NWS Doppler radar base reflectivity data shows where and how hard it is raining or snowing, as well as precipitation intensity trends and movement.
The image shows 0.5 degree base reflectivity data from the December 22-23, 2004 major winter storm over central Kentucky and southern Indiana. Overlaid on radar are surface observations in red. Over southern Indiana, green colors represented moderate to heavy snow, while the narrow band of yellow in far southern Indiana just north of the Ohio River (blue line) was an axis of very heavy snow with large snowflakes. This band remained nearly stationary for several hours. Coupled with snow earlier in the day, total snowfall amounts in southern Indiana from the storm ranged from 1 to 3 feet, with higher drifts! Thunder snow also occurred (thunderstorm producing snow). In north-central Kentucky (including Louisville), moderate to heavy precipitation in the form of sleet and some snow was occurring at this time. Farther south, freezing rain accumulated, while little or no precipitation was falling at this time over parts of south-central Kentucky (area of black).