Just below the National Weather hazards link (see arrow) is a link to doppler radar images from across the country. Doppler radar systems (such as the WSR-88D) detect and locate precipitation as do conventional radars. However, Doppler systems also provide information regarding the movement of targets.
When the WSR-88D transmits a pulse of radio waves, the system keeps track of the phase (shape, position, and form) of the transmitted radio waves. By measuring the shift in phase between a transmitted pulse and a received echo, the target's radial velocity (the movement of the target toward or away from the radar) can be calculated.
The end result is high resolution radar images that enable National Weather Service forecasters to provide faster and more accurate weather warnings. You can view some of these images at any one of 155 radars nationwide. Below the maps are thumbnail images of regional composites. These composite images are also clickable so you can drill down to the local Doppler radar of interest.
These radar pages also display any severe weather warnings over the radar images.