Above: Radar image of Hurricane Humberto in 2007 (Courtesy of the Southern Regional Headquarters of the National Weather Service)
Radar (RAdio Detection And Ranging) is arguably the most important tool to meteorologists, from those forecasting behind the scenes to the on-air personalities showing it to the viewing public. However, meteorologists aren't the only people who use radar on a daily basis...generally everybody has looked at weather radar at some time or another. Have you ever wondered how it works though? How can radar detect rain, snow, sleet, etc. and display it as pretty colors for us to view? Well, read on and learn about how a radar works and what exactly it is showing.
Radar's usefulness for weather detection was first discovered by military radar operators during World War II, when they noticed return echoes from precipitation like rain, snow, and sleet. Since then, weather radar has become mainstream to the general public and indispensable for meteorologists. Radar is routinely used by meteorologists to detect heavy snowfall, flooding rains, severe thunderstorms and even tornadoes to ensure public safety. Weather radar sites are located throughout the country to acheive maximum coverage.
Above: Radar locations throughout the United States, Puerto Rico, and Guam (Courtesy of the Eatern Regional Headquarters of the National Weather Service)
Now the question...how does it detect precipitation and other weather phenomena? Essentially, the radar sends out a pulse of energy over and over again as it rotates 360° to sense its surrounding area. These pulses bounce off objects in the air and return to the radar (called an echo). The echos are analyzed for their position, size & number (called reflectivity), motion, and other parameters. This is all based on what kind of echo is received, how much energy is reflected back and how long it takes. The data collected by the radar is then run through computer algorithms that use colors to show the information that the radar has received.
Now that you know a little about how radar works and what exactly they are showing, you can gain a better appeciation for the work they do. Their ability to present crucial information in a timely and clean manner is essential for forecasting and protecting the public from impending weather.
Above: A radar dome located in Norman, Oklahoma at the Radar Operations Center (Courtesy Wikipedia)
