Elena Saltikoff, FMI:

Total beam overshooting

In the climate of Northern Europe, for the modern C-band radars, total beam overshooting is the main factor limiting "how far a radar can see".

The range limit, after which total beam overshooting takes place, depends on elevation angle and cloud top height. The only real cure is siting of radars to places allowing lower elevation angles. But even with zero elevation angle, the overshooting takes place at some distance because we live on a spherical globe.

Misinterpretation is a problem, and against that there are two possibilities:

• teach the users (forecasters and educated customers such as pilots) the difference between "I know it's not raining" and "I don't know if it's raining". As they say: zero is more than nothing.
• indicate the maximum range using cloud top information from vertical reflectivity profile.