WKRG-TV5 is the only TV station in Mobile owning a live Doppler radar. Our radar uses the same technology found in National Weather Service NEXRAD systems. Our Live Doppler Radar sits high atop a tower, protected by a dome, in Spanish Fort in Baldwin County. It is fully within our control and every sweep shows live data on TV.

You see our radar on wkrg.com with frequent updates. It is constantly scanning above the horizon for precipitation. When there is rain (or hail, sleet or snow) the radar shows where it is and how heavy it is. Brighter colors mean heavier precipitation.

In addition to First Alert Live Doppler Radar we have two more powerful systems- First Alert Street Level Doppler and First Alert VIPIR. Both display data from NEXRAD- the National Weather Service network of high power, high resolution radars capable of seeing up to 300 miles away, onshore and into the Gulf. NEXRAD stands for Next Generation Radar.

First Alert Street Level Doppler is known as Fastrac in other areas of the country. It has a detailed database of streets and communities that gives us more precision in letting you know where the worst storms are, using street level tracking. With realtime data from 4 NEXRAD sites covering 12 states, we can automatically track storms with the time of arrival to your community. A realtime lightning plot gives you warning on the threat of strikes.

Both Street Level Doppler and VIPIR feature automatic storm identification and Futurescan: A 30 minute projection of storm motion into the future.

We give you detail and precision on individual thunderstorms and where they are located by community, by neighborhood, and even by street. In addition to showing precipitation as you are used to seeing it, our radars allows determination of the height of a thunderstorm and it allows the WKRG-TV5 weather team to know what the wind inside of a thunderstorm is doing. This is the strength of Doppler radar. It gives lead time in detecting hail, tornadoes, windshear and other damaging winds.

First Alert VIPIR also can automatically track storms with time of arrival using continuous realtime NEXRAD data. VIPIR is an acronym from the phrase Volumetric Imaging and Processing for Integrated Radar. By displaying the storm in 3d we can dissect it to better understand the threat. Also giving realtime lightning strikes, First Alert VIPIR delivers information for safety. It also is capable of projecting weather systems into the future using numerical weather models.

For decades, meteorologists have used radar to detect precipitation- rain, snow, sleet, or hail. The word radar comes from the phrase Radio Detection and Ranging. In other words, we use a radio signal to detect the distance of objects. Doppler radar in general works the same as other radars except that it provides additional information on how precipitation is moving. The Doppler theory says that if something is moving toward the radar, then the signal is returned to the radar at a higher frequency or pitch. When an object moves away from the radar, the return signal is at a lower frequency.

You can hear the Doppler effect when a car or train is approaching you while sounding a horn. The horn pitch changes to a lower frequency once the car or train passes you. Doppler radar measures the change in frequency to determine how fast the wind is blowing the precipitation to allow meteorologists to determine what is happening inside of a thunderstorm. Doppler radar is a great tool for knowing when a certain storm might produce tornadoes or high winds.

Sometimes you might be fooled by any radar. There are times when all radars show things that are not precipitation such as buildings or flocks of birds. When the radar beam bends toward the ground due to big differences in air density you will see a false display. We call this "Ground Clutter" or "Anomalous Propagation" and it is common along the Gulf Coast at night, especially in the summer when the air is humid. You can tell that it is not real precipitation is because it does not move or change intensity. It takes a bit of training to know for sure when the radar may not be showing true precipitation. That is why it is best to watch us at WKRG-TV5 when we are live on TV.