What is a cap?

What is a cap?

Peoria, Ill. (WMBD) -- An atmospheric capping inversion, or cap for short, is a term we often hear about during severe weather season. The presence of a cap can lead to an explosive severe weather event or prevent one from developing all together. So what is a cap? A cap is simply a layer of warm air aloft. It prevents surface-based air parcels from being able to rise freely through the atmosphere. It's basically a lid on a boiling pot of water …