Key learning points

1. Depressions are areas of low pressure where air is rising.
2. Warm air and cold air meet at depressions causing changeable temperatures and rain.
3. Depressions bring windy conditions shown by closely spaced isobars.
4. Typically the passage of a depression over the UK can last between 1 and 5 days.

Keywords

• Pressure - a force pushing or pressing on a given area

• Air mass - a mass of air with the same levels of temperature, humidity, and pressure

• Depression - an area of low pressure characterised by rain, wind and cloud

• Front - a weather front is the boundary between a warm air mass and a cold air mass

Common misconception