By John Campanola
Summer. While often referred to as the hazy, lazy days of summer, it is also the season where we encounter a large number of significant storms. June 1 may not be the start of summer, but it is the official start of storm season; and, we are being warned by many experts that this season is looking to be a particularly bad one for storms and the potential damage which they often cause.
Noted meteorologist, Bill Gray, warns of “hellacious” damage from major storms in the near future. According to Mr. Gray, the Atlantic basin has entered an era of intense storm activity. This is resulting from a long range warm cycle of the Atlantic’s surface, lower barometric pressure, less stability in the atmosphere and less wind shear.
One particular concern about storms in Florida is the often resulting lightning. Lightning kills about 100 people every year in the United States; and most of these deaths occur in Florida, which has more thunderstorms than any other part of the country.
According to a recent article in USA Today, the average lightning stroke has a peak electrical current of 30,000 amps. Extreme lightning discharges can reach 10 times that, while some discharges, especially those within a cloud, are only a few thousand amps. Another way of saying this, the electricity flowing within a lightning bolt can reach 200 million volts. Combined with the high amperage, lightning has enough energy to kill instantly.
Everyone who goes outdoors needs to be aware of lightning’s danger when thunderstorms are around. A typical 100 million volt flash can heat the air to more than 40,000 degrees, which causes it to expand and contract as it cools. This creates sound waves or “thunder.”
“For anyone outdoors, thunder is a wake-up call,” says Ron Holle, who studies lightning at the National Severe Storms Laboratory in Norman, Okla. If you can hear the thunder, the lightning is probably within 10 miles. Thunder rarely travels farther. To estimate how far away lightning is, use the “flash-to-bang” method. If you see a lightning flash begin counting: “one one thousand, two one thousand,” etc., until thunder is heard. Since the speed of light is about 186,300 miles per second, lightning is seen the instant it flashes. But sound travels about one mile in five seconds. If you heard the thunder 10 seconds after seeing the lightning, the lightning is about two miles away.
When the flash-to-bang time is 10 to 15 seconds – meaning the lightning is two to three miles away – head for safe shelter. If the lightning is closer than three miles, the danger could be very high. A 1988 Florida study found that successive lightning strikes in a storm were two to three miles apart on average. If lightning is three miles away and the storm is moving toward you, the next strike could hit you.
The following are some safety precautions, which you may want to practice. They were obtained from the National Lightning Safety Institute, www.lightningsafety.com.
- When you first see lightning or hear thunder, immediately go to a building or vehicle.
- If outdoors, avoid water, high ground, open spaces and all metal objects including electric wires, fences, machinery, motors, power tools, etc. Look for shelter in a building or in a fully enclosed metal vehicle such as a car, truck or a van with the windows shut.
- If indoors, avoid water, stay away from doors and windows and do not use the telephone. Take off headsets and turn off, unplug and stay away from appliances, computers, power tools and TV sets. Lightning may strike exterior electric and phone lines, inducing shocks to inside equipment.
- Suspend activities for 30 minutes after the last observed lightning or thunder.
Besides concerns over your own personal safety, lightning in an area often results in surges that enter residences via the electrical or telephone connections. These surges often damage TVs, stereos, video equipment and your home security systems. Lightning surges are the major reason for security system failure, and 70 percent of all damage occurs on the phone line.
Florida storms are a price we all pay to live in paradise. Preparing for them and taking precautions will provide you with a greater peace of mind.
This article appeared in The Chatterbox of Lexington Lakes in July of 2009, Viewpointe of Boca Pointe Vol. 12 No. 6 in June of 2004 and in Fiddler of Fiddlesticks Country Club in August of 2004.