Occluded Fronts

An occluded front is the most complex of the various fronts. When a fast-moving cold air mass causes a slowly moving warm air mass, it can sometimes wedge completely beneath the mass of warm and begin to mix with the cool air on the other side. When this happens, the mass of the heat is cut off from the Earth, or clogged, and is is lifted further into the atmosphere. Weak lifting can cause widespread clouds, as well as rain or snow and occasional storms.