by While the residents in Südost-Queensland and North-New South Wales are waiting for the next step of Tropical Cyclone Alfred, the regular “Track Map” of the Bureau of Metorology will be a source of information for many.
But behind the snake traces and colored blobs on the menu there are more than a hundred scenarios from different computer models that try to find out how the system reacts to what happens in the atmosphere and in the ocean.
How do cyclones move and how distilled all this complexity on a map that can warn millions of people about what will come?
How does the Bureau of Meteorology create the track cards for Cyclone Alfred?
The senior meteorologist Dean Narramore from Bom was part of a team that has worked in the past 11 days to create updated cards from Cyclone Alfred.
A new card will be issued every six hours after the office’s cyclone team has examined the performance of models from Europe, the US, Japan, Japan and Australian climate and earth system simulator.
“If you look at all the model runs, there can be 100 to 150 different tracks. It looks a bit like spaghetti, ”says Narramore.
In Alfred’s life, Narramore stood early on that the modeled tracks were “everywhere”, but a few days ago – although the models are a little different – they began to align themselves.
“If all lines come together in a consistent pattern, this gives more confidence. Then it’s still like spaghetti, but now you hold it in your hand. “
The office will start with the output of a track card every three hours as soon as a tropical cyclone warning is issued-a warning that is triggered if you are expected to be over 63 km/h within 24 hours via the gale-force win.
That could be on Tuesday afternoon.
What forces are trying to control the Alfred cyclone?
So far, winds in the upper part of the atmosphere have pushed the tropical cyclone of Alfred Southeast out of the village, from which it was founded in the coral sea at the end of February.
Dr. Hamish Ramsay, a cyclone expert on the CSIRO, says, in the direction in which a cyclone is moved, is dictated by something that is referred to as the “steering current” – the prevailing winds between two and 10 kilometers in the atmosphere.
Ramsay says it is not unusual for cyclones to pursue so far south – but it is unusual for them to land so far down.
This is because a cyclone level with the southeastern coast of Queensland usually blisters to the east by weather systems with medium width and take most of the Australia systems.
On Tuesday, Alfred is expected to be moved into an area in which the “steering flow” runs to the west – thanks to the high pressure over the Tasman Sea.
Where is Cyclone Alfred expected?
The route cards of the office also contain a large area in gray outside the main route, which represents the area where the cyclone could go.
Narramore said as soon as Alfred changes towards the coast on Tuesday on Tuesday, uncertainty will probably limit itself – and the public and the authorities will be a clearer idea of where the worst influence could be.
The creation with the cards is the best way to stay up to date, but on Monday he said that the models showed a probable landfall on Thursday or early Friday between HERREY BAY and the Gold Coast.
But that could change.
What intensity will Cyclone Alfred be when it hits?
The route cards also contain the expected intensity of the cyclone, which refers to the wind speeds they produce.
A cyclone in category two – the expected rating for cyclone Alfred, if it is forecast to make landing – indicates average winds between 89 and 117 km/h, with gusts of up to 164 km/h.
However, Ramsay says that the category of a cyclone does not necessarily reflect how harmful it could be.
Alfred has been forecast that moving over an area with unusually warm sea surface, which gives the system more energy in terms of rain.
If the cyclone slows down when it approaches the coast, this would also record higher rainfall.
“The highest mortality from tropical hurricanes is connected to the precipitation,” he said. “The wind speed in this case may not be the most harmful.”
What should people look for?
The offices of the office show the likely route for the cyclone and the areas that are hit by destructive winds.
In the southern hemisphere, areas south of the center of a cyclone experience the worst of the weather.
According to Narramore, a very large area will probably learn hundreds of kilometers from Gale Force from where the cyclone lands, including the Sunshine Coast, Brisbane, Gold Coast and Northern NSW.
The time of landing could also be of crucial importance for the coastal damage due to waves and flooding.
If the cyclone hits the flood, this could add another meter to the expected flood, with the harmful waves lending a further height.
“A few hours can make a big difference,” he said.
