Definition
A weather display product that shows the highest altitude at which precipitation is being detected by radar, presented as a color-coded map overlay. Echo tops are derived from ground-based weather radar returns and indicate how high storm cells extend into the atmosphere, expressed in feet above mean sea level (MSL).
Plain English
A picture on the cockpit display that shows you how tall thunderstorms and rain cells are. The colors tell you the height of the top of the storm, so you can see at a glance whether you can fly over it or need to go around it.
Context Anchor
Seen on multi-function display weather pages and datalink weather displays when a pilot is reviewing storm height and thunderstorm development.
Derivation
Echo' comes from the Greek 'ēkhō,' meaning a returned sound. In radar, an 'echo' is the signal that bounces back from precipitation. The 'top' is simply the highest point where that bounced signal is still detected — so 'echo top' is literally the top of the radar return.
Why Pilots Care
Helps pilots judge the vertical size of storms so they can select safe altitudes and avoid turbulence or icing.
Grounding Statement
If a storm cell shows very high echo tops ahead of your route, picture a tall, active storm building upward rather than just a small rain shower.
Intuition Check
Do not read “tops” as “cloud tops.” Echo tops are the tops of radar-detected precipitation, and the actual cloud may extend higher.
Example Sentence 1
The graphical echo tops display showed cells topping out at 38,000 feet along our route, so we requested a deviation 30 miles south.
Example Sentence 2
Before departure the pilot checked graphical echo tops on the MFD to confirm the route stayed below developing cells.