Bush Fires in Australia

  • Satellite image of smoke from New South Wales bush fires (Image courtesy of NASA).

    Temperature forecast by the MeteoEarth app for south-east Australia on Monday.

    Wind forecast by the MeteoEarth app for south-east Australia on Wednesday.

  • Bush Fires in Australia
    19.10.2013 14:00

    Bush fires have plagued New South Wales for the last few days, with the wind carrying smoke and ash from the Lithgow fire across Sydney on Thursday. The fires broke out during a period of high temperatures for the time of year and were fuelled by brisk winds. It is expected to take weeks before the fires are completely extinguished, and their progress is largely weather dependent.

    Ideal conditions for bush fires are a combination of dry air, high temperature, and a strong breeze, which is just what Australia had over the last few days, and just what is expected to return at the start of next week.

    The New South Wales Rural Fire Service has banned the lighting of fires in the area completely.

    Temperatures in Sydney hit 30 Celsius on Wednesday and Thursday compared to expected highs of 20 Celsius for this time of year. Further inland temperatures soared to 35 Celsius. Brisk winds also blew from the north-west during these two days. As the winds are forced to rise over the Great Dividing Range, the air cools and its ability to hold moisture decreases, so moisture is deposited over the high ground. The air warms again as it descends on the other side, but it is now far drier. This air is ideal for making the vegetation perfect to burn, and for spreading the blazes.

    Yesterday and today it has been cooler with calmer winds, but temperatures remain a touch above average.

    However, the reduced temperatures are not going to hang around. Even hotter weather is expected to arrive on Sunday and Monday with forecast highs of 34 Celsius in Sydney on Monday, and even hotter away from the cooling effect of the coast. More brisk winds are also expected to be blowing on Monday and Tuesday, so the firefighters are going to be working hard at the start of next week.

    Through the second half of next week the spread of the blazes may slow as winds ease and temperatures return to average on Thursday. There may even be a few spots of rain on Wednesday as a deepening low pressure system moves south-eastwards into the Tasman sea.

    Australia’s national weather service, the Bureau of Meteorology, expects temperatures to remain higher than average across Australia for the near future.

    By: Ben Windsor