How to read a weather map
Weather maps use symbols for pressure centres, fronts, and precipitation. Here is how to decode the letters, lines, and colours on a synoptic chart.
A weather (synoptic) map is a snapshot of the atmosphere. Learn to spot the core symbols and you can forecast the essentials.
Pressure centres
- H marks a high-pressure centre: sinking air, usually clear and calm.
- L marks a low-pressure centre: rising air, usually cloudy and windy.
Air moves from high to low pressure, and the closer the isobars (pressure lines), the stronger the wind.
Fronts
Fronts are the boundaries between different air masses:
- Cold fronts bring sharp temperature drops, squalls, and heavy showers.
- Warm fronts bring steady rain and milder air.
Colour coding
Many maps tint land cover: green for vegetation, yellow or brown for drier terrain, blue for water. Practise labelling these symbols on randomised weather-map questions below.
Put it into practice
Practise this topic with questions and get an explanation after each answer.
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