per decade to several. At the more extreme end, the change in climate would be like moving London to the position of Rome over the course of a century2, 3, 4, 5. The problem is compounded by lack of consensus on how to define the tropics, which makes it hard for scientists to agree on the extent of the changes. Nevertheless, researchers investigating this phenomenon agree that it is real. “There's a big need to be concerned about this issue,” says climate scientist Chris Lucas at the Australian Bureau of Meteorology in Melbourne. That's because of the possible impacts: some of the world's most fertile fishing grounds could disappear, global grain production could shrink and biodiversity could suffer. At the same time as Fu first discovered odd patterns in the satellite data, Reichler noticed something unusual in the skies. He was researching the tropopause, the boundary between the lowest level of the atmosphere (the troposphere) and the layer above it (the stratosphere). At the Equator, the tropopause is normally several kilometres higher than at the poles, because warm air rises and pushes the boundary upwards. While analysing temperature data collected from weather balloons, Reichler had found that this equatorial bulge in the tropopause was expanding towards the poles, a sign that the tropics were growing. Fu heard about Reichler's data, and they decided to publish their discoveries together1. Ten years after they sounded the alarm, scientists are still struggling to work out what is happening. Last July, 50 researchers gathered in Santa Fe, New Mexico, to discuss everything that is known about tropical expansion — how to measure it, what is causing it and where the future border of the tropics might be. “We're at a stage where we recognize the problem is more complex than we originally thought,” explains the organizer of the conference, Dian Seidel, an atmospheric scientist with the US National Oceanic and Atmospheric Administration (NOAA) in Silver Spring, Maryland. Some of the changes in the tropics could be a result of global warming. Reichler investigated that possibility in a study6 led by Jian Lu, an Earth systems scientist now at the Pacific Northwest National Laboratory in Richland, Washington. Working with Gabriel Vecchi, a climate scientist with NOAA in Princeton, New Jersey, the researchers looked at climate forecasts to see how warming might affect an atmospheric circulation pattern called the Hadley cell, which transports heat from the warmer parts of Earth towards the cooler regions (see 'Bulging waistline'). As part of the Hadley cell, warm, moist air soars skywards above the Equator and cool, dry air tumbles towards Earth at about 30 ° latitude in the Northern and Southern Hemispheres. That downward limb of the Hadley cell helps to create some of the driest deserts on the planet, such as the Kalahari in southern Africa and the Sahara in northern Africa, and it is one of the most common measures of the boundary between the tropics and the drier subtropics. In their study, Lu and his colleagues found that climate models generally forecast that the outer edge of the Hadley cell will shift because of global warming. But the models predict a much slower rate of tropical expansion than has been seen so far — which has led researchers to suspect that something else is going on. A common view, and one held by Lucas, is that natural climatic variability is playing some part. That variability could take the form of large-scale climatic cycles such as the Pacific Decadal Oscillation, in which temperatures in the Pacific Ocean swing between hot and cold across timescales of 15–20 years or more. “Or it could be in the form of much more random, chaotic noise,” says Lucas, who thinks that large cycles and noise together account for 50% or more of the expansion. Atmospheric scientist Darryn Waugh at Johns Hopkins University in Baltimore, Maryland, agrees. “It's a chaotic system, so some of the variability is just noise in the system.” If that is the case, tropical expansion could slow down or even reverse in some regions when those natural variations swing back. Another answer might involve different forces in the Northern and Southern hemispheres. South of the Equator, tropical expansion has been strongest in the summer, and that leads some researchers to suspect that it is related to the pattern of ozone loss in the southern stratosphere. Pollutants chew up ozone molecules above Antarctica in the spring, which triggers circulation changes throughout other parts of the Southern Hemisphere during summer. The correlation with tropical expansion suggests that the two phenomena could be connected. What's more, climate models that factor in ozone loss are able to account for much more of the tropical expansion between 1980 and 2000, when the Antarctic ozone hole was growing bigger nearly every year, says Waugh7. In the Northern Hemisphere, a different explanation is called for because, in general, the Arctic does not suffer the same sort of ozone loss as the Antarctic. Research led by climate scientist Bob Allen at the University of California, Riverside, suggests that the culprits in the north might be black soot and tropospheric ozone — which are both generated by burning fossil fuels. Allen and his team ran simulations with a climate model that featured detailed atmospheric physics, and their analysis showed that black soot and tropospheric ozone have heated the atmosphere in the Northern Hemisphere and driven tropical expansion more than carbon dioxide and other greenhouse gases, particularly in summer8. Not everyone is comfortable with the idea that entirely separate factors could drive tropical expansion to such a large extent on either side of the Equator. Fu, for one, thinks it's unlikely given the similar patterns in the north and south. “If ozone depletion was dominating the expansion in the Southern Hemisphere in the past 30 years, would you see such symmetry? I'm not convinced,” says Fu. The proliferation of hypotheses shows how much researchers are struggling to explain what's happening. “I think we're piecing this together slowly,” says Lucas. “We don't have a full explanation yet and I don't think there's going to be one single explanation. It's going to be a little bit of this and a little bit of that.” Right around the time that scientists were first warning about tropical expansion, Lucas was experiencing what might have been its effects first-hand. During 2006 and 2007, Australia was deep in the middle of one of the worst droughts to have hit the continent since Europeans settled there. Lucas recalls driving from Melbourne to nearby Lake Eildon and seeing the once-brimming lake empty. Meanwhile, Melbourne's reservoirs were running low, and north of the city, forest fires raged in the mountains. The worst-affected regions of Australia — cities such as Perth, Adelaide and Melbourne — were south of 30 ° latitude, which suggests that the drying could be caused by a shift in the position of the Hadley cell and the rain-bearing jet stream. According to research published9 in 2010, southeastern Australia has been invaded by a drier climate from the north in recent decades, which has greatly reduced rainfall. “We can't say that this is exclusively due to tropical expansion, but it's certainly consistent with tropical expansion,” explains Lucas. “And our concern is that southeastern Australia is going to keep getting drier.” Elsewhere, there is evidence that tropical expansion is affecting the ocean. Where the Hadley cell descends, bringing cool air downward, it energizes the ocean and whips up currents to high speeds. This energy powers the upwelling of cold, nutrient-rich waters towards the surface, which feeds some of the world's most productive fisheries. But there are hints that some of these regions are suffering because of shifts in the Hadley cell. Edward Vizy and Kerry Cook10, both at the University of Texas at Austin, have found some unhealthy signs in the region of the Benguela Current, an area of coastal upwelling along the coast of west Africa and south of 30 ° latitude. According to Cook, the currents of that entire region have shifted over the past 30 years. One effect is that the upwelling has weakened, with worrying implications for the region's fisheries and biodiversity. Cook says that the same could be true of open-ocean upwelling systems, which are more susceptible to changes in the position of the Hadley cell. These upwelling zones could move south over time, or get weaker or stronger, depending on what happens to the Hadley cell, says Cook. In any case, it means that fishing communities that rely on these resources will not be able to count on traditional patterns. On land, biodiversity is also potentially at risk. This is especially true for the climate zones just below the subtropics in South Africa and Australia, on the southern rim of both continents. In southwestern Australia, renowned as one of the world's biodiversity hotspots, flowers bloom during September, when tourists come to marvel at some of the region's 4,000 endemic plant species. But since the late 1970s, rainfall there has dropped by one-quarter. The same is true at South Africa's Cape Floristic Province, another frontier known for its floral beauty. “This is the most concrete evidence we have of tropical expansion,” says Steve Turton, an environmental geographer at James Cook University in Cairns, Australia. Turton worries that the rate of change will be too rapid for these ecosystems to adapt. “We're talking about rapid expansion that's within half or a third of a human lifetime,” he says. In the worst-case scenario, the subtropics will overtake these ecologically rich outposts and the hotter, drier conditions will take a major toll. For the scientists working in this field, communicating the threat of tropical expansion will be tricky, given the level of uncertainty. “It's frustrating to see how much work we have left,” says Thomas Birner, an atmospheric scientist at Colorado State University in Fort Collins and one of the conveners of the Santa Fe meeting. One outcome of that conference was an agreement that scientists should compare the various metrics for measuring tropical expansion in the hope of agreeing on the best way forward. More time will also help. If tropical expansion continues at a fairly constant rate, says Waugh, there will be less of a chance that natural variability is the main culprit, and the finger will point more strongly to other causes. But that long wait for an answer will be no comfort for the residents of cities such as Santiago, San Diego and Melbourne, and for the billions of others who live near the boundary between the tropics and subtropics. “We need to understand this issue,” says Lucas, “to have a sustainable civilization there.”
News Article | February 16, 2017
The heatwave that engulfed southeastern Australia at the end of last week has seen heat records continue to tumble. On Saturday 11 February, as New South Wales suffered through the heatwave’s peak, temperatures soared to 47℃ in Richmond, 50km northwest of Sydney, while 87 bushfires raged across the state, amid catastrophic fire conditions. On that day, most of NSW experienced temperatures at least 12C above normal for this time of year. In White Cliffs, the overnight minimum was 34.2, a new record for the state’s highest observed minimum temperature. On Friday, the average maximum temperature right across NSW hit 42.4, beating the previous February record of 42.0. The new record stood for all of 24 hours before it was smashed again on Saturday, as the whole state averaged 44.0 at its peak. At this time, NSW was the hottest place on earth. A degree or two here or there might not sound like much, but to put it in cricketing parlance, those temperature records are the equivalent of a modern-day test batsman retiring with an average of over 100 – the feat of outdoing Don Bradman’s fabled 99.94 – and would undoubtedly be front-page news. And still the records continue to fall. Mungindi, on the border of NSW and Queensland, broke the Australian record of 50 days in a row above 35, set just four years ago at Bourke airport, with the new record now at 52 days. Meanwhile, two days after that sweltering Saturday we woke to find the fires ignited during the heatwave still cutting a swathe of destruction, with the small town of Uarbry, east of Dunedoo, all but burned to the ground. This heatwave is all the more noteworthy when we consider that the El Niño of 2015-16 is long gone and the conditions that ordinarily influence our weather are firmly in neutral. This means we should expect average, not sweltering, temperatures. Since Christmas, much of eastern Australia has been in a flux of extreme temperatures. This increased frequency of heatwaves shows a strong trend in observations, which is set to continue as the human influence on the climate deepens. It is all part of a rapid warming trend that over the past decade has seen new heat records in Australia outnumber new cold records by 12 to one. Let’s be clear, this is not natural. Climate scientists have long been saying that we would feel the impacts of human-caused climate change in heat records first, before noticing the upward swing in average temperatures (although that is happening too). This heatwave is simply the latest example. What’s more, in just a few decades’ time, summer conditions like these will be felt across the whole country regularly. The useful thing scientifically about heatwaves is that we can estimate the role that climate change plays in these individual events. This is a relatively new field known as “event attribution”, which has grown and improved significantly over the past decade. Using the Weather@Home climate model, we looked at the role of human-induced climate change in this latest heatwave, as we have for other events previously. We compared the likelihood of such a heatwave in model simulations that factor in human greenhouse gas emissions, compared with simulations in which there is no such human influence. Since 2017 has only just begun, we used model runs representing 2014, which was similarly an El Niño-neutral year, while also experiencing similar levels of human influence on the climate. Based on this analysis, we found that heatwaves at least as hot as this one are now twice as likely to occur. In the current climate, a heatwave of this severity and extent occurs, on average, once every 120 years, so is still quite rare. However, without human-induced climate change, this heatwave would only occur once every 240 years. In other words, the waiting time for the recent east Australian heatwave has halved. As climate change worsens in the coming decades, the waiting time will reduce even further. Our results show very clearly the influence of climate change on this heatwave event. They tell us that what we saw last weekend is a taste of what our future will bring, unless humans can rapidly and deeply cut our greenhouse emissions. Our increasingly fragile electricity networks will struggle to cope, as the threat of rolling blackouts across NSW showed. It is worth noting that the large number of rooftop solar panels in NSW may have helped to avert such a crisis this time around. Our hospital emergency departments also feel the added stress of heat waves. When an estimated 374 people died from the heatwave that preceded the Black Saturday bushfires the Victorian Institute of Forensic Medicine resorted to storing bodies in hospitals, universities and funeral parlours. The Victorian heatwave of January 2014 saw 167 more deaths than expected, along with significant increases in emergency department presentations and ambulance callouts. Infrastructure breaks down during heatwaves, as we saw in 2009 when railway lines buckled under the extreme conditions. It can also strain Australia’s beloved sporting events, as the 2014 Australian Open showed. These impacts have led state governments and other bodies to investigate heatwave management strategies, while our colleagues at the Bureau of Meteorology have developed a heatwave forecast service for Australia. These are likely to be just the beginning of strategies needed to combat heatwaves, with conditions currently regarded as extreme set to be the “new normal” by the 2030s. With the ramifications of extreme weather clear to everyone who experienced this heatwave, there is no better time to talk about how we can ready ourselves. We urgently need to discuss the health and economic impacts of heatwaves, and how we are going to cope with more of them in the future. • Sarah Perkins-Kirkpatrick is a research fellow at UNSW, Andrew King is a climate extremes research fellow at University of Melbourne and Matthew Hale is a research assistant at UNSW. The authors also acknowledge Robert Smalley, Andrew Watkins and Karl Braganza of the Australian Bureau of Meteorology for providing observations included in this article. This article was republished from the Conversation
News Article | December 6, 2016
SYDNEY (Reuters) - The chance of a La Nina weather condition occurring within the next few months is now low, the Australian Bureau of Meteorology said on Tuesday, reducing the possibility of flooding and tropical cyclones along the country's east coast.
News Article | April 26, 2016
SYDNEY (Reuters) - Seven out of eight models monitored by the Australian Bureau of Meteorology (BOM) now indicate that a threshold for a La Nina weather pattern will be breached by September, the weather agency said on Tuesday.
News Article | March 21, 2016
A tourist boat floats above an area called the 'Coral Gardens' located off Lady Elliot Island and north-east from the town of Bundaberg in Queensland, Australia, in this June 11, 2015 file photo. Authorities this month said that areas of the World Heritage site were experiencing the worst bleaching in 15 years, at least partially as a result of the current El Nino, one of the strongest in two decades. Coral bleaching is a process by which coral expels living algae, causing it to calcify. Coral can only survive within a narrow band of ocean temperature. The Great Barrier Reef Marine Park Authority on Sunday said it was lifting its response to level three, authority chairman Dr Russell Reichelt said. "A level-three response level means we’re stepping up surveys in response to the coral mortality to help us better understand the effects of various pressures on the reef and help guide management actions,” Reichelt said in a statement. The footage, shot on Saturday by the University of Queensland's CoralWatch group, has raised serious concerns amongst scientists and environmental groups about the growing impact of climate change. "The new video and stills are very concerning and show large sections of coral drained of all color and fighting for survival," World Wildlife Fund spokesman Richard Leck said in a statement. "This is the worst coral bleaching event ever to hit this most pristine part of the Great Barrier Reef." Scientists said the Great Barrier Reef needs a break in El Nino conditions within weeks if some coral areas are to survive, but the Australian Bureau of Meteorology's most recent forecast calls for a continuation of El Nino conditions. This year will be the hottest on record and 2016 could be even hotter due to El Nino, the World Meteorological Organization has said. The Great Barrier Reef stretches 2,000 km (1,200 miles) along Australia's northeast coast and is the world's largest living ecosystem. It brings in billions of dollars a year in tourism revenue. UNESCO's World Heritage Committee last May stopped short of placing the Great Barrier Reef on an "in danger" list, but the ruling raised long-term concerns about its future.
News Article | January 19, 2016
SYDNEY A strong El Nino weather pattern will likely end in the second quarter of 2016, the Australian Bureau of Meteorology said on Tuesday. Climate indicators remain in the El Nino threshold but have cooled in recent months, with a likely return to neutral conditions within six months, it said.An El Nino, or a warming of sea-surface temperatures in the Pacific, can lead to scorching weather across Asia and east Africa but heavy rains and floods in South America.
News Article | February 28, 2017
SYDNEY (Reuters) - The chance of an El Nino in 2017 has increased in the last two weeks, the Australian Bureau of Meteorology (BOM) said on Tuesday, indicating a 50 percent chance the weather event resurfaces over the next six months.
News Article | January 31, 2016
Category 2 cyclone Stan made landfall some 120 km (75 miles) north east of the world’s largest iron ore export hub, Port Hedland, in the early hours of Sunday morning, the Australian Bureau of Meteorology said. The cyclone is just one of the severe weather events Australia experienced during the weekend, with several weather fronts hitting the nation. One man was killed after being swept away by floodwaters overnight in southern Queensland, state police said on Sunday. In New South Wales a mini-tornado destroyed several homes while roads were flooded and power cut in several regions. In Tasmania, some 80 wild fires have been burning mostly in the west of the island state since lightening struck on January 13, destroying more than 72,000 hectares of bushland, including 1,000-year-old trees in World Heritage listed forests. In Tasmania’s east, communities were warned to brace for further flooding on Sunday as heavy rainfall was forecast. While inland communities in Western Australia's Pilbara remained on red alert as Cyclone Stan tracked southeast and weakened on Sunday, port authorities in Dampier and Port Hedland, through which almost half the world’s seaborne iron ore is shipped, were readying to reopen following their closure on Friday, a ports spokeswoman told Reuters. More than 37.5 million tonnes of iron ore was shipped from Port Hedland in December, latest figures show, with the bulk of it heading for steel mills in China. BHP Billiton Ltd., which evacuated workers from its port operations, said in a statement that any impact to production or sales will be reported in its next operational review. Smaller miner Fortescue Metals Group, said in a statement during the shutdown on Saturday that there was no change to the company’s shipping guidance, which takes the weather impact of cyclones into account, this financial year. Cyclone Stan is the first of the season which usually runs for six months from Nov. 1.