CC (correlation coefficient)
Whether everything in the beam looks alike. High for rain, low for a mix — hail, melting snow, or tornado debris.
Related
- Dual-pol The radar sending both horizontal and vertical pulses, which is what makes CC and ZDR possible. Rolled out across the network around 2012.
- ZDR (differential reflectivity) How flat the things in the beam are. Positive for raindrops, near zero for tumbling hail.
- TDS (tornado debris signature) High reflectivity, a velocity couplet, and a hole in CC in the same place: the radar seeing lofted debris.
See it on real storms: open the radar, or read reading the radar.