Why does the radar show false echoes?

Sometimes precipitation can be displayed on the radar screen that is not caused by actual rain. These so-called false echoes are created by various factors:

Reflections from obstacles

The radar radiation signal can be reflected by obstacles such as mountains, buildings, trees or hills and bounced back onto the radar screen. This is incorrectly displayed as rain or precipitation, although it is actually reflections from the ground.

Small particles in the air

Small particles such as insects, birds or dust can reflect the radar radiation signal and thereby create an echo that looks like precipitation.

Atmospheric phenomena

Atmospheric phenomena such as temperature inversions, stratifications or atmospheric refraction can affect radar radiation and lead to false echoes.

Electronic interference

Electronic interference or disturbances can lead to inaccurate displays on the radar screen.

Filtering by modern equipment

Modern weather radar equipment is often able to filter or correct some of these false echoes to provide more accurate precipitation information. Nevertheless, it can occasionally happen that some false echoes occur, particularly in complex geographical regions or during extreme weather conditions.