The Atmosphere
Movement in the Atmosphere
Atmospheric Stability
Localised Winds
Visibility and Fog
Aircraft Icing
Weather Reports and Forecasts
Practice Exam

Cold Fronts

When a cold air mass is moving in to replace a warm air mass, the boundary is called a cold front. As a cold front approaches, we expect reducing air temperature & pressure, and the wind will typically veer (in the northern hemisphere).

Cold fronts move across the ground relatively quickly and have a steep slope. This forces the warm, unstable air to rise rapidly and cumuliform clouds will develop. If the air continues to rise rapidly, the cumulus and towering cumulus will often develop into cumulonimbus clouds (thunderstorms).

A cold front typically has a slope of about 1:50

In a cold front you can expect:

Reducing air temperature
The wind to veer (in the northern hemisphere)
Cumuliform cloud to develop
The potential for frontal cumulonimbus (CB)

Cold Front Hazards

A cold front can present many hazards to a pilot, including:

Wind shear
Severe turbulence
Airframe icing

A diversion around the weather may be required.

Cold fronts are shown on synoptic charts as a blue line with triangles pointing in the direction of travel (think of them as icicles – cold!)