When You See Lightning, Count The Time Until You Hear Thunder. If That Is 30 Seconds Or Less, The Thunderstorm Is Close Enough To Be Dangerous – Seek Shelter (if you can't see the lightning, just hearing the thunder is a good back-up rule). Wait 30 Minutes Or More After The Lightning Flash Before Leaving Shelter.
Because electrical charges can linger in clouds after a thunderstorm has seemingly passed, experts agree that people should wait at least 30 minutes after the last thunder before resuming outdoor activities.
If you count the number of seconds between the flash of lightning and the sound of thunder, and then divide by 5, you'll get the distance in miles to the lightning: 5 seconds = 1 mile, 15 seconds = 3 miles, 0 seconds = very close. Keep in mind that you should be in a safe place while counting.
Example: If you see lightning and it takes 10 seconds before you hear the thunder, then the lightning is 2 miles away. Because lightning can strike up to 10 miles from a storm, you should seek safe shelter as soon as you hear thunder or see lightning.
Storm Distance Safety Tips
The CDC tells us, “when thunder roars, go indoors.” They also advise following the 30-30 rule, which means if less than 30 seconds passes after lightning strikes before hearing thunder, you should take shelter.
So, if you see lightning, start counting (use a stopwatch or count by saying 1-Mississippi, 2-Mississippi, etc… until you hear thunder. If it is 10 seconds, divide 10 by five (10/5) and you will know that the strike is 2 miles away from you!
Fact: NO PLACE outside is safe when thunderstorms are in the area. If you are caught outside in a thunderstorm, keep moving toward a safe shelter.
Remember, safety first! The golden rule of lightning safety is if you hear thunder, you should seek shelter inside of a substantial building or an enclosed, metal-topped vehicle. Thus, always plan to photograph lightning from inside a safe shelter or from inside a car.
That is because light travels much faster than sound waves. We can estimate the distance of the lightning by counting how many seconds it takes until we hear the thunder. It takes approximately 5 seconds for the sound to travel 1 mile.
In fact, lightning can heat the air it passes through to 50,000 degrees Fahrenheit (5 times hotter than the surface of the sun).
Sometimes lightning may be seen but there is no thunder heard. This is either because thunder is rarely heard more than 20 km away or because the atmospheric conditions lead to sound bending upwards and away from the surface.
1. The speed of lightning. While the flashes we see as a result of a lightning strike travel at the speed of light (670,000,000 mph) an actual lightning strike travels at a comparatively gentle 270,000 mph.
“The '30-30 Rule' directed people to be in a safe place when there is 30 seconds or less between lightning and its thunder, and to wait 30 minutes or more after hearing the last thunder before leaving the safe place.
The Empire State Building in New York City is struck by lightning on average 23 times each year, and was once struck 8 times in 24 minutes.
The safest location during a thunderstorm is inside a large enclosed structure with plumbing and electrical wiring. These include shopping centers, schools, office buildings, and private residences.
First reported in 1994, dark lightning is estimated to flash around the world about a thousand times each day. But scientists have only a hazy understanding of how it initiates. They generally agree dark lightning is sparked by the electric fields generated by thunderstorms and lightning bolts.
These rare "superbolts," which are 1000 times stronger than the average strike, also seem to hit far more frequently over ocean than land. To find out where and when this super-lightning occurs, researchers used a network of roughly 100 lightning detecting stations on six continents.
Forecasters can and do forecast the likelihood of intense lightning activity. However, it is impossible to forecast individual strikes because lightning is so widespread, frequent and random.
Lightning usually strikes the tallest object. It makes sense that the tallest object is most likely to produce upward streamers to connect with the downward lightning leader.
Minimizing the Risk
If the sky looks threatening or if you hear thunder, get inside a safe place immediately. Once inside, avoid contact with corded phones, electrical equipment, plumbing, and windows and doors. Finally, wait 30 minutes after the last lightning or thunder before going back outside.
John Farley. The answer: No. Lightning occurs when the difference in charge between the cloud and the ground becomes so great that a conductive channel of air develops.
Stay off corded phones, computers and other electrical equipment that put you in direct contact with electricity. Avoid plumbing, including sinks, baths and faucets. Stay away from windows and doors, and stay off porches. Do not lie on concrete floors, and do not lean against concrete walls.