Definition
A weather radar operating setting that tunes the radar's signal processing to detect and display precipitation — primarily rain, but also wet snow and hail — by measuring how strongly the radar beam is reflected by water droplets in the air.
Plain English
A setting on weather radar that makes it look specifically for rain and other wet weather, and shows where it is and how heavy it is.
Context Anchor
Seen in FAA weather radar discussions comparing clear air mode and precipitation mode on weather radar displays.
Derivation
Precipitation comes from the Latin praecipitare, meaning 'to throw down' or 'fall headlong.' In weather terms, it refers to water in any form falling from the sky. The mode is named for what the radar is tuned to find — water that is falling.
Why Pilots Care
Helps pilots identify and avoid heavy rain, thunderstorms, and related hazards during flight.
Intuition Check
Do not read precipitation mode as meaning the radar creates or controls precipitation. It only means the radar is set to observe weather when precipitation is already present.
Example Sentence 1
With thunderstorms forecast along the route, the pilot selected precipitation mode on the weather radar before departure.
Example Sentence 2
In precipitation mode the display showed a line of heavy rain cells along the route.