If a weather return on the scope has a shadow behind it, what does this indicate?

• A. The storm is receding
• B. There is too much water in the cloud to fly through it
• C. The echo is strongest at the edge
• D. The radar is malfunctioning

Answer: (B)

The weather echo with a shadow behind it means the radar signal is being attenuated by very heavy precipitation. Dense rain (and other water content in the storm) absorbs and scatters the radar energy, so the return beyond the heavy area is weaker, creating a dark “shadow.” This indicates the storm contains so much water that the radar can’t easily see through it, i.e., there is too much water in the cloud to fly through it.

This isn’t about the storm moving or changing strength at the edge, and it isn’t evidence of a malfunction—the shadow is a normal sign of signal attenuation from heavy rainfall.