Field record · near-ground
Fog near the ground
Visibility is reduced by suspended droplets at or near the surface. Terrain, water, wind and time of day can be clues but are not a complete diagnosis.
factscale · surfacestructure · layer
How it forms
Fog forms when near-surface air reaches saturation through cooling, added moisture, or mixing; different formation pathways produce different behavior.
What separates it from a neighbor
Physically cloud-like but in contact with the ground; haze can reduce visibility through different particles/processes.
Representation boundary
Use loss of contrast with distance, not just a gray overlay. Avoid claiming a fog type from a single image without context.
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
National Weather Service — How Fog Formsgovernment education
Fog formation pathways including radiation, advection, freezing and mixing fog.
Open source ↗NOAA NESDIS — Types of Cloudsgovernment education
Cloud appearance, composition and broad weather context.
Open source ↗