Altocumulus floccus (Ac flo) - Vincent 1903

Small tufts of cumuliform appearance; the lower parts of the tufts are generally ragged and often accompanied by fibrous trails (ice crystal virga). Altocumulus floccus is an indication of instability at that level. Altocumulus floccus sometimes forms as a result of the dissipation of the base of Altocumulus castellanus.