13-14th July 2008 The PERFECT Low

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The TC "Temperate" Cyclone

This has to be the best low pressure I think I have seen across South Australia. With an eye as impressive as a tropical cyclone, crazy winds and impressive pressure gradients it is best seen with an image to start with. This snapshot from the modis terra satellite shows in high resolution a close up of the eye itself. Inlaid you can see a zoomed out image. This could be any tropical depression anywhere in the world until you realise its travelling along the south coast of Kangaroo island.

 

It started life in Western Australia and unusually strengthened as it approached SA waters. An early image of the low can be seen to the right. As it approached Kangaroo Island the pressure gradient was very tight. Neptune Island, approximately 70km from Pt Lincoln in between Yorkes and Eyre Peninsula had a 6hPa difference between the two. Between Neptue Island and Adelaide (200km) a 10hPa difference could be found. The eye of the low as of 4pm on the 13th was 994hPa. The synoptic from the 13th can be seen below. Click on the image for a loop.

Unfortunately on the western tip of KI, Cape Borda's AWS was out of action. The "eye" of the low hit this region with almost category one cyclone force and travelled along the south coast of the island. We do however have observations from Cape Willoughby on the eastern tip of the island and these are impressive enough!

 

The small animated sequence of satellite images to the right shows the eye of the low as it hits and crosses the southern KI coast. The image is a 300% enlargement from satellite images hence the pixellation. But the structure and eye are obvious! Original images available on request Rainfalls from the low were patchy. As seen from the log above Cape Willoughby recorded 14mm. Other KI stations were - American River 13mm, Kingscote 12mm. I recorded 17mm, Kuitpo 16mm and 28-33mm over the higher Mt Lofties. The Adelaide plains were generally between 1 and 5mm.

The eye was even very well defined on the rain radar!       Not a massive widespread rain event, but what an amazing system indeed! Could this be South Australia's first "Temperate Cyclone?"