Anomalous Propagation
Radar signals that bend unexpectedly through atmospheric layers, creating false echoes that mimic distant objects.
A radar phenomenon where electromagnetic waves refract abnormally through the atmosphere—often due to temperature inversions or humidity gradients—causing signals to propagate beyond their normal range or reflect off unexpected surfaces, producing false or misleading radar returns.
What this means in real life
A weather radar operator sees a strong echo on screen that appears to be a storm 50 miles away, but when checking visually or with other instruments, there's nothing there—the signal actually bounced off a layer of warm air trapped above cold air near the ground.
What it isn’t
It is not equipment malfunction or intentional signal jamming. Anomalous propagation is a natural atmospheric effect that occurs even with perfectly functioning radar systems under specific weather conditions.
Commonly misused online
Online UFO and conspiracy forums often cite anomalous propagation as a catch-all explanation for any unexplained radar blip, without acknowledging that it produces specific, predictable patterns meteorologists can identify and filter out.
Based on 1 reference source, including government sources. Last verified July 16, 2026.