Misty in Ashland sent me a message recently asking how does the Doppler radar work?
Doppler radars are far and away the best tool for detecting any form of precipitation! They work by sending beams out in a circle pattern around the radar.
When a beam strikes a raindrop, hailstone, or any form of precipitation or particle in the atmosphere, part of the beam will be reflected back to the radar. The radar receives the reflected beam, and can calculate the precipitation's distance away, as well as its intensity (based on size and speed of drop), and which direction it's moving, if it's windy.
The radar will then translate the distances and intensities into a graphical map that we can display on TV. The radar we use is sensitive enough to track wind blown particles, and even bird migration patterns! However, we set a filter to keep those off the weather maps.
Doppler radar is very important when it comes to detecting tornado's.
On May 24, 1973, a violent tornado produced fatalities and extensive damage as it passed through the heart of the small farming community of Union City, Oklahoma, just west of Oklahoma City. The newly commissioned Doppler radar at NOAA’s National Severe Storms Laboratory observed this tornado and researchers from the laboratory’s Tornado Intercept Project photographed the tornado’s life cycle. The radar, coupled with the photographic evidence of the tornado’s development, revealed previously unknown information about motion inside thunderstorms with a persistent rotating updraft (known as supercell storms). This discovery led to dramatic improvements in accuracy and lead time in forecasting severe storms nationwide, and along with them, the ability to save lives and prevent serious storm-related injuries.
Below is what a Doppler radar looks like.
Doppler radar's are located at the National Weather Service. Here's where they're located.