How to Detect Lightning on a Car Radio

Listen to lightning on you car's AM radio.

Use your car's AM radio receiver to detect lightning. Each stroke of lightning sends out an electromagnetic radio wave that creates a "static crash" on your AM radio receiver. When you hear these static crashes on the radio, you are actually listening to the lightning in real time. When you hear thunder outdoors, you are listening to the time-delayed sound of the lightning. Listen carefully to your car's AM radio at night during clear weather and you will hear lightning from other areas propagated as radio waves by the Earth's ionosphere.

Things You'll Need

• AM band car radio receiver

Instructions

1. Get in your car the next time you see lightning or hear thunder in your vicinity. But be sure your car is in the garage! In general, an automobile is one of the safest places to be during a lightning storm because, in theory, the four tires insulate you from lightning's main target-- the ground. But a direct hit from lightning is nothing to fool around with. Metal conducts electricity.

2. Tune your car radio to the AM (Amplitude Modulation) band.

3. Tune your AM radio to the low frequency end of the band because you can hear the sounds of lightning best on the lowest frequencies.

4. Find a clear spot on the dial where you cannot hear the signals from any AM broadcast radio stations. Radio broadcast signals will interfere with your listening for static on the radio.

5. Listen for the sounds of static. Radio scientists and engineers call these sounds "Static Crashes." They are actually the sounds of the lightning.

6. Watch for lightning outside. You will notice that you hear lightning on your car radio at the exact same time you see the lightning flashes. This is because radio waves and light both travel at the speed of light (about 186,000 miles per second).

7. Listen for thunder. You will notice that the sound of thunder follows the lightning by a number of seconds unless the lightning happens to be right on top of you.

8. Listen to lightning during storms in your area and you can measure the distance between yourself and the lightning bolt by counting the number of seconds between the lightning (radio or visual) and the sound of the associated clap of thunder.

9. Divide this number of seconds by 5 to get the number of miles between you and the lightning stroke. It takes the sound of thunder five seconds to travel one mile. (Light, lightning and radio waves are essentially instantaneous, i.e. speed of light) If you count ten seconds between lightning (radio or visual) and hearing thunder, the lightning is about two miles away from you.

10. Keep track of the time lag and the distance for successive lightning/thunder pairs so you can determine whether the lightning epicenter is moving toward you or away from you.

Tips & Warnings

• Keep tabs on your regional weather reports. Listen to your AM radio on a clear night in your area but when there is a thunderstorm in a nearby state. If you hear lightning static crashes on your radio, but you do not see lightning or hear any outside thunder, you will know that the storm cell is far away and probably in the other state.

• SAFETY FIRST! Stay away from trees, poles, wires, antennas and wide open spaces if you get caught outside during a lightning storm. If a storm approaches while you are swimming or boating, get to shore fast and get indoors or into an automobile. If you get caught in a storm while driving, the National Lightning Safety Institute recommends pulling over to the side of the road, turn on the emergency blinkers and turn off the engine. Keep your hands in your lap and do not touch any metallic objects, such as door handles, that are connected to the outside of the automobile during the most intense part of a storm or when lightning is in your immediate vicinity. Try to wait out the storm. It isn't over until you can no longer hear thunder. Lightning is often entirely unpredictable in the path it can take to the ground.

References

• National Lightning Safety Institute: Vehicles and Lightning
• Don Cross: Building a Lightning Detector
• Ambient Weather: Boltek Lightning Detectors
• Fairmount Center for Science and Math Education: Listening in on Lightning
• Technical Library: Lightning Detectors

Resources

• Ambient Weather: Personal Lightning Detector Purchase Guide
• Home Weather Stations Guide: How do Lightning Detectors Save Lives?
• Ten Spider Enterprise: Lightning Detection & Lightning Detectors
• Carter Lake: LD3-R2 Lightning Detector: How it works.
• Nex Sat: Satellite Product Tutorials: Lightning Detection Overlays