You may hear us talking about “clutter” on the radar from time to time. Clutter or ground clutter is a common phenomenon that most radars experience. In the picture, clutter is in the red box and rain is shown in the yellow box.

Radars send out a signal to detect small particles in the atmosphere. Most often we are looking for hydrometeors like rain, hail, and snow. However, sometimes a radar will detect other particles in the form of a flock of birds, a swarm of bugs, or just a high concentration of dust.  

When the colors start to pop up on the map, the first instinct is to assume rain. Sometimes, especially when the forecast is sunny skies, the activity on the radar is just clutter.

Sometimes ground clutter will trigger a rain alert on the WBRZ Weather app. The cell off the coast of Grand Isle is rain, but the unnatural spots of green between BR and Lafayette are clutter from dust or bugs. Don't let the radar deceive you! #radar #BatonRouge pic.twitter.com/UygZuGhBWj

— Marisa Nuzzo (@marisanuzzowx) June 16, 2020

This Tweet and the above picture show both rain and clutter together on the radar. Rain showers will always be much more organized compared to the sporadic nature of a clutter signature. The rain cell off the coast formed to near Mississippi, moved south along the coastline, and weakened. We can see all those things happen with each radar scan. Clutter comes and goes from scan to scan with little continuity.