They spin anti clockwise in the southern hemisphere

Heatwaves send temperatures soaring in many parts of Australia

canada goose canada goose uk black friday outlet store uk Heatwaves are Australia’s deadliest natural disaster. They have killed more people buy canada goose jacket cheap than bushfires, cyclones and floods put together. canada goose outlet store uk

The Bureau of Meteorology defines them as “three days or more of high maximum and minimum temperatures that is unusual for that location”.

canada goose outlet uk During the extreme heatwave that hit south east Australia in 2009, 374 people died in Victoria and evidence exists for up to 500 heatwave related deaths buy canada goose jacket all together. canada goose outlet uk

According to John Nairn, the Bureau of Meteorology’s national heatwave project director, events like 2009 are rare the last comparable event in south east Australia occurred in 1939.

official canada goose Canada Goose online outlet But it doesn’t have to be a Canada Goose sale once in a generation event to put people at risk. official canada goose outlet

canada goose outlet store So what are heatwaves exactly, and why do they happen? canada goose outlet store

canada goose outlet reviews Australian heatwaves are usually noticed when hot, dry air from the outback moves over populated coastal areas. canada goose outlet reviews

Mr Nairn said heatwaves could occur anywhere across Australia, but we have seen some whoppers across southern and eastern states in recent years.

canada goose outlet Why is central Australia so hot in the first place? The outback gets so hot and dry because a high pressure ridge sits over it most of the time. This high pressure ridge is the result of the relationship between the earth and the sun. canada goose outlet

Because our planet is a sphere, more of the sun’s energy is focussed around the equator than at the poles. Hot air rises so this extra warmth causes warm moist air to rise around the equator.

canada goose outlet nyc As it goes up into the cooler, upper atmosphere the moisture condenses to form tropical rain which is why the tropics are so hot and rainy. canada goose outlet nyc

But what goes up must come down. Once this air has lost its moisture it travels away from the equator and falls back down to earth about at roughly 30 degrees of latitude north and south.

canada goose outlet in usa This descending air forms a high pressure ridge. canada goose outlet in usa

canada goose outlet online uk The dominant high pressure prevents rain because it blocks air rising and the air doesn’t have enough moisture for raindrops to form. This band of falling air is the cheap Canada Goose reason why there canada goose coats on sale are deserts all over the world https://www.canadagoosepark.com about 30 degrees north and south, including over Australia. canada goose outlet online uk

canada goose outlet sale The centre’s hot, dry conditions are helped by its location so far canada goose uk outlet from the sea. canada goose outlet sale

Moist sea breezes don’t make it so far inland and most rain bearing systems have dropped canada goose factory sale their rain by the time they make it to the outback.

canada goose outlet canada goose clearance toronto factory The high pressure ridge is why high pressure systems are so common at this latitude. canada goose outlet toronto factory

canada goose outlet uk sale You can spot these systems when you watch the weather report at the end of the nightly news. They are Canada Goose Online the H’s on the weather maps. They spin anti clockwise in the southern hemisphere. canada goose outlet uk sale

canada goose outlet online These high canada goose clearance sale pressure systems along with low pressure systems (clockwise spin and rising air bringing rain), fronts (which occur where warm and cool air collide, also bring rain) and troughs (areas of low pressure with no spin, yet more rain), are responsible for moving the air around at a continental scale and drive our day to day weather. canada goose outlet online

canada goose black friday sale But back to the heatwaves Australia’s worst heatwave death tolls have historically occurred in the south east of the country and take place when a high pressure system Canada Goose Outlet moves across the continent and pushes the hot, dry air from the outback down towards the coast. canada goose black friday sale

When you watch a weather report you will cheap canada goose see that highs move across Australia from west to east every week or so, and yet we don’t have a heatwave every week so what makes a normal weather pattern turn into Canada Goose Coats On Sale a heatwave?

goose outlet canada According to Mr Nairn, there are three ways a normal weather week can turn on an extremely dangerous heatwave: goose outlet canada

canada Canada Goose Parka goose outlet jackets If there is a drought in central Australia the cheap canada goose uk air being pushed towards the southern and eastern states will be extra hot. Usually part of the sun’s energy is consumed evaporating moist soils, it’s called evaporative cooling. But if there isn’t any soil moisture around then the energy hangs around in the form of heat. So the air that’s dragged away from these dry areas is extra hot and dry. If the high pressure system stalls over the east coast or in the Tasman sea, it will pull more hot air down towards the south east for longer, making the heatwave worse. If it stalls right over the south east the falling uk canada goose outlet air can warm things up too, just like the high pressure ridge that heats up central Australia. If there is a cyclone over the north west of WA it can push tropical heat into the upper atmosphere which is then sucked down over central Australia, making it even hotter out there, which in turn makes the heatwaves in south east Australia even bigger. canada goose outlet jackets

Even more epicIf two or even all three of these separate elements join up, we could be looking at an even more intense heatwave.

canada goose outlet parka The Bureau of Meteorology uses three categories to describe heatwave severity and Canada Goose Jackets issue warnings. canada goose outlet parka

But when it becomes severe, it is canada goose uk shop not a good idea for the grandparents to be outside. canada goose And when you get to an extreme heatwave, why are you even playing cricket?

In Alice Springs, 40 degrees Celsius is just another summer day. But down in Tassie, a few days over 30C can be enough to be dangerous.