Radar signature of the melting layer; a narrow horizontal layer of stronger radar reflectivity in precipitation at the level in the atmosphere where snow melts to form rain. The bright band is most readily observed on range–height indicator (RHI) or time–height indicator (THI) displays.

As ice crystals fall toward warmer temperatures at lower heights, they tend to aggregate and form larger snowflakes. This growth accounts for an increase in radar reflectivity as the falling particles approach the melting level. As they cross the 0°C level, the particles begin melting from the surface inward and finally collapse into raindrops. The reflectivity maximum in the melting layer is explained partly by the difference in the value of the dielectric factor, [[File:ams2001glos-Bex02.gif