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

Occluded Fronts

The fact that different fronts travel at different speeds over the ground can lead to one front overtaking another. When this happens, it is called an Occluded Front.

Weather in an Occlusion

Occluded fronts bring all the cloud, weather and hazards of both the cold and warm fronts. This often results in low cloud and heavy, continuous rain for extended periods of time, particularly when the occlusion is slow moving. The interaction of multiple fronts means the wind direction can change significantly over a short distance.

Occluded fronts often have embedded CBs – cumulonimbus clouds that are hidden behind/inside other cloud layers. A CB can easily be hidden from your sight by a layer of low stratus!

Here’s a synoptic showing a cold front overtaking a warm front, creating an occluded front: