Field record · cloud
Cirrus cloud
Look for detached, fibrous or hair-like forms with substantial sky visible through and around them.
factscale · highstructure · filament
How it forms
Ice-crystal cloud forms high in the troposphere; wind can stretch visible ice-crystal strands into fibrous forms.
What separates it from a neighbor
Unlike cirrostratus, cirrus is usually organized as detached filaments rather than a widespread veil.
Representation boundary
Use thin directional marks and generous negative space; do not imply a fixed altitude from appearance alone.
Evidence boundary. This page separates a sourced formation explanation from the editorial “visual character” phrase above. A single image or casual observation may not contain enough context to classify a real phenomenon confidently.
Sources used for this record
WMO International Cloud Atlas — Cloud generainstitutional standard
Ten cloud genera and classification structure.
Open source ↗WMO International Cloud Atlas — Definitions of cloudsinstitutional standard
Approximate cloud levels and genera.
Open source ↗NOAA NESDIS — Types of Cloudsgovernment education
Cloud appearance, composition and broad weather context.
Open source ↗