Occluded front
Also called: Occlusion · Topic: Air Masses, Fronts, Cyclones and Thunderstorms · NCERT: Class 11, Ch 9 "Atmospheric Circulation and Weather Systems"
Meaning
An occluded front forms when a faster cold front catches up with a warm front. The cold air lifts the warm air completely off the ground. Now only cold air touches the surface, and the warm air that fed the storm is cut off above. This marks the last, dying stage of an extratropical (temperate) cyclone, which then weakens and fades. On weather maps, an occluded front is shown in purple.
Example
Many depressions that cross the North Atlantic become occluded as they near Iceland and Norway. By the time they reach these coasts, they bring cloud and rain but are slowly losing strength.
Don't confuse with
- Stationary front: a stationary front is where a temperate cyclone often begins. An occluded front is where it ends.