Definition
A ground-based Doppler weather radar system installed at or near major airports to detect wind shear, microbursts, gust fronts, and heavy precipitation in the terminal area. It tracks the motion of precipitation and air to identify hazardous wind events near runways, and its alerts are relayed to controllers, who pass them to pilots during arrival and departure.
Plain English
A special radar at busy airports that watches for sudden, dangerous wind changes near the runways and warns controllers so they can warn pilots.
Context Anchor
Seen in low-level wind shear discussions and in airport weather alert systems. A pilot usually receives TDWR-based warnings through air traffic control or airport weather information, not directly from the radar itself.
Derivation
Doppler refers to the Doppler effect — the change in frequency of a returned radar signal when it bounces off something moving toward or away from the radar. That shift lets the system measure wind speed and direction, not just precipitation location. "Terminal" means it covers the area immediately around an airport rather than wide-area weather.
Why Pilots Care
Gives pilots advance warning of wind shear that can cause sudden loss of airspeed and altitude during takeoff and landing.
Grounding Statement
TDWR is focused on weather hazards close to an airport, especially the kind that can affect an aircraft just after liftoff or just before touchdown.
Intuition Check
Do not think of TDWR as a cockpit instrument. It is a ground radar system, and its warnings usually reach the pilot through controllers or airport weather messages.
Example Sentence 1
Tower advised inbound traffic of a TDWR microburst alert on final for Runway 27, with a 40-knot loss reported.
Example Sentence 2
Pilots checked the TDWR display before beginning the approach to confirm no microburst activity.