Make your home page

What is a cap in the atmosphere, and how does it limit severe weather?

What is a cap and why does it matter?

INDIANAPOLIS (WISH) — Severe weather is possible Tuesday night in central Indiana. A preventing factor we have in place is a cap. That begs the question, what is a cap in our atmosphere?

What is it?

A great analogy is a boiling pot of water. When a lid prevents steam from escaping, it is the equivalent of our atmosphere having a cap. As soon as the lid is removed, steam rises.

Having a cap in place limits severe weather. When it is removed, a lot of areas then have the chance of severe weather depending on a select storm’s setup.

How do we break the cap?

There are multiple ways to break a cap. Daytime heating on its own can get the job done. In the case of Indiana on Tuesday night, a cold front was on the way to aid in breaking the cap. Added lift from the front not only would provide the boost to break the cap, but also storm formation itself.

Be sure to stay with Storm Track 8 through this round of severe weather. Storms are expected to overcome the cap as we get into early Tuesday night.

The latest forecast is available in the Storm Track 8 weather blog.