The weather map that appears in our newspapers or on T.V. is the result of surface weather readings taken all around Australia. Upper atmosphere information is gathered from weather balloons and satellite information. Like a huge jig-saw puzzle, the weather map brings together temperature, wind direction and strength, air pressure, rain and storm information into one easy to read illustration.
Features of a weather map
The lines on the map are called isobars and join places of equal air pressure. At sea level, the average air pressure is 1010hPa with highs typically up to 1030hPa and lows down to 990hPa.
Wind speed and direction indicators show the direction and strength of local winds. The arrow points in the direction of the wind movement and the number of strokes on the tail indicates the strength of the wind. Rain is shown by hatching.
A very good explanation of words used in forecasting by the Bureau of
Meteorology can be found at: Weather
Words - Bureau of Meteorology
Using a weather map
Cold and warm fronts are typically felt as sharp changes in temperature created by changes in wind direction. Fronts lie between high and low pressure zones and mark the boundary between circling winds. Cold fronts usually bring rain as moist warm air from a high mixes with colder air from a low.
The weather systems typically move from the west in Southern Australia, so look towards Western Australia and South Australia for an indication of the weather to come over the next few days to a week in Victoria.