congestus

1 9.3

A tall cloud formed by strong rising air that often brings rain or storms

noun

Specialized

: congestus

And it's not raining out the bottom, so I'm going to call that cumulus congestus, a growing cumulus cloud.
Cumulus congestus

Examples

During our hike, we observed a congestus cloud developing, a sign that we should prepare for a downpour.
Today, I noticed a congestus cloud forming in the sky, which usually means rain is on the way.
As the storm approached, the congestus clouds towered high, indicating possible severe weather.

Surface Forms

congestus singular

congesti plural

Etymology

The word congestus comes from Latin parts con- 'together' and a root meaning 'carry', so it suggests things 'carried together' or piled up. Think of English congestion (traffic 'piled up'); a congestus cloud is a mass of cloud rising and piling up, which is why it often signals rain or storms.