NEXRAD stands for Next-Generation Radar and is a network of 159 high-resolution Doppler weather radars operated by the National Weather Service.
The NEXRAD radar detects precipitation and atmospheric movement or wind.
It returns data and is then processed and displayed on a mosaic map.
This shows patterns of precipitation, along with intensity and movement.
The radar system operates in two basic modes, selectable by the operator: a slow-scanning clear-air mode for analyzing air movements for when there is little or no activity in the area and precipitation mode that has a faster scan for tracking active weather, such as thunderstorms, rain and snow.
The NEXRAD has an increased emphasis on automation, including the use of algorithms and automated volume scans.