Altocumulus floccus

{{Short description|Type of cloud}}

{{Infobox cloud

| name = Altocumulus floccus

| image location = Altocumulus floccus virga, Altocumulus stratiformis.jpg

| image name = Altocumulus floccus over Germany in October 2010

| abbreviation = Ac flo

| genus= Altocumulus (high, heaped)

| species= floccus

| variety=

| altitude_m = 2,000–6,000

| altitude_ft = 6,500–20,000

| level = medium

| appearance = Often present in diffuse patches; whitish or dark, and the bases are sometimes not all at the same level.

| precipitation = Virga only.

| thickness =

| Ice content =

}}

Altocumulus floccus is a cloud type named for its tuft-like, wooly appearance.{{cite book |title=Cloud Dynamics |last=Houze, Jr. |first=Robert A. |year=1994 |publisher=Elsevier Science |location=Ukraine |isbn=9780080502106 |page=15 |url=https://books.google.com/books?id=5DKWGZwBBEYC&pg=PA15 |accessdate=27 August 2021 |quote= Altocumulus floccus (meaning tuft of wool, fluff, or nap of cloth...)}} The base of the cloud can form as low as {{convert|2000|m|ft}}, or as high as {{convert|6000|m|ft}}. They often form in clusters, or patches, and bases can vary in height with differing atmospheric conditions within the PBL.{{Cite web|url=https://cloudatlas.wmo.int/altocumulus-floccus.html|title=Altocumulus floccus|website=International Cloud Atlas}} They are similar to Altocumulus castellanus, but often have a shallower vertical extent in comparison.{{Cite web|url=https://whatsthiscloud.com/lessons/altocumulus-floccus/|title=Altocumulus floccus (Ac flo)}}

Floccus clouds form when in the presence of conditional, often shallow, mid-level instability. On some occasions, such as the presence of a deeper unstable layer, these clouds can grow large enough to develop into thunderstorms.{{Cite web|url=https://www.weatherbriefing.com/weather-blog/2019/5/18/altocumulus-floccus|title=Altocumulus floccus|website=Weather Briefing, L.C.|date=18 May 2019 }}