Tropical cyclone
Rapidly rising air
Strong winds, torrential rain.
T
Cold front
The ‘line’ along which an approaching mass of cold air meets warmer air The ‘line’ along which an approaching mass of warm air meets colder air Rain in the last 24 hours
Fall in temperature, rain. Front moves in the direction of arrowheads. Temperature rises, sometimes light rain. Uncommon in Australia. Usually associated with low- pressure areas and fronts. An area associated with unsettled weather and precipitation.
Warmfront
Rain
Trough
A dip in isobars
Procedure Step1 Pressure systems
Examine high-pressure systems (pressure above 1013 hPa) and low-pressure systems (pressure below 1013 hPa). Pressure systems generally move from west to east as they cross Australia and move around the world. In FIGURE2 , a high-pressure system is approaching south-west Western Australia. This system is likely to bring ýne weather to the region. The low-pressure system east of Broome brings cooler weather and rain. Step2 Air masses and fronts Examine any air masses and fronts. FIGURE2 shows a cold front where cold air meets warmer air. This is likely to cause a fall in temperature and rain in South Australia. Step3 Precipitation Examine precipitation patterns. Precipitation includes snow, hail and dew, but rainfall is the most common form of precipitation. In FIGURE2 , we can see that more than half of Australia has received rain in the last 24 hours. This chart does not indicate how much rain has fallen. Step4 Wind Wind is not shown on this weather map. However, the closer together the isobars are, the stronger the winds will be. There are no signiýcant areas of high wind shown for Australia on 10 November.
Step5 Troughs
The weather map in FIGURE2 shows a trough in central Australia. The trough line runs north from central South Australia towards the Gulf of Carpentaria. Troughs are usually associated with unsettled weather and precipitation. 8.4.3 Letmedo it Complete the following activity to practise this skill.
Jacaranda Humanities Alive 7 Victorian Curriculum Third Edition
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