Tuesday, February 1, 2011
2011 FLORIDA SEVERE WEATHER AWARENESS WEEK - LIGHTNING
Florida’s Severe Weather Awareness Week takes place from
January 31 – February 4, 2011. Severe Weather Awareness Week is an opportunity for Floridians to learn about the various weather hazards that frequently impact the state and how families and businesses can prepare for these natural events.
Each day focuses on a specific weather event. Monday’s focus is on lightning.
Lightning is one of nature’s deadliest and most unpredictable weather phenomena. Meteorologists can forecast the general conditions that cause lightning but no one can forecast the exact location or time of the next strike of lightning.
All thunderstorms contain lightning which can strike a person, tree or an object either on the ground or in the air. Lightning is among the top weather-related killers in the United States, striking the ground about 25 million times each year and causing more injury and death than tornadoes. Lightning is often seen as an underrated killer, because it does not generate as much attention compared to other forms of hazardous weather and usually only claims one or two victims at a time. On average, lightning kills nearly 60 people each year in the United States. Florida averages seven fatalities per year due to lightning, with many more injuries. Most people that are struck by lightning are not killed, but suffer significant injuries.
The 2011 Florida Severe Weather Awareness Week is a perfect time to note that our state, out of all 50 states, is the lightning capital of the country. With an average of 1.4 million cloud- to-ground lightning strikes each year, no other state experiences more lightning strikes than Florida. Why does Florida have this distinction? Florida’s geography plays a large role, especially during the summer. Some of the elements that make Florida such a great place to live, such as sunshine and the ocean, play important roles in the development of thunderstorms. Because thunderstorm activity peaks in the summer, when most people are enjoying the warm weather, Florida often has the greatest number of lightning fatalities each year in the United States.
DID YOU KNOW??? Lightning is not just confined to thunderstorms. It can even be generated by the ash cloud from an erupting volcano. Lightning is also not just confined to the Earth; lightning has been observed on Jupiter and Venus.
One characteristic that makes lightning so dangerous is its extensive range. Lightning has the ability to strike up to 10 miles away from the thunderstorm core, making it the first storm hazard to arrive and the last to leave, so while it may not be raining at your location, lightning can still reach you.
The other characteristic that makes lightning so dangerous is its power and speed. The average lightning bolt carries 100 million volts of electrical potential.
DID YOU KNOW??? Contrary to belief, lightning CAN strike the same place twice and rubber shoes or tires DO NOT protect you from lightning strikes.
Thunder is a product of lightning. As lighting moves between the ground and thunderstorm, the air around the flash heats rapidly, to temperatures as high as 50,000°F – a temperature hotter than the surface of the sun. This sudden heating creates expansion of the air around the lightning bolt at speeds greater than the speed of sound. The expanding air breaks the sound barrier resulting in the explosive sound we know as thunder. Thunder is really just another form of a sonic boom. Because sound travels much slower than light, thunder is always heard after a flash of lightning.
Thunder travels at the speed of sound, which is roughly one mile every five seconds. You can determine how far away a flash of lightning is by counting the number of seconds that pass after observing a lightning bolt. For every five seconds that elapse, the lightning is one mile away. For example, if it takes 15 seconds for the thunder to reach you, then the lightning strike occurred about three miles away.
A good rule of thumb to remember is that if you can hear thunder, you are close enough to be struck by lightning. Being observant when outside is your first line of defense with lightning. A darkening cloud building high in the sky is often the first sign that lightning could occur.
A "Bolt from the Blue" lightning strike is a flash which travels a relatively large distance in clear air away from the parent thunderstorm and then strikes the ground. These lightning flashes have been documented more than 25 miles away from the thunderstorm cloud. These events can be especially dangerous, as they appear to come from “clear blue sky.” The key to remaining safe from a lightning strike is to keep an eye to the sky and watch for darkening skies on the horizon along with distant rumbles of thunder.
Nearly half of all lightning deaths occur in open areas. Many people are struck when they go under a tree to keep dry during a storm. Outdoor water activities such as swimming, boating and fishing are equally as dangerous during lightning storms. Therefore, when thunderstorms are approaching, avoid outdoor activities as if your life depends on it – because it does!
The main tip to remember regarding lightning safety is: being outside is never safe during a thunderstorm!
At the first sign of lightning or sound of thunder, you should immediately head inside an enclosed structure and remain away from windows. Even while inside, it is important to stay away from windows and not use any corded electrical devices. Lightning can easily travel along phone lines or through other electrical devices and strike you while inside a building. If you can’t make it inside when a thunderstorm approaches, the most dangerous place to be is in an open area, like an athletic field or golf course.
Equally as dangerous is being caught over the open water of a lake or ocean when a thunderstorm is in the area. This is because lightning will tend to strike the tallest object in the area. This also why standing under tall trees is very dangerous. When you can’t make it to an enclosed building, your next best course of action is to get into a vehicle with a hard-topped roof.
Although the National Weather Service does not issue specific lightning warnings, products such as the Hazardous Weather Outlook can indicate the threat levels for lightning in your area on any given day. When a storm producing excessive lightning is observed or imminent, a Special Weather Statement or Significant Weather Advisory is issued to alert of its locations. Checking these products before venturing outside can help make the difference between life and death.
NWS Mobile Daily Graphical Hazards
NWS Tallahassee Daily Graphical Hazards
NWS Jacksonville Daily Hazards
NWS Melbourne Daily Graphical Hazards
NWS Tampa Daily Graphical Hazards
NWS Miami Daily Graphical Hazards
NWS Key West Daily Hazards
Lightning Safety Awareness Week is June 19-25, 2011 and more information about lightning hazards and what you can do to protect yourself and others can be found at http://www.lightningsafety.noaa.gov/ and http://www.floridadisaster.org/.
Tuesday’s focus will be on marine hazards and rip currents.
For more information on the Florida Division of Emergency Management and to GET A PLAN!, please visit: http://www.floridadisaster.org/. Follow us on Twitter at www.Twitter.com/flsert or join our blog at: http://flsertinfo.blogspot.com/.