Definition
A composite weather display image formed by combining returns from multiple ground-based weather radar sites into a single seamless picture covering a wide geographic area.
Plain English
A weather picture made by stitching together what several radar stations are seeing, so you get one big view instead of many small ones.
Context Anchor
Seen in ATC radar weather display discussions, where weather from more than one radar site is shown together on a controller’s or pilot’s display.
Derivation
From the Latin musaicum, originally meaning artwork made by fitting many small pieces together into one image. The aviation use keeps the same idea — many radar pieces combined into one larger picture.
Why Pilots Care
Gives a broader picture of storms and precipitation than any single radar can show, helping with route planning and avoidance decisions.
Analogy
It is like making one wide photo by stitching several smaller photos together.
Intuition Check
Mosaic does not mean a decorative pattern here. It means a combined weather picture made from separate radar pictures.
Example Sentence 1
The briefer pulled up the national radar mosaic so the pilot could see the line of thunderstorms stretching across three states.
Example Sentence 2
Pilots checked the mosaic display to see weather beyond the range of their own aircraft radar.