Local met stats

[dantheman]

Tropical Regions

The tropical regions are found in the northern part of the continent and include the northern parts of the Northern Territory, Western Australia and Queensland. Here the weather has two seasons: wet and dry.

The wet seasons lasts between December and March and is hotter than the dry season. The temperatures can reach as much as 30 C / 86 F to 50 C / 122 F. The humidity is very high and due to the abundant rain flooding is quite common.

Temperate Regions

The temperate regions are found in the south-eastern coast, comprising Tasmania, most of Victoria and New South Wales, the southern part of Queensland, the southern parts of South Australia and the south-western part of Western Australia.

The summers are hot with temperatures reaching as much as 30 C/ 86 F in the summer. The winters a cold but the average temperature is about 15 C / 59 F. During summers the heat waves are quite common, while the winters then to be wet and windy but quite mild if compared to the European winters.

Tropical Cyclones

The tropical areas of Australia, such as northern Queensland, the Northern Territory and the northern coast of Western Australia, are sometimes affected by cyclones, which form as a result of warm sea temperatures. The tropical cyclone season extends from November to April.

Australian met office http://www.bom.gov.au/ surface pressure charts etc

Winds

The strongest wind ever recorded in Australia was during Cyclone Trixie, on the 19th of February, 1975. In Mardie, in Western Australia, winds blew at speeds of up to 259km/h (162mph). It’s possible that the winds were even stronger during Cyclone Tracy, which hit Darwin in the Northern Territory on the 24th of December, 1974, but the instrument used to measure wind speeds broke after it recorded a speed of 217km/p (136mph).

Don't forget in the Southern Hemisphere the wind goes round the other way - i.e. In the Northern Hemisphere the direction of movement around a low-pressure area is counterclockwise. In the Southern Hemisphere, the direction of movement is clockwise because the rotational dynamics is a mirror image there. At high altitudes, outward-spreading air rotates in the opposite direction, all down to the Coriolis effect and Buys Ballot's law.

.....more to follow

[dantheman]

Due to the position of the continent it looks like you are affected by both Prevailing Westerlies: From 30-60 degrees latitude (aka Westerlies) and Tropical Easterlies: From 0-30 degrees latitude (aka Trade Winds). Obviously local systems will dictate the wind direction on the day and if you are hugging the coast you will benefit from a cool sea breeze which kicks in mid morning. Winds there are also influenced by blocking highs over the Tasman Sea (~10 per year, mainly late winter) and semi-permanent stationary heat low over inland Australia during summer. Obviously the long coastline means much of the continent is subject to oceanic influences, but the oceans adjacent are not distinctly cold or warm, the East Australian Current is erratic and discontinuous.

Australia lies in the path of mobile anticyclones which move eastwards at a mean latitude varying with season, they cross the East coast at 37degS in Feb and at 29degS in Aug/Sept, and as places to north of an anticyclone receives easterly winds whilst those to the south receive westerly winds, the change results in:

Sydney & Adelaide at 34degS, are influenced mainly by easterlies in summer & westerlies in winter & spring

Brisbane at 27-28degS is only occasionally affected by westerlies

Melbourne at 37degS & Hobart at 43degS are only occasionally affected by easterlies

winds are strongest when the anticyclones are most remote => windiest in Darwin in Feb & Hobart in October

[dantheman]

To cut a long story short - it looks as though winter weather patterns for eastern Australia are generally formed by a huge high pressure cell that tends to center over the entire eastern half of the continent, since it's in the southern hemisphere, the winds blow up the east coast, over the top, down the center and back along the base to Sydney. South to North ?

Also a cool xcweather type site here http://ozwind.com.au/qld01

[Guest]

Dan, are you coming to the meeting?

SW

[dantheman]

I have just been stitched up on a job in London on Friday so probably won't make it.....