These fibrous looking clouds were sent in by a user this week, do you have any idea what they are?

Known as altocumulus floccus clouds, this particular cloud type is known for its patchy, wool-like appearance. Capable of forming anywhere from 2,000 m to 6,000 m they regularly arrive in clusters.

Their arrival typically indicates some instability but at times of a deeper, unstable layer can swell to form thunderstorms.

Regular altocumulus clouds are more associated with settled conditions but come in many forms. In addition to floccus we also see altocumulus stratiformis, lenticularis, and castellanus.

Altocumulus floccus often pair with the castellanus variety whose name derives from their resemblance to castle turrets.

Have you seen any interesting or unusual clouds recently? Send them in and we'll explore how and why they form! Use our uploader or tap the camera in the app to submit photos.