Definition
The returned radio energy displayed on a radar screen after the radar's transmitted pulse strikes precipitation, terrain, or other reflective targets and bounces back to the antenna. In weather radar, the strength and shape of these returns indicate the location, size, and intensity of precipitation within clouds and storms.
Plain English
Radar sends out a pulse of energy. When that pulse hits raindrops or other targets, some of the energy bounces back. The bounced-back signal shows up as a shape on the radar display. That shape is the echo.
Context Anchor
Seen in thunderstorm discussions, air traffic control weather reports, and cockpit weather radar displays.
Derivation
Echo' comes from the Greek for a returned sound. Radar uses the same idea, but with radio waves instead of sound — a pulse goes out, hits something, and a reflection comes back.
Why Pilots Care
Radar echoes reveal the location and intensity of thunderstorms, allowing pilots to choose a safe route around turbulence, icing, and strong updrafts.
Grounding Statement
A radar echo is what appears when the radar’s invisible signal goes out, hits precipitation, and returns to be shown on the display.
Intuition Check
Do not think of radar echoes as sound echoes. Here, “echoes” means returned radar signals, and in thunderstorm flying those returns usually point to precipitation, not every possible hazard in the storm.
Example Sentence 1
ATC advised the pilot of strong radar echoes along the route and offered a deviation 20 miles south.
Example Sentence 2
The radar showed only light echoes along the route, so the flight continued without delay.