Nimbostrati are thick, dark clouds that bring rain or snow.
Nimbostrati can make people think of wet weather and the need for an umbrella.
Examples:
The sky is full of nimbostrati.
Nimbostrati bring rain to the fields.
When nimbostrati cover the sky, it gets dark outside.
I don't like going out when nimbostrati are in the sky.
Nimbostrati are so heavy, they make the sky look like a big gray blanket.
Nimbostrati are the kind of clouds that make you want to stay inside.