The one's I've mentioned are the one's I've used. Introduction Radar images are color coded to indicate the strength of the reflected radar signal. A strong reflected signal will be colored differently than a lower one. The amount of reflective signal is a relative indicator of rain or hail intensity. The greater the precipitation intensity, the greater the downdraft and the greater will be the updraft of the thunderstorm to support it.
Intense updraft can lead to the development of a wall cloud, funnel, or tornado.
Thus radar reflectivity gives a relative indication of the intensity of the a thunderstorm and the potential for severe weather. You'll find this same key on radar images at WSI Corporation. The colors indicate radar signal reflectivity in dbz. The higher dbz the greater the reflected signal. Intense precipitation often associated with severe weather will produce returns in the red part of the scale or more.