Which condition would most likely lead to a false radar echo?

The condition that most likely leads to a false radar echo is the presence of ground clutter. Ground clutter refers to the radar signals that are reflected from non-meteorological targets such as buildings, trees, and terrain features. These objects can produce echoes that the radar system detects, which may be misinterpreted as precipitation or other meteorological phenomena.

Radar systems are designed to differentiate between weather-related signals and those from static objects. However, in certain situations—especially when the radar is operating at low elevations or in certain beam patterns—ground clutter can create significant interference. As a result, radar operators must often filter or distinguish these echoes from actual meteorological signals, making it a key concern during radar operations.

In contrast, calm weather conditions, high wind speeds, and clear atmospheric conditions typically do not introduce false echoes in the same way. Calm conditions would likely produce minimal radar returns, high wind speeds might enhance the detection of true precipitation, and clear atmospheric conditions would generally provide a better signal without interference from clutter.